diff options
| -rw-r--r-- | kolam/utils.scm | 34 |
1 files changed, 34 insertions, 0 deletions
diff --git a/kolam/utils.scm b/kolam/utils.scm new file mode 100644 index 0000000..0a7954c --- /dev/null +++ b/kolam/utils.scm @@ -0,0 +1,34 @@ +;;; 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))))) + |