match: ^#S() and ^#H(()) patterns must work

Quasiquote patterns not containing unquotes are not
working, because the parser transforms them into
quoted objects. For instance ^#S(time) becomes
the form (quote #S(time)) and not the
form (sys:qquote (sys:struct-lit time)).
The pattern matching compiler doesn't treat quote
specially, only sys:qquote.

* parser.y (unquotes_occur): Function removed.
(vector, hash, struct, tree, json_vals, json_pairs):
Remove use of unquotes_occur. Thus vector, hash,
struct, tree and JSON syntax occurring within a
backquote will be turned into a special literal
whether or not it contains unquotes.

* lib.c (obj_print_impl): Do not print the
form (sys:hash-lit) as #Hnil, but #H().

* stdlib/match.tl (transform-qquote): Add a case
which will handle ^#H(), as if it were ^H(()).
Bugfix in the ^H(() ...) case. The use of @(coll)
means it fails to match the empty syntax when
no key/value pairs are specified, whereas
@(all) respects vacuous truth.

* test/011/patmatch.tl: A few tests.

* y.tab.shipped, y.tab.h.shipped: Updated.

1 files changed, 6 insertions, 0 deletions

diff --git a/tests/011/patmatch.tl b/tests/011/patmatch.tl
index bace28ce..08de0151 100644
--- a/tests/011/patmatch.tl
+++ b/tests/011/patmatch.tl
@@ -568,3 +568,9 @@
   (if-match @(< @nil 2) 1 :y :n) :y
   (match @(@nil (< @x 0)) -1 x) -1
   (match @(@nil (< @nil 0)) -1 t) t)
+
+(mtest
+  (match ^(foo) '(foo) t) t
+  (match ^#H() #H(() (a b)) t) t
+  (match ^#H(()) #H(() (a b)) t) t
+  (match ^#S(time) #S(time year 2023) t) t)