TrieMaps are Maps using trie dats structure whic are essentially shallow trees. For example, If you have a 32 bit hash you break it up into sections for example 4 times 8 and at every level of the tree you branch to up to 256 sub trees. obviously this gives O(1) performance due to the fixe size of hash(assuming few colisions).

A trie structure can be made immutable efficently, reusing the structure of a trie to create a new trie with an added or removed element. The relative performance in time/memory affect on GC depend greatly on implementation and load so rather then attempt a generic answer I would say run a benchmark. Though for a single thread with no immutability requirement a classic hashmap will normally produce better average performance and inferior worst case performance.

As a side note I will mention since the trieMap also uses a hash it is also a hashmap so I would recommend calling it a trie backed hashmap vs array backed hashmap.

TrieMaps are Maps using trie data structure which are essentially shallow trees. For example, If you have a 32 bit hash you break it up into sections for example 4 times 8 and at every level of the tree you branch to up to 256 sub trees. Obviously this gives O(1) performance due to the fixe size of hash(assuming few collisions).

A trie structure can be made immutable efficently, reusing the structure of a trie to create a new trie with an added or removed element. The relative performance in time/memory affect on GC depend greatly on implementation and load so rather then attempt a generic answer I would say run a benchmark. Though for a single thread with no immutability requirement a classic hashmap will normally produce better average performance and inferior worst case performance.

As a side note I will mention since the trieMap also uses a hash it is also a hashmap so I would recommend calling it a trie backed hashmap vs array backed hashmap.