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

Steve Holden steve at holdenweb.com
Fri Mar 3 10:49:38 CET 2006

Tim Peters wrote:

[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 adopted them from pre-computer 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 (because of the "generator" part).

SETL and Icon, of course, both have their roots in SNOBOL4, which was designed by Griswold when he worked at (IIRC) Bell Labs. Robert Dewar produced the machine-independent SPITBOL implementation (which I ported to DecSystem 10 as an undergraduate project at Leeds University). Griswold later went to the University of Arizona and developed Icon, Dewar went to Rutgers (I think) and developed SETL.

regards Steve

Steve Holden +44 150 684 7255 +1 800 494 3119 Holden Web LLC/Ltd www.holdenweb.com Love me, love my blog holdenweb.blogspot.com

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