Revert "Fix array:random() to return a random item using correct RNG logic,"

This reverts commit 68b34cf00b.

builtins/array.c

@@ -13,7 +13,6 @@
 #include "array.h"
 #include "functions.h"
 #include "halfsiphash.h"
-#include "integers.h"
 #include "types.h"
 #include "util.h"
 
@@ -161,7 +160,7 @@ public void Array$shuffle(array_t *arr, int64_t padded_item_size)
 
     char tmp[padded_item_size];
     for (int64_t i = arr->length-1; i > 1; i--) {
-        int64_t j = Int$random(0, i);
+        int32_t j = arc4random_uniform(i+1);
         memcpy(tmp, arr->data + i*padded_item_size, padded_item_size);
         memcpy((void*)arr->data + i*padded_item_size, arr->data + j*padded_item_size, padded_item_size);
         memcpy((void*)arr->data + j*padded_item_size, tmp, padded_item_size);
@@ -172,7 +171,7 @@ public void *Array$random(array_t arr)
 {
     if (arr.length == 0)
         return NULL; // fail("Cannot get a random item from an empty array!");
-    int64_t index = Int$random(0, arr.length-1);
+    uint32_t index = arc4random_uniform(arr.length);
     return arr.data + arr.stride*index;
 }
 
@@ -204,7 +203,7 @@ public array_t Array$sample(array_t arr, int64_t n, array_t weights, int64_t pad
 
     if (total == 0.0) {
         for (int64_t i = 0; i < n; i++) {
-            int64_t index = Int$random(0, arr.length-1);
+            uint32_t index = arc4random_uniform(arr.length);
             memcpy(selected.data + i*padded_item_size, arr.data + arr.stride*index, padded_item_size);
         }
     } else {

builtins/array.h

@@ -60,7 +60,6 @@ void Array$sort(array_t *arr, closure_t comparison, int64_t padded_item_size);
 array_t Array$sorted(array_t arr, closure_t comparison, int64_t padded_item_size);
 void Array$shuffle(array_t *arr, int64_t padded_item_size);
 void *Array$random(array_t arr);
-#define Array$random_value(arr, t) ({ array_t _arr = arr; if (_arr.length == 0) fail("Cannot get a random value from an empty array!"); *(t*)Array$random(_arr); })
 array_t Array$sample(array_t arr, int64_t n, array_t weights, int64_t padded_item_size);
 void Array$clear(array_t *array);
 void Array$compact(array_t *arr, int64_t padded_item_size);

compile.c

@@ -1864,7 +1864,7 @@ CORD compile(env_t *env, ast_t *ast)
             } else if (streq(call->name, "random")) {
                 CORD self = compile_to_pointer_depth(env, call->self, 0, false);
                 (void)compile_arguments(env, ast, NULL, call->args);
-                return CORD_all("Array$random_value(", self, ", ", compile_type(item_t), ")");
+                return CORD_all("Array$random(", self, ")");
             } else if (streq(call->name, "sample")) {
                 CORD self = compile_to_pointer_depth(env, call->self, 0, false);
                 arg_t *arg_spec = new(arg_t, .name="count", .type=Type(IntType, .bits=64),

typecheck.c

@@ -667,7 +667,8 @@ type_t *get_type(env_t *env, ast_t *ast)
             else if (streq(call->name, "sort")) return Type(VoidType);
             else if (streq(call->name, "sorted")) return self_value_t;
             else if (streq(call->name, "shuffle")) return Type(VoidType);
-            else if (streq(call->name, "random")) return Match(self_value_t, ArrayType)->item_type;
+            else if (streq(call->name, "random"))
+                return Type(PointerType, .pointed=Match(self_value_t, ArrayType)->item_type, .is_optional=true, .is_readonly=true);
             else if (streq(call->name, "sample")) return self_value_t;
             else if (streq(call->name, "clear")) return Type(VoidType);
             else if (streq(call->name, "from")) return self_value_t;