[Python-ideas] Cofunctions - an enhancement to yield-from

[Cameron Simpson]

On 02Aug2010 23:16, ghazel at gmail.com <ghazel at gmail.com> wrote:
| On Mon, Aug 2, 2010 at 11:17 PM, Gregory Ewing
| <greg.ewing at canterbury.ac.nz> wrote:
| > Would you be interested in a system which requires marking
| > calls to coroutines, but tells you immediately when you
| > have forgotten to mark such a call?
| >
| > It might work something like this:
| >
| > 1. In a cofunction, a call to another cofunction must
| >   be marked with 'cocall', e,g.
| >
| >   z = cocall f(x, y)
| >
| > 2. Cofunctions *cannot* be called normally -- they do
| >   not have a __call__ method, only a __cocall__ method.
| >
| > So if you try to call a cofunction without using cocall,
| > you get an exception. If you try to call an ordinary function
| > using cocall, you get an exception. If you try to use cocall
| > but forget to declare the function with codef, you get an
| > exception (because cocall would only be allowed inside a
| > cofunction).
| 
| I like this idea.

Having just caught up with this thread, my first thought on reading the
opening post was that it could do with (2), above. So a big +1 from me.
It avoids misuse by failing early, and makes the failure reason obvious.

Cheers,
-- 
Cameron Simpson <cs at zip.com.au> DoD#743
http://www.cskk.ezoshosting.com/cs/

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