parser.sa

Java写的词法/语法分析器。可生成JAVA语言或者是C++的词法和语法分析器。并可产生语法分析树和对该树进行遍历

(* 

  ANTLR Translator Generator
  Project led by Terence Parr at http://www.jGuru.com
  Software rights: http://www.antlr.org/RIGHTS.html
 
  $Id: //depot/code/org.antlr/release/antlr-2.7.0/lib/sather/Antlr/parser.sa#1 $

*)

partial class ANTLR_PARSER{ TOKEN < $ANTLR_TOKEN, AST < $ANTLR_AST{AST} } is

   readonly attr input_state : ANTLR_PARSER_SHARED_INPUT_STATE{TOKEN};
	
   -- Table of token type to token names 
   readonly attr token_names : ARRAY{STR};

   -- AST return value for a rule is squirreled away here 
   private attr return_ast : AST;

   -- AST support code; parser and treeparser delegate to this object 
   -- attr ast_factory : $ANTLR_AST_FACTORY;

   attr ignore_invalid_debug_calls : BOOL;

   create : SAME is
      res : SAME := new;
      res.input_state := #ANTLR_PARSER_SHARED_INPUT_STATE{TOKEN};
      return res;
   end;

   create ( state : ANTLR_PARSER_SHARED_INPUT_STATE{TOKEN} ) : SAME is
      res : SAME := new;
      res.input_state := state;
      return res;
   end;
   
   -- only_valid_msg : STR := "is only valid if parser built for debugging";

   -- add_message_listener( listener : MESSAGE_LISTENER ) is
   --   err_msg : STR := "add_message_listener " + only_valid_msg;
   -- end;

   -- add_parser_listener( listener : PARSER_LISTENER ) is
   --   err_msg : STR := "add_parser_listener" + only_valid_msg;
   -- end;
   
   -- add_parser_match_listener( listener : PARSER_MATCH_LISTENER ) is
   --   err_msg : STR := "add_parser_match_listener " + only_valid_msg;
   -- end;
   
   -- add_parse_token_listener( listener : PARSER_TOKEN_LISTENER ) is
   --   err_msg : STR := "add_parser_token_listener " + only_valid_msg;
   -- end;
   
   -- add_semantic_predicate_listener( listener : SEMANTIC_PREDICATE_LISTENER ) is
   --   err_msg : STR := "add_semantic_token_listener " + only_valid_msg;
   -- end;
   
   -- add_trace_listener( listener : TRACE_LISTENER ) is
   --   err_msg : STR := "add_trace_listener " + only_valid_msg;
   -- end;
   
   -- Get another token object from the token stream
   stub consume;

   -- Consume tokens until one matches the given token

   consume_until( token_type : INT ) is
      loop while! ( LA(1) /= ANTLR_COMMON_TOKEN::EOF_TYPE and LA(1) /= token_type );
	 consume;
      end;
   end;

   consume_until( set : INT_SET ) is
      loop while! ( LA(1) /= ANTLR_COMMON_TOKEN::EOF_TYPE and ~set.member( LA(1) ) );
	 consume;
      end;
   end;

   default_debugging_setup( lexer : $ANTLR_TOKEN_STREAM{TOKEN} , 
			    tok_buf : ANTLR_TOKEN_BUFFER{TOKEN} ) is
      -- by default, do nothing -- we're not debugging
   end;
   
   ast : AST is
      return return_ast;
   end;
   
   file_name : STR is
      return input_state.file_name;
   end;
   
   is_debug_mode : BOOL is 
      return false;
   end;
   
   -- Return the token type of the ith token of lookahead where i=1
   -- is the current token being examined by the parser (i.e., it
   -- has not been matched yet).
   stub LA( i : INT ) : INT;
   
   -- Return the ith token of lookahead
   stub LT( i : INT ) : TOKEN;
   
   -- Forwarded to TokenBuffer
   mark : INT is
      return input_state.input.mark;
   end;

   -- Make sure current lookahead symbol matches token type <tt>t</tt>.
   -- Throw an exception upon mismatch, which is catch by either the
   -- error handler or by the syntactic predicate.
   match( t : INT ) is
      if ( LA(1) /= t ) then
	 raise ANTLR_MISMATCHED_TOKEN_EXCEPTION{AST}::create_from_token( token_names, LT(1), t, false, file_name );
      else
	 -- mark token as consumed -- fetch next token deferred until LA/LT
	 consume;
      end;
   end;

   -- Make sure current lookahead symbol matches the given set
   -- Throw an exception upon mismatch, which is catch by either the
   -- error handler or by the syntactic predicate.
   match( b : INT_SET ) is
      if ( ~b.member(LA(1)) ) then
	 raise ANTLR_MISMATCHED_TOKEN_EXCEPTION{AST}::create_from_token( token_names, LT(1), b, false, file_name );
      else
	 -- mark token as consumed -- fetch next token deferred until LA/LT
	 consume;
      end;
   end;

   match_not( t : INT ) is
      if ( LA(1) = t ) then
	 -- Throws inverted-sense exception
	 raise ANTLR_MISMATCHED_TOKEN_EXCEPTION{AST}::create_from_token( token_names, LT(1), t, true, file_name );
      else
	 -- mark token as consumed -- fetch next token deferred until LA/LT
	 consume;
      end;
   end;

   panic is
      #ERR + "Parser: panic\n";
      UNIX::exit(1);
   end;
   
   -- Parser error-reporting function can be overridden in subclass 
   report_error( ex : $ANTLR_RECOGNITION_EXCEPTION ) is
      #ERR + ex.str + "\n";
   end;
   
   -- Parser error-reporting function can be overridden in subclass
   report_error( s : STR ) is
      if ( void( file_name ) ) then
	 #ERR + "error: " + s + "\n";
      else
	 #ERR + file_name + ": error: " + s + "\n";
      end;
   end;
   
   -- Parser warning-reporting function can be overridden in subclass 
   report_warning( s : STR ) is
      if ( void( file_name ) ) then
	 #ERR + "warning: " + s + "\n";
      else
	 #ERR + file_name + ": warning: " + s + "\n";
      end;
   end;

   rewind ( pos : INT) is
      input_state.input.rewind(pos);
   end;

   file_name( f : STR ) is 
      input_state.file_name := f;
   end;

   -- Set or change the input token buffer 
   token_buffer( t : ANTLR_TOKEN_BUFFER{TOKEN} ) is
      input_state.input := t; 
   end;

   trace_in( rname : STR ) is
      #OUT + "enter " + rname + "; LA(1)=" + LT(1).text;
      if ( input_state.guessing > 0 ) then
	 #OUT + "[guessing]\n";
      else
	 #OUT + "\n";
      end;
   end;

   trace_out( rname : STR ) is
      #OUT + "exit "+ rname + "; LA(1)=" + LT(1).text;
      if ( input_state.guessing > 0 ) then
	 #OUT + "[guessing]\n";
      else
	 #OUT + "\n";
      end;
   end;

end;