ccwl: Document syntax-lambda** support for default arguments.

* ccwl/utils.scm (syntax-lambda**): Add example to docstring
documenting support for default arguments.
* tests/utils.scm ("syntax-lambda** with default values"): New test.

2 files changed, 15 insertions, 1 deletions

diff --git a/ccwl/utils.scm b/ccwl/utils.scm
index 067308f..c018237 100644
--- a/ccwl/utils.scm
+++ b/ccwl/utils.scm
@@ -183,7 +183,15 @@ writing macros that accept keyword arguments. For example,
 ((syntax-lambda** (a b #:key foo #:key* bar)
    (list a b foo bar))
  #'(foo 1 2 #:foo 123 #:bar 1 2 3))
-=> (#'1 #'2 #'123 (#'1 #'2 #'3))"
+=> (#'1 #'2 #'123 (#'1 #'2 #'3))
+
+Just like lambda**, syntax-lambda** also supports default values for
+arguments. For example,
+
+((syntax-lambda** (foo aal #:key vale (pal 9) #:key* naal (irandu 7) (sol 3 2 1))
+             (list foo aal vale pal naal irandu sol))
+ #'(bar 1 2 #:vale 123 #:naal 321 456))
+=> (#'1 #'2 #'123 9 (#'321 #'456) (7) (3 2 1))"
   (lambda (x)
     (apply (lambda** formal-args body ...)
            (with-ellipsis :::
diff --git a/tests/utils.scm b/tests/utils.scm
index 473bd45..5c5bfd1 100644
--- a/tests/utils.scm
+++ b/tests/utils.scm
@@ -76,6 +76,12 @@
              (list a b foo bar))
            #'(foo 1 2 #:foo 123 #:bar 1 2 3))))
 
+(test-assert "syntax-lambda** with default values"
+  (equal? (list #'1 #'2 #'123 9 #'(321 456) '(7) '(3 2 1))
+          ((syntax-lambda** (foo aal #:key vale (pal 9) #:key* naal (irandu 7) (sol 3 2 1))
+             (list foo aal vale pal naal irandu sol))
+           #'(bar 1 2 #:vale 123 #:naal 321 456))))
+
 (test-equal "filter-mapi"
   '(1 3 5 7 9)
   (filter-mapi (lambda (item index)