added random function

src/built_ins.cpp

@@ -170,7 +170,7 @@ proc load_built_ins_into_environment() -> void {
         );                                                              \
     assert_type(label(params,__LINE__), Lisp_Object_Type::Pair);        \
     assert_type(label(params,__LINE__)->value.pair.first, Lisp_Object_Type::Symbol); \
-    auto label(sym,__LINE__) = label(params,__LINE__)->value.pair.first; \
+    static auto label(sym,__LINE__) = label(params,__LINE__)->value.pair.first; \
     auto label(sfun,__LINE__) = Memory::create_lisp_object_cfunction(special); \
     /*NOTE(Felix): for evaluating default args*/                        \
     /*push_environment(get_root_environment());*/                           \
@@ -190,13 +190,13 @@ proc load_built_ins_into_environment() -> void {
         Globals::Current_Execution::envi_stack.next_index,              \
         Globals::Current_Execution::envi_stack.next_index-1)
 
-	define((helper), "") {
-		return Memory::create_lisp_object_number(101);
-	};
-	define((test (:k (helper))), "") {
-		fetch(k);
-		return k;
-	};
+        define((helper), "") {
+                return Memory::create_lisp_object_number(101);
+        };
+        define((test (:k (helper))), "") {
+                fetch(k);
+                return k;
+        };
     define((= . args),
           "Takes 0 or more arguments and returns =t= if all arguments are equal "
           "and =()= otherwise.")
@@ -354,6 +354,19 @@ proc load_built_ins_into_environment() -> void {
         return Memory::create_lisp_object_number((int)a->value.number %
                                                  (int)b->value.number);
     };
+    define((get-random-between a b), "TODO") {
+        fetch(a, b);
+        try assert_type(a, Lisp_Object_Type::Number);
+        try assert_type(b, Lisp_Object_Type::Number);
+
+        double fa = a->value.number;
+        double fb = b->value.number;
+        double x = (double)rand()/(double)(RAND_MAX);
+        x *= (fb - fa);
+        x += fa;
+
+        return Memory::create_lisp_object_number(x);
+    };
     define((assert test), "TODO") {
         fetch(test);