Create a helpers module for miscellaneous convenient procedures.

1 files changed, 37 insertions, 0 deletions

diff --git a/2d/helpers.scm b/2d/helpers.scm
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+;;; guile-2d
+;;; Copyright (C) 2013 David Thompson <dthompson2@worcester.edu>
+;;;
+;;; Guile-2d is free software: you can redistribute it and/or modify it
+;;; under the terms of the GNU Lesser General Public License as
+;;; published by the Free Software Foundation, either version 3 of the
+;;; License, or (at your option) any later version.
+;;;
+;;; Guile-2d 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
+;;; Lesser General Public License for more details.
+;;;
+;;; You should have received a copy of the GNU Lesser General Public
+;;; License along with this program.  If not, see
+;;; <http://www.gnu.org/licenses/>.
+
+;;; Commentary:
+;;
+;; Miscellaneous helper procedures.
+;;
+;;; Code:
+
+(define-module (2d helpers)
+  #:use-module (srfi srfi-1)
+  #:export (any-equal?
+            logand?))
+
+(define (any-equal? elem . args)
+  "Returns true if elem equals any of the arguments and returns false
+otherwise."
+  (any (lambda (e) (= elem e)) args))
+
+(define (logand? . args)
+  "Returns true if the result of a bitwise AND of the integer
+arguments is non-zero and returns false otherwise."
+  (not (zero? (apply logand args))))