Flesh out dynamic invocation code

lib/runtime/dart_runtime.js

 // Copyright (c) 2015, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 var dart;
 (function (dart) {
   var defineProperty = Object.defineProperty;
   var getOwnPropertyDescriptor = Object.getOwnPropertyDescriptor;
   var getOwnPropertyNames = Object.getOwnPropertyNames;
 
   // Adapted from Angular.js
   var FN_ARGS = /^function\s*[^\(]*\(\s*([^\)]*)\)/m;
+  var METHOD_ARGS = /^[^\(]*\(\s*([^\)]*)\)/m
   var FN_ARG_SPLIT = /,/;
   var FN_ARG = /^\s*(_?)(\S+?)\1\s*$/;
   var STRIP_COMMENTS = /((\/\/.*$)|(\/\*[\s\S]*?\*\/))/mg;
 
   function formalParameterList(fn) {
     var fnText,argDecl;
     var args=[];
     fnText = fn.toString().replace(STRIP_COMMENTS, '');
     argDecl = fnText.match(FN_ARGS);
+    if (!argDecl) {
+      // TODO(vsm): This appears to match current V8.  I don't see this spec'ed.
+      // ES 6 methods have a different syntax.

[Jennifer Messerly, 2015/02/26 20:53:16]

fyi, this is spec'd in Function.prototype.toString():
https://people.mozilla.org/~jorendorff/es6-draft.html#sec-function.prototype....

relevant spec text:
"The string representation must have the syntax of a FunctionDeclaration
FunctionExpression, GeneratorDeclaration, GeneratorExpression, ClassDeclaration,
ClassExpression, ArrowFunction, MethodDefinition, or GeneratorMethod depending
upon the actual characteristics of the object."

we'll likely need support for arrow functions, generators too

[vsm, 2015/03/03 21:06:12]

Thanks!  I made pointer to the spec and filed an issue.

+      argDecl = fnText.match(METHOD_ARGS);
+    }
 
     var r = argDecl[1].split(FN_ARG_SPLIT);
     for(var a in r){
       var arg = r[a];
       arg.replace(FN_ARG, function(all, underscore, name){
         args.push(name);
       });
     }
     return args;
   }
 
+  function isDartFunction(fn) {
+    // TODO(vsm): How do we differentiate?  For now, just reject native methods.

[Jennifer Messerly, 2015/02/26 20:53:16]

Assuming we still have the target object, "obj instanceof dart.Object" should do
the trick.
Definitely harder if we only have the unbound function. I added a note to
https://github.com/dart-lang/dev_compiler/issues/44

[vsm, 2015/03/03 21:06:12]

Thanks, added a pointer to the issue.

+    // TODO(vsm): Make this more robust - e.g., a regexp.
+    return fn.toString().indexOf('[native code]') == -1;
+  }
+
   function dload(obj, field) {
     if (!(field in obj)) {
       throw new core.NoSuchMethodError(obj, field);
     }
     return obj[field];
   }
   dart.dload = dload;
 
   // TODO(jmesserly): this should call noSuchMethod, not throw.
+  function dput(obj, field, value) {
+    if (!(field in obj)) {
+      throw new core.NoSuchMethodError(obj, field);
+    }
+    // TODO(vsm): Type check required.
+    obj[field] = value;
+  }
+  dart.dput = dput;
+
   function throwNoSuchMethod(obj, name, args, opt_func) {
     if (obj === void 0) obj = opt_func;
     throw new core.NoSuchMethodError(obj, name, args);
   }
 
+  function _numberInvoke(f, obj, args, name) {
+    var checkArg = function () {
+      var arg = args[0];
+      if (typeof(arg) != 'number') {
+        throw 'invalid operation';
+      }
+      return arg;
+    }
+
+    // TODO(vsm): Implement all Dart int and double instance methods.
+    switch (name) {
+      case '+':

[vsm, 2015/02/26 00:34:00]

Not sure which way we ought to go with these.  Are you thinking of something
like core.num['+']?

[Jennifer Messerly, 2015/02/26 20:53:16]

probably not anymore, given the generalize type proposal ... that would be an
instance method on the type. :)
but yeah, ideally we call the core library method here somehow, rather than
having it all in a dynamic dispatch helper. I think that's a bit cleaner design.
Then tghe num/string/bool methods are just things you link in from core.js,
rather than baked into dynamic dispatch.

reminds me of https://github.com/dart-lang/dev_compiler/issues/46 :)

+        return (args.length == 0) ? obj : obj + checkArg();
+      case '-':
+        return (args.length == 0) ? - obj : obj - checkArg();
+      case '*':
+        return obj * checkArg();
+      case '/':
+        return obj / checkArg();
+      case '~/':
+        return (obj / checkArg()).truncate();
+      case '<':
+        return obj < checkArg();
+    }
+    throw new core.UnimplementedError();
+  }
+
+  function _booleanInvoke(f, obj, args, name) {
+    // TODO(vsm): Implement all Dart bool instance methods.
+    throw new core.UnimplementedError();
+  }
+
+  function _stringInvoke(f, obj, args, name) {
+    // TODO(vsm): Implement all Dart string instance methods.
+    throw new core.UnimplementedError();
+  }
+
   function checkAndCall(f, obj, args, name) {
+    if (obj != null && !(obj instanceof dart.Object)) {
+      // Check for primitive types.

[Jennifer Messerly, 2015/02/26 20:53:16]

to build on previous comments ... Ideally, this worked more like:


var primitiveTypeMethods = {
  'number': core.num$methods,
  'boolean': core.bool$methods,
  'string': core.String$methods,
};

var methods = primitiveTypeMethods[typeof(obj)];
if (methods !== void 0) {
  f = methods[name];
} else {
 ...
}

note that this code likely lives down in "dinvoke" ... because by checkAndCall,
we already have an "f". The bug, I think, is down on this line: `return
checkAndCall(obj[method], obj, args, method);`

+      if (typeof(obj) == 'number') {
+        return _numberInvoke(f, obj, args, name);
+      } else if (typeof(obj) == 'boolean') {
+        return _booleanInvoke(f, obj, args, name);
+      } else if (typeof(obj) == 'string') {
+        return _stringInvoke(f, obj, args, name);
+      } else {
+        // obj is a JavaScript or native object.  Just call.
+        return f.apply(obj, args);
+      }
+    }
+
     if (!(f instanceof Function)) {
       // Grab the `call` method if it's not a function.
       if (f !== null) f = f.call;
       if (!(f instanceof Function)) {
         throwNoSuchMethod(obj, method, args);
       }
     }
+
+    if (!isDartFunction(f)) {

[Jennifer Messerly, 2015/02/26 20:53:16]

we could also just see if it has our type signature. If not, just call.

[vsm, 2015/03/03 21:06:12]

Right, thinking isDartFunction would do something along those lines.

+      // A JS or native function.  Just call.
+      return f.apply(obj, args);
+    }
+
     var formals = formalParameterList(f);
     // TODO(vsm): Type check args!  We need to encode sufficient type info on f.
     if (formals.length < args.length) {
       throwNoSuchMethod(obj, name, args, f);
     } else if (formals.length > args.length) {
       for (var i = args.length; i < formals.length; ++i) {
         if (formals[i].indexOf("opt$") != 0) {
           throwNoSuchMethod(obj, name, args, f);
         }
       }
@@ skipping 283 matching lines @@
     var init = this[name];
     var result = void 0;
     if (init) result = init.apply(this, arguments);
     return result === void 0 ? this : result;
   };
   // The initializer for dart.Object
   dart.Object.prototype.Object = function() {};
   dart.Object.prototype.constructor = dart.Object;
 
 })(dart || (dart = {}));