New :mandatory keyword in until/last clauses.

* match.c (mandatory_k): New keyword variable.
(h_coll, v_gather, v_collect): Implement :mandatory logic.
(syms_init): Initialize mandatory_k.

* parser.l (grammar): The UNTIL and LAST tokens must be
matched similarly to collect, without consuming the
closing parenthesis, allowing a list of items to be parsed
between the symbol and the closure, in the NESTED state.

* parser.y (gather_clause, collect_clause, elem,
repeat_parts_opt, rep_parts_opt): Adjust to new until/last
syntax. In the matching productions, the abstract syntax
changes to incorporate the options. In the output productions,
we throw an error if options are present.

* txr.1: Documented :mandatory for collect, coll and gather.

1 files changed, 4 insertions, 5 deletions

diff --git a/parser.l b/parser.l
index 79392ce3..aa7fb6dc 100644
--- a/parser.l
+++ b/parser.l
@@ -474,8 +474,8 @@ UONLY   {U2}{U}|{U3}{U}{U}|{U4}{U}{U}{U}
   return COLL;
 }
 
-<SPECIAL>\({WS}until{WS}\) {
-  yy_pop_state(yyscanner);
+<SPECIAL>\({WS}until/{ID_END} {
+  yy_push_state(NESTED, yyscanner);
   yylval->lineno = yyextra->lineno;
   return UNTIL;
 }
@@ -492,7 +492,6 @@ UONLY   {U2}{U}|{U3}{U}{U}|{U4}{U}{U}{U}
   return REPEAT;
 }
 
-
 <SPECIAL>\({WS}rep/{ID_END} {
   yy_push_state(NESTED, yyscanner);
   yylval->lineno = yyextra->lineno;
@@ -511,8 +510,8 @@ UONLY   {U2}{U}|{U3}{U}{U}|{U4}{U}{U}{U}
   return FIRST;
 }
 
-<SPECIAL>\({WS}last{WS}\) {
-  yy_pop_state(yyscanner);
+<SPECIAL>\({WS}last/{ID_END} {
+  yy_push_state(NESTED, yyscanner);
   yylval->lineno = yyextra->lineno;
   return LAST;
 }