86 lines
1.3 KiB
Go
86 lines
1.3 KiB
Go
//go:build !solution
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package iprange
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import (
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"bytes"
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"errors"
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"log"
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"strconv"
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"unicode/utf8"
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)
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const eof = 0
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type ipLex struct {
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line []byte
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peek rune
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output AddressRangeList
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err error
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}
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func (ip *ipLex) Lex(yylval *ipSymType) int {
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for {
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c := ip.next()
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switch c {
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case eof:
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return eof
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case '0', '1', '2', '3', '4', '5', '6', '7', '8', '9':
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return ip.byte(c, yylval)
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default:
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return int(c)
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}
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}
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}
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func (ip *ipLex) byte(c rune, yylval *ipSymType) int {
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add := func(b *bytes.Buffer, c rune) {
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if _, err := b.WriteRune(c); err != nil {
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log.Fatalf("WriteRune: %s", err)
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}
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}
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var b bytes.Buffer
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add(&b, c)
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L:
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for {
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c = ip.next()
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switch c {
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case '0', '1', '2', '3', '4', '5', '6', '7', '8', '9':
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add(&b, c)
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default:
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break L
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}
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}
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if c != eof {
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ip.peek = c
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}
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octet, err := strconv.ParseUint(b.String(), 10, 32)
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if err != nil {
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log.Printf("badly formatted octet")
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return eof
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}
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yylval.num = byte(octet)
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return num
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}
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func (ip *ipLex) next() rune {
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if ip.peek != eof {
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r := ip.peek
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ip.peek = eof
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return r
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}
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if len(ip.line) == 0 {
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return eof
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}
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c, size := utf8.DecodeRune(ip.line)
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ip.line = ip.line[size:]
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if c == utf8.RuneError && size == 1 {
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log.Print("invalid utf8")
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return ip.next()
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}
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return c
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}
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func (ip *ipLex) Error(s string) {
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ip.err = errors.New(s)
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}
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