I am trying to learn lisp, using emacs dialect and I have a question.
let us say list has some members, for which predicate evaluates to false. how do I create a new list without those members? something like { A in L: p(A) is true }
. in python there is filter function, is there something equivalent in lisp? if not, how do I do it?
Thanks
These functions are in the CL package, you will need to (require 'cl)
to use them:
(remove-if-not #'evenp '(1 2 3 4 5))
This will return a new list with all even numbers from the argument.
Also look up delete-if-not
, which does the same, but modifies its argument list.