diff options
Diffstat (limited to 'src/pkg/strconv/fp_test.go')
-rw-r--r-- | src/pkg/strconv/fp_test.go | 149 |
1 files changed, 149 insertions, 0 deletions
diff --git a/src/pkg/strconv/fp_test.go b/src/pkg/strconv/fp_test.go new file mode 100644 index 000000000..60d7ce6cf --- /dev/null +++ b/src/pkg/strconv/fp_test.go @@ -0,0 +1,149 @@ +// 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 strconv +import ( + "bufio"; + "fmt"; + "io"; + "os"; + "strconv"; + "strings"; + "testing"; +) + +func pow2(i int) float64 { + switch { + case i < 0: + return 1 / pow2(-i); + case i == 0: + return 1; + case i == 1: + return 2; + } + return pow2(i/2) * pow2(i-i/2); +} + +// Wrapper around strconv.Atof64. Handles dddddp+ddd (binary exponent) +// itself, passes the rest on to strconv.Atof64. +func myatof64(s string) (f float64, ok bool) { + a := strings.Split(s, "p"); + if len(a) == 2 { + n, err := strconv.Atoi64(a[0]); + if err != nil { + return 0, false; + } + e, err1 := strconv.Atoi(a[1]); + if err1 != nil { + println("bad e", a[1]); + return 0, false; + } + v := float64(n); + // We expect that v*pow2(e) fits in a float64, + // but pow2(e) by itself may not. Be careful. + if e <= -1000 { + v *= pow2(-1000); + e += 1000; + for e < 0 { + v /= 2; + e++; + } + return v, true; + } + if e >= 1000 { + v *= pow2(1000); + e -= 1000; + for e > 0 { + v *= 2; + e--; + } + return v, true; + } + return v*pow2(e), true; + } + f1, err := strconv.Atof64(s); + if err != nil { + return 0, false; + } + return f1, true; +} + +// Wrapper around strconv.Atof32. Handles dddddp+ddd (binary exponent) +// itself, passes the rest on to strconv.Atof32. +func myatof32(s string) (f float32, ok bool) { + a := strings.Split(s, "p"); + if len(a) == 2 { + n, err := strconv.Atoi(a[0]); + if err != nil { + println("bad n", a[0]); + return 0, false; + } + e, err1 := strconv.Atoi(a[1]); + if err1 != nil { + println("bad p", a[1]); + return 0, false; + } + return float32(float64(n)*pow2(e)), true; + } + f1, err1 := strconv.Atof32(s); + if err1 != nil { + return 0, false; + } + return f1, true; +} + +func TestFp(t *testing.T) { + f, err := os.Open("testfp.txt", os.O_RDONLY, 0); + if err != nil { + panicln("testfp: open testfp.txt:", err.String()); + } + defer f.Close(); + + b := bufio.NewReader(f); + + lineno := 0; + for { + line, err2 := b.ReadLineString('\n', false); + if err2 == io.ErrEOF { + break; + } + if err2 != nil { + panicln("testfp: read testfp.txt:", err2.String()); + } + lineno++; + if len(line) == 0 || line[0] == '#' { + continue + } + a := strings.Split(line, " "); + if len(a) != 4 { + t.Error("testfp.txt:", lineno, ": wrong field count\n"); + continue; + } + var s string; + var v float64; + switch a[0] { + case "float64": + var ok bool; + v, ok = myatof64(a[2]); + if !ok { + t.Error("testfp.txt:", lineno, ": cannot atof64 ", a[2]); + continue; + } + s = fmt.Sprintf(a[1], v); + case "float32": + v1, ok := myatof32(a[2]); + if !ok { + t.Error("testfp.txt:", lineno, ": cannot atof32 ", a[2]); + continue; + } + s = fmt.Sprintf(a[1], v1); + v = float64(v1); + } + if s != a[3] { + t.Error("testfp.txt:", lineno, ": ", a[0], " ", a[1], " ", a[2], " (", v, ") ", + "want ", a[3], " got ", s); + } +//else print("testfp.txt:", lineno, ": worked! ", s, "\n"); + } +} |