[Python-ideas] a new lambda syntax

Stephen J. Turnbull stephen at xemacs.org
Tue Oct 20 20:23:57 CEST 2009

Masklinn writes:
 > On 20 Oct 2009, at 07:37 , Stephen J. Turnbull wrote:

 > > That doesn't look like what "anonymous block" means to me.  It looks
 > > like a lambda.
 > >
 > An anonymous block and a lambda are the exact same thing.

Why use different names for them, then?  At least when discussing
Python which calls the concept "lambda"?

 > > The difference is that an block resolves all its non-argument
 > > references in the calling context

 > Are you talking about forming closures here?

No, I'm talking about the exact opposite, I think.  Let's forget Ruby,
since we're talking about anonymous functions after all, and what I
"know" about Ruby is all hearsay (and evidently not correctly
understood at that).  In Lisp, you can do something like this:

(defvar i)
(defvar f (lambda () (print i)))
(do ((i 10 (- i 1)))
    ((< i 1)) 
  (funcall f))

outputting 10 9 8 7 6 5 4 3 2 1 and returning nil.  Ie, it was my
understanding of "block" that free variables in the block have what in
Lisp is called "dynamic scope".

 > > So a block seems to be a conventional way of currying a more
 > > general function to the context of a specific suite.

That was a brain bubble, sorry.

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