[iterate-devel] Version plan for Iterate 1.4 and 1.5

[Hoehle, Joerg-Cyril]

Marc Battyani wrote:
>> Plans for 1.5:
>> + Move more code from the initially / loop prologue section 
>inside the let
>> binding initialization, which might cause some user code to 
>fail because of code movement

>Please don't wreck that! It's the reason I initially started 
>to use iterate.
>Those parts (prologue/epilog/var bindings) are under (and 
>badly) specified
>in LOOP and implementations differ on this. So let's keep it 
>in a sane way.

What I mean is that Iterate is inconsistent. Did you know that WITH clauses get completely placed inside the surrouding let, while FOR ... ON <list> gets set in the :initially section, while other (e.g. reducing ...) also get set inside LET?

I wanted to move as much as possible inside the surrouding LET.
There's a *small* posibility that user code will break.

In fact, I expect none of the current tests to fails as a result of such a change.


>> For a farther future: move to another design for iteration
>Do you already have some ideas on this ?
No. gclcvs (which passed most Iterate tests) reminded me of the other Iterate package featuring gathering. I'll look at that.


What really disturbs me with Iterate has a design weakness about referential transparency and inadvertent capture, e.g.
(iter (with-some-other-macro (collect foo)))
when with-some-other-macro itself expands to an iterate loop.

It similar to those cases when an implicit block would change the target of a return statement.

There's IMHO no way around that deficiency in Iterate.

LOOP OTOH is robust against that, since it knows no clauses nested inside normal Lisp forms.

Regards,
	Jörg.