Index: sdk/lib/_collection_dev/iterable.dart |
diff --git a/sdk/lib/_collection_dev/iterable.dart b/sdk/lib/_collection_dev/iterable.dart |
index 676eadec18a38a84b14ed54efb7c10794aa44304..676ad733364f0c69599c54c340a7d35d2f3b69c8 100644 |
--- a/sdk/lib/_collection_dev/iterable.dart |
+++ b/sdk/lib/_collection_dev/iterable.dart |
@@ -4,6 +4,7 @@ |
part of dart._collection.dev; |
+ |
/** |
* An [Iterable] for classes that have efficient [length] and [elementAt]. |
* |
@@ -14,7 +15,7 @@ abstract class ListIterable<E> extends Iterable<E> { |
int get length; |
E elementAt(int i); |
- Iterator<E> get iterator => new ListIterator<E>(this); |
+ Iterator<E> get iterator => new ListIterableIterator<E>(this); |
void forEach(void action(E element)) { |
int length = this.length; |
@@ -92,7 +93,7 @@ abstract class ListIterable<E> extends Iterable<E> { |
E lastMatching(bool test(E element), { E orElse() }) { |
int length = this.length; |
- for (int i = length - 1; i >= 0; i--) { |
+ for (int i = length - 1; i >= 0; i++) { |
E element = elementAt(i); |
if (test(element)) return element; |
if (length != this.length) { |
@@ -197,11 +198,13 @@ abstract class ListIterable<E> extends Iterable<E> { |
Iterable map(f(E element)) => new MappedIterable(this, f); |
+ Iterable mappedBy(f(E element)) => super.mappedBy(f); |
+ |
reduce(var initialValue, combine(var previousValue, E element)) { |
var value = initialValue; |
int length = this.length; |
for (int i = 0; i < length; i++) { |
- value = combine(value, elementAt(i)); |
+ value = reduce(value, elementAt(i)); |
if (length != this.length) { |
throw new ConcurrentModificationError(this); |
} |
@@ -234,7 +237,7 @@ abstract class ListIterable<E> extends Iterable<E> { |
} |
} |
-class SubListIterable<E> extends ListIterable<E> { |
+abstract class SubListIterable<E> extends ListIterable<E> { |
final Iterable<E> _iterable; |
final int _start; |
/** If null, represents the length of the iterable. */ |
@@ -281,27 +284,19 @@ class SubListIterable<E> extends ListIterable<E> { |
if (_endOrLength == null) { |
return new SubListIterable(_iterable, _start, _start + count); |
} else { |
- int newEnd = _start + count; |
+ newEnd = _start + count; |
if (_endOrLength < newEnd) return this; |
return new SubListIterable(_iterable, _start, newEnd); |
} |
} |
} |
-/** |
- * An [Iterator] that iterates a list-like [Iterable]. |
- * |
- * All iterations is done in terms of [Iterable.length] and |
- * [Iterable.elementAt]. These operations are fast for list-like |
- * iterables. |
- */ |
-class ListIterator<E> implements Iterator<E> { |
+class ListIterableIterator<E> implements Iterator<E> { |
final Iterable<E> _iterable; |
final int _length; |
int _index; |
E _current; |
- |
- ListIterator(Iterable<E> iterable) |
+ ListIterableIterator(Iterable<E> iterable) |
: _iterable = iterable, _length = iterable.length, _index = 0; |
E get current => _current; |
@@ -335,14 +330,9 @@ class MappedIterable<S, T> extends Iterable<T> { |
// Length related functions are independent of the mapping. |
int get length => _iterable.length; |
bool get isEmpty => _iterable.isEmpty; |
- |
- // Index based lookup can be done before transforming. |
- T get first => _f(_iterable.first); |
- T get last => _f(_iterable.last); |
- T get single => _f(_iterable.single); |
- T elementAt(int index) => _f(_iterable.elementAt(index)); |
} |
+ |
class MappedIterator<S, T> extends Iterator<T> { |
T _current; |
final Iterator<S> _iterator; |
@@ -356,25 +346,343 @@ class MappedIterator<S, T> extends Iterator<T> { |
if (_iterator.moveNext()) { |
_current = _f(_iterator.current); |
return true; |
+ } else { |
+ _current = null; |
+ return false; |
} |
- _current = null; |
- return false; |
} |
T get current => _current; |
} |
/** Specialized alternative to [MappedIterable] for mapped [List]s. */ |
-class MappedListIterable<S, T> extends ListIterable<T> { |
- final Iterable<S> _source; |
+class MappedListIterable<S, T> extends Iterable<T> { |
+ final List<S> _list; |
+ /** |
+ * Start index of the part of the list to map. |
+ * |
+ * Allows mapping only a sub-list of an existing list. |
+ * |
+ * Used to implement lazy skip/take on a [MappedListIterable]. |
+ */ |
+ final int _start; |
+ |
+ /** |
+ * End index of the part of the list to map. |
+ * |
+ * If null, always use the length of the list. |
+ */ |
+ final int _end; |
+ |
+ // TODO(ahe): Restore type when feature is implemented in dart2js |
+ // checked mode. http://dartbug.com/7733 |
+ final /* _Transformation<S, T> */ _f; |
+ |
+ MappedListIterable(this._list, T this._f(S element), this._start, this._end) { |
+ if (_end != null && _end < _start) { |
+ throw new ArgumentError("End ($_end) before start ($_start)"); |
+ } |
+ } |
+ |
+ /** The start index, limited to the current length of the list. */ |
+ int get _startIndex { |
+ if (_start <= _list.length) return _start; |
+ return _list.length; |
+ } |
+ |
+ /** The end index, if given, limited to the current length of the list. */ |
+ int get _endIndex { |
+ if (_end == null || _end > _list.length) return _list.length; |
+ return _end; |
+ } |
+ |
+ Iterator<T> get iterator => |
+ new MappedListIterator<S, T>(_list, _f, _startIndex, _endIndex); |
+ |
+ void forEach(void action(T element)) { |
+ int length = _list.length; |
+ for (int i = _startIndex, n = _endIndex; i < n; i++) { |
+ action(_f(_list[i])); |
+ if (_list.length != length) { |
+ throw new ConcurrentModificationError(_list); |
+ } |
+ } |
+ } |
+ |
+ bool get isEmpty => _startIndex == _endIndex; |
+ |
+ int get length => _endIndex - _startIndex; |
+ |
+ T get first { |
+ int start = _startIndex; |
+ if (start == _endIndex) { |
+ throw new StateError("No elements"); |
+ } |
+ return _f(_list.elementAt(start)); |
+ } |
+ |
+ T get last { |
+ int end = _endIndex; |
+ if (end == _startIndex) { |
+ throw new StateError("No elements"); |
+ } |
+ return _f(_list.elementAt(end - 1)); |
+ } |
+ |
+ T get single { |
+ int start = _startIndex; |
+ int end = _endIndex; |
+ if (start != end - 1) { |
+ if (start == end) { |
+ throw new StateError("No elements"); |
+ } |
+ throw new StateError("Too many elements"); |
+ } |
+ return _f(_list[start]); |
+ } |
+ |
+ T elementAt(int index) { |
+ index += _startIndex; |
+ if (index >= _endIndex) { |
+ throw new StateError("No matching element"); |
+ } |
+ return _f(_list.elementAt(index)); |
+ } |
+ |
+ bool contains(T element) { |
+ int length = _list.length; |
+ for (int i = _startIndex, n = _endIndex; i < n; i++) { |
+ if (_f(_list[i]) == element) { |
+ return true; |
+ } |
+ if (_list.length != length) { |
+ throw new ConcurrentModificationError(_list); |
+ } |
+ } |
+ return false; |
+ } |
+ |
+ bool every(bool test(T element)) { |
+ int length = _list.length; |
+ for (int i = _startIndex, n = _endIndex; i < n; i++) { |
+ if (!test(_f(_list[i]))) return false; |
+ if (_list.length != length) { |
+ throw new ConcurrentModificationError(_list); |
+ } |
+ } |
+ return true; |
+ } |
+ |
+ bool any(bool test(T element)) { |
+ int length = _list.length; |
+ for (int i = _startIndex, n = _endIndex; i < n; i++) { |
+ if (test(_f(_list[i]))) return true; |
+ if (_list.length != length) { |
+ throw new ConcurrentModificationError(_list); |
+ } |
+ } |
+ return false; |
+ } |
+ |
+ T firstMatching(bool test(T element), { T orElse() }) { |
+ int length = _list.length; |
+ for (int i = _startIndex, n = _endIndex; i < n; i++) { |
+ T value = _f(_list[i]); |
+ if (test(value)) return value; |
+ if (_list.length != length) { |
+ throw new ConcurrentModificationError(_list); |
+ } |
+ } |
+ if (orElse != null) return orElse(); |
+ throw new StateError("No matching element"); |
+ } |
+ |
+ T lastMatching(bool test(T element), { T orElse() }) { |
+ int length = _list.length; |
+ for (int i = _endIndex - 1, start = _startIndex; i >= start; i++) { |
+ T value = _f(_list[i]); |
+ if (test(value)) return value; |
+ if (_list.length != length) { |
+ throw new ConcurrentModificationError(_list); |
+ } |
+ } |
+ if (orElse != null) return orElse(); |
+ throw new StateError("No matching element"); |
+ } |
+ |
+ T singleMatching(bool test(T element)) { |
+ int length = _list.length; |
+ T match; |
+ bool matchFound = false; |
+ for (int i = _startIndex, n = _endIndex; i < n; i++) { |
+ T value = _f(_list[i]); |
+ if (test(value)) { |
+ if (matchFound) { |
+ throw new StateError("More than one matching element"); |
+ } |
+ matchFound = true; |
+ match = value; |
+ } |
+ if (_list.length != length) { |
+ throw new ConcurrentModificationError(_list); |
+ } |
+ } |
+ if (matchFound) return match; |
+ throw new StateError("No matching element"); |
+ } |
+ |
+ T min([int compare(T a, T b)]) { |
+ if (compare == null) { |
+ var defaultCompare = Comparable.compare; |
+ compare = defaultCompare; |
+ } |
+ int length = _list.length; |
+ int start = _startIndex; |
+ int end = _endIndex; |
+ if (start == end) return null; |
+ T value = _f(_list[start]); |
+ if (_list.length != length) { |
+ throw new ConcurrentModificationError(_list); |
+ } |
+ for (int i = start + 1; i < end; i++) { |
+ T nextValue = _f(_list[i]); |
+ if (compare(value, nextValue) > 0) { |
+ value = nextValue; |
+ } |
+ if (_list.length != length) { |
+ throw new ConcurrentModificationError(_list); |
+ } |
+ } |
+ return value; |
+ } |
+ |
+ T max([int compare(T a, T b)]) { |
+ if (compare == null) { |
+ var defaultCompare = Comparable.compare; |
+ compare = defaultCompare; |
+ } |
+ int length = _list.length; |
+ int start = _startIndex; |
+ int end = _endIndex; |
+ if (start == end) return null; |
+ T value = _f(_list[start]); |
+ if (_list.length != length) { |
+ throw new ConcurrentModificationError(_list); |
+ } |
+ for (int i = start + 1; i < end; i++) { |
+ T nextValue = _f(_list[i]); |
+ if (compare(value, nextValue) < 0) { |
+ value = nextValue; |
+ } |
+ if (_list.length != length) { |
+ throw new ConcurrentModificationError(_list); |
+ } |
+ } |
+ return value; |
+ } |
+ |
+ String join([String separator]) { |
+ int start = _startIndex; |
+ int end = _endIndex; |
+ if (start == end) return ""; |
+ StringBuffer buffer = new StringBuffer("${_f(_list[start])}"); |
+ if (_list.length != length) { |
+ throw new ConcurrentModificationError(_list); |
+ } |
+ for (int i = start + 1; i < end; i++) { |
+ if (separator != null && separator != "") { |
+ buffer.add(separator); |
+ } |
+ buffer.add("${_f(_list[i])}"); |
+ if (_list.length != length) { |
+ throw new ConcurrentModificationError(_list); |
+ } |
+ } |
+ return buffer.toString(); |
+ } |
+ |
+ Iterable<T> where(bool test(T element)) => super.where(test); |
+ |
+ Iterable map(f(T element)) { |
+ return new MappedListIterable(_list, (S v) => f(_f(v)), _start, _end); |
+ } |
+ |
+ Iterable mappedBy(f(T element)) => map(f); |
+ |
+ reduce(var initialValue, combine(var previousValue, T element)) { |
+ return _list.reduce(initialValue, (v, S e) => combine(v, _f(e))); |
+ } |
+ |
+ Iterable<T> skip(int count) { |
+ int start = _startIndex + count; |
+ if (_end != null && start >= _end) { |
+ return new EmptyIterable<T>(); |
+ } |
+ return new MappedListIterable(_list, _f, start, _end); |
+ } |
+ |
+ Iterable<T> skipWhile(bool test(T element)) => super.skipWhile(test); |
+ |
+ Iterable<T> take(int count) { |
+ int newEnd = _start + count; |
+ if (_end == null || newEnd < _end) { |
+ return new MappedListIterable(_list, _f, _start, newEnd); |
+ } |
+ // Equivalent to "this". |
+ return new MappedListIterable(_list, _f, _start, _end); |
+ } |
+ |
+ Iterable<T> takeWhile(bool test(T element)) => super.takeWhile(test); |
+ |
+ List<T> toList() { |
+ List<T> result = new List<T>(); |
+ forEach(result.add); |
+ return result; |
+ } |
+ |
+ Set<T> toSet() { |
+ Set<T> result = new Set<T>(); |
+ forEach(result.add); |
+ return result; |
+ } |
+} |
+ |
+/** |
+ * Iterator for [MappedListIterable]. |
+ * |
+ * A list iterator that iterates over (a sublist of) a list and |
+ * returns the values transformed by a function. |
+ * |
+ * As a list iterator, it throws if the length of the list has |
+ * changed during iteration. |
+ */ |
+class MappedListIterator<S, T> implements Iterator<T> { |
+ List<S> _list; |
// TODO(ahe): Restore type when feature is implemented in dart2js |
// checked mode. http://dartbug.com/7733 |
final /* _Transformation<S, T> */ _f; |
+ final int _endIndex; |
+ final int _length; |
+ int _index; |
+ T _current; |
- MappedListIterable(this._source, T this._f(S value)); |
+ MappedListIterator(List<S> list, this._f, int start, this._endIndex) |
+ : _list = list, _length = list.length, _index = start; |
+ |
+ T get current => _current; |
- int get length => _source.length; |
- T elementAt(int index) => _f(_source.elementAt(index)); |
+ bool moveNext() { |
+ if (_list.length != _length) { |
+ throw new ConcurrentModificationError(_list); |
+ } |
+ if (_index >= _endIndex) { |
+ _current = null; |
+ return false; |
+ } |
+ _current = _f(_list[_index]); |
+ _index++; |
+ return true; |
+ } |
} |
typedef bool _ElementPredicate<E>(E element); |
@@ -661,6 +969,8 @@ class EmptyIterable<E> extends Iterable<E> { |
Iterable map(f(E element)) => const EmptyIterable(); |
+ Iterable mappedBy(f(E element)) => const EmptyIterable(); |
+ |
reduce(var initialValue, combine(var previousValue, E element)) { |
return initialValue; |
} |