parser.en.rdoc

Path: rdoc/en/parser.en.rdoc
Last Update: Wed Apr 17 07:16:23 +0000 2013

class Racc::Parser

Super Class

Object

Instance Methods

: do_parse -> Object

    The entry point of parser. This method is used with #next_token.
    If Racc wants to get token (and its value), calls next_token.

      --
      # Example
      ---- inner
        def parse
          @q = [[1,1],
                [2,2],
                [3,3],
                [false, '$']]
          do_parse
        end

        def next_token
          @q.shift
        end
      --

: next_token -> [Symbol, Object]

    [abstract method]

    The method to fetch next token.  If you use #do_parse method,
    you must implement #next_token.  The format of return value is
    [TOKEN_SYMBOL, VALUE].  token-symbol is represented by Ruby's symbol
    by default, e.g. :IDENT for 'IDENT'.  ";" (String) for ';'.

    The final symbol (End of file) must be false.

: yyparse( receiver, method_id )

    The another entry point of parser.
    If you use this method, you must implement RECEIVER#METHOD_ID method.

    RECEIVER#METHOD_ID is a method to get next token.
    It must 'yield's token, which format is [TOKEN-SYMBOL, VALUE].

: on_error( error_token_id, error_value, value_stack )

    This method is called when parse error is found.

    ERROR_TOKEN_ID is an internal ID of token which caused error.
    You can get string replesentation of this ID by calling
    #token_to_str.

    ERROR_VALUE is a value of error token.

    value_stack is a stack of symbol values.
    DO NOT MODIFY this object.

    This method raises ParseError by default.

    If this method returns, parsers enter "error recovering mode".

: token_to_str( t ) -> String

    Convert internal ID of token symbol to the string.

: yyerror

    Enter error recovering mode.
    This method does not call #on_error.

: yyerrok

    Leave error recovering mode.

: yyaccept

    Exit parser.
    Return value is Symbol_Value_Stack[0].

[Validate]