Changeset 1947

Timestamp:

08/30/10 19:09:39 (1 year ago)

Author:

dsimcha

Message:

std.algorithm.reduce() should throw on empty ranges and no explicit seed instead of silently returning bogus results.

Files:

• trunk/phobos/std/algorithm.d (modified) (4 diffs)

trunk/phobos/std/algorithm.d

@@ -421 +421 @@
-            else
-            {
+                enforce(!args[$ - 1].empty,
+                    "Cannot reduce an empty range w/o an explicit seed value.");
-                alias args[0] r;
-                static if (fun.length == 1)
@@ -505 +507 @@
-            }
-
+            enforce(initialized,
+                "Cannot reduce an empty iterable w/o an explicit seed value.");
+
-            static if(fun.length == 1)
-            {
@@ -545 +550 @@
-    struct OpApply
-    {
+        bool actEmpty;
+
-        int opApply(int delegate(ref int) dg)
-        {
-            int res;
+            if(actEmpty) return res;
+
-            foreach(i; 0..100)
-            {
@@ -563 +572 @@
-    assert(reduce!("a + b", max)(oa) == tuple(hundredSum, 99));
-    assert(reduce!("a + b", max)(tuple(5, 0), oa) == tuple(hundredSum + 5, 99));
+
+    // Test for throwing on empty range plus no seed.
+    try {
+        reduce!"a + b"([1, 2][0..0]);
+        assert(0);
+    } catch(Exception) {}
+
+    oa.actEmpty = true;
+    try {
+        reduce!"a + b"(oa);
+        assert(0);
+    } catch(Exception) {}
-}
-