Maps
This chapter describes patterns that can be used to work with maps.Maps allow for an association between one fragment and another,similarly to how a dictionary associates a word with a definition.

Creates a new empty map.

Inserts key-value pairs into the given map.

If there is a value associated with the given fragment, returns it. Otherwise, returns void.

Combines many maps into one. Duplicate entries are prioritized by input index.

Removes entries from the given map which have any of the given keys.