On Thu, Aug 20, 2009 at 3:05 PM, Eduardo Cavazos<[email protected]>
wrote:
Sometimes I want the convenience of anamorphic 'if', but the version which
always uses the symbol 'it' seems funny.
I'm experimenting with a variant; here's an example:
Grant Rettke wrote:
How do you feel about the results of your experiment?
So far so good. Here's a slight variation. Instead of the 'is' keyword
I'm using '->'. So to bind to a variable, use '->'. To pass to a
procedure (like in 'cond') use '=>'.
(library (dharmatech misc if)
(export if)
(import (rename (rnrs) (if rnrs:if)))
(define-syntax if
(syntax-rules (-> =>)
( (if test -> var then else)
(let ((var test))
(rnrs:if var then else)) )
( (if test -> var then)
(let ((var test))
(rnrs:if var then)) )
( (if test => then else)
(let ((val test))
(rnrs:if val (then val) else)) )
( (if test => then)
(let ((val test))
(rnrs:if val (then val))) )
( (if test then else)
(rnrs:if test then else) )
( (if test then)
(rnrs:if test then) )))
)
