101 lines
2.9 KiB
Plaintext
101 lines
2.9 KiB
Plaintext
%{
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// Copyright 2017 The Prometheus Authors
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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package textparse
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import (
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"fmt"
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)
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const (
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sInit = iota
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sComment
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sMeta1
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sMeta2
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sLabels
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sLValue
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sValue
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sTimestamp
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)
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// Lex is called by the parser generated by "go tool yacc" to obtain each
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// token. The method is opened before the matching rules block and closed at
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// the end of the file.
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func (l *promlexer) Lex() token {
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if l.i >= len(l.b) {
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return tEOF
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}
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c := l.b[l.i]
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l.start = l.i
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%}
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D [0-9]
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L [a-zA-Z_]
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M [a-zA-Z_:]
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C [^\n]
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%x sComment sMeta1 sMeta2 sLabels sLValue sValue sTimestamp
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%yyc c
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%yyn c = l.next()
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%yyt l.state
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%%
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\0 return tEOF
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\n l.state = sInit; return tLinebreak
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<*>[ \t]+ return tWhitespace
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#[ \t]+ l.state = sComment
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# return l.consumeComment()
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<sComment>HELP[\t ]+ l.state = sMeta1; return tHelp
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<sComment>TYPE[\t ]+ l.state = sMeta1; return tType
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<sMeta1>{M}({M}|{D})* l.state = sMeta2; return tMName
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<sMeta2>{C}* l.state = sInit; return tText
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{M}({M}|{D})* l.state = sValue; return tMName
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<sValue>\{ l.state = sLabels; return tBraceOpen
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<sLabels>{L}({L}|{D})* return tLName
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<sLabels>\} l.state = sValue; return tBraceClose
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<sLabels>= l.state = sLValue; return tEqual
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<sLabels>, return tComma
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<sLValue>\"(\\.|[^\\"])*\" l.state = sLabels; return tLValue
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<sValue>[^{ \t\n]+ l.state = sTimestamp; return tValue
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<sTimestamp>{D}+ return tTimestamp
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<sTimestamp>\n l.state = sInit; return tLinebreak
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%%
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// Workaround to gobble up comments that started with a HELP or TYPE
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// prefix. We just consume all characters until we reach a newline.
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// This saves us from adding disproportionate complexity to the parser.
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if l.state == sComment {
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return l.consumeComment()
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}
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return tInvalid
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}
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func (l *promlexer) consumeComment() token {
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for c := l.cur(); ; c = l.next() {
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switch c {
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case 0:
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return tEOF
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case '\n':
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l.state = sInit
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return tComment
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}
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}
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}
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