dart.grammar

@top LibraryDeclaration {
  expression
}

expression {
  literal
}

literal[@isGroup=Literal] {
  NullLiteral |
  BoolLiteral |
  NumericLiteral |
  StringLiteral
}

NullLiteral {
  'null'
}

BoolLiteral {
  'true' | 'false'
}

NumericLiteral {
  DIGIT+ ('.' DIGIT+)? EXPONENT? |
  '.' DIGIT+ EXPONENT? |
  '0x' HEX_DIGIT+ |
  '0X' HEX_DIGIT+
}

StringLiteral {
  (SingleLineString | MultiLineString)+
}

Interpolation<startQuote> {
  startQuote expression "}"
}

@skip {} {
  SingleLineString {
    RAW_SINGLE_LINE_STRING |
    SINGLE_LINE_STRING_SQ_BEGIN (
      SINGLE_LINE_STRING_SQ_CONTENT |
      SINGLE_LINE_STRING_SQ_ESCAPE |
      Interpolation<SINGLE_LINE_STRING_SQ_START_INTER> |
      SINGLE_LINE_STRING_SQ_INTER
    )* SINGLE_LINE_STRING_SQ_END |
    SINGLE_LINE_STRING_DQ_BEGIN (
      SINGLE_LINE_STRING_DQ_CONTENT |
      SINGLE_LINE_STRING_DQ_ESCAPE |
      Interpolation<SINGLE_LINE_STRING_DQ_START_INTER> |
      SINGLE_LINE_STRING_DQ_INTER
    )* SINGLE_LINE_STRING_DQ_END
  }

  MultiLineString {
    RAW_MULTI_LINE_STRING |
    MULTI_LINE_STRING_SQ_BEGIN (
      MULTI_LINE_STRING_SQ_CONTENT |
      MULTI_LINE_STRING_SQ_ESCAPE |
      Interpolation<MULTI_LINE_STRING_SQ_START_INTER> |
      MULTI_LINE_STRING_SQ_INTER
    )* MULTI_LINE_STRING_SQ_END |
    MULTI_LINE_STRING_DQ_BEGIN (
      MULTI_LINE_STRING_DQ_CONTENT |
      MULTI_LINE_STRING_DQ_ESCAPE |
      Interpolation<MULTI_LINE_STRING_DQ_START_INTER> |
      MULTI_LINE_STRING_DQ_INTER
    )* MULTI_LINE_STRING_DQ_END
  }
}

BUILT_IN_IDENTIFIER {
  @specialize<IDENTIFIER_NO_DOLLAR, 'abstract' |
    'as' |
    'covariant' |
    'deferred' |
    'dynamic' |
    'export' |
    'external' |
    'extension' |
    'factory' |
    'Function' |
    'get' |
    'implements' |
    'import' |
    'interface' |
    'late' |
    'library' |
    'mixin' |
    'operator' |
    'part' |
    'required' |
    'set' |
    'static' |
    'typedef'>
}

@local tokens {
  SINGLE_LINE_STRING_SQ_ESCAPE { ESCAPE_SEQUENCE }
  SINGLE_LINE_STRING_SQ_START_INTER { "${" }
  SINGLE_LINE_STRING_SQ_INTER { SIMPLE_STRING_INTERPOLATION }
  SINGLE_LINE_STRING_SQ_END { "'" }
  @else SINGLE_LINE_STRING_SQ_CONTENT
}

@local tokens {
  SINGLE_LINE_STRING_DQ_ESCAPE { ESCAPE_SEQUENCE }
  SINGLE_LINE_STRING_DQ_START_INTER { "${" }
  SINGLE_LINE_STRING_DQ_INTER { SIMPLE_STRING_INTERPOLATION }
  SINGLE_LINE_STRING_DQ_END { '"' }
  @else SINGLE_LINE_STRING_DQ_CONTENT
}

@local tokens {
  MULTI_LINE_STRING_SQ_ESCAPE { ESCAPE_SEQUENCE }
  MULTI_LINE_STRING_SQ_START_INTER { "${" }
  MULTI_LINE_STRING_SQ_INTER { SIMPLE_STRING_INTERPOLATION }
  MULTI_LINE_STRING_SQ_END { "'''" }
  @else MULTI_LINE_STRING_SQ_CONTENT
}

@local tokens {
  MULTI_LINE_STRING_DQ_ESCAPE { ESCAPE_SEQUENCE }
  MULTI_LINE_STRING_DQ_START_INTER { "${" }
  MULTI_LINE_STRING_DQ_INTER { SIMPLE_STRING_INTERPOLATION }
  MULTI_LINE_STRING_DQ_END { '"""' }
  @else MULTI_LINE_STRING_DQ_CONTENT
}

@tokens {
  WHITESPACE {
    ('\t' | ' ' | '\r' | '\n'| '\r\n')+
  }

  DIGIT {
    $[0-9]
  }

  LETTER {
    $[a-zA-Z]
  }

  HEX_DIGIT {
    $[0-9a-fA-F]
  }

  EXPONENT {
    $[eE] $[+-]? DIGIT+
  }

  RAW_SINGLE_LINE_STRING {
    'r' "'" (!['\r\n])* "'" |
    'r' '"' (!['\r\n])* '"'
  }

  ESCAPE_SEQUENCE {
    '\n' | '\r' | '\f' | '\b' | '\t' | '\v' |
    '\x' HEX_DIGIT HEX_DIGIT |
    '\u' HEX_DIGIT HEX_DIGIT HEX_DIGIT HEX_DIGIT |
    '\u{' HEX_DIGIT HEX_DIGIT? HEX_DIGIT? HEX_DIGIT? HEX_DIGIT? HEX_DIGIT? '}' |
    '\\' ![nrbtvxu\r\n]
  }

  SIMPLE_STRING_INTERPOLATION {
    '$' IDENTIFIER_NO_DOLLAR
  }

  SINGLE_LINE_STRING_SQ_BEGIN { "'" }

  SINGLE_LINE_STRING_DQ_BEGIN { '"' }

  RAW_MULTI_LINE_STRING {
    'r' "'''" _* "'''" |
    'r' '"""' _* '"""'
  }

  MULTI_LINE_STRING_SQ_BEGIN { "'''" }

  MULTI_LINE_STRING_DQ_BEGIN { '"""' }

  @precedence { RAW_MULTI_LINE_STRING, RAW_SINGLE_LINE_STRING }

  IDENTIFIER_NO_DOLLAR {
    IDENTIFIER_START_NO_DOLLAR IDENTIFIER_PART_NO_DOLLAR*
  }

  IDENTIFIER_START_NO_DOLLAR {
    LETTER | '_'
  }

  IDENTIFIER_PART_NO_DOLLAR {
    IDENTIFIER_START_NO_DOLLAR | DIGIT
  }
}

@skip {
  WHITESPACE
}