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].