func parseObjectField(parser *Parser, isConst bool, fieldNames map[string]bool) (*ast.ObjectField, string, error) {
start := parser.Token.Start
name, err := parseName(parser)
if err != nil {
return nil, "", err
}
fieldName := name.Value
if _, ok := fieldNames[fieldName]; ok {
descp := fmt.Sprintf("Duplicate input object field %v.", fieldName)
return nil, "", gqlerrors.NewSyntaxError(parser.Source, start, descp)
}
_, err = expect(parser, lexer.TokenKind[lexer.COLON])
if err != nil {
return nil, "", err
}
value, err := parseValueLiteral(parser, isConst)
if err != nil {
return nil, "", err
}
return ast.NewObjectField(&ast.ObjectField{
Name: name,
Value: value,
Loc: loc(parser, start),
}), fieldName, nil
}
// If the next token is a keyword with the given value, return that token after
// advancing the parser. Otherwise, do not change the parser state and return false.
func expectKeyWord(parser *Parser, value string) (lexer.Token, error) {
token := parser.Token
if token.Kind == lexer.TokenKind[lexer.NAME] && token.Value == value {
advance(parser)
return token, nil
}
descp := fmt.Sprintf("Expected \"%s\", found %s", value, lexer.GetTokenDesc(token))
return token, gqlerrors.NewSyntaxError(parser.Source, token.Start, descp)
}
// If the next token is of the given kind, return that token after advancing
// the parser. Otherwise, do not change the parser state and return false.
func expect(parser *Parser, kind int) (lexer.Token, error) {
token := parser.Token
if token.Kind == kind {
advance(parser)
return token, nil
}
descp := fmt.Sprintf("Expected %s, found %s", lexer.GetTokenKindDesc(kind), lexer.GetTokenDesc(token))
return token, gqlerrors.NewSyntaxError(parser.Source, token.Start, descp)
}
// Helper function for creating an error when an unexpected lexed token
// is encountered.
func unexpected(parser *Parser, atToken lexer.Token) error {
var token lexer.Token
if (atToken == lexer.Token{}) {
token = parser.Token
} else {
token = parser.Token
}
description := fmt.Sprintf("Unexpected %v", lexer.GetTokenDesc(token))
return gqlerrors.NewSyntaxError(parser.Source, token.Start, description)
}
// Reads a number token from the source file, either a float
// or an int depending on whether a decimal point appears.
// Int: -?(0|[1-9][0-9]*)
// Float: -?(0|[1-9][0-9]*)(\.[0-9]+)?((E|e)(+|-)?[0-9]+)?
func readNumber(s *source.Source, start int, firstCode rune) (Token, error) {
code := firstCode
body := s.Body
position := start
isFloat := false
if code == 45 { // -
position += 1
code = charCodeAt(body, position)
}
if code == 48 { // 0
position += 1
code = charCodeAt(body, position)
if code >= 48 && code <= 57 {
description := fmt.Sprintf("Invalid number, unexpected digit after 0: \"%c\".", code)
return Token{}, gqlerrors.NewSyntaxError(s, position, description)
}
} else {
p, err := readDigits(s, position, code)
if err != nil {
return Token{}, err
}
position = p
code = charCodeAt(body, position)
}
if code == 46 { // .
isFloat = true
position += 1
code = charCodeAt(body, position)
p, err := readDigits(s, position, code)
if err != nil {
return Token{}, err
}
position = p
code = charCodeAt(body, position)
}
if code == 69 || code == 101 { // E e
isFloat = true
position += 1
code = charCodeAt(body, position)
if code == 43 || code == 45 { // + -
position += 1
code = charCodeAt(body, position)
}
p, err := readDigits(s, position, code)
if err != nil {
return Token{}, err
}
position = p
}
kind := TokenKind[INT]
if isFloat {
kind = TokenKind[FLOAT]
}
return makeToken(kind, start, position, body[start:position]), nil
}
// Returns the new position in the source after reading digits.
func readDigits(s *source.Source, start int, firstCode rune) (int, error) {
body := s.Body
position := start
code := firstCode
if code >= 48 && code <= 57 { // 0 - 9
for {
if code >= 48 && code <= 57 { // 0 - 9
position += 1
code = charCodeAt(body, position)
continue
} else {
break
}
}
return position, nil
}
var description string
if code != 0 {
description = fmt.Sprintf("Invalid number, expected digit but got: \"%c\".", code)
} else {
description = fmt.Sprintf("Invalid number, expected digit but got: EOF.")
}
return position, gqlerrors.NewSyntaxError(s, position, description)
}
func readToken(s *source.Source, fromPosition int) (Token, error) {
body := s.Body
bodyLength := len(body)
position := positionAfterWhitespace(body, fromPosition)
code := charCodeAt(body, position)
if position >= bodyLength {
return makeToken(TokenKind[EOF], position, position, ""), nil
}
switch code {
// !
case 33:
return makeToken(TokenKind[BANG], position, position+1, ""), nil
// $
case 36:
return makeToken(TokenKind[DOLLAR], position, position+1, ""), nil
// (
case 40:
return makeToken(TokenKind[PAREN_L], position, position+1, ""), nil
// )
case 41:
return makeToken(TokenKind[PAREN_R], position, position+1, ""), nil
// .
case 46:
if charCodeAt(body, position+1) == 46 && charCodeAt(body, position+2) == 46 {
return makeToken(TokenKind[SPREAD], position, position+3, ""), nil
}
break
// :
case 58:
return makeToken(TokenKind[COLON], position, position+1, ""), nil
// =
case 61:
return makeToken(TokenKind[EQUALS], position, position+1, ""), nil
// @
case 64:
return makeToken(TokenKind[AT], position, position+1, ""), nil
// [
case 91:
return makeToken(TokenKind[BRACKET_L], position, position+1, ""), nil
// ]
case 93:
return makeToken(TokenKind[BRACKET_R], position, position+1, ""), nil
// {
case 123:
return makeToken(TokenKind[BRACE_L], position, position+1, ""), nil
// |
case 124:
return makeToken(TokenKind[PIPE], position, position+1, ""), nil
// }
case 125:
return makeToken(TokenKind[BRACE_R], position, position+1, ""), nil
// A-Z
case 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81,
82, 83, 84, 85, 86, 87, 88, 89, 90:
return readName(s, position), nil
// _
// a-z
case 95, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110,
111, 112, 113, 114, 115, 116, 117, 118, 119, 120, 121, 122:
return readName(s, position), nil
// -
// 0-9
case 45, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57:
token, err := readNumber(s, position, code)
if err != nil {
return token, err
} else {
return token, nil
}
// "
case 34:
token, err := readString(s, position)
if err != nil {
return token, err
}
return token, nil
}
description := fmt.Sprintf("Unexpected character \"%c\".", code)
return Token{}, gqlerrors.NewSyntaxError(s, position, description)
}
func readString(s *source.Source, start int) (Token, error) {
body := s.Body
position := start + 1
chunkStart := position
var code rune
var value string
for {
code = charCodeAt(body, position)
if position < len(body) && code != 34 && code != 10 && code != 13 && code != 0x2028 && code != 0x2029 {
position += 1
if code == 92 { // \
value += body[chunkStart : position-1]
code = charCodeAt(body, position)
switch code {
case 34:
value += "\""
break
case 47:
value += "\\/"
break
case 92:
value += "\\"
break
case 98:
value += "\b"
break
case 102:
value += "\f"
break
case 110:
value += "\n"
break
case 114:
value += "\r"
break
case 116:
value += "\t"
break
case 117:
charCode := uniCharCode(
charCodeAt(body, position+1),
charCodeAt(body, position+2),
charCodeAt(body, position+3),
charCodeAt(body, position+4),
)
if charCode < 0 {
return Token{}, gqlerrors.NewSyntaxError(s, position, "Bad character escape sequence.")
}
value += fmt.Sprintf("%c", charCode)
position += 4
break
default:
return Token{}, gqlerrors.NewSyntaxError(s, position, "Bad character escape sequence.")
}
position += 1
chunkStart = position
}
continue
} else {
break
}
}
if code != 34 {
return Token{}, gqlerrors.NewSyntaxError(s, position, "Unterminated string.")
}
value += body[chunkStart:position]
return makeToken(TokenKind[STRING], start, position+1, value), nil
}