1 Jul
2006
1 Jul
'06
3:50 a.m.
Matthew D Swank wrote:
Matthew D Swank wrote:
Would it be possible to have destructure-case match against arbitrary, non-nil atoms (patch attached)?
Forget it. That patch obviously won't work as is, and I can't seem to find the patched version of slime I was using at the moment.
This one should work.
Matt
--
"You do not really understand something unless you can explain it to
your grandmother." — Albert Einstein.
--- slime/swank.lisp.orig 2006-06-18 13:21:54.000000000 -0500
+++ slime/swank.lisp 2006-06-30 22:07:03.000000000 -0500
@@ -293,19 +293,22 @@
A cross between `case' and `destructuring-bind'.
The pattern syntax is:
((HEAD . ARGS) . BODY)
+or:
+ (ATOM . BODY)
The list of patterns is searched for a HEAD `eq' to the car of
-VALUE. If one is found, the BODY is executed with ARGS bound to the
-corresponding values in the CDR of VALUE."
+VALUE (or ATOM `eq' to VALUE as the case may be). If one is
+found, the BODY is executed with ARGS bound to the corresponding
+values in the CDR of VALUE."
(let ((operator (gensym "op-"))
(operands (gensym "rand-"))
(tmp (gensym "tmp-")))
`(let* ((,tmp ,value)
- (,operator (car ,tmp))
- (,operands (cdr ,tmp)))
+ (,operator (or (and (listp ,tmp) (car ,tmp)) ,tmp))
+ (,operands (or (and (listp ,tmp) (cdr ,tmp)))))
(case ,operator
,@(loop for (pattern . body) in patterns collect
- (if (eq pattern t)
- `(t ,@body)
+ (if (and pattern (atom pattern))
+ `(,pattern ,@body)
(destructuring-bind (op &rest rands) pattern
`(,op (destructuring-bind ,rands ,operands
,@body)))))