blob: 0e6e90a6c66e0b80dc9ad09050fe1aaea50aa0e8 [file] [log] [blame]
 // 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) } }