Re: Question on pcase

[Michael Heerdegen <michael_heerdegen@web.de>]

Michael Heerdegen <michael_heerdegen@web.de> writes:

> Hmm, as I said before, it's impossible in the general case to separate a
> `pcase' pattern into a side effect free matching part and a
> binding/setting part.  That's because when variable binding is done,
> bindings established while performing the matching need to be in effect;
> look at the example at the end to see what I mean.

Of course could you use temporary vars to delay the actual settings
until you want to establish them.  However, the computation of the
values that will be bound can't be separated from the predicate F that
is returned by `abo-transform-pcase-pattern', unless you want to rerun
the matching code with all potential side effects.

But AFAIU `abo-transform-pcase-pattern' should be sufficient for your
purpose.


Michael.