Module map

Augmentations for maps.

Remarks

Importing this module

This module's augmentations can be applied by using the following import:

import "@neotype/extensions/map.js";
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Comparing maps

Maps have the following behavior as an equivalence relation:

• A Map<K, V> or a ReadonlyMap<K, V> implements Eq when V implements Eq.
• Two maps are equal if:
  1. they are the same size;
  2. they contain the same keys (compared strictly); and
  3. for each key, the corresponding values are equal.
• Read-only and non-read-only maps can be compared to each other.

Combining maps as a semigroup

Maps implement Semigroup.

• Maps are combined by taking their union.
• If a key is mapped to two different values, only the right-hand map's value is retained.
• Read-only and non-read-only maps can be combined with each other.
• If either map is read-only, the resulting map will also be read-only.