1//  Copyright (c) 2014 Couchbase, Inc.
2//
3// Licensed under the Apache License, Version 2.0 (the "License");
4// you may not use this file except in compliance with the License.
5// You may obtain a copy of the License at
6//
7// 		http://www.apache.org/licenses/LICENSE-2.0
8//
9// Unless required by applicable law or agreed to in writing, software
10// distributed under the License is distributed on an "AS IS" BASIS,
11// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12// See the License for the specific language governing permissions and
13// limitations under the License.
14
15// as of Go 1.8 this requires the goyacc external tool
16// available from golang.org/x/tools/cmd/goyacc
17
18//go:generate goyacc -o query_string.y.go query_string.y
19//go:generate sed -i.tmp -e 1d query_string.y.go
20//go:generate rm query_string.y.go.tmp
21
22// note: OSX sed and gnu sed handle the -i (in-place) option differently.
23// using -i.tmp works on both, at the expense of having to remove
24// the unsightly .tmp files
25
26package query
27
28import (
29	"fmt"
30	"strings"
31)
32
33var debugParser bool
34var debugLexer bool
35
36func parseQuerySyntax(query string) (rq Query, err error) {
37	if query == "" {
38		return NewMatchNoneQuery(), nil
39	}
40	lex := newLexerWrapper(newQueryStringLex(strings.NewReader(query)))
41	doParse(lex)
42
43	if len(lex.errs) > 0 {
44		return nil, fmt.Errorf(strings.Join(lex.errs, "\n"))
45	}
46	return lex.query, nil
47}
48
49func doParse(lex *lexerWrapper) {
50	defer func() {
51		r := recover()
52		if r != nil {
53			lex.errs = append(lex.errs, fmt.Sprintf("parse error: %v", r))
54		}
55	}()
56
57	yyParse(lex)
58}
59
60const (
61	queryShould = iota
62	queryMust
63	queryMustNot
64)
65
66type lexerWrapper struct {
67	lex   yyLexer
68	errs  []string
69	query *BooleanQuery
70}
71
72func newLexerWrapper(lex yyLexer) *lexerWrapper {
73	return &lexerWrapper{
74		lex:   lex,
75		query: NewBooleanQueryForQueryString(nil, nil, nil),
76	}
77}
78
79func (l *lexerWrapper) Lex(lval *yySymType) int {
80	return l.lex.Lex(lval)
81}
82
83func (l *lexerWrapper) Error(s string) {
84	l.errs = append(l.errs, s)
85}
86