Request: Implement Hash trait for JsString

[sergeyt]

Motivation

This allows using JsString value as key in HashMap.

Proposed Solution

It should be straitword, just iterate over chars and write them to hasher.

Alternatives

You can use String::from(value) to convert JsString value to String.

[sergeyt]

Perhaps it is minor thing, but it would be nice to have some day

[Pauan]

Note that iterating over the chars is going to be pretty slow, and unpaired surrogates will need to be handled somehow, so we can't just rely on Rust's char. But maybe we can use u32 instead.

[0xd4d]

The hash code could be calculated in JS, so there'd be only one call to JS instead of one call per char.

[RReverser]

@0xd4d That's not how Hash trait works. It's supposed to work with variety of different hashers, so it expects you to write bytes to the provided Hasher and it would do the rest.

Either using charCodeAt for iterating over u32s as @Pauan suggested, or encoding string into binary, would be the correct solution. Just needs measurements on which one is actually faster.