Golang lexer.Token类代码示例

func (p *Parser) duplicateNameMessage(dupeError *mojom.DuplicateNameError,
	nameToken lexer.Token) string {
	if dupeError == nil {
		return ""
	}
	if dupeError.ExistingType() != nil {
		return fmt.Sprintf("%s:%s. Duplicate definition for name '%s'. "+
			"The fully-qualified name of this type would be the same as "+
			"an existing type definition: "+
			"%s %s in %s.", p.mojomFile.FileName,
			nameToken.ShortLocationString(), nameToken.Text,
			dupeError.ExistingType().Kind(),
			dupeError.ExistingType().FullyQualifiedName(),
			dupeError.ExistingType().Scope())

	} else {
		return fmt.Sprintf("%s:%s. Duplicate definition for name '%s'. "+
			"The fully-qualified name of this value would be the same as "+
			"an existing value definition: "+
			"%s %s in %s.", p.mojomFile.FileName,
			nameToken.ShortLocationString(), nameToken.Text,
			dupeError.ExistingValue().Kind(),
			dupeError.ExistingValue().FullyQualifiedName(),
			dupeError.ExistingValue().Scope())
	}
}

// UserErrorMessageP is responsible for formatting user-facing error messages
// This function is similar to UserErrorMessage except that it also allows the
// caller to specify the message prefix.
// prefix: An error message prefix such as "Error:". It should not end with a space.
func UserErrorMessageP(file *MojomFile, token lexer.Token, prefix, message string) string {
	// TODO(rudominer) Allow users to disable the use of color in snippets.
	useColor := true

	// Optionally color the prefix red.
	if useColor && len(prefix) > 0 {
		prefix = fmt.Sprintf("\x1b[31;1m%s\x1b[0m", prefix)
	}
	if len(prefix) > 0 {
		prefix = fmt.Sprintf("%s ", prefix)
	}
	message = fmt.Sprintf("%s%s", prefix, message)

	filePath := "Unknown file"
	importedFromMessage := ""
	snippet := ""
	if file != nil {
		if len(file.fileContents) > 0 {
			snippet = fmt.Sprintf("\n%s", token.Snippet(file.fileContents, useColor))
		}
		filePath = RelPathIfShorter(file.CanonicalFileName)
		importedFromMessage = file.ImportedFromMessage()
	}
	return fmt.Sprintf("\n%s:%s: %s%s\n%s", filePath, token.ShortLocationString(),
		message, snippet, importedFromMessage)
}

func (p *Parser) matchSemicolonToken(previousToken lexer.Token) bool {
	if !p.OK() {
		return false
	}
	if p.match(lexer.Semi) {
		return true
	}
	message := fmt.Sprintf("Missing semicolon after %s at %s.",
		previousToken, previousToken.LongLocationString())
	p.err = &ParseError{ParserErrorCodeUnexpectedToken, message}
	return false
}

func (p *Parser) matchSemicolonToken(previousToken lexer.Token) bool {
	if !p.OK() {
		return false
	}
	if p.match(lexer.SEMI) {
		return true
	}
	message := fmt.Sprintf("Missing semicolon after %s at %s.",
		previousToken, previousToken.LongLocationString())
	p.err = &ParseError{E_UNEXPECTED_TOKEN, message}
	return false
}

// |unexpected| should be a string of the grammatical form "Unexpected token at %s: %s."
// |expected| should be a string of the grammatic form "a semicolon"
func (p *Parser) expectedTokenError(token lexer.Token, unexpected string, expected string) string {
	message := fmt.Sprintf(" Expecting %s.", expected)
	switch token.Kind {
	case lexer.ErrorUnknown, lexer.ErrorIllegalChar,
		lexer.ErrorUnterminatedStringLiteral,
		lexer.ErrorUnterminatedComment:
		message = fmt.Sprintf("%s at %s.", token, token.LongLocationString()) + message
	default:
		message = fmt.Sprintf(unexpected, token.LongLocationString(), token) + message
	}
	p.err = &ParseError{ParserErrorCodeUnexpectedToken, message}
	return message
}

// |unexpected| should be a string of the grammatical form "Unexpected token at %s: %s."
// |expected| should be a string of the grammatic form "a semicolon"
func (p *Parser) expectedTokenError(token lexer.Token, unexpected string, expected string) string {
	message := fmt.Sprintf(" Expecting %s.", expected)
	switch token.Kind {
	case lexer.ERROR_UNKNOWN, lexer.ERROR_ILLEGAL_CHAR,
		lexer.ERROR_UNTERMINATED_STRING_LITERAL,
		lexer.ERROR_UNTERMINATED_COMMENT:
		message = fmt.Sprintf("%s at %s.", token, token.LongLocationString()) + message
	default:
		message = fmt.Sprintf(unexpected, token.LongLocationString(), token) + message
	}
	p.err = &ParseError{E_UNEXPECTED_TOKEN, message}
	return message
}

// STRUCT_FIELD         -> TYPE name [ordinal] [equals DEFAULT_VALUE] semi
// DEFAULT_VALUE        -> APPROPRIATE_VAL_SPEC | default
// APPROPRIATE_VAL_SPEC -> VALUE_REF {{that resolves to a type that is assignment compatible to the type of the assignee}}
func (p *Parser) parseStructField(attributes *mojom.Attributes) *mojom.StructField {
	if !p.OK() {
		return nil
	}
	p.pushChildNode("structField")
	defer p.popNode()

	fieldType := p.parseType()
	fieldName := p.readName()
	nameToken := p.lastConsumed
	p.attachToken()

	ordinalValue, err := p.readOrdinal()
	if err != nil {
		p.err = p.newInvalidOrdinalError("field", fieldName, nameToken, err)
		return nil
	}

	var defaultValue mojom.ValueRef
	var defaultValueToken lexer.Token
	if p.tryMatch(lexer.Equals) {
		defaultValueToken = p.peekNextToken("Expecting a default value.")
		if defaultValueToken.Kind == lexer.Default {
			p.consumeNextToken()
			defaultValue = mojom.MakeDefaultLiteral()
		} else {
			defaultValue = p.parseValue(fieldType)
		}
	}
	if !p.matchSemicolon() {
		return nil
	}

	declData := p.DeclDataWithOrdinal(fieldName, nameToken, attributes, ordinalValue)
	field := mojom.NewStructField(declData, fieldType, defaultValue)
	if !field.ValidateDefaultValue() {
		valueString := fmt.Sprintf("%v", defaultValue)
		valueTypeString := ""
		concreteValue := defaultValue.ResolvedConcreteValue()
		if concreteValue != nil {
			valueString = fmt.Sprintf("%v", concreteValue.Value())
			valueTypeString = fmt.Sprintf(" of type %s", concreteValue.ValueType())
		}
		message := fmt.Sprintf("Illegal assignment at %s: Field %s of type %s may not be assigned the value %v%s.",
			defaultValueToken.LongLocationString(), fieldName, fieldType, valueString, valueTypeString)
		p.err = &ParseError{ParserErrorCodeNotAssignmentCompatible, message}
		return nil
	}

	return field
}

// STRUCT_FIELD         -> TYPE name [ordinal] [equals DEFAULT_VALUE] semi
// DEFAULT_VALUE        -> APPROPRIATE_VAL_SPEC | default
// APPROPRIATE_VAL_SPEC -> VALUE_REF {{that resolves to a type that is assignment compatible to the type of the assignee}}
func (p *Parser) parseStructField(attributes *mojom.Attributes) *mojom.StructField {
	if !p.OK() {
		return nil
	}
	p.pushChildNode("structField")
	defer p.popNode()

	fieldType := p.parseType()
	fieldName := p.readName()
	p.attachToken()
	ordinalValue := p.readOrdinal()
	var defaultValue mojom.ValueRef
	var defaultValueToken lexer.Token
	if p.tryMatch(lexer.EQUALS) {
		defaultValueToken = p.peekNextToken("Expecting a default value.")
		if defaultValueToken.Kind == lexer.DEFAULT {
			p.consumeNextToken()
			defaultValue = mojom.MakeDefaultLiteral()
		} else {
			defaultValue = p.parseValue(fieldType)
		}
	}
	if !p.matchSemicolon() {
		return nil
	}

	field := mojom.NewStructField(fieldType, fieldName, ordinalValue, attributes, defaultValue)
	if !field.ValidateDefaultValue() {
		valueString := fmt.Sprintf("%v", defaultValue)
		valueTypeString := ""
		concreteValue := defaultValue.ResolvedConcreteValue()
		if concreteValue != nil {
			valueString = fmt.Sprintf("%v", concreteValue.Value())
			valueTypeString = fmt.Sprintf(" of type %s", concreteValue.ValueType())
		}
		message := fmt.Sprintf("Illegal assignment at %s: Field %s of type %s may not be assigned the value %v%s.",
			defaultValueToken.LongLocationString(), fieldName, fieldType, valueString, valueTypeString)
		p.err = &ParseError{E_TYPE_NOT_ASSIGNMENT_COMPATIBLE, message}
		return nil
	}

	return field
}

func (p *Parser) newInvalidOrdinalError(objectType, objectName string, nameToken lexer.Token, err error) *ParseError {
	message := fmt.Sprintf("%s:%s %s %q: %s",
		p.mojomFile.CanonicalFileName, nameToken.ShortLocationString(),
		objectType, objectName, err.Error())
	return &ParseError{ParserErrorCodeBadOrdinal, message}
}