vrod
Is Map a Hash table?
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 getting a key O(1) operation in Elixir map? Is getting a key O(n) operation in Elixir list?
Marked As Solved
LostKobrakai
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.
Also Liked
Qqwy
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 data structures (in a snippet like x = %{a: 1, b: 2, c: 3}; y = Map.put(x, :b, 4) we do not have to copy the fields of x to construct y but can re-use all unchanged fields of x directly).
Popular in Questions
Other popular topics
Latest on Elixir Forum
Sponsor Spotlight
Supporting innovation across the BEAM ecosystem.
Categories:
Sub Categories:
Forums
Our Sponsors
Build Elixir applications with speed and confidence.
Supporting innovation across the BEAM ecosystem.
We build reliable cloud platforms for business-critical systems.
Catch errors, track performance, monitor hosts and more.
Practical resources that improve the lives of professional developers.
Producing high quality Elixir screencasts since 2017.
The deployment platform built for Elixir: PaaS ease, VPS control.
Courses that'll move you from confusion to "Aha, now I get it!"