view release on metacpan or  search on metacpan

share/endpoint/www/js/parsejavascript.js  view on Meta::CPAN

    // This makes a copy of the parser state. It stores all the
    // stateful variables in a closure, and returns a function that
    // will restore them when called with a new input stream. Note
    // that the cc array has to be copied, because it is contantly
    // being modified. Lexical objects are not mutated, and context
    // objects are not mutated in a harmful way, so they can be shared
    // between runs of the parser.
    function copy(){
      var _context = context, _lexical = lexical, _cc = cc.concat([]), _tokenState = tokens.state;
  
      return function copyParser(input){
        context = _context;
        lexical = _lexical;
        cc = _cc.concat([]); // copies the array
        column = indented = 0;
        tokens = tokenizeJavaScript(input, _tokenState);
        return parser;
      };
    }

    // Helper function for pushing a number of actions onto the cc
    // stack in reverse order.
    function push(fs){
      for (var i = fs.length - 1; i >= 0; i--)
        cc.push(fs[i]);
    }
    // cont and pass are used by the action functions to add other
    // actions to the stack. cont will cause the current token to be
    // consumed, pass will leave it for the next action.
    function cont(){
      push(arguments);
      consume = true;
    }
    function pass(){
      push(arguments);
      consume = false;
    }
    // Used to change the style of the current token.
    function mark(style){
      marked = style;
    }

    // Push a new scope. Will automatically link the current scope.
    function pushcontext(){
      context = {prev: context, vars: {"this": true, "arguments": true}};
    }
    // Pop off the current scope.
    function popcontext(){
      context = context.prev;
    }
    // Register a variable in the current scope.
    function register(varname){
      if (context){
        mark("js-variabledef");
        context.vars[varname] = true;
      }
    }
    // Check whether a variable is defined in the current scope.
    function inScope(varname){
      var cursor = context;
      while (cursor) {
        if (cursor.vars[varname])
          return true;
        cursor = cursor.prev;
      }
      return false;
    }
  
    // Push a new lexical context of the given type.
    function pushlex(type, info) {
      var result = function(){
        lexical = new JSLexical(indented, column, type, null, lexical, info)
      };
      result.lex = true;
      return result;
    }
    // Pop off the current lexical context.
    function poplex(){
      if (lexical.type == ")")
        indented = lexical.indented;
      lexical = lexical.prev;
    }
    poplex.lex = true;
    // The 'lex' flag on these actions is used by the 'next' function
    // to know they can (and have to) be ran before moving on to the
    // next token.
  
    // Creates an action that discards tokens until it finds one of
    // the given type.
    function expect(wanted){
      return function expecting(type){
        if (type == wanted) cont();
        else if (wanted == ";") pass();
        else cont(arguments.callee);
      };
    }

    // Looks for a statement, and then calls itself.
    function statements(type){
      return pass(statement, statements);
    }
    function expressions(type){
      return pass(expression, expressions);
    }
    // Dispatches various types of statements based on the type of the
    // current token.
    function statement(type){
      if (type == "var") cont(pushlex("vardef"), vardef1, expect(";"), poplex);
      else if (type == "keyword a") cont(pushlex("form"), expression, statement, poplex);
      else if (type == "keyword b") cont(pushlex("form"), statement, poplex);
      else if (type == "{") cont(pushlex("}"), block, poplex);
      else if (type == ";") cont();
      else if (type == "function") cont(functiondef);
      else if (type == "for") cont(pushlex("form"), expect("("), pushlex(")"), forspec1, expect(")"), poplex, statement, poplex);
      else if (type == "variable") cont(pushlex("stat"), maybelabel);
      else if (type == "switch") cont(pushlex("form"), expression, pushlex("}", "switch"), expect("{"), block, poplex, poplex);
      else if (type == "case") cont(expression, expect(":"));
      else if (type == "default") cont(expect(":"));
      else if (type == "catch") cont(pushlex("form"), pushcontext, expect("("), funarg, expect(")"), statement, poplex, popcontext);
      else pass(pushlex("stat"), expression, expect(";"), poplex);
    }
    // Dispatch expression types.
    function expression(type){
      if (atomicTypes.hasOwnProperty(type)) cont(maybeoperator);