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lexer.go
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lexer.go
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// Code generated by gocc; DO NOT EDIT.
package lexer
import (
"os"
"unicode/utf8"
"github.com/Desuuuu/gocc/internal/test/t1/token"
)
const (
NoState = -1
NumStates = 4
NumSymbols = 4
)
type Lexer struct {
src []byte
pos int
line int
column int
Context token.Context
}
func NewLexer(src []byte) *Lexer {
lexer := &Lexer{
src: src,
pos: 0,
line: 1,
column: 1,
Context: nil,
}
return lexer
}
// SourceContext is a simple instance of a token.Context which
// contains the name of the source file.
type SourceContext struct {
Filepath string
}
func (s *SourceContext) Source() string {
return s.Filepath
}
func NewLexerFile(fpath string) (*Lexer, error) {
src, err := os.ReadFile(fpath)
if err != nil {
return nil, err
}
lexer := NewLexer(src)
lexer.Context = &SourceContext{Filepath: fpath}
return lexer, nil
}
func (l *Lexer) Scan() (tok *token.Token) {
tok = &token.Token{}
if l.pos >= len(l.src) {
tok.Type = token.EOF
tok.Pos.Offset, tok.Pos.Line, tok.Pos.Column = l.pos, l.line, l.column
tok.Pos.Context = l.Context
return
}
start, startLine, startColumn, end := l.pos, l.line, l.column, 0
tok.Type = token.INVALID
state, rune1, size := 0, rune(-1), 0
for state != -1 {
if l.pos >= len(l.src) {
rune1 = -1
} else {
rune1, size = utf8.DecodeRune(l.src[l.pos:])
l.pos += size
}
nextState := -1
if rune1 != -1 {
nextState = TransTab[state](rune1)
}
state = nextState
if state != -1 {
switch rune1 {
case '\n':
l.line++
l.column = 1
case '\r':
l.column = 1
case '\t':
l.column += 4
default:
l.column++
}
switch {
case ActTab[state].Accept != -1:
tok.Type = ActTab[state].Accept
end = l.pos
case ActTab[state].Ignore != "":
start, startLine, startColumn = l.pos, l.line, l.column
state = 0
if start >= len(l.src) {
tok.Type = token.EOF
}
}
} else {
if tok.Type == token.INVALID {
end = l.pos
}
}
}
if end > start {
l.pos = end
tok.Lit = l.src[start:end]
} else {
tok.Lit = []byte{}
}
tok.Pos.Offset, tok.Pos.Line, tok.Pos.Column = start, startLine, startColumn
tok.Pos.Context = l.Context
return
}
func (l *Lexer) Reset() {
l.pos = 0
}
/*
Lexer symbols:
0: 'c'
1: 'b'
2: ' '
3: .
*/