Skip to content
This repository has been archived by the owner on Jan 23, 2023. It is now read-only.

Make it easier to iterate through an ArraySegment #8559

Merged
merged 5 commits into from
Dec 9, 2016
Merged

Make it easier to iterate through an ArraySegment #8559

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
5 commits
Select commit Hold shift + click to select a range
0a9b71f
Make it easier to iterate through an ArraySegment. See Make it easier…
AlexRadch Dec 9, 2016
5450b25
model.xml
AlexRadch Dec 9, 2016
9c9fe84
readonly
AlexRadch Dec 9, 2016
3df5d4b
_
AlexRadch Dec 9, 2016
82918fa
old names
AlexRadch Dec 9, 2016
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
8 changes: 8 additions & 0 deletions src/mscorlib/model.xml
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -341,13 +341,21 @@
<Member Name="get_Array" />
<Member Name="get_Count" />
<Member Name="get_Offset" />
<Member Name="GetEnumerator" />
<Member Name="GetHashCode" />
<Member Name="op_Equality(System.ArraySegment&lt;T&gt;,System.ArraySegment&lt;T&gt;)" />
<Member Name="op_Inequality(System.ArraySegment&lt;T&gt;,System.ArraySegment&lt;T&gt;)" />
<Member MemberType="Property" Name="Array" />
<Member MemberType="Property" Name="Count" />
<Member MemberType="Property" Name="Offset" />
</Type>
<Type Name="System.ArraySegment&lt;T&gt;+Enumerator">
<Member Name="Dispose" />
<Member Name="get_Current" />
<Member Name="MoveNext" />
<Member MemberType="Property" Name="Current" />
<Member Name="System.Collections.IEnumerator.Reset" />
</Type>
<Type Name="System.ArrayTypeMismatchException">
<Member Name="#ctor" />
<Member Name="#ctor(System.String)" />
Expand Down
71 changes: 32 additions & 39 deletions src/mscorlib/src/System/ArraySegment.cs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -28,10 +28,10 @@ namespace System
[Serializable]
public struct ArraySegment<T> : IList<T>, IReadOnlyList<T>
{
private T[] _array;
private int _offset;
private int _count;
private readonly T[] _array;
private readonly int _offset;
private readonly int _count;

public ArraySegment(T[] array)
{
if (array == null)
Expand Down Expand Up @@ -67,7 +67,7 @@ public T[] Array
Contract.Assert( (null == _array && 0 == _offset && 0 == _count)
|| (null != _array && _offset >= 0 && _count >= 0 && _offset + _count <= _array.Length),
"ArraySegment is invalid");

return _array;
}
}
Expand Down Expand Up @@ -109,7 +109,16 @@ public int Count
return _count;
}
}


public Enumerator GetEnumerator()
{
if (_array == null)
ThrowHelper.ThrowInvalidOperationException(ExceptionResource.InvalidOperation_NullArray);
Contract.EndContractBlock();

return new Enumerator(this);
}

public override int GetHashCode()
{
if (_array == null)
Expand Down Expand Up @@ -184,7 +193,7 @@ int IList<T>.IndexOf(T item)

int index = System.Array.IndexOf<T>(_array, item, _offset, _count);

Contract.Assert(index == -1 ||
Contract.Assert(index == -1 ||
(index >= _offset && index < _offset + _count));

return index >= 0 ? index - _offset : -1;
Expand Down Expand Up @@ -269,46 +278,34 @@ bool ICollection<T>.Remove(T item)
#endregion

#region IEnumerable<T>
IEnumerator<T> IEnumerable<T>.GetEnumerator()
{
if (_array == null)
ThrowHelper.ThrowInvalidOperationException(ExceptionResource.InvalidOperation_NullArray);
Contract.EndContractBlock();

return new ArraySegmentEnumerator(this);
}
IEnumerator<T> IEnumerable<T>.GetEnumerator() => GetEnumerator();
#endregion

#region IEnumerable
IEnumerator IEnumerable.GetEnumerator()
{
if (_array == null)
ThrowHelper.ThrowInvalidOperationException(ExceptionResource.InvalidOperation_NullArray);
Contract.EndContractBlock();

return new ArraySegmentEnumerator(this);
}
IEnumerator IEnumerable.GetEnumerator() => GetEnumerator();
#endregion

[Serializable]
private sealed class ArraySegmentEnumerator : IEnumerator<T>
public struct Enumerator : IEnumerator<T>
{
private T[] _array;
private int _start;
private int _end;
private readonly T[] _array;
private readonly int _start;
private readonly int _end; // cache Offset + Count, since it's a little slow
private int _current;
Copy link
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Keep the original names the start with underscore - it matches the coding conventions.


internal ArraySegmentEnumerator(ArraySegment<T> arraySegment)
internal Enumerator(ArraySegment<T> arraySegment)
{
Contract.Requires(arraySegment.Array != null);
Contract.Requires(arraySegment.Offset >= 0);
Contract.Requires(arraySegment.Count >= 0);
Contract.Requires(arraySegment.Offset + arraySegment.Count <= arraySegment.Array.Length);

_array = arraySegment._array;
_start = arraySegment._offset;
_end = _start + arraySegment._count;
_current = _start - 1;
_array = arraySegment.Array;
_start = arraySegment.Offset;
_end = arraySegment.Offset + arraySegment.Count;
_current = arraySegment.Offset - 1;
}

public bool MoveNext()
Expand All @@ -325,19 +322,15 @@ public T Current
{
get
{
if (_current < _start) ThrowHelper.ThrowInvalidOperationException_InvalidOperation_EnumNotStarted();
if (_current >= _end) ThrowHelper.ThrowInvalidOperationException_InvalidOperation_EnumEnded();
if (_current < _start)
ThrowHelper.ThrowInvalidOperationException_InvalidOperation_EnumNotStarted();
if (_current >= _end)
ThrowHelper.ThrowInvalidOperationException_InvalidOperation_EnumEnded();
return _array[_current];
}
}

object IEnumerator.Current
{
get
{
return Current;
}
}
object IEnumerator.Current => Current;

void IEnumerator.Reset()
{
Expand Down