Merge pull request #4836 from CyberShadow/pull-20161003-223010

Fix Issue 16587 - split("", "x") should be ""
dlang · Oct 4, 2016 · e3f842d · e3f842d
2 parents 30aca42 + d6572c2
commit e3f842d
Showing 1 changed file with 20 additions and 17 deletions.
diff --git a/std/algorithm/iteration.d b/std/algorithm/iteration.d
@@ -3573,6 +3573,8 @@ if (is(typeof(binaryFun!pred(r.front, s)) : bool)
 
                 _separatorLength = codeLength!(ElementEncodingType!Range)(separator);
             }
+            if (_input.empty)
+                _frontLength = _atEnd;
         }
 
         static if (isInfinite!Range)
@@ -3704,7 +3706,6 @@ if (is(typeof(binaryFun!pred(r.front, s)) : bool)
 
     debug(std_algorithm) scope(success)
         writeln("unittest @", __FILE__, ":", __LINE__, " done.");
-    assert(equal(splitter("", ' '), [ "" ]));
     assert(equal(splitter("hello  world", ' '), [ "hello", "", "world" ]));
     assert(equal(splitter("žlutoučkýřkůň", 'ř'), [ "žlutoučký", "kůň" ]));
     int[] a = [ 1, 2, 0, 0, 3, 0, 4, 5, 0 ];
@@ -3717,7 +3718,7 @@ if (is(typeof(binaryFun!pred(r.front, s)) : bool)
     // }
     assert(equal(splitter(a, 0), w));
     a = null;
-    assert(equal(splitter(a, 0), [ (int[]).init ][]));
+    assert(equal(splitter(a, 0),  (int[][]).init));
     a = [ 0 ];
     assert(equal(splitter(a, 0), [ (int[]).init, (int[]).init ][]));
     a = [ 0, 1 ];
@@ -3821,17 +3822,17 @@ if (is(typeof(binaryFun!pred(r.front, s.front)) : bool)
     private:
         Range _input;
         Separator _separator;
-        enum size_t _unComputed = size_t.max - 1, _atEnd = size_t.max;
-        // _frontLength == _atEnd means empty
-        size_t _frontLength = _unComputed;
+        // _frontLength == size_t.max means empty
+        size_t _frontLength = size_t.max;
         static if (isBidirectionalRange!Range)
-            size_t _backLength = _unComputed;
+            size_t _backLength = size_t.max;
 
         @property auto separatorLength() { return _separator.length; }
 
         void ensureFrontLength()
         {
-            if (_frontLength != _unComputed) return;
+            if (_frontLength != _frontLength.max) return;
+            assert(!_input.empty);
             // compute front length
             _frontLength = (_separator.empty) ? 1 :
                            _input.length - find!pred(_input, _separator).length;
@@ -3842,7 +3843,8 @@ if (is(typeof(binaryFun!pred(r.front, s.front)) : bool)
         void ensureBackLength()
         {
             static if (isBidirectionalRange!Range)
-                if (_backLength != _unComputed) return;
+                if (_backLength != _backLength.max) return;
+            assert(!_input.empty);
             // compute back length
             static if (isBidirectionalRange!Range && isBidirectionalRange!Separator)
             {
@@ -3874,7 +3876,7 @@ if (is(typeof(binaryFun!pred(r.front, s.front)) : bool)
         {
             @property bool empty()
             {
-                return _frontLength == _atEnd;
+                return _frontLength == size_t.max && _input.empty;
             }
         }
 
@@ -3886,9 +3888,9 @@ if (is(typeof(binaryFun!pred(r.front, s.front)) : bool)
             {
                 // done, there's no separator in sight
                 _input = _input[_frontLength .. _frontLength];
-                _frontLength = _atEnd;
+                _frontLength = _frontLength.max;
                 static if (isBidirectionalRange!Range)
-                    _backLength = _atEnd;
+                    _backLength = _backLength.max;
                 return;
             }
             if (_frontLength + separatorLength == _input.length)
@@ -3905,7 +3907,7 @@ if (is(typeof(binaryFun!pred(r.front, s.front)) : bool)
             // reading the next item
             _input = _input[_frontLength + separatorLength .. _input.length];
             // mark _frontLength as uninitialized
-            _frontLength = _unComputed;
+            _frontLength = _frontLength.max;
         }
 
         static if (isForwardRange!Range)
@@ -3955,8 +3957,6 @@ if (is(typeof(binaryFun!pred(r.front, s.front)) : bool)
 
     debug(std_algorithm) scope(success)
         writeln("unittest @", __FILE__, ":", __LINE__, " done.");
-    assert(equal(splitter("", "  "), [ "" ]));
-
     auto s = ",abc, de, fg,hi,";
     auto sp0 = splitter(s, ',');
     // //foreach (e; sp0) writeln("[", e, "]");
@@ -4131,7 +4131,10 @@ private struct SplitterResult(alias isTerminator, Range)
         static if (!fullSlicing)
             _next = _input.save;
 
-        findTerminator();
+        if (!_input.empty)
+            findTerminator();
+        else
+            _end = size_t.max;
     }
 
     static if (isInfinite!Range)
@@ -4240,7 +4243,7 @@ private struct SplitterResult(alias isTerminator, Range)
             ["Mary", "", "has", "a", "little", "lamb.", "", "", ""]);
     compare("Mary  has a little lamb.",
             ["Mary", "", "has", "a", "little", "lamb."]);
-    compare("", [""]);
+    compare("", (string[]).init);
     compare(" ", ["", ""]);
 
     static assert(isForwardRange!(typeof(splitter!"a == ' '"("ABC"))));
@@ -4270,7 +4273,7 @@ private struct SplitterResult(alias isTerminator, Range)
         int[][] result;
     }
     Entry[] entries = [
-        Entry(0, 0, [[]]),
+        Entry(0, 0, []),
         Entry(0, 1, [[0]]),
         Entry(1, 2, [[], []]),
         Entry(2, 7, [[2], [4], [6]]),