Parser cleanup: embed scanner in parser.

* parser.c (parser_destroy): New GC finalizer static function.
(parser_ops): Register parser_destroy.
(parser_common_init): New function, shared by parse and parse_once.
Initializes embedded scanner.
(parser_cleanup): New function, shared by parse_once and
parser_destroy.
(parser): Use parser_common_init.

* parser.h (parser_t): New member, yyscan.
(reset_scanner, parser_common_init): Declared.

* parser.l (reset_scanner): New function.

* parser.y (parse_once): Use parser_common_init, and
thus perform only a few initializations. Do not
define scanner as a local variable.
(parse): Call reset_scanner instead of
yylex_init since the scanner is being reused,
and for the same reason do not call yylex_destroy.
GC will do that now.

1 files changed, 8 insertions, 0 deletions

diff --git a/parser.l b/parser.l
index f7c717e8..4739dd59 100644
--- a/parser.l
+++ b/parser.l
@@ -960,6 +960,14 @@ void end_of_char(scanner_t *yyg)
   yy_pop_state(yyg);
 }
 
+void reset_scanner(scanner_t *yyg)
+{
+  while (YYSTATE != INITIAL)
+    yy_pop_state(yyg);
+
+  yy_flush_buffer(YY_CURRENT_BUFFER, yyg);
+}
+
 val source_loc(val form)
 {
   return gethash(form_to_ln_hash, form);