[Laszlo-dev] For Review: Change 20081021-dda-p Summary: Add return type declarations to SWF9

[André Bargull]

Was it already decided how to declare return types in LZX? So, how to 
name the attribute which specifies the type? It's now named "type", any 
other proposals? Like "return" or "returns"?
Any cast needs to be: "foo cast Bar", "Bar(foo)" is only available in 
plain AS3 code, in cross-runtime code the latter form is a function 
call. (That's why DHTML broke for you.)

We should consider to drop the lowercase "type"-declarations for 
<attribute> and instead prefer the JavaScript alternatives, because you 
need to use the Javascript-form anywhere else (typing for function 
arguments, variables,  function return types).


> Change 20081021-dda-p by dda at lester.local <http://www.openlaszlo.org/mailman/listinfo/laszlo-dev> on 2008-10-21 10:03:53 EDT
>      in /Users/dda/laszlo/src/svn/openlaszlo/trunk-a
>      for http://svn.openlaszlo.org/openlaszlo/trunk
>
> Summary: Add return type declarations to SWF9
>
> New Features:
>
> Bugs Fixed: LPP-7031 (swf9 back-end is dropping return type  
> declarations)
>
> Technical Reviewer: ptw (pending)
> QA Reviewer: promanik (pending)
> Doc Reviewer: (pending)
>
> Documentation:
>
> Release Notes:
>
> Details:
>
>      WEB-INF/lps/server/src/org/openlaszlo/sc/ParseTreePrinter.java
>      WEB-INF/lps/server/src/org/openlaszlo/sc/SWF9ParseTreePrinter.java
>
>        Explicit return types like Boolean in 'function foo () :  
> Boolean { }' were
>        not being emitted by the SWF9 backend.  The fix was  
> straightforward,
>        the fallout was not...
>
>
>      WEB-INF/lps/server/src/org/openlaszlo/compiler/NodeModel.java
>      WEB-INF/lps/server/src/org/openlaszlo/sc/Method.java
>      WEB-INF/lps/server/src/org/openlaszlo/sc/Function.java
>
>        Added a "type" attribute to <method> to set the return type.
>        This was needed to get a few cases where lzx code overrides LFC  
> functions (now with return typing!)
>        to compile.  This type must be 'Javascript' (i.e. Boolean, not  
> 'boolean' is used).
>        Some cleanup to reduce the number of constructors for Method/ 
> Function.  I think
>        this makes the code a bit clearer.
>
>      lps/components/base/datalistselector.lzx
>      lps/components/base/listselector.lzx
>      demos/lzpix/app.lzx
>
>        Added type="Boolean" to a few methods that override to allow  
> them to compile and
>        run in SWF9.
>
>
>      Fixing return typing exposed a lot of 'new' typing in LFC and  
> some in application code,
>      which caused various consistency errors in several categories.
>
>      - in many .lzs files, functions marked as returning a type did  
> not always
>        explicitly call return, or when they did they did not return a  
> value.
>        Initially, I tried to make intelligent guesses about values  
> returned (favoring 'null'),
>        but testing revealed many problems.  Ultimately, I needed to be
>        very conservative, returning 'undefined' in most cases, and false
>        for Boolean functions.  This seems to be the default behavior  
> for JS
>        when returns are missing values.  Cases that seemed most  
> questionable
>        I marked with:
>            TODO: [20081020 dda] review this return value change from  
> LPP-7031
>
>
>      - in several .lzs files, functions marked as override did not  
> always match return types.
>
>
>      - in several .lzs files, toString() is marked as :String, but in  
> others it is not.
>        For the moment, it was too big of a job to fix all these as  
> part of this (already
>        large) commit, so typing for this function was commented  
> whenever a
>        compile error showed a mismatch.
>
>
>      - in several .lzs files, functions with new typing returned a  
> value but without proper typing.
>        Type casting was added as appropriate.
>
>
>      WEB-INF/lps/lfc/kernel/swf9/LzMouseKernel.as:
>
>      - type of a local variable wasn't narrowly typed enough, leading to
>        errors in return statements.
>
>
>      WEB-INF/lps/lfc/debugger/LzDebug.lzs:
>
>      - __StringDescription() needed to be defined with exactly the  
> same argument signature
>        I don't know why return typing exposed this as a problem.
>
>
>      WEB-INF/lps/lfc/data/LzLazyReplicationManager.lzs:
>
>      - Certain local variables typed as LzView needed typing  
> commented.  Initial attempts
>        to fix the typing errors in this file involved casting, e.g.
>               var v:LzView = LzView(this.getNewClone( true ));
>        But these changes broke smokecheck for DHTML.  It seems that  
> some assumption
>        about typing is being violated and will need to be tracked down  
> later.
>        I commented out the typing for the local variables, and left  
> TODOs to clean
>        this up later.
>
>
>     Note that the compile errors fixed here only show up when building  
> the LFC (or app) for SWF9.
>     In debugging these problems it was most helpful to build the  
> debuglfc to get line number information.
>
> Tests:
>     tests: (smokecheck) * (swf8+dhtml)
>     apps: (weather+lzpix) * (swf8+swf9+dhtml), hello(swf9)
>
> Files:
> M      WEB-INF/lps/lfc/kernel/swf9/LFCApplication.as
> M      WEB-INF/lps/lfc/kernel/swf9/LzMouseKernel.as
> M      WEB-INF/lps/lfc/services/LzAudio.lzs
> M      WEB-INF/lps/lfc/debugger/LzDebug.lzs
> M      WEB-INF/lps/lfc/debugger/platform/swf9/LzFlashRemote.as
> M      WEB-INF/lps/lfc/debugger/platform/swf9/LzDebug.as
> M      WEB-INF/lps/lfc/views/LaszloView.lzs
> M      WEB-INF/lps/lfc/controllers/LzAnimatorGroup.lzs
> M      WEB-INF/lps/lfc/controllers/LaszloAnimation.lzs
> M      WEB-INF/lps/lfc/data/LzLazyReplicationManager.lzs
> M      WEB-INF/lps/lfc/data/LzReplicationManager.lzs
> M      WEB-INF/lps/lfc/data/LzDatapointer.lzs
> M      WEB-INF/lps/lfc/data/LzDataText.lzs
> M      WEB-INF/lps/lfc/data/LzDataNode.lzs
> M      WEB-INF/lps/lfc/data/LzDataElement.lzs
> M      WEB-INF/lps/lfc/data/LzDatapath.lzs
> M      WEB-INF/lps/lfc/data/LzResizeReplicationManager.lzs
> M      WEB-INF/lps/lfc/data/LzParam.lzs
> M      WEB-INF/lps/lfc/data/LzDataAttrBind.lzs
> M      WEB-INF/lps/lfc/compiler/LzBootstrapDebugService.lzs
> M      WEB-INF/lps/server/src/org/openlaszlo/sc/Method.java
> M      WEB-INF/lps/server/src/org/openlaszlo/sc/ 
> SWF9ParseTreePrinter.java
> M      WEB-INF/lps/server/src/org/openlaszlo/sc/Function.java
> M      WEB-INF/lps/server/src/org/openlaszlo/sc/ParseTreePrinter.java
> M      WEB-INF/lps/server/src/org/openlaszlo/compiler/NodeModel.java
> M      lps/components/base/datalistselector.lzx
> M      lps/components/base/listselector.lzx
> M      demos/lzpix/app.lzx
>
> Changeset: http://svn.openlaszlo.org/openlaszlo/patches/20081021-dda-p.tar
>
>
>
> --
>
> Don Anderson
> Java/C/C++, Berkeley DB, systems consultant
>
> voice: 617-547-7881
> email: dda at ddanderson.com <http://www.openlaszlo.org/mailman/listinfo/laszlo-dev>
> www: http://www.ddanderson.com
>