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, 3 insertions, 1 deletions

diff --git a/stdlib/match.tl b/stdlib/match.tl
index c59179f3..92206e0b 100644
--- a/stdlib/match.tl
+++ b/stdlib/match.tl
@@ -1065,9 +1065,11 @@
 
 (defun transform-qquote (syn)
   (match-case syn
-    ((sys:hash-lit nil . @(coll (@key @val)))
+    ((sys:hash-lit nil . @(all (@key @val)))
      ^@(hash ,*(zip [mapcar transform-qquote key]
                     [mapcar transform-qquote val])))
+    ((sys:hash-lit)
+     '@(hash))
     ((sys:struct-lit @type . @args)
      ^@(struct ,(transform-qquote type)
                ,*[mapcar transform-qquote args]))