Re: Whoa! Do Python and Lisp really have LAMBDA ?

From: Karl A. Krueger (kkrueger_at_example.edu)
Date: 10/27/03 

Date: Mon, 27 Oct 2003 16:02:20 +0000 (UTC)

In comp.lang.lisp Marco Antoniotti <marcoxa@cs.nyu.edu> wrote:
> Common Lisp does it right.
>
> (mapcar (lambda (f) (funcall f 1))
> (mapcar (lambda (i)
> (lambda (x) (+ x i)))
> (list 1 2 3)))
>
> ... This is what the Haskell code eventually boild down to.
>
> It is Python that apparently cannot do this. But, in all fairness,
> nowhere in Python there is a claim that lambda expressions are full fledged.

Python lambda isn't *that* limited. It's just that the equivalent is
rather ugly by Python standards:

[f(1) for f in
    [(lambda i: lambda x: x + i)(y)
            for y in [1, 2, 3]]]

This also works, but isn't any prettier:

map(lambda f: apply(f, (1,)),
    map(lambda i:
               lambda x: (x + i),
        [1, 2, 3]))

(Bleah. All those colons and commas are giving me MPI flashbacks.) 

-- 
Karl A. Krueger <kkrueger@example.edu>
Woods Hole Oceanographic Institution
Email address is spamtrapped.  s/example/whoi/
"Outlook not so good." -- Magic 8-Ball Software Reviews

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