-
Notifications
You must be signed in to change notification settings - Fork 48
/
symbols.go
177 lines (152 loc) · 4.42 KB
/
symbols.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
//Copyright 2013 Vastech SA (PTY) LTD
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// Support for the symbols of the language defined by the input grammar, G. This package supports code generation.
package symbols
import (
"fmt"
"strings"
"github.com/goccmack/gocc/internal/ast"
)
type Symbols struct {
//key: symbol id
//val: symbol type
idMap map[string]int
//key: symbol ntTypeMap index
//val: symbol type
ntIdMap map[string]int
ntTypeMap []string
//key: symbol id
//val: symbol type
stringLitIdMap map[string]int
stringLitList []string
//key: symbol type
//val: symbol id
typeMap []string
}
func NewSymbols(grammar *ast.Grammar) *Symbols {
symbols := &Symbols{
idMap: make(map[string]int),
typeMap: make([]string, 0, 16),
ntIdMap: make(map[string]int),
ntTypeMap: make([]string, 0, 16),
stringLitIdMap: make(map[string]int),
stringLitList: make([]string, 0, 16),
}
symbols.Add("INVALID")
symbols.Add("␚")
if grammar.SyntaxPart == nil {
return symbols
}
for _, p := range grammar.SyntaxPart.ProdList {
if _, exist := symbols.ntIdMap[p.Id]; !exist {
symbols.ntTypeMap = append(symbols.ntTypeMap, p.Id)
symbols.ntIdMap[p.Id] = len(symbols.ntTypeMap) - 1
}
symbols.Add(p.Id)
for _, sym := range p.Body.Symbols {
symStr := sym.SymbolString()
symbols.Add(symStr)
if _, ok := sym.(ast.SyntaxStringLit); ok {
if _, exist := symbols.ntIdMap[symStr]; exist {
panic(fmt.Sprintf("string_lit \"%s\" conflicts with production name %s", symStr, symStr))
}
if _, exist := symbols.stringLitIdMap[symStr]; !exist {
symbols.stringLitIdMap[symStr] = symbols.Type(symStr)
symbols.stringLitList = append(symbols.stringLitList, symStr)
}
}
}
}
return symbols
}
func (this *Symbols) Add(symbols ...string) {
for _, sym := range symbols {
if _, exist := this.idMap[sym]; !exist {
this.typeMap = append(this.typeMap, sym)
this.idMap[sym] = len(this.typeMap) - 1
}
}
}
func (this *Symbols) Id(typ int) string {
return this.typeMap[typ]
}
func (this *Symbols) IsTerminal(sym string) bool {
_, nt := this.ntIdMap[sym]
return !nt
}
func (this *Symbols) List() []string {
return this.typeMap
}
// ListStringLitSymbols will return a slice containing the ids of
// all symbols declared as string literals in the grammar.
func (this *Symbols) ListStringLitSymbols() []string {
return this.stringLitList
}
func (this *Symbols) ListTerminals() []string {
terminals := make([]string, 0, 16)
for _, sym := range this.typeMap {
if this.IsTerminal(sym) {
terminals = append(terminals, sym)
}
}
return terminals
}
func (this *Symbols) StringLitType(id string) int {
if typ, exist := this.stringLitIdMap[id]; exist {
return typ
}
return -1
}
// NTId will return the id of the NT with index idx, or "" if
// there is no NT symbol with index, idx.
func (this *Symbols) NTId(idx int) string {
if idx < 0 || idx >= len(this.ntTypeMap) {
return ""
}
return this.ntTypeMap[idx]
}
// NumNTSymbols will return the number of NT symbols in the grammar.
func (this *Symbols) NumNTSymbols() int {
return len(this.ntTypeMap)
}
// NTList returns a slice containing all the non-terminal symbols of the grammar.
func (this *Symbols) NTList() []string {
return this.ntTypeMap
}
// NTType returns the NT index of a symbol (index in 0..|NT|-1)
// or -1 if the symbol is not in NT.
func (this *Symbols) NTType(symbol string) int {
if idx, exist := this.ntIdMap[symbol]; exist {
return idx
}
return -1
}
// NumSymbols returns the total number of symbols in grammar:
// the sum of the terminals and non-terminals.
func (this *Symbols) NumSymbols() int {
return len(this.typeMap)
}
func (this *Symbols) String() string {
w := new(strings.Builder)
for i, sym := range this.typeMap {
fmt.Fprintf(w, "%3d: %s\n", i, sym)
}
return w.String()
}
func (this *Symbols) Type(id string) int {
if typ, ok := this.idMap[id]; ok {
return typ
}
return -1
}