func mainLex(args []string) {
fset := flag.NewFlagSet("asm8-lex", flag.ExitOnError)
fset.Parse(args)
files := fset.Args()
if len(files) != 1 {
fmt.Fprintln(os.Stderr, "expects one single input file.")
os.Exit(1)
}
onError := func(e error) { fmt.Fprintln(os.Stderr, e) }
f := files[0]
fin, e := os.Open(f)
if e != nil {
onError(e)
os.Exit(1)
}
lex := lexer.New(fin, f)
lex.OnError(onError)
for lex.Scan() {
tok := lex.Token()
fmt.Println(tok.String())
}
e = fin.Close()
if e != nil {
onError(e)
}
}
// New creates a new parser that parses a file into an AST.
func New(in io.Reader, filename string) *Parser {
ret := new(Parser)
ret.filename = filename
ret.lx = lexer.New(in, filename)
ret.s = lexin.NewScanner(ret.lx, func(t *tok.Token) bool {
return t.Is(tt.Comment)
})
return ret
}