short-lambda - a shorthand for defining lambda functions
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This module implements the reader macro #[...] which is used to
define short lambda functions that can be passed to functions such
as map, mapcar and maplist.
The following is an example usage:
* (map #[ + _ 1 ] '(1 2 3)
(2 3 4)
Notice the automatic definition of the variable _. This is the
argument that is passed to your function.
The macro parameter can be used to pass the number of arguments
that you would like defined in the resulting function. Variable
names follow the pattern of: _ (1st), __ (2nd), ___ (3rd), etc.
Notice that this can get a bit unwieldy, so it is not really
reccomended, but available if needed. Here's an example:
* (mapcar #3[ + _ __ ___ ] '(1 2 3) '(1 2 3) '(1 2 3))
(3 6 9)
They can also be nested, like so:
* (mapcar #2[mapcar #[ + _ 2] (append (list _ _) (list _ __))]
'(1 2 3) '(1 2 3))
((3 3 3 3) (4 4 4 4) (5 5 5 5))
Astute readers might notice the similarity to a syntax feature of
Arc. I just thought it would be interesting to write. Enjoy.
Bugs
----
- ] characters prior to the end of the #[...] sequence will cause
the reader to break ie. (#[map nil #[print _] "[abc]"] 0)
Author: Burton Samograd <kruhft@gmail.com>
Date: May 26, 2011
License
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cl-short-lambda is distributed under this license:
Copyright (c) 2011, Burton Samograd
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modification, are permitted provided that the following conditions are
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