[fpc-devel] Pure function development

[Sven Barth]

Am 29.04.2020 um 22:51 schrieb Jonas Maebe:
> On 29/04/2020 22:43, J. Gareth Moreton wrote:
>> So are you officially rejecting pure functions and my future work on
>> them in this form?
> I'm just trying to say that there is already a (primitive) framework for
> propagating constant values through functions (in the optconstprop
> unit), and also an extensive framework for evaluating constant
> expressions (the simplify methods of all nodes), and that hence there
> may not be any need to develop a completely new constant evaluation and
> propagation framework next to this.
>
> I explained before that I am absolutely no fan of a "pure" attribute,
> but that has nothing to do with my remarks here. And no, I will not veto
> the inclusion of manual annotations of pure functions.

Assuming we want to have support for constant evaluation of functions 
(and I do admit that sometimes that is a really nice to have), I don't 
really see a way around marking such functions somehow, cause otherwise 
we'd have to store the node trees of all functions that we detect as 
pure in the PPU.

Regards,
Sven