Golang Scanner.Init方法代碼示例

func format(str, dbname string, tm time.Time) string {
	buf := bytes.Buffer{}

	var s scanner.Scanner
	s.Init(strings.NewReader(str))
	s.Mode = 0
	s.Whitespace = 0
	for tok := s.Scan(); tok != scanner.EOF; tok = s.Scan() {
		if tok != '%' {
			buf.WriteRune(tok)
			continue
		}

		switch s := s.Scan(); s {
		case '%':
			buf.WriteRune('%')
		case 'n':
			buf.WriteString(dbname)
		case 'Y', 'y':
			buf.WriteString(strconv.Itoa(tm.Year()))
		case 'm':
			buf.WriteString(strconv.Itoa(int(tm.Month())))
		case 'd':
			buf.WriteString(strconv.Itoa(tm.Day()))
		case 'H':
			buf.WriteString(twodig(strconv.Itoa(tm.Hour())))
		case 'M':
			buf.WriteString(twodig(strconv.Itoa(tm.Minute())))
		case 'S':
			buf.WriteString(twodig(strconv.Itoa(tm.Second())))
		}
	}

	return buf.String()
}

func Tokenize(text string, stopwords map[string]int, words map[string]int) {
	var s scanner.Scanner
	s.Init(strings.NewReader(text))
	tok := s.Scan()
	for tok != scanner.EOF {
		if tok == scanner.String {
			Tokenize(strings.Trim(s.TokenText(), "\"`"), stopwords, words)
		} else if tok == scanner.Char {
			Tokenize(strings.Trim(s.TokenText(), "'"), stopwords, words)
		} else if tok == scanner.Ident {
			word := s.TokenText()
			if _, ok := stopwords[word]; !ok && len(word) > 2 {
				stem, err := snowball.Stem(word, "english", true)
				if err != nil {
					fmt.Errorf("Couldnt stem word: %s", word)
					stem = word
				}
				if _, ok := stopwords[stem]; !ok {
					words[stem] += 1
				}
			}
		}
		tok = s.Scan()
	}
}

// gofmtFlags looks for a comment of the form
//
//	//gofmt flags
//
// within the first maxLines lines of the given file,
// and returns the flags string, if any. Otherwise it
// returns the empty string.
func gofmtFlags(filename string, maxLines int) string {
	f, err := os.Open(filename)
	if err != nil {
		return "" // ignore errors - they will be found later
	}
	defer f.Close()

	// initialize scanner
	var s scanner.Scanner
	s.Init(f)
	s.Error = func(*scanner.Scanner, string) {}       // ignore errors
	s.Mode = scanner.GoTokens &^ scanner.SkipComments // want comments

	// look for //gofmt comment
	for s.Line <= maxLines {
		switch s.Scan() {
		case scanner.Comment:
			const prefix = "//gofmt "
			if t := s.TokenText(); strings.HasPrefix(t, prefix) {
				return strings.TrimSpace(t[len(prefix):])
			}
		case scanner.EOF:
			return ""
		}

	}

	return ""
}

func split(expr string) (keys []string, err error) {

	var msgs []string
	var s scanner.Scanner
	s.Init(strings.NewReader(expr))
	s.Mode = scanner.ScanIdents | scanner.ScanInts | scanner.ScanStrings
	s.Error = func(s *scanner.Scanner, msg string) { msgs = append(msgs, fmt.Sprintf("%s %s", s.Pos(), msg)) }

	key := ""
	keys = []string{}
	for err == nil {
		t := s.Peek()
		// fmt.Printf(">>> %s: %s %s\n", s.Pos(), scanner.TokenString(t), s.TokenText())
		switch t {
		case '[':
			key, err = scanBracketedKey(&s)
		case '.':
			s.Scan()
			continue
		case scanner.EOF:
			goto end
		default:
			key, err = scanKey(&s)
		}
		if len(msgs) > 0 {
			err = errors.New(strings.Join(msgs, "\n"))
		}
		if err == nil {
			keys = append(keys, key)
		}
	}
end:
	return
}

/**
 * This function parses a value string parameter and returns Number value
 * embedded within the string. It returns nil if it doesn't find any
 * Number value in the value string.
 * Example: "some4.56more" would return 4.56
 */
func extractFloat32(value string) Number {
	var sc scanner.Scanner
	var tok rune
	var valFloat64 float64
	var valFloat32 Number
	var err error
	var isFound bool

	if len(value) > 0 {
		sc.Init(strings.NewReader(value))
		sc.Mode = scanner.ScanFloats

		for tok != scanner.EOF {
			tok = sc.Scan()
			// fmt.Println("At position", sc.Pos(), ":", sc.TokenText())
			valFloat64, err = strconv.ParseFloat(sc.TokenText(), 64)
			if err == nil {
				isFound = true
				break
			}
		}
	}

	if isFound {
		valFloat32 = Number(valFloat64)
	}

	return valFloat32
}

func TestMapScanner(t *testing.T) {
	in := make(chan interface{})
	go func() {
		reader := strings.NewReader(mapInput)
		s := scanner.Scanner{}
		s.Init(reader)
		tok := s.Scan()
		for tok != scanner.EOF {
			tok = s.Scan()
			in <- s.TokenText()
		}
		close(in)
	}()
	out := Map(in, func(input interface{}) interface{} {
		key := input.(string)
		if len(key) == 0 {
			return ""
		} else {
			return string(key[0])
		}
	})
	for tok := range out {
		for _, val := range tok.Values {
			if !strings.HasPrefix(val.(string), tok.Key.(string)) {
				t.Error(val.(string) + ` should has "` + tok.Key.(string) + `" prefix`)
			}
		}
	}
}

func cmdFind(root *CmdNode, path string, level int) (*CmdNode, error) {

	var s scanner.Scanner
	s.Error = func(s *scanner.Scanner, msg string) {
		log.Printf("command scan error: %s [%s]", msg, path)
	}
	s.Init(strings.NewReader(path))

	parent := root
	for tok := s.Scan(); tok != scanner.EOF; tok = s.Scan() {
		//log.Printf("cmdFind: token: [%s]", s.TokenText())
		label := s.TokenText()
		children := matchChildren(parent.Children, label)
		size := len(children)
		if size < 1 {
			return nil, fmt.Errorf("cmdFind: not found: [%s] under [%s]", label, parent.Path)
		}
		if size > 1 {
			return nil, fmt.Errorf("cmdFind: ambiguous: [%s] under [%s]", label, parent.Path)
		}
		parent = children[0]
	}

	//log.Printf("cmdFind: found [%s] as [%s]", path, parent.Path)

	return parent, nil
}

func getLineToken(line string) []string {
	var tokenScanner scanner.Scanner

	tokenScanner.Init(strings.NewReader(line))

	return tokenize(&tokenScanner)
}

func TestReduceScanner(t *testing.T) {
	in := make(chan interface{})
	go func() {
		reader := strings.NewReader(mapInput)
		s := scanner.Scanner{}
		s.Init(reader)
		tok := s.Scan()
		for tok != scanner.EOF {
			tok = s.Scan()
			in <- s.TokenText()
		}
		close(in)
	}()
	mapOut := Map(in, func(input interface{}) interface{} {
		key := input.(string)
		if len(key) == 0 {
			return ""
		} else {
			return string(key[0])
		}
	})
	redOut := Reduce(mapOut, func(key interface{}, values []interface{}) interface{} {
		return len(values)
	})
	for tok := range redOut {
		if tok.Value.(int) == 0 {
			t.Error("expect reduce should be positive")
		}
	}
}

func (s *PGNSuite) TestPGNParseInfiniteLoopF4(c *C) {
	pgnstr := `[Event "BKL-Turnier"]
[Site "Leipzig"]
[Date "1984.??.??"]
[Round "5"]
[White "Polgar, Zsuzsa"]
[Black "Moehring, Guenther"]
[Result "1-0"]
[WhiteElo "2275"]
[BlackElo "2395"]
[ECO "A49"]

1.d4 Nf6 2.Nf3 d6 3.b3 g6 4.Bb2 Bg7 5.g3 c5 6.Bg2 cxd4 7.Nxd4 d5 8.O-O O-O
9.Na3 Re8 10.Nf3 Nc6 11.c4 dxc4 12.Nxc4 Be6 13.Rc1 Rc8 14.Nfe5 Nxe5 15.Bxe5 Bxc4
16.Rxc4 Rxc4 17.bxc4 Qa5 18.Bxf6 Bxf6 19.Bxb7 Rd8 20.Qb3 Rb8 21.e3 h5 22.Rb1 h4
23.Qb5 Qc7 24.a4 hxg3 25.hxg3 Be5 26.Kg2 Bd6 27.a5 Bc5 28.a6 Rd8 29.Qc6 Qxc6+
30.Bxc6 Rd2 31.Kf3 Rc2 32.Rb8+ Kg7 33.Bb5 Kf6 34.Rc8 Bb6 35.Ba4 Ra2 36.Bb5 Rc2
37.Ke4 e6 38.Kd3 Rc1 39.Kd2 Rb1 40.Kc2 Rb4 41.Rb8 Bc5 42.Rc8 Bb6 43.Rc6 Ba5
44.Rd6 g5 45.f4 gxf4 46.gxf4 Kf5 47.Rd7 Bb6 48.Rxf7+ Ke4 49.Rb7 Bc5 50.Kc3 Kxe3
51.Rc7 Bb6 52.Rc6 Ba5 53.Kc2 Kxf4 54.Rxe6 Bd8 55.Kc3 Rb1 56.Kd4 Rd1+ 57.Kc5 Kf5
58.Re8 Bb6+ 59.Kc6 Kf6 60.Kb7 Bg1 61.Ra8 Re1 62.Rf8+ Kg7 63.Rf5 Kg6 64.Rd5 Rc1
65.Ka8 Be3 66.Rd6+ Kf5 67.Rd3 Ke4 68.Rxe3+ Kxe3 69.Kxa7 Kd4 70.Kb6 Rg1 71.a7 Rg8
72.Kb7 Rg7+ 73.Kb6  1-0`

	r := strings.NewReader(pgnstr)
	sc := scanner.Scanner{}
	sc.Init(r)
	game, err := ParseGame(&sc)
	c.Assert(err, IsNil)
	//	fmt.Println(game)
	c.Assert(game.Tags["Site"], Equals, "Leipzig")
	c.Assert(len(game.Moves), Equals, 145)
}

func main() {
	var Stdin = os.NewFile(uintptr(syscall.Stdin), "/dev/stdin")
	var s scanner.Scanner
	s.Init(Stdin)
	s.Mode = scanner.ScanIdents | scanner.ScanFloats | scanner.ScanChars | scanner.ScanStrings | scanner.ScanRawStrings | scanner.ScanComments
	tok := s.Scan()
	for tok != scanner.EOF {
		switch tok {
		case scanner.Ident:
			fmt.Println("Ident")
		case scanner.Int:
			fmt.Println("Int")
		case scanner.Float:
			fmt.Println("Float")
		case scanner.Char:
			fmt.Println("Char")
		case scanner.String:
			fmt.Println("String")
		case scanner.RawString:
			fmt.Println("RawString")
		case scanner.Comment:
			fmt.Println("Comment")
		}
		tok = s.Scan()
	}
}

func Example() {
	const src = `
	// This is scanned code.
	if a > 10 {
		someParsable = text
	}`
	var s scanner.Scanner
	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 3:4 : if
	// At position 3:6 : a
	// At position 3:8 : >
	// At position 3:11 : 10
	// At position 3:13 : {
	// At position 4:15 : someParsable
	// At position 4:17 : =
	// At position 4:22 : text
	// At position 5:3 : }
	// At position 5:3 :
}

func NewDecoder(r io.Reader) *Decoder {
	var scan scanner.Scanner
	scan.Init(r)
	dec := Decoder{scan: scan}
	scan.Error = dec.setError
	return &dec
}

func (t Tokenizer) CreateTokens(request *messaging.ParserRequest) (response messaging.ParserResponse) {

	response.Body = make(map[string]string)
	b := bytes.NewBufferString(request.Query)
	var s scanner.Scanner
	s.Init(b)

	index := 0
	for {
		tok := s.Scan()
		if tok != scanner.EOF {
			response.Body[strconv.Itoa(index)] = s.TokenText()
			index++
		} else {
			break
		}

	}

	if index == 0 {
		response.IsSuccess = false
		response.Message = "Error! Nil Query Allocated!"
	} else {
		response.IsSuccess = false
		response.Message = "Success! Query Tokenized Successfully!"
	}

	return
}

// parseKey reads a private key from r. It returns a map[string]string,
// with the key-value pairs, or an error when the file is not correct.
func parseKey(r io.Reader, file string) (map[string]string, error) {
	var s scanner.Scanner
	m := make(map[string]string)
	c := make(chan lex)
	k := ""
	s.Init(r)
	s.Mode = 0
	s.Whitespace = 0
	// Start the lexer
	go klexer(s, c)
	for l := range c {
		// It should alternate
		switch l.value {
		case _KEY:
			k = l.token
		case _VALUE:
			if k == "" {
				return nil, &ParseError{file, "No key seen", l}
			}
			//println("Setting", strings.ToLower(k), "to", l.token, "b")
			m[strings.ToLower(k)] = l.token
			k = ""
		}
	}
	return m, nil
}