permuting several lists (was Re: [Python-Dev] zip() and list-comprehension with commas)
Eric S. Raymond
Wed, 12 Jul 2000 21:06:57 -0400
Guido van Rossum <email@example.com>:
> Yes, I agree. Main reason: it's trivial to combine this with list
> comprehensions, while the ';' notation had real problems there.
Perhaps this frees up semicolon for use in the list-comprehension constructor
syntax. BTW, I think whoever it was that suggested lazy eval for
comprehensions was right on -- but that ties into the larger issue of
generators and continuations. Really, a list comprehension ought to
be syntactic sugar for an Icon-like generator object.
> My bid for a name: splice().
Wearing my English-usage-pedant hat, I must regretfully judge this
inferior to weave(). The reason has to do with the spatial geometry
implied by the verbs.
You *splice* two ropes together end-to-end; the proper data-structure
analogy is with concatenation, and indeed splice() in Perl is a sort
of generalized slice'n'dicer for sequences.
On the other hand, you *weave* two threads together side by side to
form a parallel bundle. Much closer image.
OTOH, MAL's group of related constructors is pretty cool.
<a href="http://www.tuxedo.org/~esr">Eric S. Raymond</a>
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