[Haskell-cafe] ANNOUNCE: pipes-core 0.0.1

Chris Smith cdsmith at gmail.com
Mon Mar 12 04:26:32 CET 2012

On Sun, Mar 11, 2012 at 8:53 PM, Mario Blažević <blamario at acanac.net> wrote:
>    May I enquire what was the reason for the non-termination of idP? Why was
> it not defined as 'forP yield' instead? The following command runs the way I
> expected.

With pipes-core (which, recall, is known to be unsound... just felt
this is a good time for a reminder of that, even though I believe the
subset that adds tryAwait and forP to be sound), you do get both (pipe
id) and (forP yield).  So discover which is the true identity, we can

idP >+> forP yield == forP yield
forP yield >+> idP == forP yield

Yep, looks like idP is still the identity.

Of course, the real reason (aside from the fact that you can check and
see) is that forP isn't definable at all in Gabriel's pipes package.

Chris Smith

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