From ae7119045e6fae803086000ccd2b54b90f52aa85 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Hugo=20H=C3=B6rnquist?= <hugo@lysator.liu.se>
Date: Tue, 21 Apr 2020 00:26:11 +0200
Subject: Add iterate procedure.

---
 module/util.scm | 8 ++++++++
 1 file changed, 8 insertions(+)

(limited to 'module')

diff --git a/module/util.scm b/module/util.scm
index 474c7589..4981bb9a 100644
--- a/module/util.scm
+++ b/module/util.scm
@@ -463,6 +463,14 @@
     (let* ((row rest (split-at list width)))
       (cons row (group rest width)))))
 
+;; repeatedly apply proc to base unitl @var{until} is satisfied.
+;; (a → a), (a → bool), a → a
+(define-public (iterate proc until base)
+  (let loop ((o base))
+    (if (until o)
+        o
+        (loop (proc o)))))
+
 
 
 (define-syntax let-env
-- 
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