Golang Scanner.Filename方法代码示例

func Example() {
	const src = `
	// This is scanned code.
	if a > 10 {
		someParsable = text
	}`
	var s scanner.Scanner
	s.Filename = "example"
	s.Init(strings.NewReader(src))
	var tok rune
	for tok != scanner.EOF {
		tok = s.Scan()
		fmt.Println("At position", s.Pos(), ":", s.TokenText())
	}

	// Output:
	// At position example:3:4 : if
	// At position example:3:6 : a
	// At position example:3:8 : >
	// At position example:3:11 : 10
	// At position example:3:13 : {
	// At position example:4:15 : someParsable
	// At position example:4:17 : =
	// At position example:4:22 : text
	// At position example:5:3 : }
	// At position example:5:3 :
}

func resolveImportsRec(asts []ast, path string, imported []string,
	download bool) ([]ast, error) {
	var newAsts []ast
	top := true // Imports are required to be at the top of the file.

	for _, ast := range asts {
		name := parseImport(ast)
		if name == "" {
			newAsts = append(newAsts, ast)
			top = false
			continue
		}

		if !top {
			return nil, errors.New("import must be begin the module")
		}

		// Check for any import cycles.
		for _, importedModule := range imported {
			if name == importedModule {
				return nil, fmt.Errorf("import cycle: %s",
					append(imported, name))
			}
		}

		modulePath := filepath.Join(path, name+".spec")
		var sc scanner.Scanner
		sc.Filename = modulePath
		if _, err := os.Stat(modulePath); os.IsNotExist(err) && download {
			GetSpec(name)
		}

		f, err := util.Open(modulePath)
		if err != nil {
			return nil, fmt.Errorf("unable to open import %s", name)
		}

		defer f.Close()
		sc.Init(bufio.NewReader(f))
		parsed, err := parse(sc)
		if err != nil {
			return nil, err
		}

		// Rename module name to last name in import path
		name = filepath.Base(name)
		parsed, err = resolveImportsRec(parsed, path, append(imported, name),
			download)
		if err != nil {
			return nil, err
		}

		module := astModule{body: parsed, moduleName: astString(name)}
		newAsts = append(newAsts, module)
	}

	return newAsts, nil
}

func newLexer(stream io.Reader, fn string) *lexer {
	var s scanner.Scanner
	s.Init(stream)
	s.Whitespace = 1<<'\t' | 1<<'\n' | 1<<'\r' | 1<<' '
	s.Filename = fn

	return &lexer{
		scanner: s,
	}
}

func parsePo(r io.Reader, filename string) (*Po, error) {
	comment := false
	s := new(scanner.Scanner)
	var err error
	s.Init(r)
	s.Filename = filename
	s.Error = func(s *scanner.Scanner, msg string) {
		if !comment {
			err = fmt.Errorf("error parsing %s: %s", s.Pos(), msg)
		}
	}
	s.Mode = scanner.ScanIdents | scanner.ScanStrings | scanner.ScanInts
	tok := s.Scan()
	po := &Po{Attrs: make(map[string]string)}
	var trans *Translation
	for tok != scanner.EOF && err == nil {
		if tok == '#' {
			// Skip until EOL
			comment = true
			s.Whitespace = whitespace
			for tok != '\n' && tok != scanner.EOF {
				tok = s.Scan()
			}
			s.Whitespace = scanner.GoWhitespace
			comment = false
			tok = s.Scan()
			continue
		}
		if tok != scanner.Ident {
			err = unexpected(s, tok)
			break
		}
		text := s.TokenText()
		switch text {
		case "msgctxt":
			if trans != nil {
				if len(trans.Translations) == 0 {
					err = unexpected(s, tok)
					break
				}
				po.addTranslation(trans)
			}
			trans = &Translation{Context: readString(s, &tok, &err)}
		case "msgid":
			if trans != nil {
				if len(trans.Translations) > 0 || trans.Singular != "" {
					po.addTranslation(trans)
				} else if trans.Context != "" {
					trans.Singular = readString(s, &tok, &err)
					break
				}
			}
			trans = &Translation{Singular: readString(s, &tok, &err)}
		case "msgid_plural":
			if trans == nil || trans.Plural != "" {
				err = unexpected(s, tok)
				break
			}
			trans.Plural = readString(s, &tok, &err)
		case "msgstr":
			str := readString(s, &tok, &err)
			if tok == '[' {
				tok = s.Scan()
				if tok != scanner.Int {
					err = unexpected(s, tok)
					break
				}
				ii, _ := strconv.Atoi(s.TokenText())
				if ii != len(trans.Translations) {
					err = unexpected(s, tok)
					break
				}
				if tok = s.Scan(); tok != ']' {
					err = unexpected(s, tok)
					break
				}
				str = readString(s, &tok, &err)
			}
			trans.Translations = append(trans.Translations, str)
		default:
			err = unexpected(s, tok)
		}
	}
	if trans != nil {
		po.addTranslation(trans)
	}
	if err != nil {
		return nil, err
	}
	for _, v := range po.Messages {
		if v.Context == "" && v.Singular == "" {
			if len(v.Translations) > 0 {
				meta := v.Translations[0]
				for _, line := range strings.Split(meta, "\n") {
					colon := strings.Index(line, ":")
					if colon > 0 {
						key := strings.TrimSpace(line[:colon])
						value := strings.TrimSpace(line[colon+1:])
						po.Attrs[key] = value
					}
//.........这里部分代码省略.........