matcher: new @(with) operator.

* lisplib.c (match_instantiate): Ensure usr:with is interned.

* share/txr/stdlib/match.tl (compile-with-match): New
function.
(compile-match): Wire in with operator.

* tests/011/patmatch.tl: Test cases.

* txr.1: Documented.

1 files changed, 8 insertions, 0 deletions

diff --git a/tests/011/patmatch.tl b/tests/011/patmatch.tl
index f8f6b03f..0068eabb 100644
--- a/tests/011/patmatch.tl
+++ b/tests/011/patmatch.tl
@@ -116,6 +116,14 @@
 
 (test (when-match (@a @(as a @(or x @a))) '(#1=(1 2 #1# 3) #1#) :yes) :yes)
 
+(test (when-match (@(with x 42 @a) @b @c) '(1 2 3) (list a b c x))
+      (1 2 3 42))
+
+(test (let ((o 3))
+        (when-match (@(evenp x) @(with @(oddp y) o @z)) '(4 6)
+          (list x y z)))
+      (4 3 6))
+
 (defstruct node ()
   left right)