Re: [fpc-pascal] TypeInfo question

2017-03-24 Thread Sven Barth via fpc-pascal 
Am 24.03.2017 03:51 schrieb "Ryan Joseph" :
> Is there anyway I could push the type checking to runtime? I wanted to
using writeln also to perform some printing for debugging but I get stuck
at compile time again trying to mix, integers, strings, records, classes
etc… in the generic. I would use an interface but there are compiler types
and records involved so that’s not an option.
>
> type
> TLongIntMatrix = specialize TMatrix;
> TObjectMatrix = specialize TMatrix;
>
>
> function TMatrix.RetainValue (value: T): T;
> begin
> if typeKind = tkClass then
> TObject(value).Retain;
>
> result := value;
> end;
>

You could try to do it with a pointer:

PObject(@value)^.Retain;

Regards,
Sven
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Re: [fpc-pascal] TypeInfo question

2017-03-23 Thread Ryan Joseph 
I think I already learned this and I forget when I had the idea about TypeInfo. 
:) 

This is basically the pattern I’m attempting. I have a generic class and I 
thought I could avoid specializing and making a subclass so that I could call a 
method if the type of the generic was a class. So what happens as you now is 
that I can’t cast “value” to TObject because if the generic was specialized as 
an integer for example, the type cast would be illegal and I get stuck at 
compile time (Illegal type conversion: "LongInt" to "TObject”).

Is there anyway I could push the type checking to runtime? I wanted to using 
writeln also to perform some printing for debugging but I get stuck at compile 
time again trying to mix, integers, strings, records, classes etc… in the 
generic. I would use an interface but there are compiler types and records 
involved so that’s not an option.

type
TLongIntMatrix = specialize TMatrix;
TObjectMatrix = specialize TMatrix;


function TMatrix.RetainValue (value: T): T;
begin
if typeKind = tkClass then
TObject(value).Retain;

result := value;
end;



Regards,
Ryan Joseph

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Re: [fpc-pascal] TypeInfo question

2017-03-23 Thread Ryan Joseph 

> On Mar 23, 2017, at 11:16 PM, Sven Barth via fpc-pascal 
>  wrote:
> 
> TypeInfo() simply inserts the load of a pointer value, so there's not even a 
> call.
> 
> 

Great, that’s what I was hoping. Thanks.

Regards,
Ryan Joseph

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Re: [fpc-pascal] TypeInfo question

2017-03-23 Thread Sven Barth via fpc-pascal 
Am 23.03.2017 16:29 schrieb "Ryan Joseph" :
>
> I have some generics which operate on multiple types and instead of
making subclasses for certain types and overriding methods I wonder if
using the RTTI like:
>
> PTypeInfo(TypeInfo(T))^.kind = tkClass
>
> would be a good idea. How is TypeInfo() implemented exactly? I’m curious
if there are any string comparing, allocating memory etc... that would
adversely affect performance since these classes need to perform fast data
lookups/insertions.

TypeInfo() simply inserts the load of a pointer value, so there's not even
a call.

Regards,
Sven
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