func ExampleParseFile() {
tokens, err := lexer.ParseFile("../../testdata/incorrect/lexer/long-char.c")
if err != nil {
log.Fatal(err)
}
for _, tok := range tokens {
fmt.Printf("%-9v %q\n", tok.Kind.GoString(), tok.Val)
}
// Output:
// Ident "int"
// Ident "main"
// Lparen "("
// Ident "void"
// Rparen ")"
// Lbrace "{"
// Ident "char"
// Ident "c"
// Semicolon ";"
// Ident "c"
// Assign "="
// CharLit "'c'"
// Semicolon ";"
// Comment "// OK"
// Ident "c"
// Assign "="
// Error "unterminated character literal"
// Ident "cc"
// Error "unterminated character literal"
// Semicolon ";"
// Comment "// Not OK"
// Rbrace "}"
// EOF ""
}
// Open returns a new scanner lexing from path.
func Open(path string) (Scanner, error) {
toks, err := lexer.ParseFile(path)
if err != nil {
return nil, err
}
return &scanner{toks: toks}, nil
}
// lexFileHand lexes the given file and pretty-prints the n first tokens to
// standard output, using the hand-written lexer.
func lexFileHand(path string, n int) (err error) {
var toks []token.Token
if path == "-" {
fmt.Fprintln(os.Stderr, "Lexing from standard input")
toks, err = lexer.Parse(os.Stdin)
} else {
fmt.Fprintf(os.Stderr, "Lexing %q\n", path)
toks, err = lexer.ParseFile(path)
}
if err != nil {
return errutil.Err(err)
}
ntoks := len(toks)
if n > ntoks {
ntoks = n
}
pad := int(math.Ceil(math.Log10(float64(ntoks))))
for i, tok := range toks {
if n != 0 && i == n {
break
}
if tok.Kind == token.Error {
elog.Printf("ERROR %*d: %v\n", pad, i, tok)
} else {
fmt.Printf("token %*d: %v\n", pad, i, tok)
}
}
fmt.Fprintln(os.Stderr)
return nil
}