[plt-scheme] immutable strings vs. uninterned symbols

On 6/6/06, Matthias Felleisen <matthias at ccs.neu.edu> wrote:
>
>  > (string-append "hello" " world")
> "hello world"
>  >
>
> You can't do this with a symbol. -- Matthias

Sure we can.

> (define (symbol-append one two)
    (string->uninterned-symbol
     (string-append (symbol->string one) (symbol->string two))))
> (symbol-append (string->uninterned-symbol "hello")
                 (string->uninterned-symbol "world"))
helloworld

It's not Doug's fault we don't provide the symbol-append function, but
clearly it can be done.

I think the real answer is:  just about anything you can do with one,
you can do with the other, though with uninterned symbols you're
probably paying for a few extra hash table operations (to look up or
create the symbol/string associations).

-- 
Carl Eastlund
"Cynical, but technically correct."