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Merge pull request #1162 from andralex/5224
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Fix Issue 5224 - std.algorithm.remove!(SwapStrategy.unstable) doesn't work
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@AndrejMitrovic
AndrejMitrovic committed Jul 30, 2013
2 parents f2bd29c + ae8f014 commit dcd065e
Showing 1 changed file with 79 additions and 91 deletions.
170 changes: 79 additions & 91 deletions std/algorithm.d
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Expand Up @@ -7331,120 +7331,80 @@ cases.))
Range remove
(SwapStrategy s = SwapStrategy.stable, Range, Offset...)
(Range range, Offset offset)
if (isBidirectionalRange!Range && hasLength!Range && s != SwapStrategy.stable
if (s != SwapStrategy.stable
&& isBidirectionalRange!Range && hasLength!Range
&& Offset.length >= 1)
{
enum bool tupleLeft = is(typeof(offset[0][0]))
&& is(typeof(offset[0][1]));
enum bool tupleRight = is(typeof(offset[$ - 1][0]))
&& is(typeof(offset[$ - 1][1]));
static if (!tupleLeft)
Tuple!(size_t, "pos", size_t, "len")[offset.length] blackouts;
foreach (i, v; offset)
{
alias offset[0] lStart;
auto lEnd = lStart + 1;
}
else
{
auto lStart = offset[0][0];
auto lEnd = offset[0][1];
}
static if (!tupleRight)
{
alias offset[$ - 1] rStart;
auto rEnd = rStart + 1;
}
else
{
auto rStart = offset[$ - 1][0];
auto rEnd = offset[$ - 1][1];
}
// Begin. Test first to see if we need to remove the rightmost
// element(s) in the range. In that case, life is simple - chop
// and recurse.
if (rEnd == range.length)
{
// must remove the last elements of the range
range.popBackN(rEnd - rStart);
static if (Offset.length > 1)
static if (is(typeof(v[0]) : size_t) && is(typeof(v[1]) : size_t))
{
return .remove!(s, Range, Offset[0 .. $ - 1])
(range, offset[0 .. $ - 1]);
blackouts[i].pos = v[0];
blackouts[i].len = v[1] - v[0];
}
else
{
return range;
}
}

// Ok, there are "live" elements at the end of the range
auto t = range;
auto lDelta = lEnd - lStart, rDelta = rEnd - rStart;
auto rid = min(lDelta, rDelta);
foreach (i; 0 .. rid)
{
move(range.back, t.front);
range.popBack();
t.popFront();
}
if (rEnd - rStart == lEnd - lStart)
{
// We got rid of both left and right
static if (Offset.length > 2)
{
return .remove!(s, Range, Offset[1 .. $ - 1])
(range, offset[1 .. $ - 1]);
static assert(is(typeof(v) : size_t), typeof(v).stringof);
blackouts[i].pos = v;
blackouts[i].len = 1;
}
else
{
return range;
static if (i > 0)
{
enforce(blackouts[i - 1].pos + blackouts[i - 1].len
<= blackouts[i].pos,
"remove(): incorrect ordering of elements to remove");
}
}
else if (rEnd - rStart < lEnd - lStart)

size_t left = 0, right = offset.length - 1;
auto tgt = range.save;
size_t steps = 0;

while (left <= right)
{
// We got rid of the entire right subrange
static if (Offset.length > 2)
{
return .remove!(s, Range)
(range, tuple(lStart + rid, lEnd),
offset[1 .. $ - 1]);
}
else
// Look for a blackout on the right
if (blackouts[right].pos + blackouts[right].len >= range.length)
{
auto tmp = tuple(lStart + rid, lEnd);
return .remove!(s, Range, typeof(tmp))
(range, tmp);
range.popBackN(blackouts[right].len);
--right;
continue;
}
}
else
{
// We got rid of the entire left subrange
static if (Offset.length > 2)
// Advance to next blackout on the left
assert(blackouts[left].pos >= steps);
tgt.popFrontN(blackouts[left].pos - steps);
steps = blackouts[left].pos;
auto toMove = min(
blackouts[left].len,
range.length - (blackouts[right].pos + blackouts[right].len));
foreach (i; 0 .. toMove)
{
return .remove!(s, Range)
(range, offset[1 .. $ - 1],
tuple(rStart, lEnd - rid));
move(range.back, tgt.front);
range.popBack();
tgt.popFront();
}
else
steps += toMove;
if (toMove == blackouts[left].len)
{
auto tmp = tuple(rStart, lEnd - rid);
return .remove!(s, Range, typeof(tmp))
(range, tmp);
// Filled the entire left hole
++left;
continue;
}
}

return range;
}

// Ditto
Range remove
(SwapStrategy s = SwapStrategy.stable, Range, Offset...)
(Range range, Offset offset)
if ((isForwardRange!Range && !isBidirectionalRange!Range
|| !hasLength!Range || s == SwapStrategy.stable)
&& Offset.length >= 1)
if (s == SwapStrategy.stable && isForwardRange!Range && Offset.length >= 1)
{
auto result = range;
auto src = range, tgt = range;
size_t pos;
foreach (i; offset)
foreach (pass, i; offset)
{
static if (is(typeof(i[0])) && is(typeof(i[1])))
{
Expand All @@ -7455,10 +7415,20 @@ if ((isForwardRange!Range && !isBidirectionalRange!Range
auto from = i;
enum delta = 1;
}
assert(pos <= from);
for (; pos < from; ++pos, src.popFront(), tgt.popFront())
enforce(pos <= from,
"remove(): incorrect ordering of elements to remove");
if (pass > 0)
{
move(src.front, tgt.front);
for (; pos < from; ++pos, src.popFront(), tgt.popFront())
{
move(src.front, tgt.front);
}
}
else
{
src.popFrontN(from);
tgt.popFrontN(from);
pos = from;
}
// now skip source to the "to" position
src.popFrontN(delta);
Expand All @@ -7470,6 +7440,16 @@ if ((isForwardRange!Range && !isBidirectionalRange!Range
return result;
}

unittest
{
// http://d.puremagic.com/issues/show_bug.cgi?id=10173
int[] test = iota(0, 10).array();
assertThrown(remove!(SwapStrategy.stable)(test, tuple(2, 4), tuple(1, 3)));
assertThrown(remove!(SwapStrategy.unstable)(test, tuple(2, 4), tuple(1, 3)));
assertThrown(remove!(SwapStrategy.stable)(test, 2, 4, 1, 3));
assertThrown(remove!(SwapStrategy.unstable)(test, 2, 4, 1, 3));
}

unittest
{
debug(std_algorithm) scope(success)
Expand All @@ -7482,11 +7462,15 @@ unittest

a = [ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 ];
assert(remove!(SwapStrategy.unstable)(a, 0, 10) ==
[ 9, 1, 2, 3, 4, 5, 6, 7, 8 ]);
[ 9, 1, 2, 3, 4, 5, 6, 7, 8 ]);

a = [ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 ];
assert(remove!(SwapStrategy.unstable)(a, 0, tuple(9, 11)) ==
[ 8, 1, 2, 3, 4, 5, 6, 7 ]);
// http://d.puremagic.com/issues/show_bug.cgi?id=5224
a = [ 1, 2, 3, 4 ];
assert(remove!(SwapStrategy.unstable)(a, 2) ==
[ 1, 2, 4 ]);

a = [ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 ];
//writeln(remove!(SwapStrategy.stable)(a, 1, 5));
Expand All @@ -7504,6 +7488,10 @@ unittest
a = [ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 ];
assert(remove!(SwapStrategy.stable)(a, 1, tuple(3, 5))
== [ 0, 2, 5, 6, 7, 8, 9, 10]);

a = iota(0, 10).array();
assert(remove!(SwapStrategy.unstable)(a, tuple(1, 4), tuple(6, 7))
== [0, 9, 8, 7, 4, 5]);
}

/**
Expand All @@ -7529,7 +7517,7 @@ if (isBidirectionalRange!Range)
{
for (;!range.empty;)
{
if (!unaryFun!(pred)(range.front))
if (!unaryFun!pred(range.front))
{
range.popFront();
continue;
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