Changeset 1567

Timestamp:

05/29/10 14:18:18 (15 years ago)

Author:

rsinfu

Message:

Removed backByBack code from r1566. It was too slow for large input ranges.
Fixed typo.

Files:

• trunk/phobos/std/range.d (modified) (2 diffs)

trunk/phobos/std/range.d

@@ -1190 +1190 @@
-----
- */
-
-struct Take(R) if (isInputRange!(R))
-{
-private:
-    R _input;
-    size_t _maxAvailable;
-    enum bool byRef = is(typeof(&_input.front) == ElementType!(R)*);
-
-    enum bool backByIndex = // Take.back = input[min(n,$) - 1]
-        isRandomAccessRange!(R) && (hasLength!(R) || isInfinite!(R));
-
-    enum bool backByBack  = // Take.back = input.back
-        !backByIndex && isBidirectionalRange!(R) && hasLength!(R);
-
-public:
-    alias R Source;
-
-    static if (byRef)
-        alias ref .ElementType!(R) ElementType;
-    else
-        alias .ElementType!(R) ElementType;
-
-    this(R input, size_t maxAvailable)
-    {
-        static if (backByBack)
-        {
-            while (input.length > maxAvailable)
-                input.popBack;
-        }
-        _input = input;
-        _maxAvailable = maxAvailable;
-    }
-
-    bool empty()
-    {
-        return _maxAvailable == 0 || _input.empty;
-    }
-
-    void popFront()
-    {
-        enforce(_maxAvailable > 0,
-n
+m
-            ~ Take.stringof);
-        _input.popFront;
-        --_maxAvailable;
-    }
-
-    // @@@@@@@@@@@ UGLY @@@@@@@@@@@@@@@
-    mixin(
-        (byRef ? "ref " : "")~
-        q{ElementType front()
-        {
@@ -1255 +1238 @@
-        }
-    }
-    else static if (hasLength!(R))
-    {
-        @property size_t length()
-        {
-            return min(_maxAvailable, _input.length);
-        }
-    }
-
-backByIndex
+isRandomAccessRange!(R) && (hasLength!(R) || isInfinite!(R))
-    {
-        void popBack()
-        {
-            enforce(_maxAvailable > 0,
-n
+m
-                ~ Take.stringof);
-            --_maxAvailable;
-        }
-
-        mixin(
-            (byRef ? "ref " : "")~
-            q{/+auto ref+/ ElementType back()
-            {
-                return _input[this.length - 1];
-            }});
-    }
-    else static if (backByBack)
-    {
-        invariant()
-        {
-            assert(_input.length <= _maxAvailable);
-        }
-
-        void popBack()
-        {
-            enforce(_maxAvailable > 0,
-                "Attenpting to popBack() past the beginning of a "
-                ~ Take.stringof);
-            --_maxAvailable;
-            _input.popBack;
-        }
-
-        mixin(
-            (byRef ? "ref " : "")~
-            q{/+auto ref+/ ElementType back()
-            {
-                return _input.back;
-            }});
-    }
-
-    static if (isRandomAccessRange!(R))
-    {
-        mixin(
-            (byRef ? "ref " : "")~
-            q{/+auto ref+/ ElementType opIndex(size_t index)
-            {
-                enforce(index < this.length,