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// 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.
// +build ignore
package main
// This program generates tables.go:
// go run maketables.go | gofmt > tables.go
import (
"bufio"
"fmt"
"log"
"net/http"
"sort"
"strings"
)
func main() {
fmt.Printf("// generated by go run maketables.go; DO NOT EDIT\n\n")
fmt.Printf("// Package korean provides Korean encodings such as EUC-KR.\n")
fmt.Printf(`package korean // import "golang.org/x/text/encoding/korean"` + "\n\n")
res, err := http.Get("http://encoding.spec.whatwg.org/index-euc-kr.txt")
if err != nil {
log.Fatalf("Get: %v", err)
}
defer res.Body.Close()
mapping := [65536]uint16{}
reverse := [65536]uint16{}
scanner := bufio.NewScanner(res.Body)
for scanner.Scan() {
s := strings.TrimSpace(scanner.Text())
if s == "" || s[0] == '#' {
continue
}
x, y := uint16(0), uint16(0)
if _, err := fmt.Sscanf(s, "%d 0x%x", &x, &y); err != nil {
log.Fatalf("could not parse %q", s)
}
if x < 0 || 178*(0xc7-0x81)+(0xfe-0xc7)*94+(0xff-0xa1) <= x {
log.Fatalf("EUC-KR code %d is out of range", x)
}
mapping[x] = y
if reverse[y] == 0 {
c0, c1 := uint16(0), uint16(0)
if x < 178*(0xc7-0x81) {
c0 = uint16(x/178) + 0x81
c1 = uint16(x % 178)
switch {
case c1 < 1*26:
c1 += 0x41
case c1 < 2*26:
c1 += 0x47
default:
c1 += 0x4d
}
} else {
x -= 178 * (0xc7 - 0x81)
c0 = uint16(x/94) + 0xc7
c1 = uint16(x%94) + 0xa1
}
reverse[y] = c0<<8 | c1
}
}
if err := scanner.Err(); err != nil {
log.Fatalf("scanner error: %v", err)
}
fmt.Printf("// decode is the decoding table from EUC-KR code to Unicode.\n")
fmt.Printf("// It is defined at http://encoding.spec.whatwg.org/index-euc-kr.txt\n")
fmt.Printf("var decode = [...]uint16{\n")
for i, v := range mapping {
if v != 0 {
fmt.Printf("\t%d: 0x%04X,\n", i, v)
}
}
fmt.Printf("}\n\n")
// Any run of at least separation continuous zero entries in the reverse map will
// be a separate encode table.
const separation = 1024
intervals := []interval(nil)
low, high := -1, -1
for i, v := range reverse {
if v == 0 {
continue
}
if low < 0 {
low = i
} else if i-high >= separation {
if high >= 0 {
intervals = append(intervals, interval{low, high})
}
low = i
}
high = i + 1
}
if high >= 0 {
intervals = append(intervals, interval{low, high})
}
sort.Sort(byDecreasingLength(intervals))
fmt.Printf("const numEncodeTables = %d\n\n", len(intervals))
fmt.Printf("// encodeX are the encoding tables from Unicode to EUC-KR code,\n")
fmt.Printf("// sorted by decreasing length.\n")
for i, v := range intervals {
fmt.Printf("// encode%d: %5d entries for runes in [%5d, %5d).\n", i, v.len(), v.low, v.high)
}
fmt.Printf("\n")
for i, v := range intervals {
fmt.Printf("const encode%dLow, encode%dHigh = %d, %d\n\n", i, i, v.low, v.high)
fmt.Printf("var encode%d = [...]uint16{\n", i)
for j := v.low; j < v.high; j++ {
x := reverse[j]
if x == 0 {
continue
}
fmt.Printf("\t%d-%d: 0x%04X,\n", j, v.low, x)
}
fmt.Printf("}\n\n")
}
}
// interval is a half-open interval [low, high).
type interval struct {
low, high int
}
func (i interval) len() int { return i.high - i.low }
// byDecreasingLength sorts intervals by decreasing length.
type byDecreasingLength []interval
func (b byDecreasingLength) Len() int { return len(b) }
func (b byDecreasingLength) Less(i, j int) bool { return b[i].len() > b[j].len() }
func (b byDecreasingLength) Swap(i, j int) { b[i], b[j] = b[j], b[i] }