main.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

class M is

   -- Define a selector that can handle nested include files.
   -- These variables are public so the parser/lexer can see them.
   shared selector : ANTLR_TOKEN_STREAM_SELECTOR{ANTLR_COMMON_TOKEN};
   shared parser : P_PARSER{ANTLR_COMMON_TOKEN,ANTLR_COMMON_AST};
   shared main_lexer : P_LEXER{ANTLR_COMMON_TOKEN};

   create : SAME is
      res ::= new;
      res.selector := #ANTLR_TOKEN_STREAM_SELECTOR{ANTLR_COMMON_TOKEN};
      return res;
   end;

end;

class MAIN is

   main ( args : ARRAY{STR} ) is

      if ( args.size < 2 ) then
	 #OUT + "usage " + args[0] + " <filename>\n";
	 return;
      end;
	 
      f : IFSTREAM := IFSTREAM::open_for_read( args[1] );

      if ( void(f) ) then
	 #OUT + "file \"" + args[1] + "\" not found\n";
	 return;
      end;

      protect

	 m ::= #M;
	 
	 -- attach java lexer to the input stream,
	 M::main_lexer := #P_LEXER{ANTLR_COMMON_TOKEN}( f );

	 -- notify selector about starting lexer; name for convenience
	 M::selector.add_input_stream( M::main_lexer, "main");
	 M::selector.select("main"); -- start with main P lexer

	 -- Create parser attached to selector
	 M::parser := #P_PARSER{ANTLR_COMMON_TOKEN,ANTLR_COMMON_AST}( M::selector );

	 -- Parse the input language: P
	 M::parser.file_name( args[1] );
	 M::parser.startRule;
	 
      when $ANTLR_RECOGNITION_EXCEPTION then
	 #ERR + "exception: " + exception.str + "\n";	 
      end;
      
   end;
end;