Re: Strings in hash tables

[Matthew Flatt <mflatt@cs.utah.edu>]

Quoting MichaelL@frogware.com:
> Two questions:
> 
> * Is this the best way to use strings as keys in a hash table?

Yes, in version 103.X.

Using `equal?'-based tables might be better in 199.X.

> * Isn't this a strange way for this to work, given expectations about 
> "dictionary" containers?

Strings are (usually) mutable, and therefore not interned. So that's
why the normal `eq?' hashing doesn't work.

The default for hash tables is not `equal?' because that's somewhat
fragile (e.g., it gets confused by mutations or cyclic structures; I
notice that the documentation fails to mention the those pitfalls).

> I think it's worth explicity mentioning in the docs how to use 
> strings as hash table keys just to save some annoyance time.

Good idea.

Matthew