[racket] Apply proc with hasheq

On Dec 17, 2012, at 10:51 PM, Haiwei Zhou wrote:

> Hi,
> 
>   I am writing some code with json. Request may look likes (hasheq 'action "doit" 'arg1 "a" 'arg2 "b"). 
> 
>   Is there any function or library which can apply a proc with hasheq? The expected result is (proc #:action "doit" #:arg1 "a" #:args "b")?

I think the easiest way to do this would be to use "match" inside the body of the procedure being defined. So:

(define (hashy-proc ht)
  (match ht
    [(hash-table ("action" a) ("arg1" a1) ("arg2" a2))
      ... code that uses a and a1 and a2 ...])


If this is too verbose for you, you could hide it using a macro, so that it looks like

(define-hashproc (proc #:action a #:arg1 a1 #:arg2)
  ... code that uses a and a1 and a2...)


... but I would try it first with the first form, to see whether you can live with it.


That's my thought, anyhow.

John Clements

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