[fpc-devel]Nested function as argument for TList.Sort

[Florian Klaempfl]

Olle Raab wrote:

> 03-11-30 10.36, skrev Jonas Maebe följande:
> 
> 
>>On 30-nov-03, at 02:29, Pedro Lopez-Cabanillas wrote:
>>
>>
>>>Of course, if the compiler doesn't support this feature, because the
>>>internal
>>>handling of function calls, a compiler error message is better than a
>>>program
>>>crash.
>>
>>The problem is that some iterator-implementations do (and only) support
>>local functions/procedures. The collections in TP's (and as such also
>>FPC's) objects.pas are an example. They include special code for that
>>support, however. So always giving an error is going to give a lot of
>>false errors for people coming from TP/BP.
>>
>>
>>>But I was talking about Pascal language conventions. Instead of my code
>>>snippet, you can refer to the document "Extended Pascal", ISO-10206,
>>>chapter
>>>6.11.6, examples 6-9. It's available here (among other places):
>>>http://www.pascal-central.com/standards.html
>>>
>>>And GPC supports this feature, see:
>>>http://www.gnu-pascal.de/demos/iteratordemo.pas
>>
>>That's because GPC supports standard/extended Pascal, we don't. To
>>implement this, I think a procedure variable must always be a
>>pointer+it's frame pointer (nil if it's not a nested procedure), a bit
>>like procedure of object.
> 
> 
> This is correct, in some Apple docs this pointer was called the "static
> link".
> 
> It's also supported in mac pascal dialects. It would be nice if we could
> support it, it is one of the strength with pascal to be able to do such
> things, e g supporting a local compare funciton to a generic sort procedure,
> IMHO. Its a nice feature to beat C fans with.
> 

OMG, I thought the proc. var stuff is fixed finished now :)