generator/coroutine terminology

[Rustom Mody]

On Sunday, March 15, 2015 at 1:45:37 AM UTC+5:30, Ian wrote:
> Now which should be considered definitive, the language reference or
> the PEP? This question is not rhetorical; I don't know the answer.
> Regardless of the answer though, the PEP at least illuminates the
> design intent of the terminology.
>  
>  
> [1] https://docs.python.org/3/reference/expressions.html#yield-expressions
>  
> [2] https://www.python.org/dev/peps/pep-0255/

Thanks

That PEP deserves careful reading, particularly the end...

| BDFL Pronouncements 
| Issue:  Introduce another new keyword (say, "gen" or "generator") in
| place of "def", or otherwise alter the syntax, to distinguish
| generator-functions from non-generator functions.
|  
| Con:  In practice (how you think about them), generators *are*
| functions, but with the twist that they're resumable.  The mechanics of
| how they're set up is a comparatively minor technical issue, and
| introducing a new keyword would unhelpfully overemphasize the
| mechanics of how generators get started (a vital but tiny part of a
| generator's life).
|  
| Pro:  In reality (how you think about them), generator-functions are
| actually factory functions that produce generator-iterators as if by
| magic.  In this respect they're radically different from non-generator
| functions, acting more like a constructor than a function, so reusing
| "def" is at best confusing.  A "yield" statement buried in the body is
| not enough warning that the semantics are so different.
|  
| BDFL:  "def" it stays.  No argument on either side is totally
| convincing, so I have consulted my language designer's intuition.  It
| tells me that the syntax proposed in the PEP is exactly right - not too
| hot, not too cold.  But, like the Oracle at Delphi in Greek mythology,
| it doesn't tell me why, so I don't have a rebuttal for the arguments
| against the PEP syntax.  The best I can come up with (apart from
| agreeing with the rebuttals ... already made) is "FUD".  If this had
| been part of the language from day one, I very much doubt it would have
| made Andrew Kuchling's "Python Warts" page.

So while I dont go to the extent of suggesting introducing a different keyword for
generators, the fact that the overloading of def is problematic and arbitrary
comes from the horse's (ie BDFL's) mouth.