grammar: Don't hardcode the retry limit.

Override for table_sample.

Author: anse1

grammar.cc

@@ -36,7 +36,7 @@ void table_or_query_name::out(std::ostream &out) {
 
 table_sample::table_sample(prod *p) : table_ref(p) {
   match();
-
+  retry_limit = 1000; /* retries are cheap here */
   do {
     auto pick = random_pick(scope->tables);
     t = dynamic_cast<struct table*>(pick);

prod.cc

@@ -27,7 +27,7 @@ void prod::indent(std::ostream &out)
 void prod::retry()
 {
   impedance::retry(this);
-  if (retries++ <= 200)
+  if (retries++ <= retry_limit)
     return;
 
   impedance::limit(this);

prod.hh

@@ -19,6 +19,7 @@ struct prod {
   struct scope *scope;
   int level;
   long retries = 0;
+  long retry_limit = 200;
   prod(prod *parent);
   virtual void indent(std::ostream &out);
   virtual void out(std::ostream &out) = 0;