Convencience function for random + entropy function.

lib/std/math/math.random.c3

@@ -21,6 +21,11 @@ macro void seed(random, seed)
 	random.set_seed(@as_char_view(seed));
 }
 
+macro void seed_entropy(random)
+{
+	random.set_seed(&&entropy());
+}
+
 /**
  * @require is_random(random)
  **/
@@ -29,6 +34,17 @@ macro int next(random, int max)
 	return (int)(next_double(random) * max);
 }
 
+fn int rand(int max) @builtin
+{
+	tlocal Sfc64Random default_random;
+	tlocal bool initialized = false;
+	if (!initialized)
+	{
+		seed_entropy(&default_random);
+		initialized = true;
+	}
+	return next(&default_random, max);
+}
 /**
  * @require is_random(random)
  **/

lib/std/math/random/math.seeder.c3

@@ -1,4 +1,5 @@
 module std::math::random;
+import std::hash::fnv32a;
 
 const ODD_PHI64 @local = 0x9e3779b97f4a7c15;
 const MUL_MCG64 @local = 0xf1357aea2e62a9c5;
@@ -65,3 +66,27 @@ fn void seeder(char[] input, char[] out_buffer)
 		out_buffer[..] = ((char*)words.ptr)[:out_chars];
 	};
 }
+
+macro uint hash(value) @local
+{
+	return fnv32a::encode(&&bitcast(value, char[$typeof(value).sizeof]));
+}
+
+fn char[8 * 4] entropy()
+{
+	void* addr = malloc(1);
+	free(addr);
+	static uint random_int;
+	random_int += 0xedf19156;
+	uint[8] entropy_data = {
+		hash($$TIME),
+		hash(addr),
+		hash(&addr),
+		hash(&entropy),
+		random_int,
+		hash(clock::now()),
+		hash(&DString.init),
+		hash(mem::heap())
+    };
+    return bitcast(entropy_data, char[8 * 4]);
+}