Well yes, I follow the logic. I don't understand if this is a solution, why
TypeScript doesn't use the same algorithm.
I read what the developers said and they said they had talked about it in
length when the project first started and came to the conclusion there
really is no solution.
So what is different about this?
The only thing I can think of is that we introduce utility functions to do
the work and they didn't want to do that, I did get this from the
conversation, they stated they wanted it to be plain javascript, the only
helper they use is _extends function they write out for inheritance.
I was thinking about TypeScript, other than the language difference, there
is really NO difference in our compiler and what they do. Which is cool
because all the usecases that they have will apply to this emitter.
Plus we have libraries and IDE support and possible MXML in the future.
Mike
On Thu, May 28, 2015 at 8:27 AM, Frédéric THOMAS <webdoubl...@hotmail.com>
wrote:
> I'm not a javascript guru either, but it was easy to create ES6 classes
> (left pane) and see the output (right pane), so, for the setter, it creates:
>
> For class A (simple):
>
> get: function () {
> return this._property;
> },
> set: function (value) {
> this._property = value;
> }
>
> For class B:
>
>
> set: function (value) {
> _set(Object.getPrototypeOf(B.prototype), "property", value,
> this);
> }
>
> Which calls:
>
> var _set = function set(object, property, value, receiver) {
> var desc = Object.getOwnPropertyDescriptor(object, property); // Get
> the property on B
> if (desc === undefined) { // If not overrided, will set the parent
> recursively if the parent doesn't override the property either.
> var parent = Object.getPrototypeOf(object);
> if (parent !== null) {
> set(parent, property, value, receiver);
> }
> } else if ("value" in desc && desc.writable) { // didn't get this part
> desc.value = value;
> } else { // Else call the setterv of this Object
> var setter = desc.set;
> if (setter !== undefined) {
> setter.call(receiver, value);
> }
> }
> return value;
> };
>
>
> get: function () {
> return _get(Object.getPrototypeOf(B.prototype), "property",
> this);
> },
>
> Which calls:
>
> this for the getter, do recursive call to the prototype to check if the
> property has been overriden, if Yes, get the value.
>
> var _get = function get(_x, _x2, _x3) {
> var _again = true;
> _function: while (_again) {
> var object = _x, property = _x2, receiver = _x3;
> desc = parent = getter = undefined;
> _again = false;
> var desc = Object.getOwnPropertyDescriptor(object, property);
> if (desc === undefined) {
> var parent = Object.getPrototypeOf(object);
> if (parent === null) {
> return undefined;
> } else {
> _x = parent;
> _x2 = property;
> _x3 = receiver;
> _again = true;
> continue _function;
> }
> } else if ("value" in desc) {
> return desc.value;
> } else {
> var getter = desc.get;
> if (getter === undefined) {
> return undefined;
> }
> return getter.call(receiver);
> }
> }
> };
>
> Does it do the trick ?
>
> Frédéric THOMAS
>
> > Date: Thu, 28 May 2015 07:47:45 -0400
> > Subject: Re: [FalconJX] JXEmitter accessors
> > From: teotigraphix...@gmail.com
> > To: dev@flex.apache.org
> >
> > Interesting Fred, I am no javascript guru so I need people to "tell" me
> > what I should have output.
> >
> > So let me get this straight, the left pane is ES6 and it converted it to
> > ES5 in the right pane?
> >
> > Mike
> >
> > On Thu, May 28, 2015 at 7:19 AM, Frédéric THOMAS <
> webdoubl...@hotmail.com>
> > wrote:
> >
> > > I just tried in babel, see what it generates:
> > >
> > >
> > >
> http://babeljs.io/repl/#?experimental=true&evaluate=true&loose=false&spec=false&code=class%20A%20{%0A%09constructor%28%29%20{%0A%09%20%20this._property%20%3D%20%22init%22%3B%0A%09}%0A%09get%20property%28%29%3Astring%20{%0A%09%09return%20this._property%3B%0A%09}%0A%09%0A%09set%20property%28value%3Astring%29%20{%0A%09%09this._property%20%3D%20value%3B%0A%09}%20%0A%09%0A%09showMyValue%28%29%20{%0A%09%09alert%28this._property%29%3B%0A%09}%0A%0A}%0A%0Aclass%20B%20extends%20A%20{%0A%09get%20property%28%29%3Astring%20{%0A%09%09return%20super.property%3B%0A%09}%0A%09%0A%09set%20property%28value%3Astring%29%20{%0A%09%09super.property%20%3D%20value%3B%0A%09}%0A}
> > >
> > > Frédéric THOMAS
> > >
> > > > Date: Thu, 28 May 2015 06:54:31 -0400
> > > > Subject: Re: [FalconJX] JXEmitter accessors
> > > > From: teotigraphix...@gmail.com
> > > > To: dev@flex.apache.org
> > > >
> > > > > I’m still surprised that in 2015, TS hasn’t been forced to handle
> > > super.
> > > > Are people not using inheritance much in TS?
> > > >
> > > > They tell them to use standard getValue(), setValue() in the
> property if
> > > > they need inheritance overrides.
> > > >
> > > > I'm kind of bummed about this whole thing, I stuck my foot in mouth
> here,
> > > > since I totally forgot about this stuff. Since I really wanted to do
> this
> > > > for Josh's POC, I am interested in what he "needs" to get his project
> > > > working, Josh?
> > > >
> > > > Mike
> > > >
> > > >
> > > > On Wed, May 27, 2015 at 7:51 PM, Alex Harui <aha...@adobe.com>
> wrote:
> > > >
> > > > >
> > > > >
> > > > > On 5/27/15, 4:16 PM, "Michael Schmalle" <teotigraphix...@gmail.com
> >
> > > wrote:
> > > > >
> > > > > >Ok, This needs to be clear to me before I go off to OZ.
> > > > > >
> > > > > >In Flex JS you have;
> > > > > >
> > > > > >Object.defineProperties(Base.prototype, /** @lends
> {Base.prototype}
> > > */ {
> > > > > >/** @expose */
> > > > > >text: {
> > > > > >get: /** @this {Base} */ function() {
> > > > > > return "A" + org_apache_flex_utils_Language.superGetter(Base,
> this,
> > > > > >'text');
> > > > > >},
> > > > > >set: /** @this {Base} */ function(value) {
> > > > > > if (value != org_apache_flex_utils_Language.superGetter(Base,
> this,
> > > > > >'text')) {
> > > > > > org_apache_flex_utils_Language.superSetter(Base, this, 'text',
> > > "B" +
> > > > > >value);
> > > > > > }
> > > > > >}}}
> > > > > >);
> > > > > >
> > > > > >I must use this obviously since hardly any actionscript could be
> cross
> > > > > >compiled if you can't call super accessors.
> > > > >
> > > > > I’m still surprised that in 2015, TS hasn’t been forced to handle
> > > super.
> > > > > Are people not using inheritance much in TS?
> > > > >
> > > > > >
> > > > > >Alex, when you have time, can you explain what this is doing so I
> can
> > > > > >implement it.
> > > > >
> > > > > I have not read the spec, but Object.defineProperties appears to
> > > associate
> > > > > a data structure with a “class”. When asked to interpret/execute
> > > > >
> > > > > Someinstance.someprop
> > > > >
> > > > > the JS runtime appears to check this data structure first, and
> call the
> > > > > get or set as needed. As I see it, there is no way to switch from
> > > > >
> > > > > SomeSubClass.someProp
> > > > >
> > > > > back to
> > > > >
> > > > > SomeBaseClass.someProp
> > > > >
> > > > > and retain the ‘this’ pointer and scope. If you had a variable
> called
> > > > > super it would still point to the same instance so super.someProp
> would
> > > > > just cause the runtime to find the subclass’s property map.
> > > > >
> > > > > In looking around the internet, the solutions seemed to:
> > > > > 1) get the superclass
> > > > > 2) get the property map of defined properties
> > > > > 3) get the getter or setter from the data structure
> > > > > 4) call it with the right ‘this’ pointer.
> > > > >
> > > > > So that’s what is in the current JSFlexJSEmitter, but it assumes
> > > > > goog.inherit is going to leave references to the base class in a
> > > > > particular way. TS probably leaves references to base classes some
> > > how so
> > > > > some abstraction around step 1 is probably required, but steps 2
> > > through 4
> > > > > can be the same.
> > > > >
> > > > > It is step 4 that re-introduces “re-writing” that you may be
> referring
> > > to
> > > > > as hell. The super setter again becomes a function call, so the
> AST
> > > walk
> > > > > needs to know that and walk the tree differently, saving a whole
> > > branch to
> > > > > be evaluated as the parameter to the function call. IOW, a binary
> > > > > operator becomes a function call. I’ll bet there are still bugs
> in the
> > > > > current JSFlexJSEmitter.
> > > > >
> > > > > And I think I still haven’t fixed the scenario where only a getter
> or
> > > > > setter is overridden. The generated code must propagate a “pass
> > > through”
> > > > > for the missing getter or setter to the subclass’s data structure
> > > > > otherwise the runtime will not find the setter or getter and think
> the
> > > > > property is now read-only or write-only.
> > > > >
> > > > > >
> > > > > >So correct me if I am wrong but, since there is really no solution
> > > without
> > > > > >an external utility to call a super accessor, we can't really say
> that
> > > > > >this
> > > > > >transpiler is producing vanilla javascript. Chicken egg thing.
> > > > >
> > > > > Technically, you could inline everything in the utility function
> and
> > > still
> > > > > called it vanilla. But it would be high-fat vanilla. ;-)
> > > > >
> > > > > A question for Josh is whether it would be ok to have a Google
> Closure
> > > > > Library dependency. These libraries exist to encapsulate some of
> these
> > > > > object oriented patterns like finding the base class and loading
> > > > > dependency definitions in a particular order. It seems to be
> somewhat
> > > > > pay-as-you-go. If no inheritance, then almost no “goog”.
> > > > >
> > > > > -Alex
> > > > >
> > > > >
> > >
> > >
>
>
