mirror of
https://github.com/go-gitea/gitea
synced 2024-12-25 18:14:28 +00:00
138 lines
3.2 KiB
Go
138 lines
3.2 KiB
Go
|
package chroma
|
||
|
|
||
|
import (
|
||
|
"bytes"
|
||
|
)
|
||
|
|
||
|
type delegatingLexer struct {
|
||
|
root Lexer
|
||
|
language Lexer
|
||
|
}
|
||
|
|
||
|
// DelegatingLexer combines two lexers to handle the common case of a language embedded inside another, such as PHP
|
||
|
// inside HTML or PHP inside plain text.
|
||
|
//
|
||
|
// It takes two lexer as arguments: a root lexer and a language lexer. First everything is scanned using the language
|
||
|
// lexer, which must return "Other" for unrecognised tokens. Then all "Other" tokens are lexed using the root lexer.
|
||
|
// Finally, these two sets of tokens are merged.
|
||
|
//
|
||
|
// The lexers from the template lexer package use this base lexer.
|
||
|
func DelegatingLexer(root Lexer, language Lexer) Lexer {
|
||
|
return &delegatingLexer{
|
||
|
root: root,
|
||
|
language: language,
|
||
|
}
|
||
|
}
|
||
|
|
||
|
func (d *delegatingLexer) Config() *Config {
|
||
|
return d.language.Config()
|
||
|
}
|
||
|
|
||
|
// An insertion is the character range where language tokens should be inserted.
|
||
|
type insertion struct {
|
||
|
start, end int
|
||
|
tokens []Token
|
||
|
}
|
||
|
|
||
|
func (d *delegatingLexer) Tokenise(options *TokeniseOptions, text string) (Iterator, error) { // nolint: gocognit
|
||
|
tokens, err := Tokenise(Coalesce(d.language), options, text)
|
||
|
if err != nil {
|
||
|
return nil, err
|
||
|
}
|
||
|
// Compute insertions and gather "Other" tokens.
|
||
|
others := &bytes.Buffer{}
|
||
|
insertions := []*insertion{}
|
||
|
var insert *insertion
|
||
|
offset := 0
|
||
|
var last Token
|
||
|
for _, t := range tokens {
|
||
|
if t.Type == Other {
|
||
|
if last != EOF && insert != nil && last.Type != Other {
|
||
|
insert.end = offset
|
||
|
}
|
||
|
others.WriteString(t.Value)
|
||
|
} else {
|
||
|
if last == EOF || last.Type == Other {
|
||
|
insert = &insertion{start: offset}
|
||
|
insertions = append(insertions, insert)
|
||
|
}
|
||
|
insert.tokens = append(insert.tokens, t)
|
||
|
}
|
||
|
last = t
|
||
|
offset += len(t.Value)
|
||
|
}
|
||
|
|
||
|
if len(insertions) == 0 {
|
||
|
return d.root.Tokenise(options, text)
|
||
|
}
|
||
|
|
||
|
// Lex the other tokens.
|
||
|
rootTokens, err := Tokenise(Coalesce(d.root), options, others.String())
|
||
|
if err != nil {
|
||
|
return nil, err
|
||
|
}
|
||
|
|
||
|
// Interleave the two sets of tokens.
|
||
|
var out []Token
|
||
|
offset = 0 // Offset into text.
|
||
|
tokenIndex := 0
|
||
|
nextToken := func() Token {
|
||
|
if tokenIndex >= len(rootTokens) {
|
||
|
return EOF
|
||
|
}
|
||
|
t := rootTokens[tokenIndex]
|
||
|
tokenIndex++
|
||
|
return t
|
||
|
}
|
||
|
insertionIndex := 0
|
||
|
nextInsertion := func() *insertion {
|
||
|
if insertionIndex >= len(insertions) {
|
||
|
return nil
|
||
|
}
|
||
|
i := insertions[insertionIndex]
|
||
|
insertionIndex++
|
||
|
return i
|
||
|
}
|
||
|
t := nextToken()
|
||
|
i := nextInsertion()
|
||
|
for t != EOF || i != nil {
|
||
|
// fmt.Printf("%d->%d:%q %d->%d:%q\n", offset, offset+len(t.Value), t.Value, i.start, i.end, Stringify(i.tokens...))
|
||
|
if t == EOF || (i != nil && i.start < offset+len(t.Value)) {
|
||
|
var l Token
|
||
|
l, t = splitToken(t, i.start-offset)
|
||
|
if l != EOF {
|
||
|
out = append(out, l)
|
||
|
offset += len(l.Value)
|
||
|
}
|
||
|
out = append(out, i.tokens...)
|
||
|
offset += i.end - i.start
|
||
|
if t == EOF {
|
||
|
t = nextToken()
|
||
|
}
|
||
|
i = nextInsertion()
|
||
|
} else {
|
||
|
out = append(out, t)
|
||
|
offset += len(t.Value)
|
||
|
t = nextToken()
|
||
|
}
|
||
|
}
|
||
|
return Literator(out...), nil
|
||
|
}
|
||
|
|
||
|
func splitToken(t Token, offset int) (l Token, r Token) {
|
||
|
if t == EOF {
|
||
|
return EOF, EOF
|
||
|
}
|
||
|
if offset == 0 {
|
||
|
return EOF, t
|
||
|
}
|
||
|
if offset == len(t.Value) {
|
||
|
return t, EOF
|
||
|
}
|
||
|
l = t.Clone()
|
||
|
r = t.Clone()
|
||
|
l.Value = l.Value[:offset]
|
||
|
r.Value = r.Value[offset:]
|
||
|
return
|
||
|
}
|