diff options
author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-28 13:14:23 +0000 |
---|---|---|
committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-28 13:14:23 +0000 |
commit | 73df946d56c74384511a194dd01dbe099584fd1a (patch) | |
tree | fd0bcea490dd81327ddfbb31e215439672c9a068 /src/strconv/makeisprint.go | |
parent | Initial commit. (diff) | |
download | golang-1.16-73df946d56c74384511a194dd01dbe099584fd1a.tar.xz golang-1.16-73df946d56c74384511a194dd01dbe099584fd1a.zip |
Adding upstream version 1.16.10.upstream/1.16.10upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/strconv/makeisprint.go')
-rw-r--r-- | src/strconv/makeisprint.go | 203 |
1 files changed, 203 insertions, 0 deletions
diff --git a/src/strconv/makeisprint.go b/src/strconv/makeisprint.go new file mode 100644 index 0000000..0e6e90a --- /dev/null +++ b/src/strconv/makeisprint.go @@ -0,0 +1,203 @@ +// 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. + +// +build ignore + +// +// usage: +// +// go run makeisprint.go -output isprint.go +// + +package main + +import ( + "bytes" + "flag" + "fmt" + "go/format" + "log" + "os" + "unicode" +) + +var filename = flag.String("output", "isprint.go", "output file name") + +var ( + range16 []uint16 + except16 []uint16 + range32 []uint32 + except32 []uint32 +) + +// bsearch16 returns the smallest i such that a[i] >= x. +// If there is no such i, bsearch16 returns len(a). +func bsearch16(a []uint16, x uint16) int { + i, j := 0, len(a) + for i < j { + h := i + (j-i)/2 + if a[h] < x { + i = h + 1 + } else { + j = h + } + } + return i +} + +// bsearch32 returns the smallest i such that a[i] >= x. +// If there is no such i, bsearch32 returns len(a). +func bsearch32(a []uint32, x uint32) int { + i, j := 0, len(a) + for i < j { + h := i + (j-i)/2 + if a[h] < x { + i = h + 1 + } else { + j = h + } + } + return i +} + +func isPrint(r rune) bool { + // Same algorithm, either on uint16 or uint32 value. + // First, find first i such that rang[i] >= x. + // This is the index of either the start or end of a pair that might span x. + // The start is even (rang[i&^1]) and the end is odd (rang[i|1]). + // If we find x in a range, make sure x is not in exception list. + + if 0 <= r && r < 1<<16 { + rr, rang, except := uint16(r), range16, except16 + i := bsearch16(rang, rr) + if i >= len(rang) || rr < rang[i&^1] || rang[i|1] < rr { + return false + } + j := bsearch16(except, rr) + return j >= len(except) || except[j] != rr + } + + rr, rang, except := uint32(r), range32, except32 + i := bsearch32(rang, rr) + if i >= len(rang) || rr < rang[i&^1] || rang[i|1] < rr { + return false + } + j := bsearch32(except, rr) + return j >= len(except) || except[j] != rr +} + +func scan(min, max rune) (rang, except []uint32) { + lo := rune(-1) + for i := min; ; i++ { + if (i > max || !unicode.IsPrint(i)) && lo >= 0 { + // End range, but avoid flip flop. + if i+1 <= max && unicode.IsPrint(i+1) { + except = append(except, uint32(i)) + continue + } + rang = append(rang, uint32(lo), uint32(i-1)) + lo = -1 + } + if i > max { + break + } + if lo < 0 && unicode.IsPrint(i) { + lo = i + } + } + return +} + +func to16(x []uint32) []uint16 { + var y []uint16 + for _, v := range x { + if uint32(uint16(v)) != v { + panic("bad 32->16 conversion") + } + y = append(y, uint16(v)) + } + return y +} + +func main() { + flag.Parse() + + rang, except := scan(0, 0xFFFF) + range16 = to16(rang) + except16 = to16(except) + range32, except32 = scan(0x10000, unicode.MaxRune) + + for i := rune(0); i <= unicode.MaxRune; i++ { + if isPrint(i) != unicode.IsPrint(i) { + log.Fatalf("%U: isPrint=%v, want %v\n", i, isPrint(i), unicode.IsPrint(i)) + } + } + + var buf bytes.Buffer + + fmt.Fprintf(&buf, `// Copyright 2013 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.`+"\n\n") + fmt.Fprintf(&buf, "// Code generated by go run makeisprint.go -output isprint.go; DO NOT EDIT.\n\n") + fmt.Fprintf(&buf, "package strconv\n\n") + + fmt.Fprintf(&buf, "// (%d+%d+%d)*2 + (%d)*4 = %d bytes\n\n", + len(range16), len(except16), len(except32), + len(range32), + (len(range16)+len(except16)+len(except32))*2+ + (len(range32))*4) + + fmt.Fprintf(&buf, "var isPrint16 = []uint16{\n") + for i := 0; i < len(range16); i += 2 { + fmt.Fprintf(&buf, "\t%#04x, %#04x,\n", range16[i], range16[i+1]) + } + fmt.Fprintf(&buf, "}\n\n") + + fmt.Fprintf(&buf, "var isNotPrint16 = []uint16{\n") + for _, r := range except16 { + fmt.Fprintf(&buf, "\t%#04x,\n", r) + } + fmt.Fprintf(&buf, "}\n\n") + + fmt.Fprintf(&buf, "var isPrint32 = []uint32{\n") + for i := 0; i < len(range32); i += 2 { + fmt.Fprintf(&buf, "\t%#06x, %#06x,\n", range32[i], range32[i+1]) + } + fmt.Fprintf(&buf, "}\n\n") + + fmt.Fprintf(&buf, "var isNotPrint32 = []uint16{ // add 0x10000 to each entry\n") + for _, r := range except32 { + if r >= 0x20000 { + log.Fatalf("%U too big for isNotPrint32\n", r) + } + fmt.Fprintf(&buf, "\t%#04x,\n", r-0x10000) + } + fmt.Fprintf(&buf, "}\n\n") + + // The list of graphic but not "printable" runes is short. Just make one easy table. + fmt.Fprintf(&buf, "// isGraphic lists the graphic runes not matched by IsPrint.\n") + fmt.Fprintf(&buf, "var isGraphic = []uint16{\n") + for r := rune(0); r <= unicode.MaxRune; r++ { + if unicode.IsPrint(r) != unicode.IsGraphic(r) { + // Sanity check. + if !unicode.IsGraphic(r) { + log.Fatalf("%U is printable but not graphic\n", r) + } + if r > 0xFFFF { // We expect only 16-bit values. + log.Fatalf("%U too big for isGraphic\n", r) + } + fmt.Fprintf(&buf, "\t%#04x,\n", r) + } + } + fmt.Fprintf(&buf, "}\n") + + data, err := format.Source(buf.Bytes()) + if err != nil { + log.Fatal(err) + } + err = os.WriteFile(*filename, data, 0644) + if err != nil { + log.Fatal(err) + } +} |