flatten<T> function
将给定的嵌套数组全部合并成一层数组
Implementation
List<T> flatten<T>(Iterable<dynamic> list) {
List<T> rl = [];
for (var v in list) {
if (v is T) {
rl.add(v);
} else if (v is Iterable<T>) {
rl.addAll(flatten(v));
} else {
throw FlutterError('List 中只能存放一种数据');
}
}
return rl;
}