Optimization: Replace head recursion by tail recursion in matching

1 files changed, 2 insertions, 2 deletions

diff --git a/lexer.cpp b/lexer.cpp
index 0944738..a9cda32 100644
--- a/lexer.cpp
+++ b/lexer.cpp
@@ -85,14 +85,14 @@ void Lexer::addRule(const std::vector<std::string>& list, size_t list_index_from
  for (size_t i = list_index_from; i < list_index_to - 1; i++) {
   std::string symbol{list[i]};
   if (symbol == rule_symbol)
-   throw std::runtime_error("Recursion found but not allowed");
+   throw std::runtime_error("Recursion found but not allowed. Only head recursion allowed for lexer.");
 
   size_t state{newState()};
   addPathOrTransition(previousState, state, symbol);
   previousState = state;
  }
  if (list.back() == rule_symbol)
-  throw std::runtime_error("Recursion found but not allowed");
+  throw std::runtime_error("Tail recursion found but not allowed. Only head recursion allowed for lexer.");
 
  // last transition
  addPathOrTransition(previousState, state1, list.back());