Redo "special-case ListMixin.setRange from same list"
This simply reapplies
https://github.com/dart-lang/sdk/commit/001ce2aad76bf0a4af12bfa5159812c56b8cce49
R=lrn@google.com
BUG=
Review-Url: https://codereview.chromium.org/2961073002 .
diff --git a/sdk/lib/collection/list.dart b/sdk/lib/collection/list.dart
index 7f476dc..92b1110 100644
--- a/sdk/lib/collection/list.dart
+++ b/sdk/lib/collection/list.dart
@@ -256,14 +256,27 @@
bool remove(Object element) {
for (int i = 0; i < this.length; i++) {
if (this[i] == element) {
- this.setRange(i, this.length - 1, this, i + 1);
- this.length -= 1;
+ this._closeGap(i, i + 1);
return true;
}
}
return false;
}
+ /// Removes elements from the list starting at [start] up to but not including
+ /// [end]. Arguments are pre-validated.
+ void _closeGap(int start, int end) {
+ int length = this.length;
+ assert(0 <= start);
+ assert(start < end);
+ assert(end <= length);
+ int size = end - start;
+ for (int i = end; i < length; i++) {
+ this[i - size] = this[i];
+ }
+ this.length = length - size;
+ }
+
void removeWhere(bool test(E element)) {
_filter(test, false);
}
@@ -350,9 +363,9 @@
void removeRange(int start, int end) {
RangeError.checkValidRange(start, end, this.length);
- int length = end - start;
- setRange(start, this.length - length, this, end);
- this.length -= length;
+ if (end > start) {
+ _closeGap(start, end);
+ }
}
void fillRange(int start, int end, [E fill]) {
@@ -401,13 +414,10 @@
int removeLength = end - start;
int insertLength = newContents.length;
if (removeLength >= insertLength) {
- int delta = removeLength - insertLength;
int insertEnd = start + insertLength;
- int newLength = this.length - delta;
this.setRange(start, insertEnd, newContents);
- if (delta != 0) {
- this.setRange(insertEnd, newLength, this, end);
- this.length = newLength;
+ if (removeLength > insertLength) {
+ _closeGap(insertEnd, end);
}
} else {
int delta = insertLength - removeLength;
@@ -470,8 +480,7 @@
E removeAt(int index) {
E result = this[index];
- setRange(index, this.length - 1, this, index + 1);
- length--;
+ _closeGap(index, index + 1);
return result;
}
