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-rw-r--r--src/fmt/doc.go295
-rw-r--r--src/fmt/export_test.go7
-rw-r--r--src/fmt/fmt_test.go1310
-rw-r--r--src/fmt/format.go524
-rw-r--r--src/fmt/print.go1223
-rw-r--r--src/fmt/scan.go1169
-rw-r--r--src/fmt/scan_test.go992
-rw-r--r--src/fmt/stringer_test.go61
8 files changed, 5581 insertions, 0 deletions
diff --git a/src/fmt/doc.go b/src/fmt/doc.go
new file mode 100644
index 000000000..ee54463e2
--- /dev/null
+++ b/src/fmt/doc.go
@@ -0,0 +1,295 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+/*
+ Package fmt implements formatted I/O with functions analogous
+ to C's printf and scanf. The format 'verbs' are derived from C's but
+ are simpler.
+
+
+ Printing
+
+ The verbs:
+
+ General:
+ %v the value in a default format
+ when printing structs, the plus flag (%+v) adds field names
+ %#v a Go-syntax representation of the value
+ %T a Go-syntax representation of the type of the value
+ %% a literal percent sign; consumes no value
+
+ Boolean:
+ %t the word true or false
+ Integer:
+ %b base 2
+ %c the character represented by the corresponding Unicode code point
+ %d base 10
+ %o base 8
+ %q a single-quoted character literal safely escaped with Go syntax.
+ %x base 16, with lower-case letters for a-f
+ %X base 16, with upper-case letters for A-F
+ %U Unicode format: U+1234; same as "U+%04X"
+ Floating-point and complex constituents:
+ %b decimalless scientific notation with exponent a power of two,
+ in the manner of strconv.FormatFloat with the 'b' format,
+ e.g. -123456p-78
+ %e scientific notation, e.g. -1234.456e+78
+ %E scientific notation, e.g. -1234.456E+78
+ %f decimal point but no exponent, e.g. 123.456
+ %F synonym for %f
+ %g %e for large exponents, %f otherwise
+ %G %E for large exponents, %F otherwise
+ String and slice of bytes:
+ %s the uninterpreted bytes of the string or slice
+ %q a double-quoted string safely escaped with Go syntax
+ %x base 16, lower-case, two characters per byte
+ %X base 16, upper-case, two characters per byte
+ Pointer:
+ %p base 16 notation, with leading 0x
+
+ There is no 'u' flag. Integers are printed unsigned if they have unsigned type.
+ Similarly, there is no need to specify the size of the operand (int8, int64).
+
+ The default format for %v is:
+ bool: %t
+ int, int8 etc.: %d
+ uint, uint8 etc.: %d, %x if printed with %#v
+ float32, complex64, etc: %g
+ string: %s
+ chan: %p
+ pointer: %p
+ For compound objects, the elements are printed using these rules, recursively,
+ laid out like this:
+ struct: {field0 field1 ...}
+ array, slice: [elem0 elem1 ...]
+ maps: map[key1:value1 key2:value2]
+ pointer to above: &{}, &[], &map[]
+
+ Width is specified by an optional decimal number immediately following the verb.
+ If absent, the width is whatever is necessary to represent the value.
+ Precision is specified after the (optional) width by a period followed by a
+ decimal number. If no period is present, a default precision is used.
+ A period with no following number specifies a precision of zero.
+ Examples:
+ %f: default width, default precision
+ %9f width 9, default precision
+ %.2f default width, precision 2
+ %9.2f width 9, precision 2
+ %9.f width 9, precision 0
+
+ Width and precision are measured in units of Unicode code points,
+ that is, runes. (This differs from C's printf where the
+ units are always measured in bytes.) Either or both of the flags
+ may be replaced with the character '*', causing their values to be
+ obtained from the next operand, which must be of type int.
+
+ For most values, width is the minimum number of runes to output,
+ padding the formatted form with spaces if necessary.
+
+ For strings, byte slices and byte arrays, however, precision
+ limits the length of the input to be formatted (not the size of
+ the output), truncating if necessary. Normally it is measured in
+ runes, but for these types when formatted with the %x or %X format
+ it is measured in bytes.
+
+ For floating-point values, width sets the minimum width of the field and
+ precision sets the number of places after the decimal, if appropriate,
+ except that for %g/%G it sets the total number of digits. For example,
+ given 123.45 the format %6.2f prints 123.45 while %.4g prints 123.5.
+ The default precision for %e and %f is 6; for %g it is the smallest
+ number of digits necessary to identify the value uniquely.
+
+ For complex numbers, the width and precision apply to the two
+ components independently and the result is parenthesized, so %f applied
+ to 1.2+3.4i produces (1.200000+3.400000i).
+
+ Other flags:
+ + always print a sign for numeric values;
+ guarantee ASCII-only output for %q (%+q)
+ - pad with spaces on the right rather than the left (left-justify the field)
+ # alternate format: add leading 0 for octal (%#o), 0x for hex (%#x);
+ 0X for hex (%#X); suppress 0x for %p (%#p);
+ for %q, print a raw (backquoted) string if strconv.CanBackquote
+ returns true;
+ write e.g. U+0078 'x' if the character is printable for %U (%#U).
+ ' ' (space) leave a space for elided sign in numbers (% d);
+ put spaces between bytes printing strings or slices in hex (% x, % X)
+ 0 pad with leading zeros rather than spaces;
+ for numbers, this moves the padding after the sign
+
+ Flags are ignored by verbs that do not expect them.
+ For example there is no alternate decimal format, so %#d and %d
+ behave identically.
+
+ For each Printf-like function, there is also a Print function
+ that takes no format and is equivalent to saying %v for every
+ operand. Another variant Println inserts blanks between
+ operands and appends a newline.
+
+ Regardless of the verb, if an operand is an interface value,
+ the internal concrete value is used, not the interface itself.
+ Thus:
+ var i interface{} = 23
+ fmt.Printf("%v\n", i)
+ will print 23.
+
+ Except when printed using the verbs %T and %p, special
+ formatting considerations apply for operands that implement
+ certain interfaces. In order of application:
+
+ 1. If an operand implements the Formatter interface, it will
+ be invoked. Formatter provides fine control of formatting.
+
+ 2. If the %v verb is used with the # flag (%#v) and the operand
+ implements the GoStringer interface, that will be invoked.
+
+ If the format (which is implicitly %v for Println etc.) is valid
+ for a string (%s %q %v %x %X), the following two rules apply:
+
+ 3. If an operand implements the error interface, the Error method
+ will be invoked to convert the object to a string, which will then
+ be formatted as required by the verb (if any).
+
+ 4. If an operand implements method String() string, that method
+ will be invoked to convert the object to a string, which will then
+ be formatted as required by the verb (if any).
+
+ For compound operands such as slices and structs, the format
+ applies to the elements of each operand, recursively, not to the
+ operand as a whole. Thus %q will quote each element of a slice
+ of strings, and %6.2f will control formatting for each element
+ of a floating-point array.
+
+ To avoid recursion in cases such as
+ type X string
+ func (x X) String() string { return Sprintf("<%s>", x) }
+ convert the value before recurring:
+ func (x X) String() string { return Sprintf("<%s>", string(x)) }
+ Infinite recursion can also be triggered by self-referential data
+ structures, such as a slice that contains itself as an element, if
+ that type has a String method. Such pathologies are rare, however,
+ and the package does not protect against them.
+
+ Explicit argument indexes:
+
+ In Printf, Sprintf, and Fprintf, the default behavior is for each
+ formatting verb to format successive arguments passed in the call.
+ However, the notation [n] immediately before the verb indicates that the
+ nth one-indexed argument is to be formatted instead. The same notation
+ before a '*' for a width or precision selects the argument index holding
+ the value. After processing a bracketed expression [n], arguments n+1,
+ n+2, etc. will be processed unless otherwise directed.
+
+ For example,
+ fmt.Sprintf("%[2]d %[1]d\n", 11, 22)
+ will yield "22 11", while
+ fmt.Sprintf("%[3]*.[2]*[1]f", 12.0, 2, 6),
+ equivalent to
+ fmt.Sprintf("%6.2f", 12.0),
+ will yield " 12.00". Because an explicit index affects subsequent verbs,
+ this notation can be used to print the same values multiple times
+ by resetting the index for the first argument to be repeated:
+ fmt.Sprintf("%d %d %#[1]x %#x", 16, 17)
+ will yield "16 17 0x10 0x11".
+
+ Format errors:
+
+ If an invalid argument is given for a verb, such as providing
+ a string to %d, the generated string will contain a
+ description of the problem, as in these examples:
+
+ Wrong type or unknown verb: %!verb(type=value)
+ Printf("%d", hi): %!d(string=hi)
+ Too many arguments: %!(EXTRA type=value)
+ Printf("hi", "guys"): hi%!(EXTRA string=guys)
+ Too few arguments: %!verb(MISSING)
+ Printf("hi%d"): hi %!d(MISSING)
+ Non-int for width or precision: %!(BADWIDTH) or %!(BADPREC)
+ Printf("%*s", 4.5, "hi"): %!(BADWIDTH)hi
+ Printf("%.*s", 4.5, "hi"): %!(BADPREC)hi
+ Invalid or invalid use of argument index: %!(BADINDEX)
+ Printf("%*[2]d", 7): %!d(BADINDEX)
+ Printf("%.[2]d", 7): %!d(BADINDEX)
+
+ All errors begin with the string "%!" followed sometimes
+ by a single character (the verb) and end with a parenthesized
+ description.
+
+ If an Error or String method triggers a panic when called by a
+ print routine, the fmt package reformats the error message
+ from the panic, decorating it with an indication that it came
+ through the fmt package. For example, if a String method
+ calls panic("bad"), the resulting formatted message will look
+ like
+ %!s(PANIC=bad)
+
+ The %!s just shows the print verb in use when the failure
+ occurred.
+
+ Scanning
+
+ An analogous set of functions scans formatted text to yield
+ values. Scan, Scanf and Scanln read from os.Stdin; Fscan,
+ Fscanf and Fscanln read from a specified io.Reader; Sscan,
+ Sscanf and Sscanln read from an argument string. Scanln,
+ Fscanln and Sscanln stop scanning at a newline and require that
+ the items be followed by one; Scanf, Fscanf and Sscanf require
+ newlines in the input to match newlines in the format; the other
+ routines treat newlines as spaces.
+
+ Scanf, Fscanf, and Sscanf parse the arguments according to a
+ format string, analogous to that of Printf. For example, %x
+ will scan an integer as a hexadecimal number, and %v will scan
+ the default representation format for the value.
+
+ The formats behave analogously to those of Printf with the
+ following exceptions:
+
+ %p is not implemented
+ %T is not implemented
+ %e %E %f %F %g %G are all equivalent and scan any floating point or complex value
+ %s and %v on strings scan a space-delimited token
+ Flags # and + are not implemented.
+
+ The familiar base-setting prefixes 0 (octal) and 0x
+ (hexadecimal) are accepted when scanning integers without a
+ format or with the %v verb.
+
+ Width is interpreted in the input text (%5s means at most
+ five runes of input will be read to scan a string) but there
+ is no syntax for scanning with a precision (no %5.2f, just
+ %5f).
+
+ When scanning with a format, all non-empty runs of space
+ characters (except newline) are equivalent to a single
+ space in both the format and the input. With that proviso,
+ text in the format string must match the input text; scanning
+ stops if it does not, with the return value of the function
+ indicating the number of arguments scanned.
+
+ In all the scanning functions, a carriage return followed
+ immediately by a newline is treated as a plain newline
+ (\r\n means the same as \n).
+
+ In all the scanning functions, if an operand implements method
+ Scan (that is, it implements the Scanner interface) that
+ method will be used to scan the text for that operand. Also,
+ if the number of arguments scanned is less than the number of
+ arguments provided, an error is returned.
+
+ All arguments to be scanned must be either pointers to basic
+ types or implementations of the Scanner interface.
+
+ Note: Fscan etc. can read one character (rune) past the input
+ they return, which means that a loop calling a scan routine
+ may skip some of the input. This is usually a problem only
+ when there is no space between input values. If the reader
+ provided to Fscan implements ReadRune, that method will be used
+ to read characters. If the reader also implements UnreadRune,
+ that method will be used to save the character and successive
+ calls will not lose data. To attach ReadRune and UnreadRune
+ methods to a reader without that capability, use
+ bufio.NewReader.
+*/
+package fmt
diff --git a/src/fmt/export_test.go b/src/fmt/export_test.go
new file mode 100644
index 000000000..89d57ee6c
--- /dev/null
+++ b/src/fmt/export_test.go
@@ -0,0 +1,7 @@
+// Copyright 2012 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package fmt
+
+var IsSpace = isSpace
diff --git a/src/fmt/fmt_test.go b/src/fmt/fmt_test.go
new file mode 100644
index 000000000..ff5fa79a3
--- /dev/null
+++ b/src/fmt/fmt_test.go
@@ -0,0 +1,1310 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package fmt_test
+
+import (
+ "bytes"
+ . "fmt"
+ "io"
+ "math"
+ "runtime"
+ "strings"
+ "testing"
+ "time"
+ "unicode"
+)
+
+type (
+ renamedBool bool
+ renamedInt int
+ renamedInt8 int8
+ renamedInt16 int16
+ renamedInt32 int32
+ renamedInt64 int64
+ renamedUint uint
+ renamedUint8 uint8
+ renamedUint16 uint16
+ renamedUint32 uint32
+ renamedUint64 uint64
+ renamedUintptr uintptr
+ renamedString string
+ renamedBytes []byte
+ renamedFloat32 float32
+ renamedFloat64 float64
+ renamedComplex64 complex64
+ renamedComplex128 complex128
+)
+
+func TestFmtInterface(t *testing.T) {
+ var i1 interface{}
+ i1 = "abc"
+ s := Sprintf("%s", i1)
+ if s != "abc" {
+ t.Errorf(`Sprintf("%%s", empty("abc")) = %q want %q`, s, "abc")
+ }
+}
+
+const b32 uint32 = 1<<32 - 1
+const b64 uint64 = 1<<64 - 1
+
+var array = [5]int{1, 2, 3, 4, 5}
+var iarray = [4]interface{}{1, "hello", 2.5, nil}
+var slice = array[:]
+var islice = iarray[:]
+
+type A struct {
+ i int
+ j uint
+ s string
+ x []int
+}
+
+type I int
+
+func (i I) String() string { return Sprintf("<%d>", int(i)) }
+
+type B struct {
+ I I
+ j int
+}
+
+type C struct {
+ i int
+ B
+}
+
+type F int
+
+func (f F) Format(s State, c rune) {
+ Fprintf(s, "<%c=F(%d)>", c, int(f))
+}
+
+type G int
+
+func (g G) GoString() string {
+ return Sprintf("GoString(%d)", int(g))
+}
+
+type S struct {
+ F F // a struct field that Formats
+ G G // a struct field that GoStrings
+}
+
+type SI struct {
+ I interface{}
+}
+
+// P is a type with a String method with pointer receiver for testing %p.
+type P int
+
+var pValue P
+
+func (p *P) String() string {
+ return "String(p)"
+}
+
+var barray = [5]renamedUint8{1, 2, 3, 4, 5}
+var bslice = barray[:]
+
+type byteStringer byte
+
+func (byteStringer) String() string { return "X" }
+
+var byteStringerSlice = []byteStringer{97, 98, 99, 100}
+
+type byteFormatter byte
+
+func (byteFormatter) Format(f State, _ rune) {
+ Fprint(f, "X")
+}
+
+var byteFormatterSlice = []byteFormatter{97, 98, 99, 100}
+
+var b byte
+
+var fmtTests = []struct {
+ fmt string
+ val interface{}
+ out string
+}{
+ {"%d", 12345, "12345"},
+ {"%v", 12345, "12345"},
+ {"%t", true, "true"},
+
+ // basic string
+ {"%s", "abc", "abc"},
+ {"%x", "abc", "616263"},
+ {"%x", "xyz", "78797a"},
+ {"%X", "xyz", "78797A"},
+ {"%q", "abc", `"abc"`},
+ {"%#x", []byte("abc\xff"), "0x616263ff"},
+ {"%#X", []byte("abc\xff"), "0X616263FF"},
+ {"%# x", []byte("abc\xff"), "0x61 0x62 0x63 0xff"},
+ {"%# X", []byte("abc\xff"), "0X61 0X62 0X63 0XFF"},
+
+ // basic bytes
+ {"%s", []byte("abc"), "abc"},
+ {"%x", []byte("abc"), "616263"},
+ {"% x", []byte("abc\xff"), "61 62 63 ff"},
+ {"%#x", []byte("abc\xff"), "0x616263ff"},
+ {"%#X", []byte("abc\xff"), "0X616263FF"},
+ {"%# x", []byte("abc\xff"), "0x61 0x62 0x63 0xff"},
+ {"%# X", []byte("abc\xff"), "0X61 0X62 0X63 0XFF"},
+ {"% X", []byte("abc\xff"), "61 62 63 FF"},
+ {"%x", []byte("xyz"), "78797a"},
+ {"%X", []byte("xyz"), "78797A"},
+ {"%q", []byte("abc"), `"abc"`},
+
+ // escaped strings
+ {"%#q", `abc`, "`abc`"},
+ {"%#q", `"`, "`\"`"},
+ {"1 %#q", `\n`, "1 `\\n`"},
+ {"2 %#q", "\n", `2 "\n"`},
+ {"%q", `"`, `"\""`},
+ {"%q", "\a\b\f\r\n\t\v", `"\a\b\f\r\n\t\v"`},
+ {"%q", "abc\xffdef", `"abc\xffdef"`},
+ {"%q", "\u263a", `"☺"`},
+ {"%+q", "\u263a", `"\u263a"`},
+ {"%q", "\U0010ffff", `"\U0010ffff"`},
+
+ // escaped characters
+ {"%q", 'x', `'x'`},
+ {"%q", 0, `'\x00'`},
+ {"%q", '\n', `'\n'`},
+ {"%q", '\u0e00', `'\u0e00'`}, // not a printable rune.
+ {"%q", '\U000c2345', `'\U000c2345'`}, // not a printable rune.
+ {"%q", int64(0x7FFFFFFF), `%!q(int64=2147483647)`},
+ {"%q", uint64(0xFFFFFFFF), `%!q(uint64=4294967295)`},
+ {"%q", '"', `'"'`},
+ {"%q", '\'', `'\''`},
+ {"%q", "\u263a", `"☺"`},
+ {"%+q", "\u263a", `"\u263a"`},
+
+ // width
+ {"%5s", "abc", " abc"},
+ {"%2s", "\u263a", " ☺"},
+ {"%-5s", "abc", "abc "},
+ {"%-8q", "abc", `"abc" `},
+ {"%05s", "abc", "00abc"},
+ {"%08q", "abc", `000"abc"`},
+ {"%5s", "abcdefghijklmnopqrstuvwxyz", "abcdefghijklmnopqrstuvwxyz"},
+ {"%.5s", "abcdefghijklmnopqrstuvwxyz", "abcde"},
+ {"%.5s", "日本語日本語", "日本語日本"},
+ {"%.5s", []byte("日本語日本語"), "日本語日本"},
+ {"%.5q", "abcdefghijklmnopqrstuvwxyz", `"abcde"`},
+ {"%.5x", "abcdefghijklmnopqrstuvwxyz", `6162636465`},
+ {"%.5q", []byte("abcdefghijklmnopqrstuvwxyz"), `"abcde"`},
+ {"%.5x", []byte("abcdefghijklmnopqrstuvwxyz"), `6162636465`},
+ {"%.3q", "日本語日本語", `"日本語"`},
+ {"%.3q", []byte("日本語日本語"), `"日本語"`},
+ {"%.1q", "日本語", `"日"`},
+ {"%.1q", []byte("日本語"), `"日"`},
+ {"%.1x", "日本語", `e6`},
+ {"%.1X", []byte("日本語"), `E6`},
+ {"%10.1q", "日本語日本語", ` "日"`},
+ {"%3c", '⌘', " ⌘"},
+ {"%5q", '\u2026', ` '…'`},
+ {"%10v", nil, " <nil>"},
+ {"%-10v", nil, "<nil> "},
+
+ // integers
+ {"%d", 12345, "12345"},
+ {"%d", -12345, "-12345"},
+ {"%10d", 12345, " 12345"},
+ {"%10d", -12345, " -12345"},
+ {"%+10d", 12345, " +12345"},
+ {"%010d", 12345, "0000012345"},
+ {"%010d", -12345, "-000012345"},
+ {"%-10d", 12345, "12345 "},
+ {"%010.3d", 1, " 001"},
+ {"%010.3d", -1, " -001"},
+ {"%+d", 12345, "+12345"},
+ {"%+d", -12345, "-12345"},
+ {"%+d", 0, "+0"},
+ {"% d", 0, " 0"},
+ {"% d", 12345, " 12345"},
+ {"%.0d", 0, ""},
+ {"%.d", 0, ""},
+
+ // unicode format
+ {"%U", 0x1, "U+0001"},
+ {"%U", uint(0x1), "U+0001"},
+ {"%.8U", 0x2, "U+00000002"},
+ {"%U", 0x1234, "U+1234"},
+ {"%U", 0x12345, "U+12345"},
+ {"%10.6U", 0xABC, " U+000ABC"},
+ {"%-10.6U", 0xABC, "U+000ABC "},
+ {"%U", '\n', `U+000A`},
+ {"%#U", '\n', `U+000A`},
+ {"%U", 'x', `U+0078`},
+ {"%#U", 'x', `U+0078 'x'`},
+ {"%U", '\u263a', `U+263A`},
+ {"%#U", '\u263a', `U+263A '☺'`},
+
+ // floats
+ {"%+.3e", 0.0, "+0.000e+00"},
+ {"%+.3e", 1.0, "+1.000e+00"},
+ {"%+.3f", -1.0, "-1.000"},
+ {"%+.3F", -1.0, "-1.000"},
+ {"%+.3F", float32(-1.0), "-1.000"},
+ {"%+07.2f", 1.0, "+001.00"},
+ {"%+07.2f", -1.0, "-001.00"},
+ {"%+10.2f", +1.0, " +1.00"},
+ {"%+10.2f", -1.0, " -1.00"},
+ {"% .3E", -1.0, "-1.000E+00"},
+ {"% .3e", 1.0, " 1.000e+00"},
+ {"%+.3g", 0.0, "+0"},
+ {"%+.3g", 1.0, "+1"},
+ {"%+.3g", -1.0, "-1"},
+ {"% .3g", -1.0, "-1"},
+ {"% .3g", 1.0, " 1"},
+ {"%b", float32(1.0), "8388608p-23"},
+ {"%b", 1.0, "4503599627370496p-52"},
+
+ // complex values
+ {"%+.3e", 0i, "(+0.000e+00+0.000e+00i)"},
+ {"%+.3f", 0i, "(+0.000+0.000i)"},
+ {"%+.3g", 0i, "(+0+0i)"},
+ {"%+.3e", 1 + 2i, "(+1.000e+00+2.000e+00i)"},
+ {"%+.3f", 1 + 2i, "(+1.000+2.000i)"},
+ {"%+.3g", 1 + 2i, "(+1+2i)"},
+ {"%.3e", 0i, "(0.000e+00+0.000e+00i)"},
+ {"%.3f", 0i, "(0.000+0.000i)"},
+ {"%.3F", 0i, "(0.000+0.000i)"},
+ {"%.3F", complex64(0i), "(0.000+0.000i)"},
+ {"%.3g", 0i, "(0+0i)"},
+ {"%.3e", 1 + 2i, "(1.000e+00+2.000e+00i)"},
+ {"%.3f", 1 + 2i, "(1.000+2.000i)"},
+ {"%.3g", 1 + 2i, "(1+2i)"},
+ {"%.3e", -1 - 2i, "(-1.000e+00-2.000e+00i)"},
+ {"%.3f", -1 - 2i, "(-1.000-2.000i)"},
+ {"%.3g", -1 - 2i, "(-1-2i)"},
+ {"% .3E", -1 - 2i, "(-1.000E+00-2.000E+00i)"},
+ {"%+.3g", complex64(1 + 2i), "(+1+2i)"},
+ {"%+.3g", complex128(1 + 2i), "(+1+2i)"},
+ {"%b", complex64(1 + 2i), "(8388608p-23+8388608p-22i)"},
+ {"%b", 1 + 2i, "(4503599627370496p-52+4503599627370496p-51i)"},
+
+ // erroneous formats
+ {"", 2, "%!(EXTRA int=2)"},
+ {"%d", "hello", "%!d(string=hello)"},
+
+ // old test/fmt_test.go
+ {"%d", 1234, "1234"},
+ {"%d", -1234, "-1234"},
+ {"%d", uint(1234), "1234"},
+ {"%d", uint32(b32), "4294967295"},
+ {"%d", uint64(b64), "18446744073709551615"},
+ {"%o", 01234, "1234"},
+ {"%#o", 01234, "01234"},
+ {"%o", uint32(b32), "37777777777"},
+ {"%o", uint64(b64), "1777777777777777777777"},
+ {"%x", 0x1234abcd, "1234abcd"},
+ {"%#x", 0x1234abcd, "0x1234abcd"},
+ {"%x", b32 - 0x1234567, "fedcba98"},
+ {"%X", 0x1234abcd, "1234ABCD"},
+ {"%X", b32 - 0x1234567, "FEDCBA98"},
+ {"%#X", 0, "0X0"},
+ {"%x", b64, "ffffffffffffffff"},
+ {"%b", 7, "111"},
+ {"%b", b64, "1111111111111111111111111111111111111111111111111111111111111111"},
+ {"%b", -6, "-110"},
+ {"%e", 1.0, "1.000000e+00"},
+ {"%e", 1234.5678e3, "1.234568e+06"},
+ {"%e", 1234.5678e-8, "1.234568e-05"},
+ {"%e", -7.0, "-7.000000e+00"},
+ {"%e", -1e-9, "-1.000000e-09"},
+ {"%f", 1234.5678e3, "1234567.800000"},
+ {"%f", 1234.5678e-8, "0.000012"},
+ {"%f", -7.0, "-7.000000"},
+ {"%f", -1e-9, "-0.000000"},
+ {"%g", 1234.5678e3, "1.2345678e+06"},
+ {"%g", float32(1234.5678e3), "1.2345678e+06"},
+ {"%g", 1234.5678e-8, "1.2345678e-05"},
+ {"%g", -7.0, "-7"},
+ {"%g", -1e-9, "-1e-09"},
+ {"%g", float32(-1e-9), "-1e-09"},
+ {"%E", 1.0, "1.000000E+00"},
+ {"%E", 1234.5678e3, "1.234568E+06"},
+ {"%E", 1234.5678e-8, "1.234568E-05"},
+ {"%E", -7.0, "-7.000000E+00"},
+ {"%E", -1e-9, "-1.000000E-09"},
+ {"%G", 1234.5678e3, "1.2345678E+06"},
+ {"%G", float32(1234.5678e3), "1.2345678E+06"},
+ {"%G", 1234.5678e-8, "1.2345678E-05"},
+ {"%G", -7.0, "-7"},
+ {"%G", -1e-9, "-1E-09"},
+ {"%G", float32(-1e-9), "-1E-09"},
+ {"%c", 'x', "x"},
+ {"%c", 0xe4, "ä"},
+ {"%c", 0x672c, "本"},
+ {"%c", '日', "日"},
+ {"%20.8d", 1234, " 00001234"},
+ {"%20.8d", -1234, " -00001234"},
+ {"%20d", 1234, " 1234"},
+ {"%-20.8d", 1234, "00001234 "},
+ {"%-20.8d", -1234, "-00001234 "},
+ {"%-#20.8x", 0x1234abc, "0x01234abc "},
+ {"%-#20.8X", 0x1234abc, "0X01234ABC "},
+ {"%-#20.8o", 01234, "00001234 "},
+ {"%.20b", 7, "00000000000000000111"},
+ {"%20.5s", "qwertyuiop", " qwert"},
+ {"%.5s", "qwertyuiop", "qwert"},
+ {"%-20.5s", "qwertyuiop", "qwert "},
+ {"%20c", 'x', " x"},
+ {"%-20c", 'x', "x "},
+ {"%20.6e", 1.2345e3, " 1.234500e+03"},
+ {"%20.6e", 1.2345e-3, " 1.234500e-03"},
+ {"%20e", 1.2345e3, " 1.234500e+03"},
+ {"%20e", 1.2345e-3, " 1.234500e-03"},
+ {"%20.8e", 1.2345e3, " 1.23450000e+03"},
+ {"%20f", 1.23456789e3, " 1234.567890"},
+ {"%20f", 1.23456789e-3, " 0.001235"},
+ {"%20f", 12345678901.23456789, " 12345678901.234568"},
+ {"%-20f", 1.23456789e3, "1234.567890 "},
+ {"%20.8f", 1.23456789e3, " 1234.56789000"},
+ {"%20.8f", 1.23456789e-3, " 0.00123457"},
+ {"%g", 1.23456789e3, "1234.56789"},
+ {"%g", 1.23456789e-3, "0.00123456789"},
+ {"%g", 1.23456789e20, "1.23456789e+20"},
+ {"%20e", math.Inf(1), " +Inf"},
+ {"%-20f", math.Inf(-1), "-Inf "},
+ {"%20g", math.NaN(), " NaN"},
+
+ // arrays
+ {"%v", array, "[1 2 3 4 5]"},
+ {"%v", iarray, "[1 hello 2.5 <nil>]"},
+ {"%v", barray, "[1 2 3 4 5]"},
+ {"%v", &array, "&[1 2 3 4 5]"},
+ {"%v", &iarray, "&[1 hello 2.5 <nil>]"},
+ {"%v", &barray, "&[1 2 3 4 5]"},
+
+ // slices
+ {"%v", slice, "[1 2 3 4 5]"},
+ {"%v", islice, "[1 hello 2.5 <nil>]"},
+ {"%v", bslice, "[1 2 3 4 5]"},
+ {"%v", &slice, "&[1 2 3 4 5]"},
+ {"%v", &islice, "&[1 hello 2.5 <nil>]"},
+ {"%v", &bslice, "&[1 2 3 4 5]"},
+
+ // complexes with %v
+ {"%v", 1 + 2i, "(1+2i)"},
+ {"%v", complex64(1 + 2i), "(1+2i)"},
+ {"%v", complex128(1 + 2i), "(1+2i)"},
+
+ // structs
+ {"%v", A{1, 2, "a", []int{1, 2}}, `{1 2 a [1 2]}`},
+ {"%+v", A{1, 2, "a", []int{1, 2}}, `{i:1 j:2 s:a x:[1 2]}`},
+
+ // +v on structs with Stringable items
+ {"%+v", B{1, 2}, `{I:<1> j:2}`},
+ {"%+v", C{1, B{2, 3}}, `{i:1 B:{I:<2> j:3}}`},
+
+ // other formats on Stringable items
+ {"%s", I(23), `<23>`},
+ {"%q", I(23), `"<23>"`},
+ {"%x", I(23), `3c32333e`},
+ {"%#x", I(23), `0x3c32333e`},
+ {"%# x", I(23), `0x3c 0x32 0x33 0x3e`},
+ {"%d", I(23), `23`}, // Stringer applies only to string formats.
+
+ // go syntax
+ {"%#v", A{1, 2, "a", []int{1, 2}}, `fmt_test.A{i:1, j:0x2, s:"a", x:[]int{1, 2}}`},
+ {"%#v", &b, "(*uint8)(0xPTR)"},
+ {"%#v", TestFmtInterface, "(func(*testing.T))(0xPTR)"},
+ {"%#v", make(chan int), "(chan int)(0xPTR)"},
+ {"%#v", uint64(1<<64 - 1), "0xffffffffffffffff"},
+ {"%#v", 1000000000, "1000000000"},
+ {"%#v", map[string]int{"a": 1}, `map[string]int{"a":1}`},
+ {"%#v", map[string]B{"a": {1, 2}}, `map[string]fmt_test.B{"a":fmt_test.B{I:1, j:2}}`},
+ {"%#v", []string{"a", "b"}, `[]string{"a", "b"}`},
+ {"%#v", SI{}, `fmt_test.SI{I:interface {}(nil)}`},
+ {"%#v", []int(nil), `[]int(nil)`},
+ {"%#v", []int{}, `[]int{}`},
+ {"%#v", array, `[5]int{1, 2, 3, 4, 5}`},
+ {"%#v", &array, `&[5]int{1, 2, 3, 4, 5}`},
+ {"%#v", iarray, `[4]interface {}{1, "hello", 2.5, interface {}(nil)}`},
+ {"%#v", &iarray, `&[4]interface {}{1, "hello", 2.5, interface {}(nil)}`},
+ {"%#v", map[int]byte(nil), `map[int]uint8(nil)`},
+ {"%#v", map[int]byte{}, `map[int]uint8{}`},
+ {"%#v", "foo", `"foo"`},
+ {"%#v", barray, `[5]fmt_test.renamedUint8{0x1, 0x2, 0x3, 0x4, 0x5}`},
+ {"%#v", bslice, `[]fmt_test.renamedUint8{0x1, 0x2, 0x3, 0x4, 0x5}`},
+ {"%#v", []byte(nil), "[]byte(nil)"},
+ {"%#v", []int32(nil), "[]int32(nil)"},
+
+ // slices with other formats
+ {"%#x", []int{1, 2, 15}, `[0x1 0x2 0xf]`},
+ {"%x", []int{1, 2, 15}, `[1 2 f]`},
+ {"%d", []int{1, 2, 15}, `[1 2 15]`},
+ {"%d", []byte{1, 2, 15}, `[1 2 15]`},
+ {"%q", []string{"a", "b"}, `["a" "b"]`},
+
+ // renamings
+ {"%v", renamedBool(true), "true"},
+ {"%d", renamedBool(true), "%!d(fmt_test.renamedBool=true)"},
+ {"%o", renamedInt(8), "10"},
+ {"%d", renamedInt8(-9), "-9"},
+ {"%v", renamedInt16(10), "10"},
+ {"%v", renamedInt32(-11), "-11"},
+ {"%X", renamedInt64(255), "FF"},
+ {"%v", renamedUint(13), "13"},
+ {"%o", renamedUint8(14), "16"},
+ {"%X", renamedUint16(15), "F"},
+ {"%d", renamedUint32(16), "16"},
+ {"%X", renamedUint64(17), "11"},
+ {"%o", renamedUintptr(18), "22"},
+ {"%x", renamedString("thing"), "7468696e67"},
+ {"%d", renamedBytes([]byte{1, 2, 15}), `[1 2 15]`},
+ {"%q", renamedBytes([]byte("hello")), `"hello"`},
+ {"%x", []renamedUint8{'a', 'b', 'c'}, "616263"},
+ {"%s", []renamedUint8{'h', 'e', 'l', 'l', 'o'}, "hello"},
+ {"%q", []renamedUint8{'h', 'e', 'l', 'l', 'o'}, `"hello"`},
+ {"%v", renamedFloat32(22), "22"},
+ {"%v", renamedFloat64(33), "33"},
+ {"%v", renamedComplex64(3 + 4i), "(3+4i)"},
+ {"%v", renamedComplex128(4 - 3i), "(4-3i)"},
+
+ // Formatter
+ {"%x", F(1), "<x=F(1)>"},
+ {"%x", G(2), "2"},
+ {"%+v", S{F(4), G(5)}, "{F:<v=F(4)> G:5}"},
+
+ // GoStringer
+ {"%#v", G(6), "GoString(6)"},
+ {"%#v", S{F(7), G(8)}, "fmt_test.S{F:<v=F(7)>, G:GoString(8)}"},
+
+ // %T
+ {"%T", (4 - 3i), "complex128"},
+ {"%T", renamedComplex128(4 - 3i), "fmt_test.renamedComplex128"},
+ {"%T", intVal, "int"},
+ {"%6T", &intVal, " *int"},
+ {"%10T", nil, " <nil>"},
+ {"%-10T", nil, "<nil> "},
+
+ // %p
+ {"p0=%p", new(int), "p0=0xPTR"},
+ {"p1=%s", &pValue, "p1=String(p)"}, // String method...
+ {"p2=%p", &pValue, "p2=0xPTR"}, // ... not called with %p
+ {"p3=%p", (*int)(nil), "p3=0x0"},
+ {"p4=%#p", new(int), "p4=PTR"},
+
+ // %p on non-pointers
+ {"%p", make(chan int), "0xPTR"},
+ {"%p", make(map[int]int), "0xPTR"},
+ {"%p", make([]int, 1), "0xPTR"},
+ {"%p", 27, "%!p(int=27)"}, // not a pointer at all
+
+ // %q on pointers
+ {"%q", (*int)(nil), "%!q(*int=<nil>)"},
+ {"%q", new(int), "%!q(*int=0xPTR)"},
+
+ // %v on pointers formats 0 as <nil>
+ {"%v", (*int)(nil), "<nil>"},
+ {"%v", new(int), "0xPTR"},
+
+ // %d etc. pointers use specified base.
+ {"%d", new(int), "PTR_d"},
+ {"%o", new(int), "PTR_o"},
+ {"%x", new(int), "PTR_x"},
+
+ // %d on Stringer should give integer if possible
+ {"%s", time.Time{}.Month(), "January"},
+ {"%d", time.Time{}.Month(), "1"},
+
+ // erroneous things
+ {"%s %", "hello", "hello %!(NOVERB)"},
+ {"%s %.2", "hello", "hello %!(NOVERB)"},
+ {"%d", "hello", "%!d(string=hello)"},
+ {"no args", "hello", "no args%!(EXTRA string=hello)"},
+ {"%s", nil, "%!s(<nil>)"},
+ {"%T", nil, "<nil>"},
+ {"%-1", 100, "%!(NOVERB)%!(EXTRA int=100)"},
+
+ // The "<nil>" show up because maps are printed by
+ // first obtaining a list of keys and then looking up
+ // each key. Since NaNs can be map keys but cannot
+ // be fetched directly, the lookup fails and returns a
+ // zero reflect.Value, which formats as <nil>.
+ // This test is just to check that it shows the two NaNs at all.
+ {"%v", map[float64]int{math.NaN(): 1, math.NaN(): 2}, "map[NaN:<nil> NaN:<nil>]"},
+
+ // Used to crash because nByte didn't allow for a sign.
+ {"%b", int64(-1 << 63), zeroFill("-1", 63, "")},
+
+ // Used to panic.
+ {"%0100d", 1, zeroFill("", 100, "1")},
+ {"%0100d", -1, zeroFill("-", 99, "1")},
+ {"%0.100f", 1.0, zeroFill("1.", 100, "")},
+ {"%0.100f", -1.0, zeroFill("-1.", 100, "")},
+
+ // Comparison of padding rules with C printf.
+ /*
+ C program:
+ #include <stdio.h>
+
+ char *format[] = {
+ "[%.2f]",
+ "[% .2f]",
+ "[%+.2f]",
+ "[%7.2f]",
+ "[% 7.2f]",
+ "[%+7.2f]",
+ "[%07.2f]",
+ "[% 07.2f]",
+ "[%+07.2f]",
+ };
+
+ int main(void) {
+ int i;
+ for(i = 0; i < 9; i++) {
+ printf("%s: ", format[i]);
+ printf(format[i], 1.0);
+ printf(" ");
+ printf(format[i], -1.0);
+ printf("\n");
+ }
+ }
+
+ Output:
+ [%.2f]: [1.00] [-1.00]
+ [% .2f]: [ 1.00] [-1.00]
+ [%+.2f]: [+1.00] [-1.00]
+ [%7.2f]: [ 1.00] [ -1.00]
+ [% 7.2f]: [ 1.00] [ -1.00]
+ [%+7.2f]: [ +1.00] [ -1.00]
+ [%07.2f]: [0001.00] [-001.00]
+ [% 07.2f]: [ 001.00] [-001.00]
+ [%+07.2f]: [+001.00] [-001.00]
+ */
+ {"%.2f", 1.0, "1.00"},
+ {"%.2f", -1.0, "-1.00"},
+ {"% .2f", 1.0, " 1.00"},
+ {"% .2f", -1.0, "-1.00"},
+ {"%+.2f", 1.0, "+1.00"},
+ {"%+.2f", -1.0, "-1.00"},
+ {"%7.2f", 1.0, " 1.00"},
+ {"%7.2f", -1.0, " -1.00"},
+ {"% 7.2f", 1.0, " 1.00"},
+ {"% 7.2f", -1.0, " -1.00"},
+ {"%+7.2f", 1.0, " +1.00"},
+ {"%+7.2f", -1.0, " -1.00"},
+ {"%07.2f", 1.0, "0001.00"},
+ {"%07.2f", -1.0, "-001.00"},
+ {"% 07.2f", 1.0, " 001.00"},
+ {"% 07.2f", -1.0, "-001.00"},
+ {"%+07.2f", 1.0, "+001.00"},
+ {"%+07.2f", -1.0, "-001.00"},
+
+ // Complex numbers: exhaustively tested in TestComplexFormatting.
+ {"%7.2f", 1 + 2i, "( 1.00 +2.00i)"},
+ {"%+07.2f", -1 - 2i, "(-001.00-002.00i)"},
+ // Zero padding does not apply to infinities.
+ {"%020f", math.Inf(-1), " -Inf"},
+ {"%020f", math.Inf(+1), " +Inf"},
+ {"% 020f", math.Inf(-1), " -Inf"},
+ {"% 020f", math.Inf(+1), " Inf"},
+ {"%+020f", math.Inf(-1), " -Inf"},
+ {"%+020f", math.Inf(+1), " +Inf"},
+ {"%20f", -1.0, " -1.000000"},
+ // Make sure we can handle very large widths.
+ {"%0100f", -1.0, zeroFill("-", 99, "1.000000")},
+
+ // Complex fmt used to leave the plus flag set for future entries in the array
+ // causing +2+0i and +3+0i instead of 2+0i and 3+0i.
+ {"%v", []complex64{1, 2, 3}, "[(1+0i) (2+0i) (3+0i)]"},
+ {"%v", []complex128{1, 2, 3}, "[(1+0i) (2+0i) (3+0i)]"},
+
+ // Incomplete format specification caused crash.
+ {"%.", 3, "%!.(int=3)"},
+
+ // Used to panic with out-of-bounds for very large numeric representations.
+ // nByte is set to handle one bit per uint64 in %b format, with a negative number.
+ // See issue 6777.
+ {"%#064x", 1, zeroFill("0x", 64, "1")},
+ {"%#064x", -1, zeroFill("-0x", 63, "1")},
+ {"%#064b", 1, zeroFill("", 64, "1")},
+ {"%#064b", -1, zeroFill("-", 63, "1")},
+ {"%#064o", 1, zeroFill("", 64, "1")},
+ {"%#064o", -1, zeroFill("-", 63, "1")},
+ {"%#064d", 1, zeroFill("", 64, "1")},
+ {"%#064d", -1, zeroFill("-", 63, "1")},
+ // Test that we handle the crossover above the size of uint64
+ {"%#072x", 1, zeroFill("0x", 72, "1")},
+ {"%#072x", -1, zeroFill("-0x", 71, "1")},
+ {"%#072b", 1, zeroFill("", 72, "1")},
+ {"%#072b", -1, zeroFill("-", 71, "1")},
+ {"%#072o", 1, zeroFill("", 72, "1")},
+ {"%#072o", -1, zeroFill("-", 71, "1")},
+ {"%#072d", 1, zeroFill("", 72, "1")},
+ {"%#072d", -1, zeroFill("-", 71, "1")},
+
+ // Padding for complex numbers. Has been bad, then fixed, then bad again.
+ {"%+10.2f", +104.66 + 440.51i, "( +104.66 +440.51i)"},
+ {"%+10.2f", -104.66 + 440.51i, "( -104.66 +440.51i)"},
+ {"%+10.2f", +104.66 - 440.51i, "( +104.66 -440.51i)"},
+ {"%+10.2f", -104.66 - 440.51i, "( -104.66 -440.51i)"},
+ {"%+010.2f", +104.66 + 440.51i, "(+000104.66+000440.51i)"},
+ {"%+010.2f", -104.66 + 440.51i, "(-000104.66+000440.51i)"},
+ {"%+010.2f", +104.66 - 440.51i, "(+000104.66-000440.51i)"},
+ {"%+010.2f", -104.66 - 440.51i, "(-000104.66-000440.51i)"},
+
+ // []T where type T is a byte with a Stringer method.
+ {"%v", byteStringerSlice, "[X X X X]"},
+ {"%s", byteStringerSlice, "abcd"},
+ {"%q", byteStringerSlice, "\"abcd\""},
+ {"%x", byteStringerSlice, "61626364"},
+ {"%#v", byteStringerSlice, "[]fmt_test.byteStringer{0x61, 0x62, 0x63, 0x64}"},
+
+ // And the same for Formatter.
+ {"%v", byteFormatterSlice, "[X X X X]"},
+ {"%s", byteFormatterSlice, "abcd"},
+ {"%q", byteFormatterSlice, "\"abcd\""},
+ {"%x", byteFormatterSlice, "61626364"},
+ // This next case seems wrong, but the docs say the Formatter wins here.
+ {"%#v", byteFormatterSlice, "[]fmt_test.byteFormatter{X, X, X, X}"},
+}
+
+// zeroFill generates zero-filled strings of the specified width. The length
+// of the suffix (but not the prefix) is compensated for in the width calculation.
+func zeroFill(prefix string, width int, suffix string) string {
+ return prefix + strings.Repeat("0", width-len(suffix)) + suffix
+}
+
+func TestSprintf(t *testing.T) {
+ for _, tt := range fmtTests {
+ s := Sprintf(tt.fmt, tt.val)
+ if i := strings.Index(tt.out, "PTR"); i >= 0 {
+ pattern := "PTR"
+ chars := "0123456789abcdefABCDEF"
+ switch {
+ case strings.HasPrefix(tt.out[i:], "PTR_d"):
+ pattern = "PTR_d"
+ chars = chars[:10]
+ case strings.HasPrefix(tt.out[i:], "PTR_o"):
+ pattern = "PTR_o"
+ chars = chars[:8]
+ case strings.HasPrefix(tt.out[i:], "PTR_x"):
+ pattern = "PTR_x"
+ }
+ j := i
+ for ; j < len(s); j++ {
+ c := s[j]
+ if !strings.ContainsRune(chars, rune(c)) {
+ break
+ }
+ }
+ s = s[0:i] + pattern + s[j:]
+ }
+ if s != tt.out {
+ if _, ok := tt.val.(string); ok {
+ // Don't requote the already-quoted strings.
+ // It's too confusing to read the errors.
+ t.Errorf("Sprintf(%q, %q) = <%s> want <%s>", tt.fmt, tt.val, s, tt.out)
+ } else {
+ t.Errorf("Sprintf(%q, %v) = %q want %q", tt.fmt, tt.val, s, tt.out)
+ }
+ }
+ }
+}
+
+// TestComplexFormatting checks that a complex always formats to the same
+// thing as if done by hand with two singleton prints.
+func TestComplexFormatting(t *testing.T) {
+ var yesNo = []bool{true, false}
+ var values = []float64{1, 0, -1, math.Inf(1), math.Inf(-1), math.NaN()}
+ for _, plus := range yesNo {
+ for _, zero := range yesNo {
+ for _, space := range yesNo {
+ for _, char := range "fFeEgG" {
+ realFmt := "%"
+ if zero {
+ realFmt += "0"
+ }
+ if space {
+ realFmt += " "
+ }
+ if plus {
+ realFmt += "+"
+ }
+ realFmt += "10.2"
+ realFmt += string(char)
+ // Imaginary part always has a sign, so force + and ignore space.
+ imagFmt := "%"
+ if zero {
+ imagFmt += "0"
+ }
+ imagFmt += "+"
+ imagFmt += "10.2"
+ imagFmt += string(char)
+ for _, realValue := range values {
+ for _, imagValue := range values {
+ one := Sprintf(realFmt, complex(realValue, imagValue))
+ two := Sprintf("("+realFmt+imagFmt+"i)", realValue, imagValue)
+ if one != two {
+ t.Error(f, one, two)
+ }
+ }
+ }
+ }
+ }
+ }
+ }
+}
+
+type SE []interface{} // slice of empty; notational compactness.
+
+var reorderTests = []struct {
+ fmt string
+ val SE
+ out string
+}{
+ {"%[1]d", SE{1}, "1"},
+ {"%[2]d", SE{2, 1}, "1"},
+ {"%[2]d %[1]d", SE{1, 2}, "2 1"},
+ {"%[2]*[1]d", SE{2, 5}, " 2"},
+ {"%6.2f", SE{12.0}, " 12.00"}, // Explicit version of next line.
+ {"%[3]*.[2]*[1]f", SE{12.0, 2, 6}, " 12.00"},
+ {"%[1]*.[2]*[3]f", SE{6, 2, 12.0}, " 12.00"},
+ {"%10f", SE{12.0}, " 12.000000"},
+ {"%[1]*[3]f", SE{10, 99, 12.0}, " 12.000000"},
+ {"%.6f", SE{12.0}, "12.000000"}, // Explicit version of next line.
+ {"%.[1]*[3]f", SE{6, 99, 12.0}, "12.000000"},
+ {"%6.f", SE{12.0}, " 12"}, // // Explicit version of next line; empty precision means zero.
+ {"%[1]*.[3]f", SE{6, 3, 12.0}, " 12"},
+ // An actual use! Print the same arguments twice.
+ {"%d %d %d %#[1]o %#o %#o", SE{11, 12, 13}, "11 12 13 013 014 015"},
+
+ // Erroneous cases.
+ {"%[d", SE{2, 1}, "%!d(BADINDEX)"},
+ {"%]d", SE{2, 1}, "%!](int=2)d%!(EXTRA int=1)"},
+ {"%[]d", SE{2, 1}, "%!d(BADINDEX)"},
+ {"%[-3]d", SE{2, 1}, "%!d(BADINDEX)"},
+ {"%[99]d", SE{2, 1}, "%!d(BADINDEX)"},
+ {"%[3]", SE{2, 1}, "%!(NOVERB)"},
+ {"%[1].2d", SE{5, 6}, "%!d(BADINDEX)"},
+ {"%[1]2d", SE{2, 1}, "%!d(BADINDEX)"},
+ {"%3.[2]d", SE{7}, "%!d(BADINDEX)"},
+ {"%.[2]d", SE{7}, "%!d(BADINDEX)"},
+ {"%d %d %d %#[1]o %#o %#o %#o", SE{11, 12, 13}, "11 12 13 013 014 015 %!o(MISSING)"},
+ {"%[5]d %[2]d %d", SE{1, 2, 3}, "%!d(BADINDEX) 2 3"},
+ {"%d %[3]d %d", SE{1, 2}, "1 %!d(BADINDEX) 2"}, // Erroneous index does not affect sequence.
+}
+
+func TestReorder(t *testing.T) {
+ for _, tt := range reorderTests {
+ s := Sprintf(tt.fmt, tt.val...)
+ if s != tt.out {
+ t.Errorf("Sprintf(%q, %v) = <%s> want <%s>", tt.fmt, tt.val, s, tt.out)
+ } else {
+ }
+ }
+}
+
+func BenchmarkSprintfEmpty(b *testing.B) {
+ b.RunParallel(func(pb *testing.PB) {
+ for pb.Next() {
+ Sprintf("")
+ }
+ })
+}
+
+func BenchmarkSprintfString(b *testing.B) {
+ b.RunParallel(func(pb *testing.PB) {
+ for pb.Next() {
+ Sprintf("%s", "hello")
+ }
+ })
+}
+
+func BenchmarkSprintfInt(b *testing.B) {
+ b.RunParallel(func(pb *testing.PB) {
+ for pb.Next() {
+ Sprintf("%d", 5)
+ }
+ })
+}
+
+func BenchmarkSprintfIntInt(b *testing.B) {
+ b.RunParallel(func(pb *testing.PB) {
+ for pb.Next() {
+ Sprintf("%d %d", 5, 6)
+ }
+ })
+}
+
+func BenchmarkSprintfPrefixedInt(b *testing.B) {
+ b.RunParallel(func(pb *testing.PB) {
+ for pb.Next() {
+ Sprintf("This is some meaningless prefix text that needs to be scanned %d", 6)
+ }
+ })
+}
+
+func BenchmarkSprintfFloat(b *testing.B) {
+ b.RunParallel(func(pb *testing.PB) {
+ for pb.Next() {
+ Sprintf("%g", 5.23184)
+ }
+ })
+}
+
+func BenchmarkManyArgs(b *testing.B) {
+ b.RunParallel(func(pb *testing.PB) {
+ var buf bytes.Buffer
+ for pb.Next() {
+ buf.Reset()
+ Fprintf(&buf, "%2d/%2d/%2d %d:%d:%d %s %s\n", 3, 4, 5, 11, 12, 13, "hello", "world")
+ }
+ })
+}
+
+func BenchmarkFprintInt(b *testing.B) {
+ var buf bytes.Buffer
+ for i := 0; i < b.N; i++ {
+ buf.Reset()
+ Fprint(&buf, 123456)
+ }
+}
+
+func BenchmarkFprintIntNoAlloc(b *testing.B) {
+ var x interface{} = 123456
+ var buf bytes.Buffer
+ for i := 0; i < b.N; i++ {
+ buf.Reset()
+ Fprint(&buf, x)
+ }
+}
+
+var mallocBuf bytes.Buffer
+var mallocPointer *int // A pointer so we know the interface value won't allocate.
+
+var mallocTest = []struct {
+ count int
+ desc string
+ fn func()
+}{
+ {0, `Sprintf("")`, func() { Sprintf("") }},
+ {1, `Sprintf("xxx")`, func() { Sprintf("xxx") }},
+ {2, `Sprintf("%x")`, func() { Sprintf("%x", 7) }},
+ {2, `Sprintf("%s")`, func() { Sprintf("%s", "hello") }},
+ {3, `Sprintf("%x %x")`, func() { Sprintf("%x %x", 7, 112) }},
+ {2, `Sprintf("%g")`, func() { Sprintf("%g", float32(3.14159)) }}, // TODO: Can this be 1?
+ {1, `Fprintf(buf, "%s")`, func() { mallocBuf.Reset(); Fprintf(&mallocBuf, "%s", "hello") }},
+ // If the interface value doesn't need to allocate, amortized allocation overhead should be zero.
+ {0, `Fprintf(buf, "%x %x %x")`, func() {
+ mallocBuf.Reset()
+ Fprintf(&mallocBuf, "%x %x %x", mallocPointer, mallocPointer, mallocPointer)
+ }},
+}
+
+var _ bytes.Buffer
+
+func TestCountMallocs(t *testing.T) {
+ if testing.Short() {
+ t.Skip("skipping malloc count in short mode")
+ }
+ if runtime.GOMAXPROCS(0) > 1 {
+ t.Skip("skipping; GOMAXPROCS>1")
+ }
+ for _, mt := range mallocTest {
+ mallocs := testing.AllocsPerRun(100, mt.fn)
+ if got, max := mallocs, float64(mt.count); got > max {
+ t.Errorf("%s: got %v allocs, want <=%v", mt.desc, got, max)
+ }
+ }
+}
+
+type flagPrinter struct{}
+
+func (flagPrinter) Format(f State, c rune) {
+ s := "%"
+ for i := 0; i < 128; i++ {
+ if f.Flag(i) {
+ s += string(i)
+ }
+ }
+ if w, ok := f.Width(); ok {
+ s += Sprintf("%d", w)
+ }
+ if p, ok := f.Precision(); ok {
+ s += Sprintf(".%d", p)
+ }
+ s += string(c)
+ io.WriteString(f, "["+s+"]")
+}
+
+var flagtests = []struct {
+ in string
+ out string
+}{
+ {"%a", "[%a]"},
+ {"%-a", "[%-a]"},
+ {"%+a", "[%+a]"},
+ {"%#a", "[%#a]"},
+ {"% a", "[% a]"},
+ {"%0a", "[%0a]"},
+ {"%1.2a", "[%1.2a]"},
+ {"%-1.2a", "[%-1.2a]"},
+ {"%+1.2a", "[%+1.2a]"},
+ {"%-+1.2a", "[%+-1.2a]"},
+ {"%-+1.2abc", "[%+-1.2a]bc"},
+ {"%-1.2abc", "[%-1.2a]bc"},
+}
+
+func TestFlagParser(t *testing.T) {
+ var flagprinter flagPrinter
+ for _, tt := range flagtests {
+ s := Sprintf(tt.in, &flagprinter)
+ if s != tt.out {
+ t.Errorf("Sprintf(%q, &flagprinter) => %q, want %q", tt.in, s, tt.out)
+ }
+ }
+}
+
+func TestStructPrinter(t *testing.T) {
+ type T struct {
+ a string
+ b string
+ c int
+ }
+ var s T
+ s.a = "abc"
+ s.b = "def"
+ s.c = 123
+ var tests = []struct {
+ fmt string
+ out string
+ }{
+ {"%v", "{abc def 123}"},
+ {"%+v", "{a:abc b:def c:123}"},
+ {"%#v", `fmt_test.T{a:"abc", b:"def", c:123}`},
+ }
+ for _, tt := range tests {
+ out := Sprintf(tt.fmt, s)
+ if out != tt.out {
+ t.Errorf("Sprintf(%q, s) = %#q, want %#q", tt.fmt, out, tt.out)
+ }
+ // The same but with a pointer.
+ out = Sprintf(tt.fmt, &s)
+ if out != "&"+tt.out {
+ t.Errorf("Sprintf(%q, &s) = %#q, want %#q", tt.fmt, out, "&"+tt.out)
+ }
+ }
+}
+
+func TestSlicePrinter(t *testing.T) {
+ slice := []int{}
+ s := Sprint(slice)
+ if s != "[]" {
+ t.Errorf("empty slice printed as %q not %q", s, "[]")
+ }
+ slice = []int{1, 2, 3}
+ s = Sprint(slice)
+ if s != "[1 2 3]" {
+ t.Errorf("slice: got %q expected %q", s, "[1 2 3]")
+ }
+ s = Sprint(&slice)
+ if s != "&[1 2 3]" {
+ t.Errorf("&slice: got %q expected %q", s, "&[1 2 3]")
+ }
+}
+
+// presentInMap checks map printing using substrings so we don't depend on the
+// print order.
+func presentInMap(s string, a []string, t *testing.T) {
+ for i := 0; i < len(a); i++ {
+ loc := strings.Index(s, a[i])
+ if loc < 0 {
+ t.Errorf("map print: expected to find %q in %q", a[i], s)
+ }
+ // make sure the match ends here
+ loc += len(a[i])
+ if loc >= len(s) || (s[loc] != ' ' && s[loc] != ']') {
+ t.Errorf("map print: %q not properly terminated in %q", a[i], s)
+ }
+ }
+}
+
+func TestMapPrinter(t *testing.T) {
+ m0 := make(map[int]string)
+ s := Sprint(m0)
+ if s != "map[]" {
+ t.Errorf("empty map printed as %q not %q", s, "map[]")
+ }
+ m1 := map[int]string{1: "one", 2: "two", 3: "three"}
+ a := []string{"1:one", "2:two", "3:three"}
+ presentInMap(Sprintf("%v", m1), a, t)
+ presentInMap(Sprint(m1), a, t)
+ // Pointer to map prints the same but with initial &.
+ if !strings.HasPrefix(Sprint(&m1), "&") {
+ t.Errorf("no initial & for address of map")
+ }
+ presentInMap(Sprintf("%v", &m1), a, t)
+ presentInMap(Sprint(&m1), a, t)
+}
+
+func TestEmptyMap(t *testing.T) {
+ const emptyMapStr = "map[]"
+ var m map[string]int
+ s := Sprint(m)
+ if s != emptyMapStr {
+ t.Errorf("nil map printed as %q not %q", s, emptyMapStr)
+ }
+ m = make(map[string]int)
+ s = Sprint(m)
+ if s != emptyMapStr {
+ t.Errorf("empty map printed as %q not %q", s, emptyMapStr)
+ }
+}
+
+// TestBlank checks that Sprint (and hence Print, Fprint) puts spaces in the
+// right places, that is, between arg pairs in which neither is a string.
+func TestBlank(t *testing.T) {
+ got := Sprint("<", 1, ">:", 1, 2, 3, "!")
+ expect := "<1>:1 2 3!"
+ if got != expect {
+ t.Errorf("got %q expected %q", got, expect)
+ }
+}
+
+// TestBlankln checks that Sprintln (and hence Println, Fprintln) puts spaces in
+// the right places, that is, between all arg pairs.
+func TestBlankln(t *testing.T) {
+ got := Sprintln("<", 1, ">:", 1, 2, 3, "!")
+ expect := "< 1 >: 1 2 3 !\n"
+ if got != expect {
+ t.Errorf("got %q expected %q", got, expect)
+ }
+}
+
+// TestFormatterPrintln checks Formatter with Sprint, Sprintln, Sprintf.
+func TestFormatterPrintln(t *testing.T) {
+ f := F(1)
+ expect := "<v=F(1)>\n"
+ s := Sprint(f, "\n")
+ if s != expect {
+ t.Errorf("Sprint wrong with Formatter: expected %q got %q", expect, s)
+ }
+ s = Sprintln(f)
+ if s != expect {
+ t.Errorf("Sprintln wrong with Formatter: expected %q got %q", expect, s)
+ }
+ s = Sprintf("%v\n", f)
+ if s != expect {
+ t.Errorf("Sprintf wrong with Formatter: expected %q got %q", expect, s)
+ }
+}
+
+func args(a ...interface{}) []interface{} { return a }
+
+var startests = []struct {
+ fmt string
+ in []interface{}
+ out string
+}{
+ {"%*d", args(4, 42), " 42"},
+ {"%.*d", args(4, 42), "0042"},
+ {"%*.*d", args(8, 4, 42), " 0042"},
+ {"%0*d", args(4, 42), "0042"},
+ {"%-*d", args(4, 42), "42 "},
+
+ // erroneous
+ {"%*d", args(nil, 42), "%!(BADWIDTH)42"},
+ {"%.*d", args(nil, 42), "%!(BADPREC)42"},
+ {"%*d", args(5, "foo"), "%!d(string= foo)"},
+ {"%*% %d", args(20, 5), "% 5"},
+ {"%*", args(4), "%!(NOVERB)"},
+ {"%*d", args(int32(4), 42), "%!(BADWIDTH)42"},
+}
+
+func TestWidthAndPrecision(t *testing.T) {
+ for _, tt := range startests {
+ s := Sprintf(tt.fmt, tt.in...)
+ if s != tt.out {
+ t.Errorf("%q: got %q expected %q", tt.fmt, s, tt.out)
+ }
+ }
+}
+
+// Panic is a type that panics in String.
+type Panic struct {
+ message interface{}
+}
+
+// Value receiver.
+func (p Panic) GoString() string {
+ panic(p.message)
+}
+
+// Value receiver.
+func (p Panic) String() string {
+ panic(p.message)
+}
+
+// PanicF is a type that panics in Format.
+type PanicF struct {
+ message interface{}
+}
+
+// Value receiver.
+func (p PanicF) Format(f State, c rune) {
+ panic(p.message)
+}
+
+var panictests = []struct {
+ fmt string
+ in interface{}
+ out string
+}{
+ // String
+ {"%s", (*Panic)(nil), "<nil>"}, // nil pointer special case
+ {"%s", Panic{io.ErrUnexpectedEOF}, "%!s(PANIC=unexpected EOF)"},
+ {"%s", Panic{3}, "%!s(PANIC=3)"},
+ // GoString
+ {"%#v", (*Panic)(nil), "<nil>"}, // nil pointer special case
+ {"%#v", Panic{io.ErrUnexpectedEOF}, "%!v(PANIC=unexpected EOF)"},
+ {"%#v", Panic{3}, "%!v(PANIC=3)"},
+ // Format
+ {"%s", (*PanicF)(nil), "<nil>"}, // nil pointer special case
+ {"%s", PanicF{io.ErrUnexpectedEOF}, "%!s(PANIC=unexpected EOF)"},
+ {"%s", PanicF{3}, "%!s(PANIC=3)"},
+}
+
+func TestPanics(t *testing.T) {
+ for i, tt := range panictests {
+ s := Sprintf(tt.fmt, tt.in)
+ if s != tt.out {
+ t.Errorf("%d: %q: got %q expected %q", i, tt.fmt, s, tt.out)
+ }
+ }
+}
+
+// recurCount tests that erroneous String routine doesn't cause fatal recursion.
+var recurCount = 0
+
+type Recur struct {
+ i int
+ failed *bool
+}
+
+func (r *Recur) String() string {
+ if recurCount++; recurCount > 10 {
+ *r.failed = true
+ return "FAIL"
+ }
+ // This will call badVerb. Before the fix, that would cause us to recur into
+ // this routine to print %!p(value). Now we don't call the user's method
+ // during an error.
+ return Sprintf("recur@%p value: %d", r, r.i)
+}
+
+func TestBadVerbRecursion(t *testing.T) {
+ failed := false
+ r := &Recur{3, &failed}
+ Sprintf("recur@%p value: %d\n", &r, r.i)
+ if failed {
+ t.Error("fail with pointer")
+ }
+ failed = false
+ r = &Recur{4, &failed}
+ Sprintf("recur@%p, value: %d\n", r, r.i)
+ if failed {
+ t.Error("fail with value")
+ }
+}
+
+func TestIsSpace(t *testing.T) {
+ // This tests the internal isSpace function.
+ // IsSpace = isSpace is defined in export_test.go.
+ for i := rune(0); i <= unicode.MaxRune; i++ {
+ if IsSpace(i) != unicode.IsSpace(i) {
+ t.Errorf("isSpace(%U) = %v, want %v", i, IsSpace(i), unicode.IsSpace(i))
+ }
+ }
+}
+
+func TestNilDoesNotBecomeTyped(t *testing.T) {
+ type A struct{}
+ type B struct{}
+ var a *A = nil
+ var b B = B{}
+ got := Sprintf("%s %s %s %s %s", nil, a, nil, b, nil)
+ const expect = "%!s(<nil>) %!s(*fmt_test.A=<nil>) %!s(<nil>) {} %!s(<nil>)"
+ if got != expect {
+ t.Errorf("expected:\n\t%q\ngot:\n\t%q", expect, got)
+ }
+}
+
+var formatterFlagTests = []struct {
+ in string
+ val interface{}
+ out string
+}{
+ // scalar values with the (unused by fmt) 'a' verb.
+ {"%a", flagPrinter{}, "[%a]"},
+ {"%-a", flagPrinter{}, "[%-a]"},
+ {"%+a", flagPrinter{}, "[%+a]"},
+ {"%#a", flagPrinter{}, "[%#a]"},
+ {"% a", flagPrinter{}, "[% a]"},
+ {"%0a", flagPrinter{}, "[%0a]"},
+ {"%1.2a", flagPrinter{}, "[%1.2a]"},
+ {"%-1.2a", flagPrinter{}, "[%-1.2a]"},
+ {"%+1.2a", flagPrinter{}, "[%+1.2a]"},
+ {"%-+1.2a", flagPrinter{}, "[%+-1.2a]"},
+ {"%-+1.2abc", flagPrinter{}, "[%+-1.2a]bc"},
+ {"%-1.2abc", flagPrinter{}, "[%-1.2a]bc"},
+
+ // composite values with the 'a' verb
+ {"%a", [1]flagPrinter{}, "[[%a]]"},
+ {"%-a", [1]flagPrinter{}, "[[%-a]]"},
+ {"%+a", [1]flagPrinter{}, "[[%+a]]"},
+ {"%#a", [1]flagPrinter{}, "[[%#a]]"},
+ {"% a", [1]flagPrinter{}, "[[% a]]"},
+ {"%0a", [1]flagPrinter{}, "[[%0a]]"},
+ {"%1.2a", [1]flagPrinter{}, "[[%1.2a]]"},
+ {"%-1.2a", [1]flagPrinter{}, "[[%-1.2a]]"},
+ {"%+1.2a", [1]flagPrinter{}, "[[%+1.2a]]"},
+ {"%-+1.2a", [1]flagPrinter{}, "[[%+-1.2a]]"},
+ {"%-+1.2abc", [1]flagPrinter{}, "[[%+-1.2a]]bc"},
+ {"%-1.2abc", [1]flagPrinter{}, "[[%-1.2a]]bc"},
+
+ // simple values with the 'v' verb
+ {"%v", flagPrinter{}, "[%v]"},
+ {"%-v", flagPrinter{}, "[%-v]"},
+ {"%+v", flagPrinter{}, "[%+v]"},
+ {"%#v", flagPrinter{}, "[%#v]"},
+ {"% v", flagPrinter{}, "[% v]"},
+ {"%0v", flagPrinter{}, "[%0v]"},
+ {"%1.2v", flagPrinter{}, "[%1.2v]"},
+ {"%-1.2v", flagPrinter{}, "[%-1.2v]"},
+ {"%+1.2v", flagPrinter{}, "[%+1.2v]"},
+ {"%-+1.2v", flagPrinter{}, "[%+-1.2v]"},
+ {"%-+1.2vbc", flagPrinter{}, "[%+-1.2v]bc"},
+ {"%-1.2vbc", flagPrinter{}, "[%-1.2v]bc"},
+
+ // composite values with the 'v' verb.
+ {"%v", [1]flagPrinter{}, "[[%v]]"},
+ {"%-v", [1]flagPrinter{}, "[[%-v]]"},
+ {"%+v", [1]flagPrinter{}, "[[%+v]]"},
+ {"%#v", [1]flagPrinter{}, "[1]fmt_test.flagPrinter{[%#v]}"},
+ {"% v", [1]flagPrinter{}, "[[% v]]"},
+ {"%0v", [1]flagPrinter{}, "[[%0v]]"},
+ {"%1.2v", [1]flagPrinter{}, "[[%1.2v]]"},
+ {"%-1.2v", [1]flagPrinter{}, "[[%-1.2v]]"},
+ {"%+1.2v", [1]flagPrinter{}, "[[%+1.2v]]"},
+ {"%-+1.2v", [1]flagPrinter{}, "[[%+-1.2v]]"},
+ {"%-+1.2vbc", [1]flagPrinter{}, "[[%+-1.2v]]bc"},
+ {"%-1.2vbc", [1]flagPrinter{}, "[[%-1.2v]]bc"},
+}
+
+func TestFormatterFlags(t *testing.T) {
+ for _, tt := range formatterFlagTests {
+ s := Sprintf(tt.in, tt.val)
+ if s != tt.out {
+ t.Errorf("Sprintf(%q, %T) = %q, want %q", tt.in, tt.val, s, tt.out)
+ }
+ }
+}
diff --git a/src/fmt/format.go b/src/fmt/format.go
new file mode 100644
index 000000000..4d97d1443
--- /dev/null
+++ b/src/fmt/format.go
@@ -0,0 +1,524 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package fmt
+
+import (
+ "math"
+ "strconv"
+ "unicode/utf8"
+)
+
+const (
+ // %b of an int64, plus a sign.
+ // Hex can add 0x and we handle it specially.
+ nByte = 65
+
+ ldigits = "0123456789abcdef"
+ udigits = "0123456789ABCDEF"
+)
+
+const (
+ signed = true
+ unsigned = false
+)
+
+var padZeroBytes = make([]byte, nByte)
+var padSpaceBytes = make([]byte, nByte)
+
+func init() {
+ for i := 0; i < nByte; i++ {
+ padZeroBytes[i] = '0'
+ padSpaceBytes[i] = ' '
+ }
+}
+
+// flags placed in a separate struct for easy clearing.
+type fmtFlags struct {
+ widPresent bool
+ precPresent bool
+ minus bool
+ plus bool
+ sharp bool
+ space bool
+ unicode bool
+ uniQuote bool // Use 'x'= prefix for %U if printable.
+ zero bool
+
+ // For the formats %+v %#v, we set the plusV/sharpV flags
+ // and clear the plus/sharp flags since %+v and %#v are in effect
+ // different, flagless formats set at the top level.
+ plusV bool
+ sharpV bool
+}
+
+// A fmt is the raw formatter used by Printf etc.
+// It prints into a buffer that must be set up separately.
+type fmt struct {
+ intbuf [nByte]byte
+ buf *buffer
+ // width, precision
+ wid int
+ prec int
+ fmtFlags
+}
+
+func (f *fmt) clearflags() {
+ f.fmtFlags = fmtFlags{}
+}
+
+func (f *fmt) init(buf *buffer) {
+ f.buf = buf
+ f.clearflags()
+}
+
+// computePadding computes left and right padding widths (only one will be non-zero).
+func (f *fmt) computePadding(width int) (padding []byte, leftWidth, rightWidth int) {
+ left := !f.minus
+ w := f.wid
+ if w < 0 {
+ left = false
+ w = -w
+ }
+ w -= width
+ if w > 0 {
+ if left && f.zero {
+ return padZeroBytes, w, 0
+ }
+ if left {
+ return padSpaceBytes, w, 0
+ } else {
+ // can't be zero padding on the right
+ return padSpaceBytes, 0, w
+ }
+ }
+ return
+}
+
+// writePadding generates n bytes of padding.
+func (f *fmt) writePadding(n int, padding []byte) {
+ for n > 0 {
+ m := n
+ if m > nByte {
+ m = nByte
+ }
+ f.buf.Write(padding[0:m])
+ n -= m
+ }
+}
+
+// pad appends b to f.buf, padded on left (w > 0) or right (w < 0 or f.minus).
+func (f *fmt) pad(b []byte) {
+ if !f.widPresent || f.wid == 0 {
+ f.buf.Write(b)
+ return
+ }
+ padding, left, right := f.computePadding(utf8.RuneCount(b))
+ if left > 0 {
+ f.writePadding(left, padding)
+ }
+ f.buf.Write(b)
+ if right > 0 {
+ f.writePadding(right, padding)
+ }
+}
+
+// padString appends s to buf, padded on left (w > 0) or right (w < 0 or f.minus).
+func (f *fmt) padString(s string) {
+ if !f.widPresent || f.wid == 0 {
+ f.buf.WriteString(s)
+ return
+ }
+ padding, left, right := f.computePadding(utf8.RuneCountInString(s))
+ if left > 0 {
+ f.writePadding(left, padding)
+ }
+ f.buf.WriteString(s)
+ if right > 0 {
+ f.writePadding(right, padding)
+ }
+}
+
+var (
+ trueBytes = []byte("true")
+ falseBytes = []byte("false")
+)
+
+// fmt_boolean formats a boolean.
+func (f *fmt) fmt_boolean(v bool) {
+ if v {
+ f.pad(trueBytes)
+ } else {
+ f.pad(falseBytes)
+ }
+}
+
+// integer; interprets prec but not wid. Once formatted, result is sent to pad()
+// and then flags are cleared.
+func (f *fmt) integer(a int64, base uint64, signedness bool, digits string) {
+ // precision of 0 and value of 0 means "print nothing"
+ if f.precPresent && f.prec == 0 && a == 0 {
+ return
+ }
+
+ var buf []byte = f.intbuf[0:]
+ if f.widPresent {
+ width := f.wid
+ if base == 16 && f.sharp {
+ // Also adds "0x".
+ width += 2
+ }
+ if width > nByte {
+ // We're going to need a bigger boat.
+ buf = make([]byte, width)
+ }
+ }
+
+ negative := signedness == signed && a < 0
+ if negative {
+ a = -a
+ }
+
+ // two ways to ask for extra leading zero digits: %.3d or %03d.
+ // apparently the first cancels the second.
+ prec := 0
+ if f.precPresent {
+ prec = f.prec
+ f.zero = false
+ } else if f.zero && f.widPresent && !f.minus && f.wid > 0 {
+ prec = f.wid
+ if negative || f.plus || f.space {
+ prec-- // leave room for sign
+ }
+ }
+
+ // format a into buf, ending at buf[i]. (printing is easier right-to-left.)
+ // a is made into unsigned ua. we could make things
+ // marginally faster by splitting the 32-bit case out into a separate
+ // block but it's not worth the duplication, so ua has 64 bits.
+ i := len(buf)
+ ua := uint64(a)
+ // use constants for the division and modulo for more efficient code.
+ // switch cases ordered by popularity.
+ switch base {
+ case 10:
+ for ua >= 10 {
+ i--
+ next := ua / 10
+ buf[i] = byte('0' + ua - next*10)
+ ua = next
+ }
+ case 16:
+ for ua >= 16 {
+ i--
+ buf[i] = digits[ua&0xF]
+ ua >>= 4
+ }
+ case 8:
+ for ua >= 8 {
+ i--
+ buf[i] = byte('0' + ua&7)
+ ua >>= 3
+ }
+ case 2:
+ for ua >= 2 {
+ i--
+ buf[i] = byte('0' + ua&1)
+ ua >>= 1
+ }
+ default:
+ panic("fmt: unknown base; can't happen")
+ }
+ i--
+ buf[i] = digits[ua]
+ for i > 0 && prec > len(buf)-i {
+ i--
+ buf[i] = '0'
+ }
+
+ // Various prefixes: 0x, -, etc.
+ if f.sharp {
+ switch base {
+ case 8:
+ if buf[i] != '0' {
+ i--
+ buf[i] = '0'
+ }
+ case 16:
+ i--
+ buf[i] = 'x' + digits[10] - 'a'
+ i--
+ buf[i] = '0'
+ }
+ }
+ if f.unicode {
+ i--
+ buf[i] = '+'
+ i--
+ buf[i] = 'U'
+ }
+
+ if negative {
+ i--
+ buf[i] = '-'
+ } else if f.plus {
+ i--
+ buf[i] = '+'
+ } else if f.space {
+ i--
+ buf[i] = ' '
+ }
+
+ // If we want a quoted char for %#U, move the data up to make room.
+ if f.unicode && f.uniQuote && a >= 0 && a <= utf8.MaxRune && strconv.IsPrint(rune(a)) {
+ runeWidth := utf8.RuneLen(rune(a))
+ width := 1 + 1 + runeWidth + 1 // space, quote, rune, quote
+ copy(buf[i-width:], buf[i:]) // guaranteed to have enough room.
+ i -= width
+ // Now put " 'x'" at the end.
+ j := len(buf) - width
+ buf[j] = ' '
+ j++
+ buf[j] = '\''
+ j++
+ utf8.EncodeRune(buf[j:], rune(a))
+ j += runeWidth
+ buf[j] = '\''
+ }
+
+ f.pad(buf[i:])
+}
+
+// truncate truncates the string to the specified precision, if present.
+func (f *fmt) truncate(s string) string {
+ if f.precPresent && f.prec < utf8.RuneCountInString(s) {
+ n := f.prec
+ for i := range s {
+ if n == 0 {
+ s = s[:i]
+ break
+ }
+ n--
+ }
+ }
+ return s
+}
+
+// fmt_s formats a string.
+func (f *fmt) fmt_s(s string) {
+ s = f.truncate(s)
+ f.padString(s)
+}
+
+// fmt_sbx formats a string or byte slice as a hexadecimal encoding of its bytes.
+func (f *fmt) fmt_sbx(s string, b []byte, digits string) {
+ n := len(b)
+ if b == nil {
+ n = len(s)
+ }
+ x := digits[10] - 'a' + 'x'
+ // TODO: Avoid buffer by pre-padding.
+ var buf []byte
+ for i := 0; i < n; i++ {
+ if i > 0 && f.space {
+ buf = append(buf, ' ')
+ }
+ if f.sharp && (f.space || i == 0) {
+ buf = append(buf, '0', x)
+ }
+ var c byte
+ if b == nil {
+ c = s[i]
+ } else {
+ c = b[i]
+ }
+ buf = append(buf, digits[c>>4], digits[c&0xF])
+ }
+ f.pad(buf)
+}
+
+// fmt_sx formats a string as a hexadecimal encoding of its bytes.
+func (f *fmt) fmt_sx(s, digits string) {
+ if f.precPresent && f.prec < len(s) {
+ s = s[:f.prec]
+ }
+ f.fmt_sbx(s, nil, digits)
+}
+
+// fmt_bx formats a byte slice as a hexadecimal encoding of its bytes.
+func (f *fmt) fmt_bx(b []byte, digits string) {
+ if f.precPresent && f.prec < len(b) {
+ b = b[:f.prec]
+ }
+ f.fmt_sbx("", b, digits)
+}
+
+// fmt_q formats a string as a double-quoted, escaped Go string constant.
+func (f *fmt) fmt_q(s string) {
+ s = f.truncate(s)
+ var quoted string
+ if f.sharp && strconv.CanBackquote(s) {
+ quoted = "`" + s + "`"
+ } else {
+ if f.plus {
+ quoted = strconv.QuoteToASCII(s)
+ } else {
+ quoted = strconv.Quote(s)
+ }
+ }
+ f.padString(quoted)
+}
+
+// fmt_qc formats the integer as a single-quoted, escaped Go character constant.
+// If the character is not valid Unicode, it will print '\ufffd'.
+func (f *fmt) fmt_qc(c int64) {
+ var quoted []byte
+ if f.plus {
+ quoted = strconv.AppendQuoteRuneToASCII(f.intbuf[0:0], rune(c))
+ } else {
+ quoted = strconv.AppendQuoteRune(f.intbuf[0:0], rune(c))
+ }
+ f.pad(quoted)
+}
+
+// floating-point
+
+func doPrec(f *fmt, def int) int {
+ if f.precPresent {
+ return f.prec
+ }
+ return def
+}
+
+// formatFloat formats a float64; it is an efficient equivalent to f.pad(strconv.FormatFloat()...).
+func (f *fmt) formatFloat(v float64, verb byte, prec, n int) {
+ // Format number, reserving space for leading + sign if needed.
+ num := strconv.AppendFloat(f.intbuf[0:1], v, verb, prec, n)
+ if num[1] == '-' || num[1] == '+' {
+ num = num[1:]
+ } else {
+ num[0] = '+'
+ }
+ // Special handling for infinity, which doesn't look like a number so shouldn't be padded with zeros.
+ if math.IsInf(v, 0) {
+ if f.zero {
+ defer func() { f.zero = true }()
+ f.zero = false
+ }
+ }
+ // num is now a signed version of the number.
+ // If we're zero padding, want the sign before the leading zeros.
+ // Achieve this by writing the sign out and then padding the unsigned number.
+ if f.zero && f.widPresent && f.wid > len(num) {
+ if f.space && v >= 0 {
+ f.buf.WriteByte(' ') // This is what C does: even with zero, f.space means space.
+ f.wid--
+ } else if f.plus || v < 0 {
+ f.buf.WriteByte(num[0])
+ f.wid--
+ }
+ f.pad(num[1:])
+ return
+ }
+ // f.space says to replace a leading + with a space.
+ if f.space && num[0] == '+' {
+ num[0] = ' '
+ f.pad(num)
+ return
+ }
+ // Now we know the sign is attached directly to the number, if present at all.
+ // We want a sign if asked for, if it's negative, or if it's infinity (+Inf vs. -Inf).
+ if f.plus || num[0] == '-' || math.IsInf(v, 0) {
+ f.pad(num)
+ return
+ }
+ // No sign to show and the number is positive; just print the unsigned number.
+ f.pad(num[1:])
+}
+
+// fmt_e64 formats a float64 in the form -1.23e+12.
+func (f *fmt) fmt_e64(v float64) { f.formatFloat(v, 'e', doPrec(f, 6), 64) }
+
+// fmt_E64 formats a float64 in the form -1.23E+12.
+func (f *fmt) fmt_E64(v float64) { f.formatFloat(v, 'E', doPrec(f, 6), 64) }
+
+// fmt_f64 formats a float64 in the form -1.23.
+func (f *fmt) fmt_f64(v float64) { f.formatFloat(v, 'f', doPrec(f, 6), 64) }
+
+// fmt_g64 formats a float64 in the 'f' or 'e' form according to size.
+func (f *fmt) fmt_g64(v float64) { f.formatFloat(v, 'g', doPrec(f, -1), 64) }
+
+// fmt_G64 formats a float64 in the 'f' or 'E' form according to size.
+func (f *fmt) fmt_G64(v float64) { f.formatFloat(v, 'G', doPrec(f, -1), 64) }
+
+// fmt_fb64 formats a float64 in the form -123p3 (exponent is power of 2).
+func (f *fmt) fmt_fb64(v float64) { f.formatFloat(v, 'b', 0, 64) }
+
+// float32
+// cannot defer to float64 versions
+// because it will get rounding wrong in corner cases.
+
+// fmt_e32 formats a float32 in the form -1.23e+12.
+func (f *fmt) fmt_e32(v float32) { f.formatFloat(float64(v), 'e', doPrec(f, 6), 32) }
+
+// fmt_E32 formats a float32 in the form -1.23E+12.
+func (f *fmt) fmt_E32(v float32) { f.formatFloat(float64(v), 'E', doPrec(f, 6), 32) }
+
+// fmt_f32 formats a float32 in the form -1.23.
+func (f *fmt) fmt_f32(v float32) { f.formatFloat(float64(v), 'f', doPrec(f, 6), 32) }
+
+// fmt_g32 formats a float32 in the 'f' or 'e' form according to size.
+func (f *fmt) fmt_g32(v float32) { f.formatFloat(float64(v), 'g', doPrec(f, -1), 32) }
+
+// fmt_G32 formats a float32 in the 'f' or 'E' form according to size.
+func (f *fmt) fmt_G32(v float32) { f.formatFloat(float64(v), 'G', doPrec(f, -1), 32) }
+
+// fmt_fb32 formats a float32 in the form -123p3 (exponent is power of 2).
+func (f *fmt) fmt_fb32(v float32) { f.formatFloat(float64(v), 'b', 0, 32) }
+
+// fmt_c64 formats a complex64 according to the verb.
+func (f *fmt) fmt_c64(v complex64, verb rune) {
+ f.fmt_complex(float64(real(v)), float64(imag(v)), 32, verb)
+}
+
+// fmt_c128 formats a complex128 according to the verb.
+func (f *fmt) fmt_c128(v complex128, verb rune) {
+ f.fmt_complex(real(v), imag(v), 64, verb)
+}
+
+// fmt_complex formats a complex number as (r+ji).
+func (f *fmt) fmt_complex(r, j float64, size int, verb rune) {
+ f.buf.WriteByte('(')
+ oldPlus := f.plus
+ oldSpace := f.space
+ oldWid := f.wid
+ for i := 0; ; i++ {
+ switch verb {
+ case 'b':
+ f.formatFloat(r, 'b', 0, size)
+ case 'e':
+ f.formatFloat(r, 'e', doPrec(f, 6), size)
+ case 'E':
+ f.formatFloat(r, 'E', doPrec(f, 6), size)
+ case 'f', 'F':
+ f.formatFloat(r, 'f', doPrec(f, 6), size)
+ case 'g':
+ f.formatFloat(r, 'g', doPrec(f, -1), size)
+ case 'G':
+ f.formatFloat(r, 'G', doPrec(f, -1), size)
+ }
+ if i != 0 {
+ break
+ }
+ // Imaginary part always has a sign.
+ f.plus = true
+ f.space = false
+ f.wid = oldWid
+ r = j
+ }
+ f.space = oldSpace
+ f.plus = oldPlus
+ f.wid = oldWid
+ f.buf.Write(irparenBytes)
+}
diff --git a/src/fmt/print.go b/src/fmt/print.go
new file mode 100644
index 000000000..59a30d221
--- /dev/null
+++ b/src/fmt/print.go
@@ -0,0 +1,1223 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package fmt
+
+import (
+ "errors"
+ "io"
+ "os"
+ "reflect"
+ "sync"
+ "unicode/utf8"
+)
+
+// Some constants in the form of bytes, to avoid string overhead.
+// Needlessly fastidious, I suppose.
+var (
+ commaSpaceBytes = []byte(", ")
+ nilAngleBytes = []byte("<nil>")
+ nilParenBytes = []byte("(nil)")
+ nilBytes = []byte("nil")
+ mapBytes = []byte("map[")
+ percentBangBytes = []byte("%!")
+ missingBytes = []byte("(MISSING)")
+ badIndexBytes = []byte("(BADINDEX)")
+ panicBytes = []byte("(PANIC=")
+ extraBytes = []byte("%!(EXTRA ")
+ irparenBytes = []byte("i)")
+ bytesBytes = []byte("[]byte{")
+ badWidthBytes = []byte("%!(BADWIDTH)")
+ badPrecBytes = []byte("%!(BADPREC)")
+ noVerbBytes = []byte("%!(NOVERB)")
+)
+
+// State represents the printer state passed to custom formatters.
+// It provides access to the io.Writer interface plus information about
+// the flags and options for the operand's format specifier.
+type State interface {
+ // Write is the function to call to emit formatted output to be printed.
+ Write(b []byte) (ret int, err error)
+ // Width returns the value of the width option and whether it has been set.
+ Width() (wid int, ok bool)
+ // Precision returns the value of the precision option and whether it has been set.
+ Precision() (prec int, ok bool)
+
+ // Flag reports whether the flag c, a character, has been set.
+ Flag(c int) bool
+}
+
+// Formatter is the interface implemented by values with a custom formatter.
+// The implementation of Format may call Sprint(f) or Fprint(f) etc.
+// to generate its output.
+type Formatter interface {
+ Format(f State, c rune)
+}
+
+// Stringer is implemented by any value that has a String method,
+// which defines the ``native'' format for that value.
+// The String method is used to print values passed as an operand
+// to any format that accepts a string or to an unformatted printer
+// such as Print.
+type Stringer interface {
+ String() string
+}
+
+// GoStringer is implemented by any value that has a GoString method,
+// which defines the Go syntax for that value.
+// The GoString method is used to print values passed as an operand
+// to a %#v format.
+type GoStringer interface {
+ GoString() string
+}
+
+// Use simple []byte instead of bytes.Buffer to avoid large dependency.
+type buffer []byte
+
+func (b *buffer) Write(p []byte) (n int, err error) {
+ *b = append(*b, p...)
+ return len(p), nil
+}
+
+func (b *buffer) WriteString(s string) (n int, err error) {
+ *b = append(*b, s...)
+ return len(s), nil
+}
+
+func (b *buffer) WriteByte(c byte) error {
+ *b = append(*b, c)
+ return nil
+}
+
+func (bp *buffer) WriteRune(r rune) error {
+ if r < utf8.RuneSelf {
+ *bp = append(*bp, byte(r))
+ return nil
+ }
+
+ b := *bp
+ n := len(b)
+ for n+utf8.UTFMax > cap(b) {
+ b = append(b, 0)
+ }
+ w := utf8.EncodeRune(b[n:n+utf8.UTFMax], r)
+ *bp = b[:n+w]
+ return nil
+}
+
+type pp struct {
+ n int
+ panicking bool
+ erroring bool // printing an error condition
+ buf buffer
+ // arg holds the current item, as an interface{}.
+ arg interface{}
+ // value holds the current item, as a reflect.Value, and will be
+ // the zero Value if the item has not been reflected.
+ value reflect.Value
+ // reordered records whether the format string used argument reordering.
+ reordered bool
+ // goodArgNum records whether the most recent reordering directive was valid.
+ goodArgNum bool
+ runeBuf [utf8.UTFMax]byte
+ fmt fmt
+}
+
+var ppFree = sync.Pool{
+ New: func() interface{} { return new(pp) },
+}
+
+// newPrinter allocates a new pp struct or grabs a cached one.
+func newPrinter() *pp {
+ p := ppFree.Get().(*pp)
+ p.panicking = false
+ p.erroring = false
+ p.fmt.init(&p.buf)
+ return p
+}
+
+// free saves used pp structs in ppFree; avoids an allocation per invocation.
+func (p *pp) free() {
+ // Don't hold on to pp structs with large buffers.
+ if cap(p.buf) > 1024 {
+ return
+ }
+ p.buf = p.buf[:0]
+ p.arg = nil
+ p.value = reflect.Value{}
+ ppFree.Put(p)
+}
+
+func (p *pp) Width() (wid int, ok bool) { return p.fmt.wid, p.fmt.widPresent }
+
+func (p *pp) Precision() (prec int, ok bool) { return p.fmt.prec, p.fmt.precPresent }
+
+func (p *pp) Flag(b int) bool {
+ switch b {
+ case '-':
+ return p.fmt.minus
+ case '+':
+ return p.fmt.plus
+ case '#':
+ return p.fmt.sharp
+ case ' ':
+ return p.fmt.space
+ case '0':
+ return p.fmt.zero
+ }
+ return false
+}
+
+func (p *pp) add(c rune) {
+ p.buf.WriteRune(c)
+}
+
+// Implement Write so we can call Fprintf on a pp (through State), for
+// recursive use in custom verbs.
+func (p *pp) Write(b []byte) (ret int, err error) {
+ return p.buf.Write(b)
+}
+
+// These routines end in 'f' and take a format string.
+
+// Fprintf formats according to a format specifier and writes to w.
+// It returns the number of bytes written and any write error encountered.
+func Fprintf(w io.Writer, format string, a ...interface{}) (n int, err error) {
+ p := newPrinter()
+ p.doPrintf(format, a)
+ n, err = w.Write(p.buf)
+ p.free()
+ return
+}
+
+// Printf formats according to a format specifier and writes to standard output.
+// It returns the number of bytes written and any write error encountered.
+func Printf(format string, a ...interface{}) (n int, err error) {
+ return Fprintf(os.Stdout, format, a...)
+}
+
+// Sprintf formats according to a format specifier and returns the resulting string.
+func Sprintf(format string, a ...interface{}) string {
+ p := newPrinter()
+ p.doPrintf(format, a)
+ s := string(p.buf)
+ p.free()
+ return s
+}
+
+// Errorf formats according to a format specifier and returns the string
+// as a value that satisfies error.
+func Errorf(format string, a ...interface{}) error {
+ return errors.New(Sprintf(format, a...))
+}
+
+// These routines do not take a format string
+
+// Fprint formats using the default formats for its operands and writes to w.
+// Spaces are added between operands when neither is a string.
+// It returns the number of bytes written and any write error encountered.
+func Fprint(w io.Writer, a ...interface{}) (n int, err error) {
+ p := newPrinter()
+ p.doPrint(a, false, false)
+ n, err = w.Write(p.buf)
+ p.free()
+ return
+}
+
+// Print formats using the default formats for its operands and writes to standard output.
+// Spaces are added between operands when neither is a string.
+// It returns the number of bytes written and any write error encountered.
+func Print(a ...interface{}) (n int, err error) {
+ return Fprint(os.Stdout, a...)
+}
+
+// Sprint formats using the default formats for its operands and returns the resulting string.
+// Spaces are added between operands when neither is a string.
+func Sprint(a ...interface{}) string {
+ p := newPrinter()
+ p.doPrint(a, false, false)
+ s := string(p.buf)
+ p.free()
+ return s
+}
+
+// These routines end in 'ln', do not take a format string,
+// always add spaces between operands, and add a newline
+// after the last operand.
+
+// Fprintln formats using the default formats for its operands and writes to w.
+// Spaces are always added between operands and a newline is appended.
+// It returns the number of bytes written and any write error encountered.
+func Fprintln(w io.Writer, a ...interface{}) (n int, err error) {
+ p := newPrinter()
+ p.doPrint(a, true, true)
+ n, err = w.Write(p.buf)
+ p.free()
+ return
+}
+
+// Println formats using the default formats for its operands and writes to standard output.
+// Spaces are always added between operands and a newline is appended.
+// It returns the number of bytes written and any write error encountered.
+func Println(a ...interface{}) (n int, err error) {
+ return Fprintln(os.Stdout, a...)
+}
+
+// Sprintln formats using the default formats for its operands and returns the resulting string.
+// Spaces are always added between operands and a newline is appended.
+func Sprintln(a ...interface{}) string {
+ p := newPrinter()
+ p.doPrint(a, true, true)
+ s := string(p.buf)
+ p.free()
+ return s
+}
+
+// getField gets the i'th field of the struct value.
+// If the field is itself is an interface, return a value for
+// the thing inside the interface, not the interface itself.
+func getField(v reflect.Value, i int) reflect.Value {
+ val := v.Field(i)
+ if val.Kind() == reflect.Interface && !val.IsNil() {
+ val = val.Elem()
+ }
+ return val
+}
+
+// parsenum converts ASCII to integer. num is 0 (and isnum is false) if no number present.
+func parsenum(s string, start, end int) (num int, isnum bool, newi int) {
+ if start >= end {
+ return 0, false, end
+ }
+ for newi = start; newi < end && '0' <= s[newi] && s[newi] <= '9'; newi++ {
+ num = num*10 + int(s[newi]-'0')
+ isnum = true
+ }
+ return
+}
+
+func (p *pp) unknownType(v reflect.Value) {
+ if !v.IsValid() {
+ p.buf.Write(nilAngleBytes)
+ return
+ }
+ p.buf.WriteByte('?')
+ p.buf.WriteString(v.Type().String())
+ p.buf.WriteByte('?')
+}
+
+func (p *pp) badVerb(verb rune) {
+ p.erroring = true
+ p.add('%')
+ p.add('!')
+ p.add(verb)
+ p.add('(')
+ switch {
+ case p.arg != nil:
+ p.buf.WriteString(reflect.TypeOf(p.arg).String())
+ p.add('=')
+ p.printArg(p.arg, 'v', 0)
+ case p.value.IsValid():
+ p.buf.WriteString(p.value.Type().String())
+ p.add('=')
+ p.printValue(p.value, 'v', 0)
+ default:
+ p.buf.Write(nilAngleBytes)
+ }
+ p.add(')')
+ p.erroring = false
+}
+
+func (p *pp) fmtBool(v bool, verb rune) {
+ switch verb {
+ case 't', 'v':
+ p.fmt.fmt_boolean(v)
+ default:
+ p.badVerb(verb)
+ }
+}
+
+// fmtC formats a rune for the 'c' format.
+func (p *pp) fmtC(c int64) {
+ r := rune(c) // Check for overflow.
+ if int64(r) != c {
+ r = utf8.RuneError
+ }
+ w := utf8.EncodeRune(p.runeBuf[0:utf8.UTFMax], r)
+ p.fmt.pad(p.runeBuf[0:w])
+}
+
+func (p *pp) fmtInt64(v int64, verb rune) {
+ switch verb {
+ case 'b':
+ p.fmt.integer(v, 2, signed, ldigits)
+ case 'c':
+ p.fmtC(v)
+ case 'd', 'v':
+ p.fmt.integer(v, 10, signed, ldigits)
+ case 'o':
+ p.fmt.integer(v, 8, signed, ldigits)
+ case 'q':
+ if 0 <= v && v <= utf8.MaxRune {
+ p.fmt.fmt_qc(v)
+ } else {
+ p.badVerb(verb)
+ }
+ case 'x':
+ p.fmt.integer(v, 16, signed, ldigits)
+ case 'U':
+ p.fmtUnicode(v)
+ case 'X':
+ p.fmt.integer(v, 16, signed, udigits)
+ default:
+ p.badVerb(verb)
+ }
+}
+
+// fmt0x64 formats a uint64 in hexadecimal and prefixes it with 0x or
+// not, as requested, by temporarily setting the sharp flag.
+func (p *pp) fmt0x64(v uint64, leading0x bool) {
+ sharp := p.fmt.sharp
+ p.fmt.sharp = leading0x
+ p.fmt.integer(int64(v), 16, unsigned, ldigits)
+ p.fmt.sharp = sharp
+}
+
+// fmtUnicode formats a uint64 in U+1234 form by
+// temporarily turning on the unicode flag and tweaking the precision.
+func (p *pp) fmtUnicode(v int64) {
+ precPresent := p.fmt.precPresent
+ sharp := p.fmt.sharp
+ p.fmt.sharp = false
+ prec := p.fmt.prec
+ if !precPresent {
+ // If prec is already set, leave it alone; otherwise 4 is minimum.
+ p.fmt.prec = 4
+ p.fmt.precPresent = true
+ }
+ p.fmt.unicode = true // turn on U+
+ p.fmt.uniQuote = sharp
+ p.fmt.integer(int64(v), 16, unsigned, udigits)
+ p.fmt.unicode = false
+ p.fmt.uniQuote = false
+ p.fmt.prec = prec
+ p.fmt.precPresent = precPresent
+ p.fmt.sharp = sharp
+}
+
+func (p *pp) fmtUint64(v uint64, verb rune) {
+ switch verb {
+ case 'b':
+ p.fmt.integer(int64(v), 2, unsigned, ldigits)
+ case 'c':
+ p.fmtC(int64(v))
+ case 'd':
+ p.fmt.integer(int64(v), 10, unsigned, ldigits)
+ case 'v':
+ if p.fmt.sharpV {
+ p.fmt0x64(v, true)
+ } else {
+ p.fmt.integer(int64(v), 10, unsigned, ldigits)
+ }
+ case 'o':
+ p.fmt.integer(int64(v), 8, unsigned, ldigits)
+ case 'q':
+ if 0 <= v && v <= utf8.MaxRune {
+ p.fmt.fmt_qc(int64(v))
+ } else {
+ p.badVerb(verb)
+ }
+ case 'x':
+ p.fmt.integer(int64(v), 16, unsigned, ldigits)
+ case 'X':
+ p.fmt.integer(int64(v), 16, unsigned, udigits)
+ case 'U':
+ p.fmtUnicode(int64(v))
+ default:
+ p.badVerb(verb)
+ }
+}
+
+func (p *pp) fmtFloat32(v float32, verb rune) {
+ switch verb {
+ case 'b':
+ p.fmt.fmt_fb32(v)
+ case 'e':
+ p.fmt.fmt_e32(v)
+ case 'E':
+ p.fmt.fmt_E32(v)
+ case 'f', 'F':
+ p.fmt.fmt_f32(v)
+ case 'g', 'v':
+ p.fmt.fmt_g32(v)
+ case 'G':
+ p.fmt.fmt_G32(v)
+ default:
+ p.badVerb(verb)
+ }
+}
+
+func (p *pp) fmtFloat64(v float64, verb rune) {
+ switch verb {
+ case 'b':
+ p.fmt.fmt_fb64(v)
+ case 'e':
+ p.fmt.fmt_e64(v)
+ case 'E':
+ p.fmt.fmt_E64(v)
+ case 'f', 'F':
+ p.fmt.fmt_f64(v)
+ case 'g', 'v':
+ p.fmt.fmt_g64(v)
+ case 'G':
+ p.fmt.fmt_G64(v)
+ default:
+ p.badVerb(verb)
+ }
+}
+
+func (p *pp) fmtComplex64(v complex64, verb rune) {
+ switch verb {
+ case 'b', 'e', 'E', 'f', 'F', 'g', 'G':
+ p.fmt.fmt_c64(v, verb)
+ case 'v':
+ p.fmt.fmt_c64(v, 'g')
+ default:
+ p.badVerb(verb)
+ }
+}
+
+func (p *pp) fmtComplex128(v complex128, verb rune) {
+ switch verb {
+ case 'b', 'e', 'E', 'f', 'F', 'g', 'G':
+ p.fmt.fmt_c128(v, verb)
+ case 'v':
+ p.fmt.fmt_c128(v, 'g')
+ default:
+ p.badVerb(verb)
+ }
+}
+
+func (p *pp) fmtString(v string, verb rune) {
+ switch verb {
+ case 'v':
+ if p.fmt.sharpV {
+ p.fmt.fmt_q(v)
+ } else {
+ p.fmt.fmt_s(v)
+ }
+ case 's':
+ p.fmt.fmt_s(v)
+ case 'x':
+ p.fmt.fmt_sx(v, ldigits)
+ case 'X':
+ p.fmt.fmt_sx(v, udigits)
+ case 'q':
+ p.fmt.fmt_q(v)
+ default:
+ p.badVerb(verb)
+ }
+}
+
+func (p *pp) fmtBytes(v []byte, verb rune, typ reflect.Type, depth int) {
+ if verb == 'v' || verb == 'd' {
+ if p.fmt.sharpV {
+ if v == nil {
+ if typ == nil {
+ p.buf.WriteString("[]byte(nil)")
+ } else {
+ p.buf.WriteString(typ.String())
+ p.buf.Write(nilParenBytes)
+ }
+ return
+ }
+ if typ == nil {
+ p.buf.Write(bytesBytes)
+ } else {
+ p.buf.WriteString(typ.String())
+ p.buf.WriteByte('{')
+ }
+ } else {
+ p.buf.WriteByte('[')
+ }
+ for i, c := range v {
+ if i > 0 {
+ if p.fmt.sharpV {
+ p.buf.Write(commaSpaceBytes)
+ } else {
+ p.buf.WriteByte(' ')
+ }
+ }
+ p.printArg(c, 'v', depth+1)
+ }
+ if p.fmt.sharpV {
+ p.buf.WriteByte('}')
+ } else {
+ p.buf.WriteByte(']')
+ }
+ return
+ }
+ switch verb {
+ case 's':
+ p.fmt.fmt_s(string(v))
+ case 'x':
+ p.fmt.fmt_bx(v, ldigits)
+ case 'X':
+ p.fmt.fmt_bx(v, udigits)
+ case 'q':
+ p.fmt.fmt_q(string(v))
+ default:
+ p.badVerb(verb)
+ }
+}
+
+func (p *pp) fmtPointer(value reflect.Value, verb rune) {
+ use0x64 := true
+ switch verb {
+ case 'p', 'v':
+ // ok
+ case 'b', 'd', 'o', 'x', 'X':
+ use0x64 = false
+ // ok
+ default:
+ p.badVerb(verb)
+ return
+ }
+
+ var u uintptr
+ switch value.Kind() {
+ case reflect.Chan, reflect.Func, reflect.Map, reflect.Ptr, reflect.Slice, reflect.UnsafePointer:
+ u = value.Pointer()
+ default:
+ p.badVerb(verb)
+ return
+ }
+
+ if p.fmt.sharpV {
+ p.add('(')
+ p.buf.WriteString(value.Type().String())
+ p.add(')')
+ p.add('(')
+ if u == 0 {
+ p.buf.Write(nilBytes)
+ } else {
+ p.fmt0x64(uint64(u), true)
+ }
+ p.add(')')
+ } else if verb == 'v' && u == 0 {
+ p.buf.Write(nilAngleBytes)
+ } else {
+ if use0x64 {
+ p.fmt0x64(uint64(u), !p.fmt.sharp)
+ } else {
+ p.fmtUint64(uint64(u), verb)
+ }
+ }
+}
+
+var (
+ intBits = reflect.TypeOf(0).Bits()
+ uintptrBits = reflect.TypeOf(uintptr(0)).Bits()
+)
+
+func (p *pp) catchPanic(arg interface{}, verb rune) {
+ if err := recover(); err != nil {
+ // If it's a nil pointer, just say "<nil>". The likeliest causes are a
+ // Stringer that fails to guard against nil or a nil pointer for a
+ // value receiver, and in either case, "<nil>" is a nice result.
+ if v := reflect.ValueOf(arg); v.Kind() == reflect.Ptr && v.IsNil() {
+ p.buf.Write(nilAngleBytes)
+ return
+ }
+ // Otherwise print a concise panic message. Most of the time the panic
+ // value will print itself nicely.
+ if p.panicking {
+ // Nested panics; the recursion in printArg cannot succeed.
+ panic(err)
+ }
+ p.fmt.clearflags() // We are done, and for this output we want default behavior.
+ p.buf.Write(percentBangBytes)
+ p.add(verb)
+ p.buf.Write(panicBytes)
+ p.panicking = true
+ p.printArg(err, 'v', 0)
+ p.panicking = false
+ p.buf.WriteByte(')')
+ }
+}
+
+// clearSpecialFlags pushes %#v back into the regular flags and returns their old state.
+func (p *pp) clearSpecialFlags() (plusV, sharpV bool) {
+ plusV = p.fmt.plusV
+ if plusV {
+ p.fmt.plus = true
+ p.fmt.plusV = false
+ }
+ sharpV = p.fmt.sharpV
+ if sharpV {
+ p.fmt.sharp = true
+ p.fmt.sharpV = false
+ }
+ return
+}
+
+// restoreSpecialFlags, whose argument should be a call to clearSpecialFlags,
+// restores the setting of the plusV and sharpV flags.
+func (p *pp) restoreSpecialFlags(plusV, sharpV bool) {
+ if plusV {
+ p.fmt.plus = false
+ p.fmt.plusV = true
+ }
+ if sharpV {
+ p.fmt.sharp = false
+ p.fmt.sharpV = true
+ }
+}
+
+func (p *pp) handleMethods(verb rune, depth int) (handled bool) {
+ if p.erroring {
+ return
+ }
+ // Is it a Formatter?
+ if formatter, ok := p.arg.(Formatter); ok {
+ handled = true
+ defer p.restoreSpecialFlags(p.clearSpecialFlags())
+ defer p.catchPanic(p.arg, verb)
+ formatter.Format(p, verb)
+ return
+ }
+
+ // If we're doing Go syntax and the argument knows how to supply it, take care of it now.
+ if p.fmt.sharpV {
+ if stringer, ok := p.arg.(GoStringer); ok {
+ handled = true
+ defer p.catchPanic(p.arg, verb)
+ // Print the result of GoString unadorned.
+ p.fmt.fmt_s(stringer.GoString())
+ return
+ }
+ } else {
+ // If a string is acceptable according to the format, see if
+ // the value satisfies one of the string-valued interfaces.
+ // Println etc. set verb to %v, which is "stringable".
+ switch verb {
+ case 'v', 's', 'x', 'X', 'q':
+ // Is it an error or Stringer?
+ // The duplication in the bodies is necessary:
+ // setting handled and deferring catchPanic
+ // must happen before calling the method.
+ switch v := p.arg.(type) {
+ case error:
+ handled = true
+ defer p.catchPanic(p.arg, verb)
+ p.printArg(v.Error(), verb, depth)
+ return
+
+ case Stringer:
+ handled = true
+ defer p.catchPanic(p.arg, verb)
+ p.printArg(v.String(), verb, depth)
+ return
+ }
+ }
+ }
+ return false
+}
+
+func (p *pp) printArg(arg interface{}, verb rune, depth int) (wasString bool) {
+ p.arg = arg
+ p.value = reflect.Value{}
+
+ if arg == nil {
+ if verb == 'T' || verb == 'v' {
+ p.fmt.pad(nilAngleBytes)
+ } else {
+ p.badVerb(verb)
+ }
+ return false
+ }
+
+ // Special processing considerations.
+ // %T (the value's type) and %p (its address) are special; we always do them first.
+ switch verb {
+ case 'T':
+ p.printArg(reflect.TypeOf(arg).String(), 's', 0)
+ return false
+ case 'p':
+ p.fmtPointer(reflect.ValueOf(arg), verb)
+ return false
+ }
+
+ // Some types can be done without reflection.
+ switch f := arg.(type) {
+ case bool:
+ p.fmtBool(f, verb)
+ case float32:
+ p.fmtFloat32(f, verb)
+ case float64:
+ p.fmtFloat64(f, verb)
+ case complex64:
+ p.fmtComplex64(f, verb)
+ case complex128:
+ p.fmtComplex128(f, verb)
+ case int:
+ p.fmtInt64(int64(f), verb)
+ case int8:
+ p.fmtInt64(int64(f), verb)
+ case int16:
+ p.fmtInt64(int64(f), verb)
+ case int32:
+ p.fmtInt64(int64(f), verb)
+ case int64:
+ p.fmtInt64(f, verb)
+ case uint:
+ p.fmtUint64(uint64(f), verb)
+ case uint8:
+ p.fmtUint64(uint64(f), verb)
+ case uint16:
+ p.fmtUint64(uint64(f), verb)
+ case uint32:
+ p.fmtUint64(uint64(f), verb)
+ case uint64:
+ p.fmtUint64(f, verb)
+ case uintptr:
+ p.fmtUint64(uint64(f), verb)
+ case string:
+ p.fmtString(f, verb)
+ wasString = verb == 's' || verb == 'v'
+ case []byte:
+ p.fmtBytes(f, verb, nil, depth)
+ wasString = verb == 's'
+ default:
+ // If the type is not simple, it might have methods.
+ if handled := p.handleMethods(verb, depth); handled {
+ return false
+ }
+ // Need to use reflection
+ return p.printReflectValue(reflect.ValueOf(arg), verb, depth)
+ }
+ p.arg = nil
+ return
+}
+
+// printValue is like printArg but starts with a reflect value, not an interface{} value.
+func (p *pp) printValue(value reflect.Value, verb rune, depth int) (wasString bool) {
+ if !value.IsValid() {
+ if verb == 'T' || verb == 'v' {
+ p.buf.Write(nilAngleBytes)
+ } else {
+ p.badVerb(verb)
+ }
+ return false
+ }
+
+ // Special processing considerations.
+ // %T (the value's type) and %p (its address) are special; we always do them first.
+ switch verb {
+ case 'T':
+ p.printArg(value.Type().String(), 's', 0)
+ return false
+ case 'p':
+ p.fmtPointer(value, verb)
+ return false
+ }
+
+ // Handle values with special methods.
+ // Call always, even when arg == nil, because handleMethods clears p.fmt.plus for us.
+ p.arg = nil // Make sure it's cleared, for safety.
+ if value.CanInterface() {
+ p.arg = value.Interface()
+ }
+ if handled := p.handleMethods(verb, depth); handled {
+ return false
+ }
+
+ return p.printReflectValue(value, verb, depth)
+}
+
+var byteType = reflect.TypeOf(byte(0))
+
+// printReflectValue is the fallback for both printArg and printValue.
+// It uses reflect to print the value.
+func (p *pp) printReflectValue(value reflect.Value, verb rune, depth int) (wasString bool) {
+ oldValue := p.value
+ p.value = value
+BigSwitch:
+ switch f := value; f.Kind() {
+ case reflect.Bool:
+ p.fmtBool(f.Bool(), verb)
+ case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
+ p.fmtInt64(f.Int(), verb)
+ case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
+ p.fmtUint64(f.Uint(), verb)
+ case reflect.Float32, reflect.Float64:
+ if f.Type().Size() == 4 {
+ p.fmtFloat32(float32(f.Float()), verb)
+ } else {
+ p.fmtFloat64(f.Float(), verb)
+ }
+ case reflect.Complex64, reflect.Complex128:
+ if f.Type().Size() == 8 {
+ p.fmtComplex64(complex64(f.Complex()), verb)
+ } else {
+ p.fmtComplex128(f.Complex(), verb)
+ }
+ case reflect.String:
+ p.fmtString(f.String(), verb)
+ case reflect.Map:
+ if p.fmt.sharpV {
+ p.buf.WriteString(f.Type().String())
+ if f.IsNil() {
+ p.buf.WriteString("(nil)")
+ break
+ }
+ p.buf.WriteByte('{')
+ } else {
+ p.buf.Write(mapBytes)
+ }
+ keys := f.MapKeys()
+ for i, key := range keys {
+ if i > 0 {
+ if p.fmt.sharpV {
+ p.buf.Write(commaSpaceBytes)
+ } else {
+ p.buf.WriteByte(' ')
+ }
+ }
+ p.printValue(key, verb, depth+1)
+ p.buf.WriteByte(':')
+ p.printValue(f.MapIndex(key), verb, depth+1)
+ }
+ if p.fmt.sharpV {
+ p.buf.WriteByte('}')
+ } else {
+ p.buf.WriteByte(']')
+ }
+ case reflect.Struct:
+ if p.fmt.sharpV {
+ p.buf.WriteString(value.Type().String())
+ }
+ p.add('{')
+ v := f
+ t := v.Type()
+ for i := 0; i < v.NumField(); i++ {
+ if i > 0 {
+ if p.fmt.sharpV {
+ p.buf.Write(commaSpaceBytes)
+ } else {
+ p.buf.WriteByte(' ')
+ }
+ }
+ if p.fmt.plusV || p.fmt.sharpV {
+ if f := t.Field(i); f.Name != "" {
+ p.buf.WriteString(f.Name)
+ p.buf.WriteByte(':')
+ }
+ }
+ p.printValue(getField(v, i), verb, depth+1)
+ }
+ p.buf.WriteByte('}')
+ case reflect.Interface:
+ value := f.Elem()
+ if !value.IsValid() {
+ if p.fmt.sharpV {
+ p.buf.WriteString(f.Type().String())
+ p.buf.Write(nilParenBytes)
+ } else {
+ p.buf.Write(nilAngleBytes)
+ }
+ } else {
+ wasString = p.printValue(value, verb, depth+1)
+ }
+ case reflect.Array, reflect.Slice:
+ // Byte slices are special:
+ // - Handle []byte (== []uint8) with fmtBytes.
+ // - Handle []T, where T is a named byte type, with fmtBytes only
+ // for the s, q, an x verbs. For other verbs, T might be a
+ // Stringer, so we use printValue to print each element.
+ if typ := f.Type(); typ.Elem().Kind() == reflect.Uint8 && (typ.Elem() == byteType || verb == 's' || verb == 'q' || verb == 'x') {
+ var bytes []byte
+ if f.Kind() == reflect.Slice {
+ bytes = f.Bytes()
+ } else if f.CanAddr() {
+ bytes = f.Slice(0, f.Len()).Bytes()
+ } else {
+ // We have an array, but we cannot Slice() a non-addressable array,
+ // so we build a slice by hand. This is a rare case but it would be nice
+ // if reflection could help a little more.
+ bytes = make([]byte, f.Len())
+ for i := range bytes {
+ bytes[i] = byte(f.Index(i).Uint())
+ }
+ }
+ p.fmtBytes(bytes, verb, typ, depth)
+ wasString = verb == 's'
+ break
+ }
+ if p.fmt.sharpV {
+ p.buf.WriteString(value.Type().String())
+ if f.Kind() == reflect.Slice && f.IsNil() {
+ p.buf.WriteString("(nil)")
+ break
+ }
+ p.buf.WriteByte('{')
+ } else {
+ p.buf.WriteByte('[')
+ }
+ for i := 0; i < f.Len(); i++ {
+ if i > 0 {
+ if p.fmt.sharpV {
+ p.buf.Write(commaSpaceBytes)
+ } else {
+ p.buf.WriteByte(' ')
+ }
+ }
+ p.printValue(f.Index(i), verb, depth+1)
+ }
+ if p.fmt.sharpV {
+ p.buf.WriteByte('}')
+ } else {
+ p.buf.WriteByte(']')
+ }
+ case reflect.Ptr:
+ v := f.Pointer()
+ // pointer to array or slice or struct? ok at top level
+ // but not embedded (avoid loops)
+ if v != 0 && depth == 0 {
+ switch a := f.Elem(); a.Kind() {
+ case reflect.Array, reflect.Slice:
+ p.buf.WriteByte('&')
+ p.printValue(a, verb, depth+1)
+ break BigSwitch
+ case reflect.Struct:
+ p.buf.WriteByte('&')
+ p.printValue(a, verb, depth+1)
+ break BigSwitch
+ case reflect.Map:
+ p.buf.WriteByte('&')
+ p.printValue(a, verb, depth+1)
+ break BigSwitch
+ }
+ }
+ fallthrough
+ case reflect.Chan, reflect.Func, reflect.UnsafePointer:
+ p.fmtPointer(value, verb)
+ default:
+ p.unknownType(f)
+ }
+ p.value = oldValue
+ return wasString
+}
+
+// intFromArg gets the argNumth element of a. On return, isInt reports whether the argument has type int.
+func intFromArg(a []interface{}, argNum int) (num int, isInt bool, newArgNum int) {
+ newArgNum = argNum
+ if argNum < len(a) {
+ num, isInt = a[argNum].(int)
+ newArgNum = argNum + 1
+ }
+ return
+}
+
+// parseArgNumber returns the value of the bracketed number, minus 1
+// (explicit argument numbers are one-indexed but we want zero-indexed).
+// The opening bracket is known to be present at format[0].
+// The returned values are the index, the number of bytes to consume
+// up to the closing paren, if present, and whether the number parsed
+// ok. The bytes to consume will be 1 if no closing paren is present.
+func parseArgNumber(format string) (index int, wid int, ok bool) {
+ // Find closing bracket.
+ for i := 1; i < len(format); i++ {
+ if format[i] == ']' {
+ width, ok, newi := parsenum(format, 1, i)
+ if !ok || newi != i {
+ return 0, i + 1, false
+ }
+ return width - 1, i + 1, true // arg numbers are one-indexed and skip paren.
+ }
+ }
+ return 0, 1, false
+}
+
+// argNumber returns the next argument to evaluate, which is either the value of the passed-in
+// argNum or the value of the bracketed integer that begins format[i:]. It also returns
+// the new value of i, that is, the index of the next byte of the format to process.
+func (p *pp) argNumber(argNum int, format string, i int, numArgs int) (newArgNum, newi int, found bool) {
+ if len(format) <= i || format[i] != '[' {
+ return argNum, i, false
+ }
+ p.reordered = true
+ index, wid, ok := parseArgNumber(format[i:])
+ if ok && 0 <= index && index < numArgs {
+ return index, i + wid, true
+ }
+ p.goodArgNum = false
+ return argNum, i + wid, true
+}
+
+func (p *pp) doPrintf(format string, a []interface{}) {
+ end := len(format)
+ argNum := 0 // we process one argument per non-trivial format
+ afterIndex := false // previous item in format was an index like [3].
+ p.reordered = false
+ for i := 0; i < end; {
+ p.goodArgNum = true
+ lasti := i
+ for i < end && format[i] != '%' {
+ i++
+ }
+ if i > lasti {
+ p.buf.WriteString(format[lasti:i])
+ }
+ if i >= end {
+ // done processing format string
+ break
+ }
+
+ // Process one verb
+ i++
+
+ // Do we have flags?
+ p.fmt.clearflags()
+ F:
+ for ; i < end; i++ {
+ switch format[i] {
+ case '#':
+ p.fmt.sharp = true
+ case '0':
+ p.fmt.zero = true
+ case '+':
+ p.fmt.plus = true
+ case '-':
+ p.fmt.minus = true
+ case ' ':
+ p.fmt.space = true
+ default:
+ break F
+ }
+ }
+
+ // Do we have an explicit argument index?
+ argNum, i, afterIndex = p.argNumber(argNum, format, i, len(a))
+
+ // Do we have width?
+ if i < end && format[i] == '*' {
+ i++
+ p.fmt.wid, p.fmt.widPresent, argNum = intFromArg(a, argNum)
+ if !p.fmt.widPresent {
+ p.buf.Write(badWidthBytes)
+ }
+ afterIndex = false
+ } else {
+ p.fmt.wid, p.fmt.widPresent, i = parsenum(format, i, end)
+ if afterIndex && p.fmt.widPresent { // "%[3]2d"
+ p.goodArgNum = false
+ }
+ }
+
+ // Do we have precision?
+ if i+1 < end && format[i] == '.' {
+ i++
+ if afterIndex { // "%[3].2d"
+ p.goodArgNum = false
+ }
+ argNum, i, afterIndex = p.argNumber(argNum, format, i, len(a))
+ if format[i] == '*' {
+ i++
+ p.fmt.prec, p.fmt.precPresent, argNum = intFromArg(a, argNum)
+ if !p.fmt.precPresent {
+ p.buf.Write(badPrecBytes)
+ }
+ afterIndex = false
+ } else {
+ p.fmt.prec, p.fmt.precPresent, i = parsenum(format, i, end)
+ if !p.fmt.precPresent {
+ p.fmt.prec = 0
+ p.fmt.precPresent = true
+ }
+ }
+ }
+
+ if !afterIndex {
+ argNum, i, afterIndex = p.argNumber(argNum, format, i, len(a))
+ }
+
+ if i >= end {
+ p.buf.Write(noVerbBytes)
+ continue
+ }
+ c, w := utf8.DecodeRuneInString(format[i:])
+ i += w
+ // percent is special - absorbs no operand
+ if c == '%' {
+ p.buf.WriteByte('%') // We ignore width and prec.
+ continue
+ }
+ if !p.goodArgNum {
+ p.buf.Write(percentBangBytes)
+ p.add(c)
+ p.buf.Write(badIndexBytes)
+ continue
+ } else if argNum >= len(a) { // out of operands
+ p.buf.Write(percentBangBytes)
+ p.add(c)
+ p.buf.Write(missingBytes)
+ continue
+ }
+ arg := a[argNum]
+ argNum++
+
+ if c == 'v' {
+ if p.fmt.sharp {
+ // Go syntax. Set the flag in the fmt and clear the sharp flag.
+ p.fmt.sharp = false
+ p.fmt.sharpV = true
+ }
+ if p.fmt.plus {
+ // Struct-field syntax. Set the flag in the fmt and clear the plus flag.
+ p.fmt.plus = false
+ p.fmt.plusV = true
+ }
+ }
+ p.printArg(arg, c, 0)
+ }
+
+ // Check for extra arguments unless the call accessed the arguments
+ // out of order, in which case it's too expensive to detect if they've all
+ // been used and arguably OK if they're not.
+ if !p.reordered && argNum < len(a) {
+ p.buf.Write(extraBytes)
+ for ; argNum < len(a); argNum++ {
+ arg := a[argNum]
+ if arg != nil {
+ p.buf.WriteString(reflect.TypeOf(arg).String())
+ p.buf.WriteByte('=')
+ }
+ p.printArg(arg, 'v', 0)
+ if argNum+1 < len(a) {
+ p.buf.Write(commaSpaceBytes)
+ }
+ }
+ p.buf.WriteByte(')')
+ }
+}
+
+func (p *pp) doPrint(a []interface{}, addspace, addnewline bool) {
+ prevString := false
+ for argNum := 0; argNum < len(a); argNum++ {
+ p.fmt.clearflags()
+ // always add spaces if we're doing Println
+ arg := a[argNum]
+ if argNum > 0 {
+ isString := arg != nil && reflect.TypeOf(arg).Kind() == reflect.String
+ if addspace || !isString && !prevString {
+ p.buf.WriteByte(' ')
+ }
+ }
+ prevString = p.printArg(arg, 'v', 0)
+ }
+ if addnewline {
+ p.buf.WriteByte('\n')
+ }
+}
diff --git a/src/fmt/scan.go b/src/fmt/scan.go
new file mode 100644
index 000000000..d7befeae4
--- /dev/null
+++ b/src/fmt/scan.go
@@ -0,0 +1,1169 @@
+// Copyright 2010 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package fmt
+
+import (
+ "errors"
+ "io"
+ "math"
+ "os"
+ "reflect"
+ "strconv"
+ "sync"
+ "unicode/utf8"
+)
+
+// runeUnreader is the interface to something that can unread runes.
+// If the object provided to Scan does not satisfy this interface,
+// a local buffer will be used to back up the input, but its contents
+// will be lost when Scan returns.
+type runeUnreader interface {
+ UnreadRune() error
+}
+
+// ScanState represents the scanner state passed to custom scanners.
+// Scanners may do rune-at-a-time scanning or ask the ScanState
+// to discover the next space-delimited token.
+type ScanState interface {
+ // ReadRune reads the next rune (Unicode code point) from the input.
+ // If invoked during Scanln, Fscanln, or Sscanln, ReadRune() will
+ // return EOF after returning the first '\n' or when reading beyond
+ // the specified width.
+ ReadRune() (r rune, size int, err error)
+ // UnreadRune causes the next call to ReadRune to return the same rune.
+ UnreadRune() error
+ // SkipSpace skips space in the input. Newlines are treated as space
+ // unless the scan operation is Scanln, Fscanln or Sscanln, in which case
+ // a newline is treated as EOF.
+ SkipSpace()
+ // Token skips space in the input if skipSpace is true, then returns the
+ // run of Unicode code points c satisfying f(c). If f is nil,
+ // !unicode.IsSpace(c) is used; that is, the token will hold non-space
+ // characters. Newlines are treated as space unless the scan operation
+ // is Scanln, Fscanln or Sscanln, in which case a newline is treated as
+ // EOF. The returned slice points to shared data that may be overwritten
+ // by the next call to Token, a call to a Scan function using the ScanState
+ // as input, or when the calling Scan method returns.
+ Token(skipSpace bool, f func(rune) bool) (token []byte, err error)
+ // Width returns the value of the width option and whether it has been set.
+ // The unit is Unicode code points.
+ Width() (wid int, ok bool)
+ // Because ReadRune is implemented by the interface, Read should never be
+ // called by the scanning routines and a valid implementation of
+ // ScanState may choose always to return an error from Read.
+ Read(buf []byte) (n int, err error)
+}
+
+// Scanner is implemented by any value that has a Scan method, which scans
+// the input for the representation of a value and stores the result in the
+// receiver, which must be a pointer to be useful. The Scan method is called
+// for any argument to Scan, Scanf, or Scanln that implements it.
+type Scanner interface {
+ Scan(state ScanState, verb rune) error
+}
+
+// Scan scans text read from standard input, storing successive
+// space-separated values into successive arguments. Newlines count
+// as space. It returns the number of items successfully scanned.
+// If that is less than the number of arguments, err will report why.
+func Scan(a ...interface{}) (n int, err error) {
+ return Fscan(os.Stdin, a...)
+}
+
+// Scanln is similar to Scan, but stops scanning at a newline and
+// after the final item there must be a newline or EOF.
+func Scanln(a ...interface{}) (n int, err error) {
+ return Fscanln(os.Stdin, a...)
+}
+
+// Scanf scans text read from standard input, storing successive
+// space-separated values into successive arguments as determined by
+// the format. It returns the number of items successfully scanned.
+func Scanf(format string, a ...interface{}) (n int, err error) {
+ return Fscanf(os.Stdin, format, a...)
+}
+
+type stringReader string
+
+func (r *stringReader) Read(b []byte) (n int, err error) {
+ n = copy(b, *r)
+ *r = (*r)[n:]
+ if n == 0 {
+ err = io.EOF
+ }
+ return
+}
+
+// Sscan scans the argument string, storing successive space-separated
+// values into successive arguments. Newlines count as space. It
+// returns the number of items successfully scanned. If that is less
+// than the number of arguments, err will report why.
+func Sscan(str string, a ...interface{}) (n int, err error) {
+ return Fscan((*stringReader)(&str), a...)
+}
+
+// Sscanln is similar to Sscan, but stops scanning at a newline and
+// after the final item there must be a newline or EOF.
+func Sscanln(str string, a ...interface{}) (n int, err error) {
+ return Fscanln((*stringReader)(&str), a...)
+}
+
+// Sscanf scans the argument string, storing successive space-separated
+// values into successive arguments as determined by the format. It
+// returns the number of items successfully parsed.
+func Sscanf(str string, format string, a ...interface{}) (n int, err error) {
+ return Fscanf((*stringReader)(&str), format, a...)
+}
+
+// Fscan scans text read from r, storing successive space-separated
+// values into successive arguments. Newlines count as space. It
+// returns the number of items successfully scanned. If that is less
+// than the number of arguments, err will report why.
+func Fscan(r io.Reader, a ...interface{}) (n int, err error) {
+ s, old := newScanState(r, true, false)
+ n, err = s.doScan(a)
+ s.free(old)
+ return
+}
+
+// Fscanln is similar to Fscan, but stops scanning at a newline and
+// after the final item there must be a newline or EOF.
+func Fscanln(r io.Reader, a ...interface{}) (n int, err error) {
+ s, old := newScanState(r, false, true)
+ n, err = s.doScan(a)
+ s.free(old)
+ return
+}
+
+// Fscanf scans text read from r, storing successive space-separated
+// values into successive arguments as determined by the format. It
+// returns the number of items successfully parsed.
+func Fscanf(r io.Reader, format string, a ...interface{}) (n int, err error) {
+ s, old := newScanState(r, false, false)
+ n, err = s.doScanf(format, a)
+ s.free(old)
+ return
+}
+
+// scanError represents an error generated by the scanning software.
+// It's used as a unique signature to identify such errors when recovering.
+type scanError struct {
+ err error
+}
+
+const eof = -1
+
+// ss is the internal implementation of ScanState.
+type ss struct {
+ rr io.RuneReader // where to read input
+ buf buffer // token accumulator
+ peekRune rune // one-rune lookahead
+ prevRune rune // last rune returned by ReadRune
+ count int // runes consumed so far.
+ atEOF bool // already read EOF
+ ssave
+}
+
+// ssave holds the parts of ss that need to be
+// saved and restored on recursive scans.
+type ssave struct {
+ validSave bool // is or was a part of an actual ss.
+ nlIsEnd bool // whether newline terminates scan
+ nlIsSpace bool // whether newline counts as white space
+ argLimit int // max value of ss.count for this arg; argLimit <= limit
+ limit int // max value of ss.count.
+ maxWid int // width of this arg.
+}
+
+// The Read method is only in ScanState so that ScanState
+// satisfies io.Reader. It will never be called when used as
+// intended, so there is no need to make it actually work.
+func (s *ss) Read(buf []byte) (n int, err error) {
+ return 0, errors.New("ScanState's Read should not be called. Use ReadRune")
+}
+
+func (s *ss) ReadRune() (r rune, size int, err error) {
+ if s.peekRune >= 0 {
+ s.count++
+ r = s.peekRune
+ size = utf8.RuneLen(r)
+ s.prevRune = r
+ s.peekRune = -1
+ return
+ }
+ if s.atEOF || s.nlIsEnd && s.prevRune == '\n' || s.count >= s.argLimit {
+ err = io.EOF
+ return
+ }
+
+ r, size, err = s.rr.ReadRune()
+ if err == nil {
+ s.count++
+ s.prevRune = r
+ } else if err == io.EOF {
+ s.atEOF = true
+ }
+ return
+}
+
+func (s *ss) Width() (wid int, ok bool) {
+ if s.maxWid == hugeWid {
+ return 0, false
+ }
+ return s.maxWid, true
+}
+
+// The public method returns an error; this private one panics.
+// If getRune reaches EOF, the return value is EOF (-1).
+func (s *ss) getRune() (r rune) {
+ r, _, err := s.ReadRune()
+ if err != nil {
+ if err == io.EOF {
+ return eof
+ }
+ s.error(err)
+ }
+ return
+}
+
+// mustReadRune turns io.EOF into a panic(io.ErrUnexpectedEOF).
+// It is called in cases such as string scanning where an EOF is a
+// syntax error.
+func (s *ss) mustReadRune() (r rune) {
+ r = s.getRune()
+ if r == eof {
+ s.error(io.ErrUnexpectedEOF)
+ }
+ return
+}
+
+func (s *ss) UnreadRune() error {
+ if u, ok := s.rr.(runeUnreader); ok {
+ u.UnreadRune()
+ } else {
+ s.peekRune = s.prevRune
+ }
+ s.prevRune = -1
+ s.count--
+ return nil
+}
+
+func (s *ss) error(err error) {
+ panic(scanError{err})
+}
+
+func (s *ss) errorString(err string) {
+ panic(scanError{errors.New(err)})
+}
+
+func (s *ss) Token(skipSpace bool, f func(rune) bool) (tok []byte, err error) {
+ defer func() {
+ if e := recover(); e != nil {
+ if se, ok := e.(scanError); ok {
+ err = se.err
+ } else {
+ panic(e)
+ }
+ }
+ }()
+ if f == nil {
+ f = notSpace
+ }
+ s.buf = s.buf[:0]
+ tok = s.token(skipSpace, f)
+ return
+}
+
+// space is a copy of the unicode.White_Space ranges,
+// to avoid depending on package unicode.
+var space = [][2]uint16{
+ {0x0009, 0x000d},
+ {0x0020, 0x0020},
+ {0x0085, 0x0085},
+ {0x00a0, 0x00a0},
+ {0x1680, 0x1680},
+ {0x2000, 0x200a},
+ {0x2028, 0x2029},
+ {0x202f, 0x202f},
+ {0x205f, 0x205f},
+ {0x3000, 0x3000},
+}
+
+func isSpace(r rune) bool {
+ if r >= 1<<16 {
+ return false
+ }
+ rx := uint16(r)
+ for _, rng := range space {
+ if rx < rng[0] {
+ return false
+ }
+ if rx <= rng[1] {
+ return true
+ }
+ }
+ return false
+}
+
+// notSpace is the default scanning function used in Token.
+func notSpace(r rune) bool {
+ return !isSpace(r)
+}
+
+// SkipSpace provides Scan methods the ability to skip space and newline
+// characters in keeping with the current scanning mode set by format strings
+// and Scan/Scanln.
+func (s *ss) SkipSpace() {
+ s.skipSpace(false)
+}
+
+// readRune is a structure to enable reading UTF-8 encoded code points
+// from an io.Reader. It is used if the Reader given to the scanner does
+// not already implement io.RuneReader.
+type readRune struct {
+ reader io.Reader
+ buf [utf8.UTFMax]byte // used only inside ReadRune
+ pending int // number of bytes in pendBuf; only >0 for bad UTF-8
+ pendBuf [utf8.UTFMax]byte // bytes left over
+}
+
+// readByte returns the next byte from the input, which may be
+// left over from a previous read if the UTF-8 was ill-formed.
+func (r *readRune) readByte() (b byte, err error) {
+ if r.pending > 0 {
+ b = r.pendBuf[0]
+ copy(r.pendBuf[0:], r.pendBuf[1:])
+ r.pending--
+ return
+ }
+ n, err := io.ReadFull(r.reader, r.pendBuf[0:1])
+ if n != 1 {
+ return 0, err
+ }
+ return r.pendBuf[0], err
+}
+
+// unread saves the bytes for the next read.
+func (r *readRune) unread(buf []byte) {
+ copy(r.pendBuf[r.pending:], buf)
+ r.pending += len(buf)
+}
+
+// ReadRune returns the next UTF-8 encoded code point from the
+// io.Reader inside r.
+func (r *readRune) ReadRune() (rr rune, size int, err error) {
+ r.buf[0], err = r.readByte()
+ if err != nil {
+ return 0, 0, err
+ }
+ if r.buf[0] < utf8.RuneSelf { // fast check for common ASCII case
+ rr = rune(r.buf[0])
+ size = 1 // Known to be 1.
+ return
+ }
+ var n int
+ for n = 1; !utf8.FullRune(r.buf[0:n]); n++ {
+ r.buf[n], err = r.readByte()
+ if err != nil {
+ if err == io.EOF {
+ err = nil
+ break
+ }
+ return
+ }
+ }
+ rr, size = utf8.DecodeRune(r.buf[0:n])
+ if size < n { // an error
+ r.unread(r.buf[size:n])
+ }
+ return
+}
+
+var ssFree = sync.Pool{
+ New: func() interface{} { return new(ss) },
+}
+
+// newScanState allocates a new ss struct or grab a cached one.
+func newScanState(r io.Reader, nlIsSpace, nlIsEnd bool) (s *ss, old ssave) {
+ // If the reader is a *ss, then we've got a recursive
+ // call to Scan, so re-use the scan state.
+ s, ok := r.(*ss)
+ if ok {
+ old = s.ssave
+ s.limit = s.argLimit
+ s.nlIsEnd = nlIsEnd || s.nlIsEnd
+ s.nlIsSpace = nlIsSpace
+ return
+ }
+
+ s = ssFree.Get().(*ss)
+ if rr, ok := r.(io.RuneReader); ok {
+ s.rr = rr
+ } else {
+ s.rr = &readRune{reader: r}
+ }
+ s.nlIsSpace = nlIsSpace
+ s.nlIsEnd = nlIsEnd
+ s.prevRune = -1
+ s.peekRune = -1
+ s.atEOF = false
+ s.limit = hugeWid
+ s.argLimit = hugeWid
+ s.maxWid = hugeWid
+ s.validSave = true
+ s.count = 0
+ return
+}
+
+// free saves used ss structs in ssFree; avoid an allocation per invocation.
+func (s *ss) free(old ssave) {
+ // If it was used recursively, just restore the old state.
+ if old.validSave {
+ s.ssave = old
+ return
+ }
+ // Don't hold on to ss structs with large buffers.
+ if cap(s.buf) > 1024 {
+ return
+ }
+ s.buf = s.buf[:0]
+ s.rr = nil
+ ssFree.Put(s)
+}
+
+// skipSpace skips spaces and maybe newlines.
+func (s *ss) skipSpace(stopAtNewline bool) {
+ for {
+ r := s.getRune()
+ if r == eof {
+ return
+ }
+ if r == '\r' && s.peek("\n") {
+ continue
+ }
+ if r == '\n' {
+ if stopAtNewline {
+ break
+ }
+ if s.nlIsSpace {
+ continue
+ }
+ s.errorString("unexpected newline")
+ return
+ }
+ if !isSpace(r) {
+ s.UnreadRune()
+ break
+ }
+ }
+}
+
+// token returns the next space-delimited string from the input. It
+// skips white space. For Scanln, it stops at newlines. For Scan,
+// newlines are treated as spaces.
+func (s *ss) token(skipSpace bool, f func(rune) bool) []byte {
+ if skipSpace {
+ s.skipSpace(false)
+ }
+ // read until white space or newline
+ for {
+ r := s.getRune()
+ if r == eof {
+ break
+ }
+ if !f(r) {
+ s.UnreadRune()
+ break
+ }
+ s.buf.WriteRune(r)
+ }
+ return s.buf
+}
+
+var complexError = errors.New("syntax error scanning complex number")
+var boolError = errors.New("syntax error scanning boolean")
+
+func indexRune(s string, r rune) int {
+ for i, c := range s {
+ if c == r {
+ return i
+ }
+ }
+ return -1
+}
+
+// consume reads the next rune in the input and reports whether it is in the ok string.
+// If accept is true, it puts the character into the input token.
+func (s *ss) consume(ok string, accept bool) bool {
+ r := s.getRune()
+ if r == eof {
+ return false
+ }
+ if indexRune(ok, r) >= 0 {
+ if accept {
+ s.buf.WriteRune(r)
+ }
+ return true
+ }
+ if r != eof && accept {
+ s.UnreadRune()
+ }
+ return false
+}
+
+// peek reports whether the next character is in the ok string, without consuming it.
+func (s *ss) peek(ok string) bool {
+ r := s.getRune()
+ if r != eof {
+ s.UnreadRune()
+ }
+ return indexRune(ok, r) >= 0
+}
+
+func (s *ss) notEOF() {
+ // Guarantee there is data to be read.
+ if r := s.getRune(); r == eof {
+ panic(io.EOF)
+ }
+ s.UnreadRune()
+}
+
+// accept checks the next rune in the input. If it's a byte (sic) in the string, it puts it in the
+// buffer and returns true. Otherwise it return false.
+func (s *ss) accept(ok string) bool {
+ return s.consume(ok, true)
+}
+
+// okVerb verifies that the verb is present in the list, setting s.err appropriately if not.
+func (s *ss) okVerb(verb rune, okVerbs, typ string) bool {
+ for _, v := range okVerbs {
+ if v == verb {
+ return true
+ }
+ }
+ s.errorString("bad verb %" + string(verb) + " for " + typ)
+ return false
+}
+
+// scanBool returns the value of the boolean represented by the next token.
+func (s *ss) scanBool(verb rune) bool {
+ s.skipSpace(false)
+ s.notEOF()
+ if !s.okVerb(verb, "tv", "boolean") {
+ return false
+ }
+ // Syntax-checking a boolean is annoying. We're not fastidious about case.
+ switch s.getRune() {
+ case '0':
+ return false
+ case '1':
+ return true
+ case 't', 'T':
+ if s.accept("rR") && (!s.accept("uU") || !s.accept("eE")) {
+ s.error(boolError)
+ }
+ return true
+ case 'f', 'F':
+ if s.accept("aA") && (!s.accept("lL") || !s.accept("sS") || !s.accept("eE")) {
+ s.error(boolError)
+ }
+ return false
+ }
+ return false
+}
+
+// Numerical elements
+const (
+ binaryDigits = "01"
+ octalDigits = "01234567"
+ decimalDigits = "0123456789"
+ hexadecimalDigits = "0123456789aAbBcCdDeEfF"
+ sign = "+-"
+ period = "."
+ exponent = "eEp"
+)
+
+// getBase returns the numeric base represented by the verb and its digit string.
+func (s *ss) getBase(verb rune) (base int, digits string) {
+ s.okVerb(verb, "bdoUxXv", "integer") // sets s.err
+ base = 10
+ digits = decimalDigits
+ switch verb {
+ case 'b':
+ base = 2
+ digits = binaryDigits
+ case 'o':
+ base = 8
+ digits = octalDigits
+ case 'x', 'X', 'U':
+ base = 16
+ digits = hexadecimalDigits
+ }
+ return
+}
+
+// scanNumber returns the numerical string with specified digits starting here.
+func (s *ss) scanNumber(digits string, haveDigits bool) string {
+ if !haveDigits {
+ s.notEOF()
+ if !s.accept(digits) {
+ s.errorString("expected integer")
+ }
+ }
+ for s.accept(digits) {
+ }
+ return string(s.buf)
+}
+
+// scanRune returns the next rune value in the input.
+func (s *ss) scanRune(bitSize int) int64 {
+ s.notEOF()
+ r := int64(s.getRune())
+ n := uint(bitSize)
+ x := (r << (64 - n)) >> (64 - n)
+ if x != r {
+ s.errorString("overflow on character value " + string(r))
+ }
+ return r
+}
+
+// scanBasePrefix reports whether the integer begins with a 0 or 0x,
+// and returns the base, digit string, and whether a zero was found.
+// It is called only if the verb is %v.
+func (s *ss) scanBasePrefix() (base int, digits string, found bool) {
+ if !s.peek("0") {
+ return 10, decimalDigits, false
+ }
+ s.accept("0")
+ found = true // We've put a digit into the token buffer.
+ // Special cases for '0' && '0x'
+ base, digits = 8, octalDigits
+ if s.peek("xX") {
+ s.consume("xX", false)
+ base, digits = 16, hexadecimalDigits
+ }
+ return
+}
+
+// scanInt returns the value of the integer represented by the next
+// token, checking for overflow. Any error is stored in s.err.
+func (s *ss) scanInt(verb rune, bitSize int) int64 {
+ if verb == 'c' {
+ return s.scanRune(bitSize)
+ }
+ s.skipSpace(false)
+ s.notEOF()
+ base, digits := s.getBase(verb)
+ haveDigits := false
+ if verb == 'U' {
+ if !s.consume("U", false) || !s.consume("+", false) {
+ s.errorString("bad unicode format ")
+ }
+ } else {
+ s.accept(sign) // If there's a sign, it will be left in the token buffer.
+ if verb == 'v' {
+ base, digits, haveDigits = s.scanBasePrefix()
+ }
+ }
+ tok := s.scanNumber(digits, haveDigits)
+ i, err := strconv.ParseInt(tok, base, 64)
+ if err != nil {
+ s.error(err)
+ }
+ n := uint(bitSize)
+ x := (i << (64 - n)) >> (64 - n)
+ if x != i {
+ s.errorString("integer overflow on token " + tok)
+ }
+ return i
+}
+
+// scanUint returns the value of the unsigned integer represented
+// by the next token, checking for overflow. Any error is stored in s.err.
+func (s *ss) scanUint(verb rune, bitSize int) uint64 {
+ if verb == 'c' {
+ return uint64(s.scanRune(bitSize))
+ }
+ s.skipSpace(false)
+ s.notEOF()
+ base, digits := s.getBase(verb)
+ haveDigits := false
+ if verb == 'U' {
+ if !s.consume("U", false) || !s.consume("+", false) {
+ s.errorString("bad unicode format ")
+ }
+ } else if verb == 'v' {
+ base, digits, haveDigits = s.scanBasePrefix()
+ }
+ tok := s.scanNumber(digits, haveDigits)
+ i, err := strconv.ParseUint(tok, base, 64)
+ if err != nil {
+ s.error(err)
+ }
+ n := uint(bitSize)
+ x := (i << (64 - n)) >> (64 - n)
+ if x != i {
+ s.errorString("unsigned integer overflow on token " + tok)
+ }
+ return i
+}
+
+// floatToken returns the floating-point number starting here, no longer than swid
+// if the width is specified. It's not rigorous about syntax because it doesn't check that
+// we have at least some digits, but Atof will do that.
+func (s *ss) floatToken() string {
+ s.buf = s.buf[:0]
+ // NaN?
+ if s.accept("nN") && s.accept("aA") && s.accept("nN") {
+ return string(s.buf)
+ }
+ // leading sign?
+ s.accept(sign)
+ // Inf?
+ if s.accept("iI") && s.accept("nN") && s.accept("fF") {
+ return string(s.buf)
+ }
+ // digits?
+ for s.accept(decimalDigits) {
+ }
+ // decimal point?
+ if s.accept(period) {
+ // fraction?
+ for s.accept(decimalDigits) {
+ }
+ }
+ // exponent?
+ if s.accept(exponent) {
+ // leading sign?
+ s.accept(sign)
+ // digits?
+ for s.accept(decimalDigits) {
+ }
+ }
+ return string(s.buf)
+}
+
+// complexTokens returns the real and imaginary parts of the complex number starting here.
+// The number might be parenthesized and has the format (N+Ni) where N is a floating-point
+// number and there are no spaces within.
+func (s *ss) complexTokens() (real, imag string) {
+ // TODO: accept N and Ni independently?
+ parens := s.accept("(")
+ real = s.floatToken()
+ s.buf = s.buf[:0]
+ // Must now have a sign.
+ if !s.accept("+-") {
+ s.error(complexError)
+ }
+ // Sign is now in buffer
+ imagSign := string(s.buf)
+ imag = s.floatToken()
+ if !s.accept("i") {
+ s.error(complexError)
+ }
+ if parens && !s.accept(")") {
+ s.error(complexError)
+ }
+ return real, imagSign + imag
+}
+
+// convertFloat converts the string to a float64value.
+func (s *ss) convertFloat(str string, n int) float64 {
+ if p := indexRune(str, 'p'); p >= 0 {
+ // Atof doesn't handle power-of-2 exponents,
+ // but they're easy to evaluate.
+ f, err := strconv.ParseFloat(str[:p], n)
+ if err != nil {
+ // Put full string into error.
+ if e, ok := err.(*strconv.NumError); ok {
+ e.Num = str
+ }
+ s.error(err)
+ }
+ m, err := strconv.Atoi(str[p+1:])
+ if err != nil {
+ // Put full string into error.
+ if e, ok := err.(*strconv.NumError); ok {
+ e.Num = str
+ }
+ s.error(err)
+ }
+ return math.Ldexp(f, m)
+ }
+ f, err := strconv.ParseFloat(str, n)
+ if err != nil {
+ s.error(err)
+ }
+ return f
+}
+
+// convertComplex converts the next token to a complex128 value.
+// The atof argument is a type-specific reader for the underlying type.
+// If we're reading complex64, atof will parse float32s and convert them
+// to float64's to avoid reproducing this code for each complex type.
+func (s *ss) scanComplex(verb rune, n int) complex128 {
+ if !s.okVerb(verb, floatVerbs, "complex") {
+ return 0
+ }
+ s.skipSpace(false)
+ s.notEOF()
+ sreal, simag := s.complexTokens()
+ real := s.convertFloat(sreal, n/2)
+ imag := s.convertFloat(simag, n/2)
+ return complex(real, imag)
+}
+
+// convertString returns the string represented by the next input characters.
+// The format of the input is determined by the verb.
+func (s *ss) convertString(verb rune) (str string) {
+ if !s.okVerb(verb, "svqx", "string") {
+ return ""
+ }
+ s.skipSpace(false)
+ s.notEOF()
+ switch verb {
+ case 'q':
+ str = s.quotedString()
+ case 'x':
+ str = s.hexString()
+ default:
+ str = string(s.token(true, notSpace)) // %s and %v just return the next word
+ }
+ return
+}
+
+// quotedString returns the double- or back-quoted string represented by the next input characters.
+func (s *ss) quotedString() string {
+ s.notEOF()
+ quote := s.getRune()
+ switch quote {
+ case '`':
+ // Back-quoted: Anything goes until EOF or back quote.
+ for {
+ r := s.mustReadRune()
+ if r == quote {
+ break
+ }
+ s.buf.WriteRune(r)
+ }
+ return string(s.buf)
+ case '"':
+ // Double-quoted: Include the quotes and let strconv.Unquote do the backslash escapes.
+ s.buf.WriteRune(quote)
+ for {
+ r := s.mustReadRune()
+ s.buf.WriteRune(r)
+ if r == '\\' {
+ // In a legal backslash escape, no matter how long, only the character
+ // immediately after the escape can itself be a backslash or quote.
+ // Thus we only need to protect the first character after the backslash.
+ s.buf.WriteRune(s.mustReadRune())
+ } else if r == '"' {
+ break
+ }
+ }
+ result, err := strconv.Unquote(string(s.buf))
+ if err != nil {
+ s.error(err)
+ }
+ return result
+ default:
+ s.errorString("expected quoted string")
+ }
+ return ""
+}
+
+// hexDigit returns the value of the hexadecimal digit
+func (s *ss) hexDigit(d rune) int {
+ digit := int(d)
+ switch digit {
+ case '0', '1', '2', '3', '4', '5', '6', '7', '8', '9':
+ return digit - '0'
+ case 'a', 'b', 'c', 'd', 'e', 'f':
+ return 10 + digit - 'a'
+ case 'A', 'B', 'C', 'D', 'E', 'F':
+ return 10 + digit - 'A'
+ }
+ s.errorString("illegal hex digit")
+ return 0
+}
+
+// hexByte returns the next hex-encoded (two-character) byte from the input.
+// There must be either two hexadecimal digits or a space character in the input.
+func (s *ss) hexByte() (b byte, ok bool) {
+ rune1 := s.getRune()
+ if rune1 == eof {
+ return
+ }
+ if isSpace(rune1) {
+ s.UnreadRune()
+ return
+ }
+ rune2 := s.mustReadRune()
+ return byte(s.hexDigit(rune1)<<4 | s.hexDigit(rune2)), true
+}
+
+// hexString returns the space-delimited hexpair-encoded string.
+func (s *ss) hexString() string {
+ s.notEOF()
+ for {
+ b, ok := s.hexByte()
+ if !ok {
+ break
+ }
+ s.buf.WriteByte(b)
+ }
+ if len(s.buf) == 0 {
+ s.errorString("no hex data for %x string")
+ return ""
+ }
+ return string(s.buf)
+}
+
+const floatVerbs = "beEfFgGv"
+
+const hugeWid = 1 << 30
+
+// scanOne scans a single value, deriving the scanner from the type of the argument.
+func (s *ss) scanOne(verb rune, arg interface{}) {
+ s.buf = s.buf[:0]
+ var err error
+ // If the parameter has its own Scan method, use that.
+ if v, ok := arg.(Scanner); ok {
+ err = v.Scan(s, verb)
+ if err != nil {
+ if err == io.EOF {
+ err = io.ErrUnexpectedEOF
+ }
+ s.error(err)
+ }
+ return
+ }
+
+ switch v := arg.(type) {
+ case *bool:
+ *v = s.scanBool(verb)
+ case *complex64:
+ *v = complex64(s.scanComplex(verb, 64))
+ case *complex128:
+ *v = s.scanComplex(verb, 128)
+ case *int:
+ *v = int(s.scanInt(verb, intBits))
+ case *int8:
+ *v = int8(s.scanInt(verb, 8))
+ case *int16:
+ *v = int16(s.scanInt(verb, 16))
+ case *int32:
+ *v = int32(s.scanInt(verb, 32))
+ case *int64:
+ *v = s.scanInt(verb, 64)
+ case *uint:
+ *v = uint(s.scanUint(verb, intBits))
+ case *uint8:
+ *v = uint8(s.scanUint(verb, 8))
+ case *uint16:
+ *v = uint16(s.scanUint(verb, 16))
+ case *uint32:
+ *v = uint32(s.scanUint(verb, 32))
+ case *uint64:
+ *v = s.scanUint(verb, 64)
+ case *uintptr:
+ *v = uintptr(s.scanUint(verb, uintptrBits))
+ // Floats are tricky because you want to scan in the precision of the result, not
+ // scan in high precision and convert, in order to preserve the correct error condition.
+ case *float32:
+ if s.okVerb(verb, floatVerbs, "float32") {
+ s.skipSpace(false)
+ s.notEOF()
+ *v = float32(s.convertFloat(s.floatToken(), 32))
+ }
+ case *float64:
+ if s.okVerb(verb, floatVerbs, "float64") {
+ s.skipSpace(false)
+ s.notEOF()
+ *v = s.convertFloat(s.floatToken(), 64)
+ }
+ case *string:
+ *v = s.convertString(verb)
+ case *[]byte:
+ // We scan to string and convert so we get a copy of the data.
+ // If we scanned to bytes, the slice would point at the buffer.
+ *v = []byte(s.convertString(verb))
+ default:
+ val := reflect.ValueOf(v)
+ ptr := val
+ if ptr.Kind() != reflect.Ptr {
+ s.errorString("type not a pointer: " + val.Type().String())
+ return
+ }
+ switch v := ptr.Elem(); v.Kind() {
+ case reflect.Bool:
+ v.SetBool(s.scanBool(verb))
+ case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
+ v.SetInt(s.scanInt(verb, v.Type().Bits()))
+ case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
+ v.SetUint(s.scanUint(verb, v.Type().Bits()))
+ case reflect.String:
+ v.SetString(s.convertString(verb))
+ case reflect.Slice:
+ // For now, can only handle (renamed) []byte.
+ typ := v.Type()
+ if typ.Elem().Kind() != reflect.Uint8 {
+ s.errorString("can't scan type: " + val.Type().String())
+ }
+ str := s.convertString(verb)
+ v.Set(reflect.MakeSlice(typ, len(str), len(str)))
+ for i := 0; i < len(str); i++ {
+ v.Index(i).SetUint(uint64(str[i]))
+ }
+ case reflect.Float32, reflect.Float64:
+ s.skipSpace(false)
+ s.notEOF()
+ v.SetFloat(s.convertFloat(s.floatToken(), v.Type().Bits()))
+ case reflect.Complex64, reflect.Complex128:
+ v.SetComplex(s.scanComplex(verb, v.Type().Bits()))
+ default:
+ s.errorString("can't scan type: " + val.Type().String())
+ }
+ }
+}
+
+// errorHandler turns local panics into error returns.
+func errorHandler(errp *error) {
+ if e := recover(); e != nil {
+ if se, ok := e.(scanError); ok { // catch local error
+ *errp = se.err
+ } else if eof, ok := e.(error); ok && eof == io.EOF { // out of input
+ *errp = eof
+ } else {
+ panic(e)
+ }
+ }
+}
+
+// doScan does the real work for scanning without a format string.
+func (s *ss) doScan(a []interface{}) (numProcessed int, err error) {
+ defer errorHandler(&err)
+ for _, arg := range a {
+ s.scanOne('v', arg)
+ numProcessed++
+ }
+ // Check for newline if required.
+ if !s.nlIsSpace {
+ for {
+ r := s.getRune()
+ if r == '\n' || r == eof {
+ break
+ }
+ if !isSpace(r) {
+ s.errorString("expected newline")
+ break
+ }
+ }
+ }
+ return
+}
+
+// advance determines whether the next characters in the input match
+// those of the format. It returns the number of bytes (sic) consumed
+// in the format. Newlines included, all runs of space characters in
+// either input or format behave as a single space. This routine also
+// handles the %% case. If the return value is zero, either format
+// starts with a % (with no following %) or the input is empty.
+// If it is negative, the input did not match the string.
+func (s *ss) advance(format string) (i int) {
+ for i < len(format) {
+ fmtc, w := utf8.DecodeRuneInString(format[i:])
+ if fmtc == '%' {
+ // %% acts like a real percent
+ nextc, _ := utf8.DecodeRuneInString(format[i+w:]) // will not match % if string is empty
+ if nextc != '%' {
+ return
+ }
+ i += w // skip the first %
+ }
+ sawSpace := false
+ for isSpace(fmtc) && i < len(format) {
+ sawSpace = true
+ i += w
+ fmtc, w = utf8.DecodeRuneInString(format[i:])
+ }
+ if sawSpace {
+ // There was space in the format, so there should be space (EOF)
+ // in the input.
+ inputc := s.getRune()
+ if inputc == eof || inputc == '\n' {
+ // If we've reached a newline, stop now; don't read ahead.
+ return
+ }
+ if !isSpace(inputc) {
+ // Space in format but not in input: error
+ s.errorString("expected space in input to match format")
+ }
+ s.skipSpace(true)
+ continue
+ }
+ inputc := s.mustReadRune()
+ if fmtc != inputc {
+ s.UnreadRune()
+ return -1
+ }
+ i += w
+ }
+ return
+}
+
+// doScanf does the real work when scanning with a format string.
+// At the moment, it handles only pointers to basic types.
+func (s *ss) doScanf(format string, a []interface{}) (numProcessed int, err error) {
+ defer errorHandler(&err)
+ end := len(format) - 1
+ // We process one item per non-trivial format
+ for i := 0; i <= end; {
+ w := s.advance(format[i:])
+ if w > 0 {
+ i += w
+ continue
+ }
+ // Either we failed to advance, we have a percent character, or we ran out of input.
+ if format[i] != '%' {
+ // Can't advance format. Why not?
+ if w < 0 {
+ s.errorString("input does not match format")
+ }
+ // Otherwise at EOF; "too many operands" error handled below
+ break
+ }
+ i++ // % is one byte
+
+ // do we have 20 (width)?
+ var widPresent bool
+ s.maxWid, widPresent, i = parsenum(format, i, end)
+ if !widPresent {
+ s.maxWid = hugeWid
+ }
+ s.argLimit = s.limit
+ if f := s.count + s.maxWid; f < s.argLimit {
+ s.argLimit = f
+ }
+
+ c, w := utf8.DecodeRuneInString(format[i:])
+ i += w
+
+ if numProcessed >= len(a) { // out of operands
+ s.errorString("too few operands for format %" + format[i-w:])
+ break
+ }
+ arg := a[numProcessed]
+
+ s.scanOne(c, arg)
+ numProcessed++
+ s.argLimit = s.limit
+ }
+ if numProcessed < len(a) {
+ s.errorString("too many operands")
+ }
+ return
+}
diff --git a/src/fmt/scan_test.go b/src/fmt/scan_test.go
new file mode 100644
index 000000000..541e12df2
--- /dev/null
+++ b/src/fmt/scan_test.go
@@ -0,0 +1,992 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package fmt_test
+
+import (
+ "bufio"
+ "bytes"
+ "errors"
+ . "fmt"
+ "io"
+ "math"
+ "reflect"
+ "regexp"
+ "strings"
+ "testing"
+ "unicode/utf8"
+)
+
+type ScanTest struct {
+ text string
+ in interface{}
+ out interface{}
+}
+
+type ScanfTest struct {
+ format string
+ text string
+ in interface{}
+ out interface{}
+}
+
+type ScanfMultiTest struct {
+ format string
+ text string
+ in []interface{}
+ out []interface{}
+ err string
+}
+
+var (
+ boolVal bool
+ intVal int
+ int8Val int8
+ int16Val int16
+ int32Val int32
+ int64Val int64
+ uintVal uint
+ uint8Val uint8
+ uint16Val uint16
+ uint32Val uint32
+ uint64Val uint64
+ float32Val float32
+ float64Val float64
+ stringVal string
+ bytesVal []byte
+ runeVal rune
+ complex64Val complex64
+ complex128Val complex128
+ renamedBoolVal renamedBool
+ renamedIntVal renamedInt
+ renamedInt8Val renamedInt8
+ renamedInt16Val renamedInt16
+ renamedInt32Val renamedInt32
+ renamedInt64Val renamedInt64
+ renamedUintVal renamedUint
+ renamedUint8Val renamedUint8
+ renamedUint16Val renamedUint16
+ renamedUint32Val renamedUint32
+ renamedUint64Val renamedUint64
+ renamedUintptrVal renamedUintptr
+ renamedStringVal renamedString
+ renamedBytesVal renamedBytes
+ renamedFloat32Val renamedFloat32
+ renamedFloat64Val renamedFloat64
+ renamedComplex64Val renamedComplex64
+ renamedComplex128Val renamedComplex128
+)
+
+type FloatTest struct {
+ text string
+ in float64
+ out float64
+}
+
+// Xs accepts any non-empty run of the verb character
+type Xs string
+
+func (x *Xs) Scan(state ScanState, verb rune) error {
+ tok, err := state.Token(true, func(r rune) bool { return r == verb })
+ if err != nil {
+ return err
+ }
+ s := string(tok)
+ if !regexp.MustCompile("^" + string(verb) + "+$").MatchString(s) {
+ return errors.New("syntax error for xs")
+ }
+ *x = Xs(s)
+ return nil
+}
+
+var xVal Xs
+
+// IntString accepts an integer followed immediately by a string.
+// It tests the embedding of a scan within a scan.
+type IntString struct {
+ i int
+ s string
+}
+
+func (s *IntString) Scan(state ScanState, verb rune) error {
+ if _, err := Fscan(state, &s.i); err != nil {
+ return err
+ }
+
+ tok, err := state.Token(true, nil)
+ if err != nil {
+ return err
+ }
+ s.s = string(tok)
+ return nil
+}
+
+var intStringVal IntString
+
+// myStringReader implements Read but not ReadRune, allowing us to test our readRune wrapper
+// type that creates something that can read runes given only Read().
+type myStringReader struct {
+ r *strings.Reader
+}
+
+func (s *myStringReader) Read(p []byte) (n int, err error) {
+ return s.r.Read(p)
+}
+
+func newReader(s string) *myStringReader {
+ return &myStringReader{strings.NewReader(s)}
+}
+
+var scanTests = []ScanTest{
+ // Basic types
+ {"T\n", &boolVal, true}, // boolean test vals toggle to be sure they are written
+ {"F\n", &boolVal, false}, // restored to zero value
+ {"21\n", &intVal, 21},
+ {"0\n", &intVal, 0},
+ {"000\n", &intVal, 0},
+ {"0x10\n", &intVal, 0x10},
+ {"-0x10\n", &intVal, -0x10},
+ {"0377\n", &intVal, 0377},
+ {"-0377\n", &intVal, -0377},
+ {"0\n", &uintVal, uint(0)},
+ {"000\n", &uintVal, uint(0)},
+ {"0x10\n", &uintVal, uint(0x10)},
+ {"0377\n", &uintVal, uint(0377)},
+ {"22\n", &int8Val, int8(22)},
+ {"23\n", &int16Val, int16(23)},
+ {"24\n", &int32Val, int32(24)},
+ {"25\n", &int64Val, int64(25)},
+ {"127\n", &int8Val, int8(127)},
+ {"-21\n", &intVal, -21},
+ {"-22\n", &int8Val, int8(-22)},
+ {"-23\n", &int16Val, int16(-23)},
+ {"-24\n", &int32Val, int32(-24)},
+ {"-25\n", &int64Val, int64(-25)},
+ {"-128\n", &int8Val, int8(-128)},
+ {"+21\n", &intVal, +21},
+ {"+22\n", &int8Val, int8(+22)},
+ {"+23\n", &int16Val, int16(+23)},
+ {"+24\n", &int32Val, int32(+24)},
+ {"+25\n", &int64Val, int64(+25)},
+ {"+127\n", &int8Val, int8(+127)},
+ {"26\n", &uintVal, uint(26)},
+ {"27\n", &uint8Val, uint8(27)},
+ {"28\n", &uint16Val, uint16(28)},
+ {"29\n", &uint32Val, uint32(29)},
+ {"30\n", &uint64Val, uint64(30)},
+ {"255\n", &uint8Val, uint8(255)},
+ {"32767\n", &int16Val, int16(32767)},
+ {"2.3\n", &float64Val, 2.3},
+ {"2.3e1\n", &float32Val, float32(2.3e1)},
+ {"2.3e2\n", &float64Val, 2.3e2},
+ {"2.3p2\n", &float64Val, 2.3 * 4},
+ {"2.3p+2\n", &float64Val, 2.3 * 4},
+ {"2.3p+66\n", &float64Val, 2.3 * (1 << 32) * (1 << 32) * 4},
+ {"2.3p-66\n", &float64Val, 2.3 / ((1 << 32) * (1 << 32) * 4)},
+ {"2.35\n", &stringVal, "2.35"},
+ {"2345678\n", &bytesVal, []byte("2345678")},
+ {"(3.4e1-2i)\n", &complex128Val, 3.4e1 - 2i},
+ {"-3.45e1-3i\n", &complex64Val, complex64(-3.45e1 - 3i)},
+ {"-.45e1-1e2i\n", &complex128Val, complex128(-.45e1 - 100i)},
+ {"hello\n", &stringVal, "hello"},
+
+ // Carriage-return followed by newline. (We treat \r\n as \n always.)
+ {"hello\r\n", &stringVal, "hello"},
+ {"27\r\n", &uint8Val, uint8(27)},
+
+ // Renamed types
+ {"true\n", &renamedBoolVal, renamedBool(true)},
+ {"F\n", &renamedBoolVal, renamedBool(false)},
+ {"101\n", &renamedIntVal, renamedInt(101)},
+ {"102\n", &renamedIntVal, renamedInt(102)},
+ {"103\n", &renamedUintVal, renamedUint(103)},
+ {"104\n", &renamedUintVal, renamedUint(104)},
+ {"105\n", &renamedInt8Val, renamedInt8(105)},
+ {"106\n", &renamedInt16Val, renamedInt16(106)},
+ {"107\n", &renamedInt32Val, renamedInt32(107)},
+ {"108\n", &renamedInt64Val, renamedInt64(108)},
+ {"109\n", &renamedUint8Val, renamedUint8(109)},
+ {"110\n", &renamedUint16Val, renamedUint16(110)},
+ {"111\n", &renamedUint32Val, renamedUint32(111)},
+ {"112\n", &renamedUint64Val, renamedUint64(112)},
+ {"113\n", &renamedUintptrVal, renamedUintptr(113)},
+ {"114\n", &renamedStringVal, renamedString("114")},
+ {"115\n", &renamedBytesVal, renamedBytes([]byte("115"))},
+
+ // Custom scanners.
+ {" vvv ", &xVal, Xs("vvv")},
+ {" 1234hello", &intStringVal, IntString{1234, "hello"}},
+
+ // Fixed bugs
+ {"2147483648\n", &int64Val, int64(2147483648)}, // was: integer overflow
+}
+
+var scanfTests = []ScanfTest{
+ {"%v", "TRUE\n", &boolVal, true},
+ {"%t", "false\n", &boolVal, false},
+ {"%v", "-71\n", &intVal, -71},
+ {"%v", "0377\n", &intVal, 0377},
+ {"%v", "0x44\n", &intVal, 0x44},
+ {"%d", "72\n", &intVal, 72},
+ {"%c", "a\n", &runeVal, 'a'},
+ {"%c", "\u5072\n", &runeVal, '\u5072'},
+ {"%c", "\u1234\n", &runeVal, '\u1234'},
+ {"%d", "73\n", &int8Val, int8(73)},
+ {"%d", "+74\n", &int16Val, int16(74)},
+ {"%d", "75\n", &int32Val, int32(75)},
+ {"%d", "76\n", &int64Val, int64(76)},
+ {"%b", "1001001\n", &intVal, 73},
+ {"%o", "075\n", &intVal, 075},
+ {"%x", "a75\n", &intVal, 0xa75},
+ {"%v", "71\n", &uintVal, uint(71)},
+ {"%d", "72\n", &uintVal, uint(72)},
+ {"%d", "73\n", &uint8Val, uint8(73)},
+ {"%d", "74\n", &uint16Val, uint16(74)},
+ {"%d", "75\n", &uint32Val, uint32(75)},
+ {"%d", "76\n", &uint64Val, uint64(76)},
+ {"%b", "1001001\n", &uintVal, uint(73)},
+ {"%o", "075\n", &uintVal, uint(075)},
+ {"%x", "a75\n", &uintVal, uint(0xa75)},
+ {"%x", "A75\n", &uintVal, uint(0xa75)},
+ {"%U", "U+1234\n", &intVal, int(0x1234)},
+ {"%U", "U+4567\n", &uintVal, uint(0x4567)},
+
+ // Strings
+ {"%s", "using-%s\n", &stringVal, "using-%s"},
+ {"%x", "7573696e672d2578\n", &stringVal, "using-%x"},
+ {"%q", `"quoted\twith\\do\u0075bl\x65s"` + "\n", &stringVal, "quoted\twith\\doubles"},
+ {"%q", "`quoted with backs`\n", &stringVal, "quoted with backs"},
+
+ // Byte slices
+ {"%s", "bytes-%s\n", &bytesVal, []byte("bytes-%s")},
+ {"%x", "62797465732d2578\n", &bytesVal, []byte("bytes-%x")},
+ {"%q", `"bytes\rwith\vdo\u0075bl\x65s"` + "\n", &bytesVal, []byte("bytes\rwith\vdoubles")},
+ {"%q", "`bytes with backs`\n", &bytesVal, []byte("bytes with backs")},
+
+ // Renamed types
+ {"%v\n", "true\n", &renamedBoolVal, renamedBool(true)},
+ {"%t\n", "F\n", &renamedBoolVal, renamedBool(false)},
+ {"%v", "101\n", &renamedIntVal, renamedInt(101)},
+ {"%c", "\u0101\n", &renamedIntVal, renamedInt('\u0101')},
+ {"%o", "0146\n", &renamedIntVal, renamedInt(102)},
+ {"%v", "103\n", &renamedUintVal, renamedUint(103)},
+ {"%d", "104\n", &renamedUintVal, renamedUint(104)},
+ {"%d", "105\n", &renamedInt8Val, renamedInt8(105)},
+ {"%d", "106\n", &renamedInt16Val, renamedInt16(106)},
+ {"%d", "107\n", &renamedInt32Val, renamedInt32(107)},
+ {"%d", "108\n", &renamedInt64Val, renamedInt64(108)},
+ {"%x", "6D\n", &renamedUint8Val, renamedUint8(109)},
+ {"%o", "0156\n", &renamedUint16Val, renamedUint16(110)},
+ {"%d", "111\n", &renamedUint32Val, renamedUint32(111)},
+ {"%d", "112\n", &renamedUint64Val, renamedUint64(112)},
+ {"%d", "113\n", &renamedUintptrVal, renamedUintptr(113)},
+ {"%s", "114\n", &renamedStringVal, renamedString("114")},
+ {"%q", "\"1155\"\n", &renamedBytesVal, renamedBytes([]byte("1155"))},
+ {"%g", "116e1\n", &renamedFloat32Val, renamedFloat32(116e1)},
+ {"%g", "-11.7e+1", &renamedFloat64Val, renamedFloat64(-11.7e+1)},
+ {"%g", "11+6e1i\n", &renamedComplex64Val, renamedComplex64(11 + 6e1i)},
+ {"%g", "-11.+7e+1i", &renamedComplex128Val, renamedComplex128(-11. + 7e+1i)},
+
+ // Interesting formats
+ {"here is\tthe value:%d", "here is the\tvalue:118\n", &intVal, 118},
+ {"%% %%:%d", "% %:119\n", &intVal, 119},
+
+ // Corner cases
+ {"%x", "FFFFFFFF\n", &uint32Val, uint32(0xFFFFFFFF)},
+
+ // Custom scanner.
+ {"%s", " sss ", &xVal, Xs("sss")},
+ {"%2s", "sssss", &xVal, Xs("ss")},
+
+ // Fixed bugs
+ {"%d\n", "27\n", &intVal, 27}, // ok
+ {"%d\n", "28 \n", &intVal, 28}, // was: "unexpected newline"
+ {"%v", "0", &intVal, 0}, // was: "EOF"; 0 was taken as base prefix and not counted.
+ {"%v", "0", &uintVal, uint(0)}, // was: "EOF"; 0 was taken as base prefix and not counted.
+}
+
+var overflowTests = []ScanTest{
+ {"128", &int8Val, 0},
+ {"32768", &int16Val, 0},
+ {"-129", &int8Val, 0},
+ {"-32769", &int16Val, 0},
+ {"256", &uint8Val, 0},
+ {"65536", &uint16Val, 0},
+ {"1e100", &float32Val, 0},
+ {"1e500", &float64Val, 0},
+ {"(1e100+0i)", &complex64Val, 0},
+ {"(1+1e100i)", &complex64Val, 0},
+ {"(1-1e500i)", &complex128Val, 0},
+}
+
+var truth bool
+var i, j, k int
+var f float64
+var s, t string
+var c complex128
+var x, y Xs
+var z IntString
+var r1, r2, r3 rune
+
+var multiTests = []ScanfMultiTest{
+ {"", "", []interface{}{}, []interface{}{}, ""},
+ {"%d", "23", args(&i), args(23), ""},
+ {"%2s%3s", "22333", args(&s, &t), args("22", "333"), ""},
+ {"%2d%3d", "44555", args(&i, &j), args(44, 555), ""},
+ {"%2d.%3d", "66.777", args(&i, &j), args(66, 777), ""},
+ {"%d, %d", "23, 18", args(&i, &j), args(23, 18), ""},
+ {"%3d22%3d", "33322333", args(&i, &j), args(333, 333), ""},
+ {"%6vX=%3fY", "3+2iX=2.5Y", args(&c, &f), args((3 + 2i), 2.5), ""},
+ {"%d%s", "123abc", args(&i, &s), args(123, "abc"), ""},
+ {"%c%c%c", "2\u50c2X", args(&r1, &r2, &r3), args('2', '\u50c2', 'X'), ""},
+
+ // Custom scanners.
+ {"%e%f", "eefffff", args(&x, &y), args(Xs("ee"), Xs("fffff")), ""},
+ {"%4v%s", "12abcd", args(&z, &s), args(IntString{12, "ab"}, "cd"), ""},
+
+ // Errors
+ {"%t", "23 18", args(&i), nil, "bad verb"},
+ {"%d %d %d", "23 18", args(&i, &j), args(23, 18), "too few operands"},
+ {"%d %d", "23 18 27", args(&i, &j, &k), args(23, 18), "too many operands"},
+ {"%c", "\u0100", args(&int8Val), nil, "overflow"},
+ {"X%d", "10X", args(&intVal), nil, "input does not match format"},
+
+ // Bad UTF-8: should see every byte.
+ {"%c%c%c", "\xc2X\xc2", args(&r1, &r2, &r3), args(utf8.RuneError, 'X', utf8.RuneError), ""},
+
+ // Fixed bugs
+ {"%v%v", "FALSE23", args(&truth, &i), args(false, 23), ""},
+}
+
+func testScan(name string, t *testing.T, scan func(r io.Reader, a ...interface{}) (int, error)) {
+ for _, test := range scanTests {
+ var r io.Reader
+ if name == "StringReader" {
+ r = strings.NewReader(test.text)
+ } else {
+ r = newReader(test.text)
+ }
+ n, err := scan(r, test.in)
+ if err != nil {
+ m := ""
+ if n > 0 {
+ m = Sprintf(" (%d fields ok)", n)
+ }
+ t.Errorf("%s got error scanning %q: %s%s", name, test.text, err, m)
+ continue
+ }
+ if n != 1 {
+ t.Errorf("%s count error on entry %q: got %d", name, test.text, n)
+ continue
+ }
+ // The incoming value may be a pointer
+ v := reflect.ValueOf(test.in)
+ if p := v; p.Kind() == reflect.Ptr {
+ v = p.Elem()
+ }
+ val := v.Interface()
+ if !reflect.DeepEqual(val, test.out) {
+ t.Errorf("%s scanning %q: expected %#v got %#v, type %T", name, test.text, test.out, val, val)
+ }
+ }
+}
+
+func TestScan(t *testing.T) {
+ testScan("StringReader", t, Fscan)
+}
+
+func TestMyReaderScan(t *testing.T) {
+ testScan("myStringReader", t, Fscan)
+}
+
+func TestScanln(t *testing.T) {
+ testScan("StringReader", t, Fscanln)
+}
+
+func TestMyReaderScanln(t *testing.T) {
+ testScan("myStringReader", t, Fscanln)
+}
+
+func TestScanf(t *testing.T) {
+ for _, test := range scanfTests {
+ n, err := Sscanf(test.text, test.format, test.in)
+ if err != nil {
+ t.Errorf("got error scanning (%q, %q): %s", test.format, test.text, err)
+ continue
+ }
+ if n != 1 {
+ t.Errorf("count error on entry (%q, %q): got %d", test.format, test.text, n)
+ continue
+ }
+ // The incoming value may be a pointer
+ v := reflect.ValueOf(test.in)
+ if p := v; p.Kind() == reflect.Ptr {
+ v = p.Elem()
+ }
+ val := v.Interface()
+ if !reflect.DeepEqual(val, test.out) {
+ t.Errorf("scanning (%q, %q): expected %#v got %#v, type %T", test.format, test.text, test.out, val, val)
+ }
+ }
+}
+
+func TestScanOverflow(t *testing.T) {
+ // different machines and different types report errors with different strings.
+ re := regexp.MustCompile("overflow|too large|out of range|not representable")
+ for _, test := range overflowTests {
+ _, err := Sscan(test.text, test.in)
+ if err == nil {
+ t.Errorf("expected overflow scanning %q", test.text)
+ continue
+ }
+ if !re.MatchString(err.Error()) {
+ t.Errorf("expected overflow error scanning %q: %s", test.text, err)
+ }
+ }
+}
+
+func verifyNaN(str string, t *testing.T) {
+ var f float64
+ var f32 float32
+ var f64 float64
+ text := str + " " + str + " " + str
+ n, err := Fscan(strings.NewReader(text), &f, &f32, &f64)
+ if err != nil {
+ t.Errorf("got error scanning %q: %s", text, err)
+ }
+ if n != 3 {
+ t.Errorf("count error scanning %q: got %d", text, n)
+ }
+ if !math.IsNaN(float64(f)) || !math.IsNaN(float64(f32)) || !math.IsNaN(f64) {
+ t.Errorf("didn't get NaNs scanning %q: got %g %g %g", text, f, f32, f64)
+ }
+}
+
+func TestNaN(t *testing.T) {
+ for _, s := range []string{"nan", "NAN", "NaN"} {
+ verifyNaN(s, t)
+ }
+}
+
+func verifyInf(str string, t *testing.T) {
+ var f float64
+ var f32 float32
+ var f64 float64
+ text := str + " " + str + " " + str
+ n, err := Fscan(strings.NewReader(text), &f, &f32, &f64)
+ if err != nil {
+ t.Errorf("got error scanning %q: %s", text, err)
+ }
+ if n != 3 {
+ t.Errorf("count error scanning %q: got %d", text, n)
+ }
+ sign := 1
+ if str[0] == '-' {
+ sign = -1
+ }
+ if !math.IsInf(float64(f), sign) || !math.IsInf(float64(f32), sign) || !math.IsInf(f64, sign) {
+ t.Errorf("didn't get right Infs scanning %q: got %g %g %g", text, f, f32, f64)
+ }
+}
+
+func TestInf(t *testing.T) {
+ for _, s := range []string{"inf", "+inf", "-inf", "INF", "-INF", "+INF", "Inf", "-Inf", "+Inf"} {
+ verifyInf(s, t)
+ }
+}
+
+func testScanfMulti(name string, t *testing.T) {
+ sliceType := reflect.TypeOf(make([]interface{}, 1))
+ for _, test := range multiTests {
+ var r io.Reader
+ if name == "StringReader" {
+ r = strings.NewReader(test.text)
+ } else {
+ r = newReader(test.text)
+ }
+ n, err := Fscanf(r, test.format, test.in...)
+ if err != nil {
+ if test.err == "" {
+ t.Errorf("got error scanning (%q, %q): %q", test.format, test.text, err)
+ } else if strings.Index(err.Error(), test.err) < 0 {
+ t.Errorf("got wrong error scanning (%q, %q): %q; expected %q", test.format, test.text, err, test.err)
+ }
+ continue
+ }
+ if test.err != "" {
+ t.Errorf("expected error %q error scanning (%q, %q)", test.err, test.format, test.text)
+ }
+ if n != len(test.out) {
+ t.Errorf("count error on entry (%q, %q): expected %d got %d", test.format, test.text, len(test.out), n)
+ continue
+ }
+ // Convert the slice of pointers into a slice of values
+ resultVal := reflect.MakeSlice(sliceType, n, n)
+ for i := 0; i < n; i++ {
+ v := reflect.ValueOf(test.in[i]).Elem()
+ resultVal.Index(i).Set(v)
+ }
+ result := resultVal.Interface()
+ if !reflect.DeepEqual(result, test.out) {
+ t.Errorf("scanning (%q, %q): expected %#v got %#v", test.format, test.text, test.out, result)
+ }
+ }
+}
+
+func TestScanfMulti(t *testing.T) {
+ testScanfMulti("StringReader", t)
+}
+
+func TestMyReaderScanfMulti(t *testing.T) {
+ testScanfMulti("myStringReader", t)
+}
+
+func TestScanMultiple(t *testing.T) {
+ var a int
+ var s string
+ n, err := Sscan("123abc", &a, &s)
+ if n != 2 {
+ t.Errorf("Sscan count error: expected 2: got %d", n)
+ }
+ if err != nil {
+ t.Errorf("Sscan expected no error; got %s", err)
+ }
+ if a != 123 || s != "abc" {
+ t.Errorf("Sscan wrong values: got (%d %q) expected (123 \"abc\")", a, s)
+ }
+ n, err = Sscan("asdf", &s, &a)
+ if n != 1 {
+ t.Errorf("Sscan count error: expected 1: got %d", n)
+ }
+ if err == nil {
+ t.Errorf("Sscan expected error; got none: %s", err)
+ }
+ if s != "asdf" {
+ t.Errorf("Sscan wrong values: got %q expected \"asdf\"", s)
+ }
+}
+
+// Empty strings are not valid input when scanning a string.
+func TestScanEmpty(t *testing.T) {
+ var s1, s2 string
+ n, err := Sscan("abc", &s1, &s2)
+ if n != 1 {
+ t.Errorf("Sscan count error: expected 1: got %d", n)
+ }
+ if err == nil {
+ t.Error("Sscan <one item> expected error; got none")
+ }
+ if s1 != "abc" {
+ t.Errorf("Sscan wrong values: got %q expected \"abc\"", s1)
+ }
+ n, err = Sscan("", &s1, &s2)
+ if n != 0 {
+ t.Errorf("Sscan count error: expected 0: got %d", n)
+ }
+ if err == nil {
+ t.Error("Sscan <empty> expected error; got none")
+ }
+ // Quoted empty string is OK.
+ n, err = Sscanf(`""`, "%q", &s1)
+ if n != 1 {
+ t.Errorf("Sscanf count error: expected 1: got %d", n)
+ }
+ if err != nil {
+ t.Errorf("Sscanf <empty> expected no error with quoted string; got %s", err)
+ }
+}
+
+func TestScanNotPointer(t *testing.T) {
+ r := strings.NewReader("1")
+ var a int
+ _, err := Fscan(r, a)
+ if err == nil {
+ t.Error("expected error scanning non-pointer")
+ } else if strings.Index(err.Error(), "pointer") < 0 {
+ t.Errorf("expected pointer error scanning non-pointer, got: %s", err)
+ }
+}
+
+func TestScanlnNoNewline(t *testing.T) {
+ var a int
+ _, err := Sscanln("1 x\n", &a)
+ if err == nil {
+ t.Error("expected error scanning string missing newline")
+ } else if strings.Index(err.Error(), "newline") < 0 {
+ t.Errorf("expected newline error scanning string missing newline, got: %s", err)
+ }
+}
+
+func TestScanlnWithMiddleNewline(t *testing.T) {
+ r := strings.NewReader("123\n456\n")
+ var a, b int
+ _, err := Fscanln(r, &a, &b)
+ if err == nil {
+ t.Error("expected error scanning string with extra newline")
+ } else if strings.Index(err.Error(), "newline") < 0 {
+ t.Errorf("expected newline error scanning string with extra newline, got: %s", err)
+ }
+}
+
+// eofCounter is a special Reader that counts reads at end of file.
+type eofCounter struct {
+ reader *strings.Reader
+ eofCount int
+}
+
+func (ec *eofCounter) Read(b []byte) (n int, err error) {
+ n, err = ec.reader.Read(b)
+ if n == 0 {
+ ec.eofCount++
+ }
+ return
+}
+
+// TestEOF verifies that when we scan, we see at most EOF once per call to a
+// Scan function, and then only when it's really an EOF.
+func TestEOF(t *testing.T) {
+ ec := &eofCounter{strings.NewReader("123\n"), 0}
+ var a int
+ n, err := Fscanln(ec, &a)
+ if err != nil {
+ t.Error("unexpected error", err)
+ }
+ if n != 1 {
+ t.Error("expected to scan one item, got", n)
+ }
+ if ec.eofCount != 0 {
+ t.Error("expected zero EOFs", ec.eofCount)
+ ec.eofCount = 0 // reset for next test
+ }
+ n, err = Fscanln(ec, &a)
+ if err == nil {
+ t.Error("expected error scanning empty string")
+ }
+ if n != 0 {
+ t.Error("expected to scan zero items, got", n)
+ }
+ if ec.eofCount != 1 {
+ t.Error("expected one EOF, got", ec.eofCount)
+ }
+}
+
+// TestEOFAtEndOfInput verifies that we see an EOF error if we run out of input.
+// This was a buglet: we used to get "expected integer".
+func TestEOFAtEndOfInput(t *testing.T) {
+ var i, j int
+ n, err := Sscanf("23", "%d %d", &i, &j)
+ if n != 1 || i != 23 {
+ t.Errorf("Sscanf expected one value of 23; got %d %d", n, i)
+ }
+ if err != io.EOF {
+ t.Errorf("Sscanf expected EOF; got %q", err)
+ }
+ n, err = Sscan("234", &i, &j)
+ if n != 1 || i != 234 {
+ t.Errorf("Sscan expected one value of 234; got %d %d", n, i)
+ }
+ if err != io.EOF {
+ t.Errorf("Sscan expected EOF; got %q", err)
+ }
+ // Trailing space is tougher.
+ n, err = Sscan("234 ", &i, &j)
+ if n != 1 || i != 234 {
+ t.Errorf("Sscan expected one value of 234; got %d %d", n, i)
+ }
+ if err != io.EOF {
+ t.Errorf("Sscan expected EOF; got %q", err)
+ }
+}
+
+var eofTests = []struct {
+ format string
+ v interface{}
+}{
+ {"%s", &stringVal},
+ {"%q", &stringVal},
+ {"%x", &stringVal},
+ {"%v", &stringVal},
+ {"%v", &bytesVal},
+ {"%v", &intVal},
+ {"%v", &uintVal},
+ {"%v", &boolVal},
+ {"%v", &float32Val},
+ {"%v", &complex64Val},
+ {"%v", &renamedStringVal},
+ {"%v", &renamedBytesVal},
+ {"%v", &renamedIntVal},
+ {"%v", &renamedUintVal},
+ {"%v", &renamedBoolVal},
+ {"%v", &renamedFloat32Val},
+ {"%v", &renamedComplex64Val},
+}
+
+func TestEOFAllTypes(t *testing.T) {
+ for i, test := range eofTests {
+ if _, err := Sscanf("", test.format, test.v); err != io.EOF {
+ t.Errorf("#%d: %s %T not eof on empty string: %s", i, test.format, test.v, err)
+ }
+ if _, err := Sscanf(" ", test.format, test.v); err != io.EOF {
+ t.Errorf("#%d: %s %T not eof on trailing blanks: %s", i, test.format, test.v, err)
+ }
+ }
+}
+
+// TestUnreadRuneWithBufio verifies that, at least when using bufio, successive
+// calls to Fscan do not lose runes.
+func TestUnreadRuneWithBufio(t *testing.T) {
+ r := bufio.NewReader(strings.NewReader("123αb"))
+ var i int
+ var a string
+ n, err := Fscanf(r, "%d", &i)
+ if n != 1 || err != nil {
+ t.Errorf("reading int expected one item, no errors; got %d %q", n, err)
+ }
+ if i != 123 {
+ t.Errorf("expected 123; got %d", i)
+ }
+ n, err = Fscanf(r, "%s", &a)
+ if n != 1 || err != nil {
+ t.Errorf("reading string expected one item, no errors; got %d %q", n, err)
+ }
+ if a != "αb" {
+ t.Errorf("expected αb; got %q", a)
+ }
+}
+
+type TwoLines string
+
+// Scan attempts to read two lines into the object. Scanln should prevent this
+// because it stops at newline; Scan and Scanf should be fine.
+func (t *TwoLines) Scan(state ScanState, verb rune) error {
+ chars := make([]rune, 0, 100)
+ for nlCount := 0; nlCount < 2; {
+ c, _, err := state.ReadRune()
+ if err != nil {
+ return err
+ }
+ chars = append(chars, c)
+ if c == '\n' {
+ nlCount++
+ }
+ }
+ *t = TwoLines(string(chars))
+ return nil
+}
+
+func TestMultiLine(t *testing.T) {
+ input := "abc\ndef\n"
+ // Sscan should work
+ var tscan TwoLines
+ n, err := Sscan(input, &tscan)
+ if n != 1 {
+ t.Errorf("Sscan: expected 1 item; got %d", n)
+ }
+ if err != nil {
+ t.Errorf("Sscan: expected no error; got %s", err)
+ }
+ if string(tscan) != input {
+ t.Errorf("Sscan: expected %q; got %q", input, tscan)
+ }
+ // Sscanf should work
+ var tscanf TwoLines
+ n, err = Sscanf(input, "%s", &tscanf)
+ if n != 1 {
+ t.Errorf("Sscanf: expected 1 item; got %d", n)
+ }
+ if err != nil {
+ t.Errorf("Sscanf: expected no error; got %s", err)
+ }
+ if string(tscanf) != input {
+ t.Errorf("Sscanf: expected %q; got %q", input, tscanf)
+ }
+ // Sscanln should not work
+ var tscanln TwoLines
+ n, err = Sscanln(input, &tscanln)
+ if n != 0 {
+ t.Errorf("Sscanln: expected 0 items; got %d: %q", n, tscanln)
+ }
+ if err == nil {
+ t.Error("Sscanln: expected error; got none")
+ } else if err != io.ErrUnexpectedEOF {
+ t.Errorf("Sscanln: expected io.ErrUnexpectedEOF (ha!); got %s", err)
+ }
+}
+
+// simpleReader is a strings.Reader that implements only Read, not ReadRune.
+// Good for testing readahead.
+type simpleReader struct {
+ sr *strings.Reader
+}
+
+func (s *simpleReader) Read(b []byte) (n int, err error) {
+ return s.sr.Read(b)
+}
+
+// TestLineByLineFscanf tests that Fscanf does not read past newline. Issue
+// 3481.
+func TestLineByLineFscanf(t *testing.T) {
+ r := &simpleReader{strings.NewReader("1\n2\n")}
+ var i, j int
+ n, err := Fscanf(r, "%v\n", &i)
+ if n != 1 || err != nil {
+ t.Fatalf("first read: %d %q", n, err)
+ }
+ n, err = Fscanf(r, "%v\n", &j)
+ if n != 1 || err != nil {
+ t.Fatalf("second read: %d %q", n, err)
+ }
+ if i != 1 || j != 2 {
+ t.Errorf("wrong values; wanted 1 2 got %d %d", i, j)
+ }
+}
+
+// TestScanStateCount verifies the correct byte count is returned. Issue 8512.
+
+// runeScanner implements the Scanner interface for TestScanStateCount.
+type runeScanner struct {
+ rune rune
+ size int
+}
+
+func (rs *runeScanner) Scan(state ScanState, verb rune) error {
+ r, size, err := state.ReadRune()
+ rs.rune = r
+ rs.size = size
+ return err
+}
+
+func TestScanStateCount(t *testing.T) {
+ var a, b, c runeScanner
+ n, err := Sscanf("12➂", "%c%c%c", &a, &b, &c)
+ if err != nil {
+ t.Fatal(err)
+ }
+ if n != 3 {
+ t.Fatalf("expected 3 items consumed, got %d")
+ }
+ if a.rune != '1' || b.rune != '2' || c.rune != '➂' {
+ t.Errorf("bad scan rune: %q %q %q should be '1' '2' '➂'", a.rune, b.rune, c.rune)
+ }
+ if a.size != 1 || b.size != 1 || c.size != 3 {
+ t.Errorf("bad scan size: %q %q %q should be 1 1 3", a.size, b.size, c.size)
+ }
+}
+
+// RecursiveInt accepts a string matching %d.%d.%d....
+// and parses it into a linked list.
+// It allows us to benchmark recursive descent style scanners.
+type RecursiveInt struct {
+ i int
+ next *RecursiveInt
+}
+
+func (r *RecursiveInt) Scan(state ScanState, verb rune) (err error) {
+ _, err = Fscan(state, &r.i)
+ if err != nil {
+ return
+ }
+ next := new(RecursiveInt)
+ _, err = Fscanf(state, ".%v", next)
+ if err != nil {
+ if err == io.ErrUnexpectedEOF {
+ err = nil
+ }
+ return
+ }
+ r.next = next
+ return
+}
+
+// scanInts performs the same scanning task as RecursiveInt.Scan
+// but without recurring through scanner, so we can compare
+// performance more directly.
+func scanInts(r *RecursiveInt, b *bytes.Buffer) (err error) {
+ r.next = nil
+ _, err = Fscan(b, &r.i)
+ if err != nil {
+ return
+ }
+ c, _, err := b.ReadRune()
+ if err != nil {
+ if err == io.EOF {
+ err = nil
+ }
+ return
+ }
+ if c != '.' {
+ return
+ }
+ next := new(RecursiveInt)
+ err = scanInts(next, b)
+ if err == nil {
+ r.next = next
+ }
+ return
+}
+
+func makeInts(n int) []byte {
+ var buf bytes.Buffer
+ Fprintf(&buf, "1")
+ for i := 1; i < n; i++ {
+ Fprintf(&buf, ".%d", i+1)
+ }
+ return buf.Bytes()
+}
+
+func TestScanInts(t *testing.T) {
+ testScanInts(t, scanInts)
+ testScanInts(t, func(r *RecursiveInt, b *bytes.Buffer) (err error) {
+ _, err = Fscan(b, r)
+ return
+ })
+}
+
+// 800 is small enough to not overflow the stack when using gccgo on a
+// platform that does not support split stack.
+const intCount = 800
+
+func testScanInts(t *testing.T, scan func(*RecursiveInt, *bytes.Buffer) error) {
+ r := new(RecursiveInt)
+ ints := makeInts(intCount)
+ buf := bytes.NewBuffer(ints)
+ err := scan(r, buf)
+ if err != nil {
+ t.Error("unexpected error", err)
+ }
+ i := 1
+ for ; r != nil; r = r.next {
+ if r.i != i {
+ t.Fatalf("bad scan: expected %d got %d", i, r.i)
+ }
+ i++
+ }
+ if i-1 != intCount {
+ t.Fatalf("bad scan count: expected %d got %d", intCount, i-1)
+ }
+}
+
+func BenchmarkScanInts(b *testing.B) {
+ b.ResetTimer()
+ ints := makeInts(intCount)
+ var r RecursiveInt
+ for i := b.N - 1; i >= 0; i-- {
+ buf := bytes.NewBuffer(ints)
+ b.StartTimer()
+ scanInts(&r, buf)
+ b.StopTimer()
+ }
+}
+
+func BenchmarkScanRecursiveInt(b *testing.B) {
+ b.ResetTimer()
+ ints := makeInts(intCount)
+ var r RecursiveInt
+ for i := b.N - 1; i >= 0; i-- {
+ buf := bytes.NewBuffer(ints)
+ b.StartTimer()
+ Fscan(buf, &r)
+ b.StopTimer()
+ }
+}
diff --git a/src/fmt/stringer_test.go b/src/fmt/stringer_test.go
new file mode 100644
index 000000000..0ca3f522d
--- /dev/null
+++ b/src/fmt/stringer_test.go
@@ -0,0 +1,61 @@
+// Copyright 2010 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package fmt_test
+
+import (
+ . "fmt"
+ "testing"
+)
+
+type TI int
+type TI8 int8
+type TI16 int16
+type TI32 int32
+type TI64 int64
+type TU uint
+type TU8 uint8
+type TU16 uint16
+type TU32 uint32
+type TU64 uint64
+type TUI uintptr
+type TF float64
+type TF32 float32
+type TF64 float64
+type TB bool
+type TS string
+
+func (v TI) String() string { return Sprintf("I: %d", int(v)) }
+func (v TI8) String() string { return Sprintf("I8: %d", int8(v)) }
+func (v TI16) String() string { return Sprintf("I16: %d", int16(v)) }
+func (v TI32) String() string { return Sprintf("I32: %d", int32(v)) }
+func (v TI64) String() string { return Sprintf("I64: %d", int64(v)) }
+func (v TU) String() string { return Sprintf("U: %d", uint(v)) }
+func (v TU8) String() string { return Sprintf("U8: %d", uint8(v)) }
+func (v TU16) String() string { return Sprintf("U16: %d", uint16(v)) }
+func (v TU32) String() string { return Sprintf("U32: %d", uint32(v)) }
+func (v TU64) String() string { return Sprintf("U64: %d", uint64(v)) }
+func (v TUI) String() string { return Sprintf("UI: %d", uintptr(v)) }
+func (v TF) String() string { return Sprintf("F: %f", float64(v)) }
+func (v TF32) String() string { return Sprintf("F32: %f", float32(v)) }
+func (v TF64) String() string { return Sprintf("F64: %f", float64(v)) }
+func (v TB) String() string { return Sprintf("B: %t", bool(v)) }
+func (v TS) String() string { return Sprintf("S: %q", string(v)) }
+
+func check(t *testing.T, got, want string) {
+ if got != want {
+ t.Error(got, "!=", want)
+ }
+}
+
+func TestStringer(t *testing.T) {
+ s := Sprintf("%v %v %v %v %v", TI(0), TI8(1), TI16(2), TI32(3), TI64(4))
+ check(t, s, "I: 0 I8: 1 I16: 2 I32: 3 I64: 4")
+ s = Sprintf("%v %v %v %v %v %v", TU(5), TU8(6), TU16(7), TU32(8), TU64(9), TUI(10))
+ check(t, s, "U: 5 U8: 6 U16: 7 U32: 8 U64: 9 UI: 10")
+ s = Sprintf("%v %v %v", TF(1.0), TF32(2.0), TF64(3.0))
+ check(t, s, "F: 1.000000 F32: 2.000000 F64: 3.000000")
+ s = Sprintf("%v %v", TB(true), TS("x"))
+ check(t, s, "B: true S: \"x\"")
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-06-03 04:18:51 +0000