this is a question of the computer science. Is Elixir map a hash table? Or is it a keyword list having unique keys? I ask this because of the shape of Enum functions looking the same… for example fn {key, value} -> ... end looks same for maps and keyword lists How is map stored in memory? Is …

Maps are stored either as hash map or as tuple (when small enough). Keyword lists are normal linked lists with {atom, term} for all items. Enum functions work with any value implementing Enumerable.t. Datatype specific functions are in Map, Keyword or List.

If you want to take a deep-dive in how maps are implemented internally, I recommend the blog article Breaking Erlang Maps by @jlouis . Small maps are stored as a ‘flatmap’: a sorted array of keys + their values. Big maps are stored as a ‘ hash-array mapped trie ’, which allows them to be persistent dat…

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Is Map a Hash table?

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vrod July 23, 2020, 3:07pm 3

Thank you!