[m-dev.] proposal for promise_pure scope warning

[Peter Schachte]

Julien Fischer wrote:
> I think you only want to emit a warning for promise_pure scopes around
> impure goals that do not have any outputs and have determinism det or
> cc_multi however.

That's a lot clearer:  the promise really looks like it must be a lie.  The 
warning could ask the user to plug in their polygraph equipment into the USB 
port and prepare to answer a series of questions.  But the promise still 
might be correct.  The code might destructively modify some data structure in 
an equivalence-preserving way, eg caching the result of a computation.

-- 
Peter Schachte              It is the function of the citizen to keep the
schachte at cs.mu.OZ.AU        Government from falling into error.
www.cs.mu.oz.au/~schachte/      -- Robert H. Jackson
Phone: +61 3 8344 1338
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