Bugfix: lexer loses unmatched "hold char" between top-level forms.

Test case: file containing 4(prinl 3). Scanner consumes 4 and (.
The ( is lost when the scanner is reset for the next call to yyparse,
resulting in jut prinl being read and interpreted as a variable.

* parser.c (prime_parser): If present, append hold byte to priming
string. Takes parser_t * instead of parser, and returns void now.

* parser.l (reset_scanner): Now returns int value, the value
of the scanner's yy_hold_char variable which is nonzero when
the scanner is hanging on to an unmatched byte of input.

* parser.h (reset_scanner, prime_parser): Declarations updated.

* parser.y (parse): Pass hold byte returned by reset_scanner to
prime_parser.

1 files changed, 5 insertions, 1 deletions

diff --git a/parser.l b/parser.l
index 4739dd59..29a45ab1 100644
--- a/parser.l
+++ b/parser.l
@@ -960,12 +960,16 @@ void end_of_char(scanner_t *yyg)
   yy_pop_state(yyg);
 }
 
-void reset_scanner(scanner_t *yyg)
+int reset_scanner(scanner_t *yyg)
 {
+  int hold_byte = yyg->yy_hold_char;
+
   while (YYSTATE != INITIAL)
     yy_pop_state(yyg);
 
   yy_flush_buffer(YY_CURRENT_BUFFER, yyg);
+
+  return hold_byte;
 }
 
 val source_loc(val form)