core: added random & random-between to char, random to string

core/Char.carp

@@ -5,6 +5,12 @@
   (register from-int (Fn [Int] Char))
   (register copy (Fn [&Char] Char))
 
+  (defn random []
+    (from-int (Int.random) 255))
+
+  (defn random-between [a b]
+    (from-int (Int.random-between (to-int a) (to-int b)) 255))
+
   (defn meaning [char-ref]
     (cond
       (= @char-ref \0) 0

core/String.carp

@@ -75,6 +75,9 @@
 
   (defn empty? [s]
     (Int.= (count s) 0))
+
+  (defn random-sized [n]
+    (from-chars (Array.repeat n Char.random)))
 )
 
 (defmodule StringCopy

core/core.h

@@ -437,7 +437,7 @@ double Double_random() {
 
 double Double_random_MINUS_between(double lower, double upper) {
     float diff = upper - lower;
-    float r = ((float)(rand() % INT_MAX)) / ((float)INT_MAX);
+    double r = ((double)(rand() % INT_MAX)) / ((double)INT_MAX);
     return lower + diff * r;
 }