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comparison vendor/github.com/alecthomas/chroma/v2/emitters.go @ 66:787b5ee0289d draft

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Use vendored modules Signed-off-by: Izuru Yakumo <yakumo.izuru@chaotic.ninja>
author yakumo.izuru
date Sun, 23 Jul 2023 13:18:53 +0000
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65:6d985efa0f7a 66:787b5ee0289d
1 package chroma
2
3 import (
4 "fmt"
5 )
6
7 // An Emitter takes group matches and returns tokens.
8 type Emitter interface {
9 // Emit tokens for the given regex groups.
10 Emit(groups []string, state *LexerState) Iterator
11 }
12
13 // SerialisableEmitter is an Emitter that can be serialised and deserialised to/from JSON.
14 type SerialisableEmitter interface {
15 Emitter
16 EmitterKind() string
17 }
18
19 // EmitterFunc is a function that is an Emitter.
20 type EmitterFunc func(groups []string, state *LexerState) Iterator
21
22 // Emit tokens for groups.
23 func (e EmitterFunc) Emit(groups []string, state *LexerState) Iterator {
24 return e(groups, state)
25 }
26
27 type Emitters []Emitter
28
29 type byGroupsEmitter struct {
30 Emitters
31 }
32
33 // ByGroups emits a token for each matching group in the rule's regex.
34 func ByGroups(emitters ...Emitter) Emitter {
35 return &byGroupsEmitter{Emitters: emitters}
36 }
37
38 func (b *byGroupsEmitter) EmitterKind() string { return "bygroups" }
39
40 func (b *byGroupsEmitter) Emit(groups []string, state *LexerState) Iterator {
41 iterators := make([]Iterator, 0, len(groups)-1)
42 if len(b.Emitters) != len(groups)-1 {
43 iterators = append(iterators, Error.Emit(groups, state))
44 // panic(errors.Errorf("number of groups %q does not match number of emitters %v", groups, emitters))
45 } else {
46 for i, group := range groups[1:] {
47 if b.Emitters[i] != nil {
48 iterators = append(iterators, b.Emitters[i].Emit([]string{group}, state))
49 }
50 }
51 }
52 return Concaterator(iterators...)
53 }
54
55 // ByGroupNames emits a token for each named matching group in the rule's regex.
56 func ByGroupNames(emitters map[string]Emitter) Emitter {
57 return EmitterFunc(func(groups []string, state *LexerState) Iterator {
58 iterators := make([]Iterator, 0, len(state.NamedGroups)-1)
59 if len(state.NamedGroups)-1 == 0 {
60 if emitter, ok := emitters[`0`]; ok {
61 iterators = append(iterators, emitter.Emit(groups, state))
62 } else {
63 iterators = append(iterators, Error.Emit(groups, state))
64 }
65 } else {
66 ruleRegex := state.Rules[state.State][state.Rule].Regexp
67 for i := 1; i < len(state.NamedGroups); i++ {
68 groupName := ruleRegex.GroupNameFromNumber(i)
69 group := state.NamedGroups[groupName]
70 if emitter, ok := emitters[groupName]; ok {
71 if emitter != nil {
72 iterators = append(iterators, emitter.Emit([]string{group}, state))
73 }
74 } else {
75 iterators = append(iterators, Error.Emit([]string{group}, state))
76 }
77 }
78 }
79 return Concaterator(iterators...)
80 })
81 }
82
83 // UsingByGroup emits tokens for the matched groups in the regex using a
84 // "sublexer". Used when lexing code blocks where the name of a sublexer is
85 // contained within the block, for example on a Markdown text block or SQL
86 // language block.
87 //
88 // The sublexer will be retrieved using sublexerGetFunc (typically
89 // internal.Get), using the captured value from the matched sublexerNameGroup.
90 //
91 // If sublexerGetFunc returns a non-nil lexer for the captured sublexerNameGroup,
92 // then tokens for the matched codeGroup will be emitted using the retrieved
93 // lexer. Otherwise, if the sublexer is nil, then tokens will be emitted from
94 // the passed emitter.
95 //
96 // Example:
97 //
98 // var Markdown = internal.Register(MustNewLexer(
99 // &Config{
100 // Name: "markdown",
101 // Aliases: []string{"md", "mkd"},
102 // Filenames: []string{"*.md", "*.mkd", "*.markdown"},
103 // MimeTypes: []string{"text/x-markdown"},
104 // },
105 // Rules{
106 // "root": {
107 // {"^(```)(\\w+)(\\n)([\\w\\W]*?)(^```$)",
108 // UsingByGroup(
109 // internal.Get,
110 // 2, 4,
111 // String, String, String, Text, String,
112 // ),
113 // nil,
114 // },
115 // },
116 // },
117 // ))
118 //
119 // See the lexers/m/markdown.go for the complete example.
120 //
121 // Note: panic's if the number of emitters does not equal the number of matched
122 // groups in the regex.
123 func UsingByGroup(sublexerNameGroup, codeGroup int, emitters ...Emitter) Emitter {
124 return &usingByGroup{
125 SublexerNameGroup: sublexerNameGroup,
126 CodeGroup: codeGroup,
127 Emitters: emitters,
128 }
129 }
130
131 type usingByGroup struct {
132 SublexerNameGroup int `xml:"sublexer_name_group"`
133 CodeGroup int `xml:"code_group"`
134 Emitters Emitters `xml:"emitters"`
135 }
136
137 func (u *usingByGroup) EmitterKind() string { return "usingbygroup" }
138 func (u *usingByGroup) Emit(groups []string, state *LexerState) Iterator {
139 // bounds check
140 if len(u.Emitters) != len(groups)-1 {
141 panic("UsingByGroup expects number of emitters to be the same as len(groups)-1")
142 }
143
144 // grab sublexer
145 sublexer := state.Registry.Get(groups[u.SublexerNameGroup])
146
147 // build iterators
148 iterators := make([]Iterator, len(groups)-1)
149 for i, group := range groups[1:] {
150 if i == u.CodeGroup-1 && sublexer != nil {
151 var err error
152 iterators[i], err = sublexer.Tokenise(nil, groups[u.CodeGroup])
153 if err != nil {
154 panic(err)
155 }
156 } else if u.Emitters[i] != nil {
157 iterators[i] = u.Emitters[i].Emit([]string{group}, state)
158 }
159 }
160 return Concaterator(iterators...)
161 }
162
163 // UsingLexer returns an Emitter that uses a given Lexer for parsing and emitting.
164 //
165 // This Emitter is not serialisable.
166 func UsingLexer(lexer Lexer) Emitter {
167 return EmitterFunc(func(groups []string, _ *LexerState) Iterator {
168 it, err := lexer.Tokenise(&TokeniseOptions{State: "root", Nested: true}, groups[0])
169 if err != nil {
170 panic(err)
171 }
172 return it
173 })
174 }
175
176 type usingEmitter struct {
177 Lexer string `xml:"lexer,attr"`
178 }
179
180 func (u *usingEmitter) EmitterKind() string { return "using" }
181
182 func (u *usingEmitter) Emit(groups []string, state *LexerState) Iterator {
183 if state.Registry == nil {
184 panic(fmt.Sprintf("no LexerRegistry available for Using(%q)", u.Lexer))
185 }
186 lexer := state.Registry.Get(u.Lexer)
187 if lexer == nil {
188 panic(fmt.Sprintf("no such lexer %q", u.Lexer))
189 }
190 it, err := lexer.Tokenise(&TokeniseOptions{State: "root", Nested: true}, groups[0])
191 if err != nil {
192 panic(err)
193 }
194 return it
195 }
196
197 // Using returns an Emitter that uses a given Lexer reference for parsing and emitting.
198 //
199 // The referenced lexer must be stored in the same LexerRegistry.
200 func Using(lexer string) Emitter {
201 return &usingEmitter{Lexer: lexer}
202 }
203
204 type usingSelfEmitter struct {
205 State string `xml:"state,attr"`
206 }
207
208 func (u *usingSelfEmitter) EmitterKind() string { return "usingself" }
209
210 func (u *usingSelfEmitter) Emit(groups []string, state *LexerState) Iterator {
211 it, err := state.Lexer.Tokenise(&TokeniseOptions{State: u.State, Nested: true}, groups[0])
212 if err != nil {
213 panic(err)
214 }
215 return it
216 }
217
218 // UsingSelf is like Using, but uses the current Lexer.
219 func UsingSelf(stateName string) Emitter {
220 return &usingSelfEmitter{stateName}
221 }