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From Alex Harui <aha...@adobe.com>
Subject Re: [FlaconJS] pseudo emitter algorithm
Date Thu, 29 Nov 2012 17:49:48 GMT
So if I understand you, the notion of traits is a SWF thing?  The AST has
different representations maybe like member, variable, function?


On 11/29/12 9:42 AM, "Michael Schmalle" <apache@teotigraphix.com> wrote:

> Quoting Alex Harui <aharui@adobe.com>:
> 
>> Very nice.  Have you figured out the role of the generated CMCEmitter in
>> this process?
> 
> Yes,
> 
> The CmcJSEmitter (autogenerated by cmc-js.jbg) is used to traverse the
> ISWF that is created.
> 
> The CmcJSEmitter and JSGeneratingReducer are created in the
> JSGenerator constructor.
> 
> The actual CmcJSEmitter is used during the
> JSClassDirectiveProcessor.delcareVariable() etc. methods.
> 
> Basically the processor is using the emitter to create SWF
> instructions that ultimately end up creating class traits. Once the
> tratis are created, they just keep getting recursively visited and
> more instructions created.
> 
> So it's like
> 
> - JSCompilationUnit.processABCBytesRequest()
>    - handleABCBytesRequest()
>    - JSGenerator.generate()
>      - then see below ....
> 
> When it gets to methods called declarePackage() for instance, block
> code instructions are created using the cmc emitter. Traits are then
> created based of them.
> 
> For FalconJS this process is totally bound to SWF format.
> 
> This was my point. For any developer to fix bugs here they have to
> know the SWF format. Which I don't.
> 
> This is why I propsed another solution using pure AST like Jangaroo does.
> 
> I am not skilled enough to understand the trade offs currently. But I
> am going to try and see if I can create the same JS code using a
> different algorithm.
> 
> Mike
> 
> 
> 
>> 
>> On 11/29/12 7:30 AM, "Michael Schmalle" <apache@teotigraphix.com> wrote:
>> 
>>> Hi,
>>> 
>>> For those asking question about "where to alter" code, it's not pretty
>>> but I think I know exactly what is going on now.
>>> 
>>> If you can understand below, you will now have some insight to where
>>> and how the JS code actually gets created.
>>> 
>>> 
>>> ! Call the compiler load config compile().
>>> 
>>> 
>>> JSGenerator.generate() - creates the package, class, member traits
>>> 
>>>   - DirectiveProcessor.processNode(IFileNode)
>>>     - recusrsivly fill traits
>>> 
>>> -----------------------------------------------------
>>> 
>>> Basically a snippet of the recursion;
>>> 
>>> DirectiveProcessor.processNode(IFileNode)
>>>    - declarePackage(PackageNode)
>>>      - emitter.visitPackage(packageName)
>>>      - data.registerPackage(packageName)
>>>      - super.declarePackage(PackageNode)
>>>        - DirectiveProcessor.traverse(p.getScopedNode()) <- ClassNode (class
>>> {})
>>>          - for each ClassNode.getChild(i)
>>>            - processNode(ScopedBlockNode)
>>>              - JSGlobalDirectiveProcessor.declareClass(ClassNode)
>>>                - verifyClassModifiers(ClassNode)
>>>                - skins
>>>                - JSClassDirectiveProcessor cp =
>>> backend.createClassDirectiveProcessor()
>>>                - cp.traverse(ClassNode.getScopedNode()) <- TypeScope
>>>                  - for each TypeScope.getChild(i)
>>>                    - processNode(TypeScope)
>>>                      -
>>> JSGlobalDirectiveProcessor.declareFunction(FunctionNode)
>>> 
>>> 
>>> --------------------------------------------------------
>>> 
>>> !!!!
>>> JavaScript source code creation after class traits have been traversed
>>> and created;
>>> 
>>> 
>>> JSEmiter.emit()
>>>    - emitClass(EmitterClassVisitor)
>>>      - IClassDefinition = getDefinition(ii.name)
>>>      - write class JSDoc
>>> 
>>> 
>>> 
>>> - JSEmitter.emitClass()
>>>    - Line: 3267 - 3269 is What creates a class
>>>      - "MainCode=adobe.extend("MainCode",Object,{ ... });"
>>> 
>>> 
>>> 
>>> - JSEmitter.emitInstanceTraits() is then called to write out the
>>> class traits
>>>    - emitTraits() is then called to do the specific if the closure
>>> compiler flag is not set
>>>      1. emitCtor() emit constructor
>>>       - emit comma
>>>      2. emit all variables before methods
>>>        - assembles the code "MainCode.foo"
>>>          - warns if there is a private namespace collision
>>>        -
>>>      3. emit all methods other than constructor
>>>        - emit ",\n"
>>>          - emitMethod()
>>>            - emitJSDocForMethod()
>>>            - write("\tget_baz")
>>>            - write(" : ") <- assignmentOp
>>>            - write("function(")
>>>              - emitParameters(methodInfo)
>>>                - write("baz")
>>>            - write(")")
>>>            - if (returnType != null)
>>>              - write(JSDoc for return type)
>>>            - if interface method
>>>              - write(" {};\n")
>>>            - else
>>>              - write("\n")
>>>              - write("  {")
>>>              - write("\n")
>>>              - emitMethodBody()
>>>                ... you get the drift
>>>              - write("  }")
>>> 
>>> - After all traits are written, control flow goes back to
>>> JSEmitter.emitClass() line 3269
>>>    - write("\n});\n\n") // end class
>>> - add _CLASS member to instance
>>>    - add JSDoc for prototype._CLASS
>>>    - write("MainCode.prototype._CLASS = MainCode;\n")
>>> 
>>> It will then go onto
>>>    - emitClassInfo()
>>>    - emitNamespaceInfo()
>>>    - emitJSONInfo()
>>> 
>>> if (JSSharedData.JS_FRAMEWORK_NAME)
>>>    - emitFrameworkInit();
>>> 
>>> It will then finally emit register class
>>>    - "adobe.classes.MainCode=MainCode;"
>>> 
>>> ---------------
>>> MainCode._PACKAGE=adobe.globals;MainCode._NAME="MainCode";
>>> MainCode._FULLNAME="MainCode";
>>> MainCode._SUPER=Object;
>>> MainCode._NAMESPACES={"foo::2":!0,"bar::7:MainCode":!0,"baz::2":!0,"baz::2":
>>> !0
>>> };
>>> adobe.classes.MainCode=MainCode;
>>> ---------------
>>> 
>>> Mike
>>> 
>>> 
>>> 
>>> 
>> 
>> --
>> Alex Harui
>> Flex SDK Team
>> Adobe Systems, Inc.
>> http://blogs.adobe.com/aharui
>> 
>> 

-- 
Alex Harui
Flex SDK Team
Adobe Systems, Inc.
http://blogs.adobe.com/aharui


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