Re: [Chicken-users] Creating new types and their representation in the REPL

[Peter Bex]

On Wed, Jul 07, 2010 at 01:45:39PM -0500, Jack Trades wrote:
> I'm sure this is a simple question but I can't quite figure it out.  Is
> there a way to get (define-record ...) to print out something other than the
> tag of the record?
> 
> Example of current behavior:
> 
> (define-record point x y)
> (define p (make-point 5 10))
> p
> ===> #<point>
> 

Use define-record-printer:
http://chicken.wiki.br/man/4/Non-standard%20macros%20and%20special%20forms#define-record-printer

> Example of desired behavior:
> 
> (define-record point x y)
> (define p (make-point 5 10))
> p
> ===> (5 10)

(define-record-printer (point p outport)
  (display (list (point-x p) (point-y p)) outport)

> -- or --
> ===> (point 5 10)

(define-record-printer (point p outport)
  (display (list 'point (point-x p) (point-y p)) outport)

Cheers,
Peter
-- 
http://sjamaan.ath.cx
--
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