109 lines
2.3 KiB
Go
109 lines
2.3 KiB
Go
// Copyright 2023 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 parse
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import (
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"errors"
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"fmt"
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"strconv"
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"unicode/utf8"
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)
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type tokenKind int
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const (
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tokenEOF tokenKind = iota
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tokenOpenBrace
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tokenCloseBrace
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tokenComma
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tokenEquals
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tokenNotEquals
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tokenMatches
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tokenNotMatches
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tokenQuoted
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tokenUnquoted
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)
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func (k tokenKind) String() string {
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switch k {
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case tokenOpenBrace:
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return "OpenBrace"
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case tokenCloseBrace:
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return "CloseBrace"
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case tokenComma:
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return "Comma"
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case tokenEquals:
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return "Equals"
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case tokenNotEquals:
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return "NotEquals"
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case tokenMatches:
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return "Matches"
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case tokenNotMatches:
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return "NotMatches"
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case tokenQuoted:
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return "Quoted"
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case tokenUnquoted:
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return "Unquoted"
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default:
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return "EOF"
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}
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}
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type token struct {
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kind tokenKind
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value string
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position
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}
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// isEOF returns true if the token is an end of file token.
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func (t token) isEOF() bool {
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return t.kind == tokenEOF
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}
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// isOneOf returns true if the token is one of the specified kinds.
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func (t token) isOneOf(kinds ...tokenKind) bool {
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for _, k := range kinds {
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if k == t.kind {
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return true
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}
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}
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return false
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}
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// unquote the value in token. If unquoted returns it unmodified.
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func (t token) unquote() (string, error) {
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if t.kind == tokenQuoted {
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unquoted, err := strconv.Unquote(t.value)
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if err != nil {
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return "", err
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}
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if !utf8.ValidString(unquoted) {
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return "", errors.New("quoted string contains invalid UTF-8 code points")
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}
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return unquoted, nil
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}
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return t.value, nil
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}
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func (t token) String() string {
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return fmt.Sprintf("(%s) '%s'", t.kind, t.value)
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}
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type position struct {
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offsetStart int // The start position in the input.
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offsetEnd int // The end position in the input.
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columnStart int // The column number.
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columnEnd int // The end of the column.
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}
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