New #; syntax for erasing following object.

* parser.c (parser_circ_ref): Don't generate the
circular reference if circular suppression is in
effect.

* parser.h (struct parser): New member, circ_suppress.
We use this for suppressing the generation of
circular #n# references in erased objects.

* parser.l (grammar): Scan #; producing HASH_SEMI token.

* parser.y (HASH_SEMI): New token.
(hash_semis_n_expr, hash_semis_i_expr, ignored_i_exprs,
ignored_n_exprs): New nonterminals, needed for supporting
the use of #; in front of top-level forms.
(spec): Use hash_semis_n_expr and hash_semis_i_expr
instead of n_expr and i_expr.
(r_expr): Support object erasure within nested syntax.
(yybadtoken): Handle H_SEMI token.
(parse): Initialize new circ_suppress member of parser
struct to zero.

* txr.1: Documented.

* genvim.txr (txr_ign_par, txr_ign_bkt, txr_ign_par_interior,
txr_ign_bkt_interior): New regions for colorizing erased
objects (partial support).
(txr_list, txr_bracket, txr_mlist, txr_mbrackets): Include
erased objects by including regions txr_ign_par and
txr_ign_bkt.

* txr.vim, tl.vim: Regenerated.

1 files changed, 1 insertions, 0 deletions

diff --git a/parser.h b/parser.h
index a12d45ee..6980e0f4 100644
--- a/parser.h
+++ b/parser.h
@@ -56,6 +56,7 @@ struct parser {
   val syntax_tree;
   val circ_ref_hash;
   cnum circ_count;
+  int circ_suppress;
   scanner_t *scanner;
   struct yy_token recent_tok;
   struct yy_token tok_pushback[4];