[Python-Dev] Using and binding relative names (was Re: PEP forBetter Control of Nested Lexical Scopes)

[Tim Peters]

[Alex Martelli]
>> We stole list comprehensions and genexps from Haskell

[Greg Ewing]
> The idea predates Haskell, I think. I first saw it in
> Miranda, and it may have come from something even
> earlier -- SETL, maybe?

Haskell indeed took list comprehensions from SETL.  SETL in turn took
them from much earlier standard notation in set theory, related to the
oddly named (but not universally so named) "axiom of comprehension".

genexps were more directly taken from Icon, but tying them into
Python's iteration protocol is a powerful twist not directly present
in Icon.