Suggestion: Add immutable string

[dubek]

It seems that using a Rope data structure is efficient for string operations. Maybe holding string parts in a Hamster::Vector achieves the same tree-like idea?

Before starting any implementation, I started this issue as a place for discussion.

[alexdowad]

Sounds like a good idea, though a dedicated implementation (perhaps based on Hamster::Trie) would be better than relying on Vector.

The first thing would be to come up with a POC and see if the performance advantage over just using frozen strings is compelling.