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
|
//go:generate maleeni compile -l lexspec.json -o clexspec.json
package spec
import (
_ "embed"
"encoding/json"
"fmt"
"io"
"strings"
mldriver "github.com/nihei9/maleeni/driver"
mlspec "github.com/nihei9/maleeni/spec"
)
type tokenKind string
const (
tokenKindKWFragment = tokenKind("fragment")
tokenKindID = tokenKind("id")
tokenKindTerminalPattern = tokenKind("terminal pattern")
tokenKindColon = tokenKind(":")
tokenKindOr = tokenKind("|")
tokenKindSemicolon = tokenKind(";")
tokenKindModifierMarker = tokenKind("@")
tokenKindActionLeader = tokenKind("#")
tokenKindEOF = tokenKind("eof")
tokenKindInvalid = tokenKind("invalid")
)
type token struct {
kind tokenKind
text string
}
func newSymbolToken(kind tokenKind) *token {
return &token{
kind: kind,
}
}
func newIDToken(text string) *token {
return &token{
kind: tokenKindID,
text: text,
}
}
func newTerminalPatternToken(text string) *token {
return &token{
kind: tokenKindTerminalPattern,
text: text,
}
}
func newEOFToken() *token {
return &token{
kind: tokenKindEOF,
}
}
func newInvalidToken(text string) *token {
return &token{
kind: tokenKindInvalid,
text: text,
}
}
type lexer struct {
s *mlspec.CompiledLexSpec
d *mldriver.Lexer
dufTok *token
}
//go:embed clexspec.json
var lexspec []byte
func newLexer(src io.Reader) (*lexer, error) {
s := &mlspec.CompiledLexSpec{}
err := json.Unmarshal(lexspec, s)
if err != nil {
return nil, err
}
d, err := mldriver.NewLexer(s, src)
if err != nil {
return nil, err
}
return &lexer{
s: s,
d: d,
}, nil
}
func (l *lexer) next() (*token, error) {
for {
tok, err := l.d.Next()
if err != nil {
return nil, err
}
if tok.Invalid {
newInvalidToken(tok.Text())
}
if tok.EOF {
return newEOFToken(), nil
}
switch tok.KindName {
case "white_space":
continue
case "newline":
continue
case "line_comment":
continue
case "kw_fragment":
return newSymbolToken(tokenKindKWFragment), nil
case "identifier":
return newIDToken(tok.Text()), nil
case "terminal_open":
var b strings.Builder
for {
tok, err := l.d.Next()
if err != nil {
return nil, err
}
if tok.EOF {
return nil, synErrUnclosedTerminal
}
switch tok.KindName {
case "pattern":
// Remove '\' character.
fmt.Fprintf(&b, strings.ReplaceAll(tok.Text(), `\"`, `"`))
case "escape_symbol":
return nil, synErrIncompletedEscSeq
case "terminal_close":
return newTerminalPatternToken(b.String()), nil
}
}
case "colon":
return newSymbolToken(tokenKindColon), nil
case "or":
return newSymbolToken(tokenKindOr), nil
case "semicolon":
return newSymbolToken(tokenKindSemicolon), nil
case "modifier_marker":
return newSymbolToken(tokenKindModifierMarker), nil
case "action_leader":
return newSymbolToken(tokenKindActionLeader), nil
default:
return newInvalidToken(tok.Text()), nil
}
}
}
|
