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Diffstat (limited to 'src/pkg/fmt/format.go')
-rw-r--r-- | src/pkg/fmt/format.go | 447 |
1 files changed, 0 insertions, 447 deletions
diff --git a/src/pkg/fmt/format.go b/src/pkg/fmt/format.go deleted file mode 100644 index bec55f75b..000000000 --- a/src/pkg/fmt/format.go +++ /dev/null @@ -1,447 +0,0 @@ -// 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 ( - "bytes" - "strconv" - "unicode" - "utf8" -) - -const ( - nByte = 64 - - ldigits = "0123456789abcdef" - udigits = "0123456789ABCDEF" -) - -const ( - signed = true - unsigned = false -) - -var padZeroBytes = make([]byte, nByte) -var padSpaceBytes = make([]byte, nByte) - -var newline = []byte{'\n'} - -func init() { - for i := 0; i < nByte; i++ { - padZeroBytes[i] = '0' - padSpaceBytes[i] = ' ' - } -} - -// A fmt is the raw formatter used by Printf etc. -// It prints into a bytes.Buffer that must be set up externally. -type fmt struct { - intbuf [nByte]byte - buf *bytes.Buffer - // width, precision - wid int - prec int - // flags - 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 -} - -func (f *fmt) clearflags() { - f.wid = 0 - f.widPresent = false - f.prec = 0 - f.precPresent = false - f.minus = false - f.plus = false - f.sharp = false - f.space = false - f.unicode = false - f.uniQuote = false - f.zero = false -} - -func (f *fmt) init(buf *bytes.Buffer) { - f.buf = buf - f.clearflags() -} - -// Compute 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 -} - -// Generate 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 - } -} - -// Append b to f.buf, padded on left (w > 0) or right (w < 0 or f.minus) -// clear flags afterwards. -func (f *fmt) pad(b []byte) { - var padding []byte - var left, right int - if f.widPresent && f.wid != 0 { - padding, left, right = f.computePadding(len(b)) - } - if left > 0 { - f.writePadding(left, padding) - } - f.buf.Write(b) - if right > 0 { - f.writePadding(right, padding) - } -} - -// append s to buf, padded on left (w > 0) or right (w < 0 or f.minus). -// clear flags afterwards. -func (f *fmt) padString(s string) { - var padding []byte - var left, right int - if f.widPresent && f.wid != 0 { - 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) - } -} - -func putint(buf []byte, base, val uint64, digits string) int { - i := len(buf) - 1 - for val >= base { - buf[i] = digits[val%base] - i-- - val /= base - } - buf[i] = digits[val] - return i - 1 -} - -// fmt_boolean formats a boolean. -func (f *fmt) fmt_boolean(v bool) { - if v { - f.padString("true") - } else { - f.padString("false") - } -} - -// 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) { - var buf []byte = f.intbuf[0:] - 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(f.intbuf) - ua := uint64(a) - for ua >= base { - i-- - buf[i] = digits[ua%base] - ua /= base - } - i-- - buf[i] = digits[ua] - for i > 0 && prec > nByte-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 <= unicode.MaxRune && unicode.IsPrint(int(a)) { - runeWidth := utf8.RuneLen(int(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:], int(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_sx formats a string as a hexadecimal encoding of its bytes. -func (f *fmt) fmt_sx(s string) { - t := "" - for i := 0; i < len(s); i++ { - if i > 0 && f.space { - t += " " - } - v := s[i] - t += string(ldigits[v>>4]) - t += string(ldigits[v&0xF]) - } - f.padString(t) -} - -// fmt_sX formats a string as an uppercase hexadecimal encoding of its bytes. -func (f *fmt) fmt_sX(s string) { - t := "" - for i := 0; i < len(s); i++ { - if i > 0 && f.space { - t += " " - } - v := s[i] - t += string(udigits[v>>4]) - t += string(udigits[v&0xF]) - } - f.padString(t) -} - -// 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 string - if f.plus { - quoted = strconv.QuoteRuneToASCII(int(c)) - } else { - quoted = strconv.QuoteRune(int(c)) - } - f.padString(quoted) -} - -// floating-point - -func doPrec(f *fmt, def int) int { - if f.precPresent { - return f.prec - } - return def -} - -// Add a plus sign or space to the floating-point string representation if missing and required. -func (f *fmt) plusSpace(s string) { - if s[0] != '-' { - if f.plus { - s = "+" + s - } else if f.space { - s = " " + s - } - } - f.padString(s) -} - -// fmt_e64 formats a float64 in the form -1.23e+12. -func (f *fmt) fmt_e64(v float64) { f.plusSpace(strconv.Ftoa64(v, 'e', doPrec(f, 6))) } - -// fmt_E64 formats a float64 in the form -1.23E+12. -func (f *fmt) fmt_E64(v float64) { f.plusSpace(strconv.Ftoa64(v, 'E', doPrec(f, 6))) } - -// fmt_f64 formats a float64 in the form -1.23. -func (f *fmt) fmt_f64(v float64) { f.plusSpace(strconv.Ftoa64(v, 'f', doPrec(f, 6))) } - -// fmt_g64 formats a float64 in the 'f' or 'e' form according to size. -func (f *fmt) fmt_g64(v float64) { f.plusSpace(strconv.Ftoa64(v, 'g', doPrec(f, -1))) } - -// fmt_g64 formats a float64 in the 'f' or 'E' form according to size. -func (f *fmt) fmt_G64(v float64) { f.plusSpace(strconv.Ftoa64(v, 'G', doPrec(f, -1))) } - -// fmt_fb64 formats a float64 in the form -123p3 (exponent is power of 2). -func (f *fmt) fmt_fb64(v float64) { f.plusSpace(strconv.Ftoa64(v, 'b', 0)) } - -// 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.plusSpace(strconv.Ftoa32(v, 'e', doPrec(f, 6))) } - -// fmt_E32 formats a float32 in the form -1.23E+12. -func (f *fmt) fmt_E32(v float32) { f.plusSpace(strconv.Ftoa32(v, 'E', doPrec(f, 6))) } - -// fmt_f32 formats a float32 in the form -1.23. -func (f *fmt) fmt_f32(v float32) { f.plusSpace(strconv.Ftoa32(v, 'f', doPrec(f, 6))) } - -// fmt_g32 formats a float32 in the 'f' or 'e' form according to size. -func (f *fmt) fmt_g32(v float32) { f.plusSpace(strconv.Ftoa32(v, 'g', doPrec(f, -1))) } - -// fmt_G32 formats a float32 in the 'f' or 'E' form according to size. -func (f *fmt) fmt_G32(v float32) { f.plusSpace(strconv.Ftoa32(v, 'G', doPrec(f, -1))) } - -// fmt_fb32 formats a float32 in the form -123p3 (exponent is power of 2). -func (f *fmt) fmt_fb32(v float32) { f.padString(strconv.Ftoa32(v, 'b', 0)) } - -// fmt_c64 formats a complex64 according to the verb. -func (f *fmt) fmt_c64(v complex64, verb int) { - f.buf.WriteByte('(') - r := real(v) - for i := 0; ; i++ { - switch verb { - case 'e': - f.fmt_e32(r) - case 'E': - f.fmt_E32(r) - case 'f': - f.fmt_f32(r) - case 'g': - f.fmt_g32(r) - case 'G': - f.fmt_G32(r) - } - if i != 0 { - break - } - f.plus = true - r = imag(v) - } - f.buf.Write(irparenBytes) -} - -// fmt_c128 formats a complex128 according to the verb. -func (f *fmt) fmt_c128(v complex128, verb int) { - f.buf.WriteByte('(') - r := real(v) - for i := 0; ; i++ { - switch verb { - case 'e': - f.fmt_e64(r) - case 'E': - f.fmt_E64(r) - case 'f': - f.fmt_f64(r) - case 'g': - f.fmt_g64(r) - case 'G': - f.fmt_G64(r) - } - if i != 0 { - break - } - f.plus = true - r = imag(v) - } - f.buf.Write(irparenBytes) -} |