reshape method
Implementation
Array reshape(int m, int n) {
var flatten = flat();
assert(flatten.length == m * n);
var array = Array.fromValue(0, shape: Tuple2(m, n));
for (var kVal in enumerate(flatten)) {
var k = kVal.item1;
var val = kVal.item2;
var i = k % m;
var j = k ~/ m;
array.values[i][j] = val;
}
return array;
}