另一种方法:
extension IterableExtensions<E> on Iterable<E> {
Iterable<List<E>> chunked(int chunkSize) sync* {
if (length <= 0) {
yield [];
return;
}
int skip = 0;
while (skip < length) {
final chunk = this.skip(skip).take(chunkSize);
yield chunk.toList(growable: false);
skip += chunkSize;
if (chunk.length < chunkSize) return;
}
}
}
测试:
void main() {
test("list chunked", () {
final emptyList = [];
final letters = ['a', 'b', 'c', 'd', 'e', 'f'];
final digits = List.generate(32, (index) => index);
print(emptyList.chunked(2));
print(letters.chunked(2));
print(digits.chunked(2));
print(emptyList.chunked(3));
print(letters.chunked(3));
print(digits.chunked(3));
print(emptyList.chunked(5));
print(letters.chunked(5));
print(digits.chunked(5));
});
}
输出:
([])
([a, b], [c, d], [e, f])
([0, 1], [2, 3], [4, 5], [6, 7], [8, 9], [10, 11], ..., [28, 29], [30, 31])
([])
([a, b, c], [d, e, f])
([0, 1, 2], [3, 4, 5], [6, 7, 8], [9, 10, 11], ..., [27, 28, 29], [30, 31])
([])
([a, b, c, d, e], [f])
([0, 1, 2, 3, 4], [5, 6, 7, 8, 9], [10, 11, 12, 13, 14], ..., [25, 26, 27, 28, 29], [30, 31])
RangeError (end): Invalid value: Not in range 14..15, inclusive: 16
。请注意不要改变原意。 - Pom12