static function parse_string( $s ){
		if( $s == '' ){
			throw new Exception('Cannot parse empty string');
		}
		// instantiate self
		$Parser = new BNFParser;
		// perform external tokenizing on string input 
		$tokens = bnf_tokenize( $s );
		return $Parser->parse( $tokens );
	}
static function parse_string( $s ){
		if( $s == '' ){
			throw new Exception('Cannot parse empty string');
		}
		// instantiate self
		$Parser = new BNFParser;
		// perform external tokenizing on string input 
		$tokens = bnf_tokenize( $s );
		return $Parser->parse( $tokens );
	}
static function parse_string ( $ s ) { if ( $ s == '' ) { throw new Exception ( 'Cannot parse empty string' ) ; } // instantiate self $ Parser = new BNFParser ; // perform external tokenizing on string input  $ tokens = bnf_tokenize ( $ s ) ; return $ Parser -> parse ( $ tokens ) ; }
parse input string
@param string input source
@return ParseNode
parse input string