procedure-name-symbol to procedure

[Chuah Teong Leong <teongleong at gmail dot com>]

Hi, is it possible to construct a symbol and retrieve the procedure
from the interactive environment associated the symbol name?

I have the following code
;;  (if (w-key-event? e)
;;      (begin
;;        (set! last-key 'w)
;;        (register-key-down 'w)
;;        ))
;;  (if (a-key-event? e)
;;      (begin
;;        (set! last-key 'a)
;;        (register-key-down 'a)
;;        ))
;;  (if (s-key-event? e)
;;      (begin
;;        (set! last-key 's)
;;        (register-key-down 's)
;;        ))
;;  (if (d-key-event? e)
;;      (begin
;;        (set! last-key 'd)
;;        (register-key-down 'd)
;;        ))

and I'm probably going to do the same for every key I care about.

I however would like to do shorten the code to look like this

(vector-map
         (lambda (key-sym)
                (define proc-sym
                  (string->symbol
                   (string-append (symbol->string key-sym) "-key-event?")))

                (if (eval (list proc-sym 'e))
                    (begin
                      (set! last-key 'key-sym)
                      (register-key-down 'key-sym)
                      ))
                ) supported-keys))

(define supported-keys (vector 'w 'a 's 'd ))

This did not work because it couldn't find w-key-down? and the other procedures.