frequencies method

Map<T, int> frequencies()

Returns a map of each element to its occurrence count.

['a','b','a','c'].frequencies() // {'a': 2, 'b': 1, 'c': 1}

Implementation

Map<T, int> frequencies() {
  final freq = <T, int>{};
  for (final e in this) {
    freq[e] = (freq[e] ?? 0) + 1;
  }
  return freq;
}