/
lexer.go
57 lines (51 loc) · 1.26 KB
/
lexer.go
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/*
* This file is part of drones.
*
* drones is free software: you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* drones is distributed in the hope that it will be useful,
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with drones. If not, see <http://www.gnu.org/licenses/>.
*/
package asm
import (
"bufio"
"fmt"
)
type lexer struct {
src *bufio.Reader
buf []byte
current byte
empty bool
line int
}
func newLexer(in *bufio.Reader) *lexer {
l := &lexer{src: in, line: 1}
if b, err := in.ReadByte(); err == nil {
l.current = b
}
return l
}
func (l *lexer) getc() byte {
if l.current != 0 {
l.buf = append(l.buf, l.current)
if l.current == '\n' {
l.line++
}
}
l.current = 0
if b, err := l.src.ReadByte(); err == nil {
l.current = b
}
return l.current
}
func (l *lexer) Error(e string) {
errorCodes = append(errorCodes, fmt.Sprintf("Line %d: %s", l.line, e))
}