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;;; kolam --- GraphQL implementation
;;; Copyright © 2021 Arun Isaac <arunisaac@systemreboot.net>
;;;
;;; This file is part of kolam.
;;;
;;; kolam is free software; you can redistribute it and/or modify it
;;; under the terms of the GNU Affero General Public License as
;;; published by the Free Software Foundation; either version 3 of the
;;; License, or (at your option) any later version.
;;;
;;; kolam is distributed in the hope that it will be useful, but
;;; WITHOUT ANY WARRANTY; without even the implied warranty of
;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
;;; Affero General Public License for more details.
;;;
;;; You should have received a copy of the GNU Affero General Public
;;; License along with kolam. If not, see
;;; <http://www.gnu.org/licenses/>.
(define-module (kolam utils)
#:use-module (ice-9 match)
#:export (pairify))
(define (pairify lst)
"Return a list of pairs of successive elements of LST. For example,
(pairify (list 1 2 3 4 5 6))
=> ((1 . 2) (3 . 4) (5 . 6))"
(match lst
(() '())
((first second tail ...)
(cons (cons first second)
(pairify tail)))))
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