src/lists.lisp @ 19519aba4cb5

Add `:key` for `extrema`
author Steve Losh <steve@stevelosh.com>
date Thu, 05 Dec 2019 19:41:57 -0500
parents de9d10a9b4b5
children ea581753e904
(in-package :losh.lists)

(defun somelist (predicate list &rest more-lists)
  "Call `predicate` on successive sublists of `list`, returning the first true result.

  `somelist` is to `some` as `maplist` is to `mapcar`.

  "
  (if more-lists
    (iterate
      (for lists :first (cons list more-lists) :then (mapcar #'cdr lists))
      (until (some #'null lists))
      (thereis (apply predicate lists)))
    (iterate (for l :on list)
             (thereis (funcall predicate l)))))