1
0
mirror of https://github.com/go-gitea/gitea.git synced 2024-12-04 14:46:57 -05:00
gitea/vendor/golang.org/x/text/width/gen.go
Antoine GIRARD 9fe4437bda Use vendored go-swagger (#8087)
* Use vendored go-swagger

* vendor go-swagger

* revert un wanteed change

* remove un-needed GO111MODULE

* Update Makefile

Co-Authored-By: techknowlogick <matti@mdranta.net>
2019-09-04 22:53:54 +03:00

116 lines
3.1 KiB
Go
Raw Blame History

This file contains ambiguous Unicode characters

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

// Copyright 2015 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
// This program generates the trie for width operations. The generated table
// includes width category information as well as the normalization mappings.
package main
import (
"bytes"
"fmt"
"io"
"log"
"math"
"unicode/utf8"
"golang.org/x/text/internal/gen"
"golang.org/x/text/internal/triegen"
)
// See gen_common.go for flags.
func main() {
gen.Init()
genTables()
genTests()
gen.Repackage("gen_trieval.go", "trieval.go", "width")
gen.Repackage("gen_common.go", "common_test.go", "width")
}
func genTables() {
t := triegen.NewTrie("width")
// fold and inverse mappings. See mapComment for a description of the format
// of each entry. Add dummy value to make an index of 0 mean no mapping.
inverse := [][4]byte{{}}
mapping := map[[4]byte]int{[4]byte{}: 0}
getWidthData(func(r rune, tag elem, alt rune) {
idx := 0
if alt != 0 {
var buf [4]byte
buf[0] = byte(utf8.EncodeRune(buf[1:], alt))
s := string(r)
buf[buf[0]] ^= s[len(s)-1]
var ok bool
if idx, ok = mapping[buf]; !ok {
idx = len(mapping)
if idx > math.MaxUint8 {
log.Fatalf("Index %d does not fit in a byte.", idx)
}
mapping[buf] = idx
inverse = append(inverse, buf)
}
}
t.Insert(r, uint64(tag|elem(idx)))
})
w := &bytes.Buffer{}
gen.WriteUnicodeVersion(w)
sz, err := t.Gen(w)
if err != nil {
log.Fatal(err)
}
sz += writeMappings(w, inverse)
fmt.Fprintf(w, "// Total table size %d bytes (%dKiB)\n", sz, sz/1024)
gen.WriteVersionedGoFile(*outputFile, "width", w.Bytes())
}
const inverseDataComment = `
// inverseData contains 4-byte entries of the following format:
// <length> <modified UTF-8-encoded rune> <0 padding>
// The last byte of the UTF-8-encoded rune is xor-ed with the last byte of the
// UTF-8 encoding of the original rune. Mappings often have the following
// pattern:
// -> A (U+FF21 -> U+0041)
// -> B (U+FF22 -> U+0042)
// ...
// By xor-ing the last byte the same entry can be shared by many mappings. This
// reduces the total number of distinct entries by about two thirds.
// The resulting entry for the aforementioned mappings is
// { 0x01, 0xE0, 0x00, 0x00 }
// Using this entry to map U+FF21 (UTF-8 [EF BC A1]), we get
// E0 ^ A1 = 41.
// Similarly, for U+FF22 (UTF-8 [EF BC A2]), we get
// E0 ^ A2 = 42.
// Note that because of the xor-ing, the byte sequence stored in the entry is
// not valid UTF-8.`
func writeMappings(w io.Writer, data [][4]byte) int {
fmt.Fprintln(w, inverseDataComment)
fmt.Fprintf(w, "var inverseData = [%d][4]byte{\n", len(data))
for _, x := range data {
fmt.Fprintf(w, "{ 0x%02x, 0x%02x, 0x%02x, 0x%02x },\n", x[0], x[1], x[2], x[3])
}
fmt.Fprintln(w, "}")
return len(data) * 4
}
func genTests() {
w := &bytes.Buffer{}
fmt.Fprintf(w, "\nvar mapRunes = map[rune]struct{r rune; e elem}{\n")
getWidthData(func(r rune, tag elem, alt rune) {
if alt != 0 {
fmt.Fprintf(w, "\t0x%X: {0x%X, 0x%X},\n", r, alt, tag)
}
})
fmt.Fprintln(w, "}")
gen.WriteGoFile("runes_test.go", "width", w.Bytes())
}