[fpc-devel] Could FPC add the PLM "based" construct?

Giuliano Colla giuliano.colla at fastwebnet.it
Mon Nov 16 12:56:03 CET 2009

Micha Nelissen ha scritto:
> Giuliano Colla wrote:
>> var
>>   Pfoo: pointer;
>>   foo: "any valid FPC Type" based Pfoo;
>> or
>>   foo: based Pfoo "any valid FPC type";
>> .....
>>   Pfoo: pointer;
>>   PBfoo: PByte absolute Pfoo;
>>   PIfoo: PInteger absolute Pfoo;
> I don't see the difference between "based" and absolute, except order of 
> keywords?

With "based" you declare a variable name, which you access directly, 
without need of an extra type declaration. Pfoo is the pointer, foo is 
the variable, no ambiguity.

With "absolute" you need a) to declare an extra type (PByte, or 
whatever), b) to explicitly access the variable through the pointer 
(PBfoo^ as opposed to foo). But if the variable is an array or a string, 
then you have ambiguities wether Pfoo means the variable or the pointer.

Order of keywords of course is not relevant, I just picked up the first 
one coming to my mind.

Giuliano Colla

Whenever people agree with me, I always feel I must be wrong (O. Wilde)

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