CountingSet

A data structure for counting the occurrances of a thing. This is essentially a wrapper around Map, and follows the same equality checking rules.

Usage

npm install counting-set

import CountingSet from "counting-set";

const letters = new CountingSet();

for (const letter of "hadjetesdnsfgkfghkfgkdffgasdfa") {
  letters.add(letter);
}

console.log(letters);

Outputs:

CountingSet(11) [Map] {
  'h' => 2,
  'a' => 3,
  'd' => 4,
  'j' => 1,
  'e' => 2,
  't' => 1,
  's' => 3,
  'n' => 1,
  'f' => 6,
  'g' => 4,
  'k' => 3
}

API

CountingSet.add(value);

Add another instance of value to the count. If the item wasn't previously in the counting set, it is added and the count is set to one.

CountingSet.count(value)

Returns the current count for value, or zero if the value is not in the set.

CountingSet.remove(value)

Removes a single instance of value from the set. If the value does not currently exist, it gets added to the set with a count of zero. If the count for the value is already zero, nothing happens.

All other Map functions are also present, except for set(), which will throw a TypeError. CountingSet does not permit setting values for keys directly.