parser: new *read-unknown-structs* variable.

* parser.c (read_unknown_structs_s): New symbol variable.
(parser_common_init): Initialize read_unknown_structs flag
member of the parser structure from the new special variable.
(parse_init): Initialize read_unknown_struct_s variable.
Register the *read-unknown-structs* dynamic variable.

* parser.h (struct parser): New member, read_unknown_structs.
(read_unknown_structs_s): Declared.

* parser.y (struct): Generate the struct literal syntax not
only for quasiquoted structures, but for structures with an
unknown type name, if the read_unkonwn_structs flag is set.

* txr.1: Documented.

* share/txr/stdlib/doc-syms.tl: Regenerated.

* y.tab.c.shipped: Regenerated.

1 files changed, 5 insertions, 1 deletions

diff --git a/parser.c b/parser.c
index 85b80202..ad7694e6 100644
--- a/parser.c
+++ b/parser.c
@@ -72,7 +72,7 @@
 val parser_s, unique_s, circref_s;
 val listener_hist_len_s, listener_multi_line_p_s, listener_sel_inclusive_p_s;
 val listener_pprint_s, listener_greedy_eval_s;
-val rec_source_loc_s;
+val rec_source_loc_s, read_unknown_structs_s;
 val json_s;
 val intr_s;
 static lino_t *lino_ctx;
@@ -120,6 +120,7 @@ void parser_common_init(parser_t *p)
   int i;
   yyscan_t yyscan;
   val rec_source_loc_var = lookup_var(nil, rec_source_loc_s);
+  val read_unknown_structs_var = lookup_var(nil, read_unknown_structs_s);
 
   p->parser = nil;
   p->lineno = 1;
@@ -146,6 +147,7 @@ void parser_common_init(parser_t *p)
   }
   p->tok_idx = 0;
   p->rec_source_loc = !nilp(cdr(rec_source_loc_var));
+  p->read_unknown_structs = !nilp(cdr(read_unknown_structs_var));
 }
 
 void parser_cleanup(parser_t *p)
@@ -1850,6 +1852,7 @@ void parse_init(void)
   listener_pprint_s = intern(lit("*listener-pprint-p*"), user_package);
   listener_greedy_eval_s = intern(lit("*listener-greedy-eval-p*"), user_package);
   rec_source_loc_s = intern(lit("*rec-source-loc*"), user_package);
+  read_unknown_structs_s = intern(lit("*read-unknown-structs*"), user_package);
   json_s = intern(lit("json"), user_package);
   unique_s = gensym(nil);
   protect(&stream_parser_hash, &unique_s, &catch_all, convert(val *, 0));
@@ -1863,6 +1866,7 @@ void parse_init(void)
   reg_var(listener_pprint_s, nil);
   reg_var(listener_greedy_eval_s, nil);
   reg_var(rec_source_loc_s, nil);
+  reg_var(read_unknown_structs_s, nil);
   reg_fun(circref_s, func_n1(circref));
   reg_fun(intern(lit("parse-errors"), user_package), func_n1(parse_errors));
   reg_fun(intern(lit("repl"), system_package), func_n4(repl));