generator_slr: fix follow set generation

Looks like my source of information was incomplete...

1 files changed, 18 insertions, 18 deletions

diff --git a/src/generator_slr.cpp b/src/generator_slr.cpp
index a8e081a..2989ee1 100644
--- a/src/generator_slr.cpp
+++ b/src/generator_slr.cpp
@@ -92,31 +92,31 @@ void generator_slr_t::generate_follow_sets() {
 				const std::set<symbol_t> &lhs = follow_sets[item.get_lhs()];
 				std::set<symbol_t> &rhs = follow_sets[sym.get_value()];
 
+				bool has_empty = true;
 				item_t next = item;
-				next.shift();
 
-				bool next_empty = false;
+				while (has_empty) {
+					has_empty = false;
+					next.shift();
 
-				if (next.has_next()) {
-					const symbol_t &next_sym = next.get_next_symbol();
+					if (next.has_next()) {
+						const symbol_t &next_sym = next.get_next_symbol();
 
-					if (next_sym.get_type() == SYMBOL_TYPE_NONTERM) {
-						for (const symbol_t &sym2 : first_sets[next_sym.get_value()]) {
-							if (sym2 == symbol_t::empty())
-								next_empty = true;
-							else
-								changed = changed || rhs.insert(sym2).second;
+						if (next_sym.get_type() == SYMBOL_TYPE_NONTERM) {
+							for (const symbol_t &sym2 : first_sets[next_sym.get_value()]) {
+								if (sym2 == symbol_t::empty())
+									has_empty = true;
+								else
+									changed = changed || rhs.insert(sym2).second;
+							}
 						}
+						else {
+							changed = changed || rhs.insert(next_sym).second;
+						}
+
+						continue;
 					}
-					else {
-						changed = changed || rhs.insert(next_sym).second;
-					}
-				}
-				else {
-					next_empty = true;
-				}
 
-				if (next_empty) {
 					for (const symbol_t &sym2 : lhs)
 						changed = changed || rhs.insert(sym2).second;
 				}