publish

CHANGELOG.md

@@ -1,6 +1,7 @@
 # 0.7.1
 
 - fixed: `nextInt` results for `max >= 0x80000000` were not uniformly distributed
+- narrowed the range of possible `max` values for `Drandom`
 
 # 0.7.0+1
 

lib/src/80_drandom.dart

@@ -13,15 +13,15 @@ class Drandom extends Xoshiro128pp {
   ///
   /// This implementation is slightly faster than the standard one for
   /// all [max] values, except for [max], which are powers of two.
-  // @override
-  // int nextInt(int max) {
-  //   if (max < 1 || max > 0x7FFFFFFF) {
-  //     throw RangeError.range(max, 1, 0x7FFFFFFF);
-  //   }
-  //   int r = nextRaw32();
-  //   int m = max - 1;
-  //   for (int u = r; u - (r = u % max) + m < 0; u = nextRaw32()) {}
-  //   return r;
-  // }
+  @override
+  int nextInt(int max) {
+    if (max < 1 || max > 0x80000000) {
+      throw RangeError.range(max, 1, 0x80000000);
+    }
+    int r = nextRaw32();
+    int m = max - 1;
+    for (int u = r; u - (r = u % max) + m < 0; u = nextRaw32()) {}
+    return r;
+  }
 
 }

test/drandom_test.dart

@@ -17,4 +17,11 @@ void main() {
         [1686059242, 361797217, 1133571596, 465717623, 1522544346] );
   });
 
+  test('Drandom nextInt range', () {
+    final random = Drandom();
+
+    expect(()=>random.nextInt(0x80000000), throwsRangeError); // no problem
+    random.nextInt(0x80000001); // problem
+  });
+
 }