[Laszlo-dev] defining classes in any order in LZX

[Donald Anderson]

Are you suggesting we handle this in the tag compiler?  Are there  
advantages to that?
Might be useful to have the capability in lzs code too.

- Don

On Feb 11, 2009, at 5:29 PM, P T Withington wrote:

> This should be fairly easy. We already allow forward references to  
> classes when instantiating them. It would just mean delaying  
> completing the model until you need it, rather than at the time you  
> parse it.
>
> On Feb 11, 2009, at 16:22, Henry Minsky <henry.minsky at gmail.com>  
> wrote:
>
>> Currently the way the LZX compiler works, this code gives an error
>> "undefined superclass foo for class bar"
>>
>> <class name="bar" extends="foo"/>
>> <class name="foo"/>
>>
>>
>>
>> because the compiler parses classes internally in the lexical order
>> they occur in the source, and foo is not defined
>> yet when it tries to compile bar.
>>
>> However, we could make the compiler do a pass that stores the class
>> declarations and parses them on demand
>> so that the order you declare them lexically doesn't matter.
>>
>> I guess we've gotten this far without the compiler doing this for  
>> you,
>> but I'm wondering if it would
>> be a useful thing to do, considering that other object oriented
>> languages generally seem to allow
>> it.
>>
>> -- 
>> Henry Minsky
>> Software Architect
>> hminsky at laszlosystems.com


--

Don Anderson
Java/C/C++, Berkeley DB, systems consultant

voice: 617-306-2057
email: dda at ddanderson.com
www: http://www.ddanderson.com





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