Re: [FWP] Iternating over multiple lists

[Ronald J Kimball <rjk@linguist.dartmouth.edu>]

On Thu, May 18, 2000 at 04:47:05PM -0500, David L. Nicol wrote:
> Adam Sampson wrote:
> > 
> > On Wed, Apr 12, 2000 at 05:54:19AM +0000, John Carter wrote:
> > > > What perl needed to make the solution to this problem trivial (and
> > > > elegant) is "multiple map" (or, if you rather "parallel map").  That
> > > > is, imagine if you could do:
> > > >
> > > >    mmap {BLOCK} list1 list2 list3 list4 
> 
> I'm missing something.  What is this supposed to return
> that 
> 
> map {BLOCK} (list1, list2, list3, list4)
> 
> 
> or even, if they're all list references,
> 
> map {[map {BLOCK} @$_]} (list1, list2, list3, list4)
> 
> 
> doesn't?

Those both operate on a single element from a single list at a time.  The
proposed "multi map" would operate on a single element from *each list* at
a time.  If you had four lists, BLOCK would get four elements at once.

Ronald

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