refactor

src/__comm__/_str_hash.scad

@@ -1,11 +1,8 @@
 use <../util/sum.scad>;
 
 function _str_hash(value) = 
-    let(
+    let(s = str(value))
-	    s = str(value),
-		leng = len(s)
-	)
 	sum([
-	    for(i = [0:leng - 1])
+		for(i = len(s) - 1; i > -1; i = i - 1)
-		ord(s[i]) * 31 ^ (leng - 1 - i)
+		ord(s[i]) * 31 ^ i
 	]);