[racket] (procedure? (hash)) -> true

Consider overriding #%app for your modules. And 

(define (curt-style-receiver data)
 (cond 
  [(data 'COMPANY) => (curry db-exec ...)]  
  [else .. what are you doing in the #f case? nothing? ...]))


On Aug 5, 2013, at 11:30 AM, John Griffin wrote:

> I do a lot of work with hash as the result of JSON-RPC calls, with considerable use of hash-ref.   In most places, I've replaced the hash with a local result of transforming the hash to a procedure so that I can:
> 
> (stuff 'COMPANY)
> 
> rather than
> 
> (hash-ref stuff 'COMPANY)
> 
> Of course, the setup call to exchange the hash for the procedure takes another line, such that I only bother on longer functions with repeated benefit.
> 
> It certainly would be handy from a succinctness standpoint if a hash acted like a procedure (Any -> Any).  Noticing that struct can be a procedure? via a property , I wonder if there's a way for hash? and procedure? to both hold true.
> 
> It's more than simply saving the 9 letters of hash-ref followed by a space.  Performance is not an issue and given a curt enough representation, I'd prefer calling it twice rather than making a local define.  My current choices are:
> 
> ; current STYLE #1
> (define (current-rpc-receiver data)
>     (define company (hash-ref data 'COMPANY #f))
>     (when company
>         (db-exec … company))
> 
> ; current STYLE #2
> (define (curt-style-rpc-receiver data)
>    (define HF (hash->procedure data))
>     (when (HF 'COMPANY)
>         (db-exec …. (HF 'COMPANY))
> 
> ; what would be handier….
> 
> (define (handy-style data)
>     (when (data 'COMPANY)
>        (db-exec … (data 'COMPANY))
> 
> Thanks in advance for any advice leading to more succinct hash access.
> 
> ------
> John Griffin, CTO
> IT Talent Team, LLC
> www.ittalentteam.com
> 855-488-8326
> 
> 
> 
> 
> 
> 
> ____________________
>  Racket Users list:
>  http://lists.racket-lang.org/users

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