From b7e304433a230fb45407ec106e8cc72b600bc45e Mon Sep 17 00:00:00 2001
From: Frederic <frederic@git.blinkenbunt.org>
Date: Sun, 7 Jul 2019 12:54:08 +0200
Subject: [PATCH] add support for functions in production rules

---
 lindenmayer-system/lindenmeyer-system.js | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/lindenmayer-system/lindenmeyer-system.js b/lindenmayer-system/lindenmeyer-system.js
index 11310c0..23e29a6 100644
--- a/lindenmayer-system/lindenmeyer-system.js
+++ b/lindenmayer-system/lindenmeyer-system.js
@@ -20,7 +20,13 @@ function generate(start, rules, iterations) {
         while(pos < start.length) {
             let w = start.slice(pos, pos + rule[0].length);
             if(startswith(w, rule[0])) {
-                start.splice(pos, rule[0].length, rule[1])
+                var ruleres;
+                if(typeof rule[1] == 'function') {
+                    ruleres = rule[1]();
+                } else {
+                    ruleres = rule[1];
+                }
+                start.splice(pos, rule[0].length, ruleres)
                 pos += rule[0].length;
             } else {
                 pos += 1;