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

Jonas Maebe jonas at zeus.ugent.be
Sun Nov 30 10:36:13 CET 2003

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.


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