From f08878aceddb07057f8d423b05918433d63c5cdc Mon Sep 17 00:00:00 2001
From: Emiel Bruijntjes <emiel.bruijntjes@copernica.com>
Date: Thu, 16 Dec 2021 11:39:22 +0100
Subject: [PATCH] simplified handling of syntax errors, the old code made
 assumptions about how lemon was internally implemented, that were no longer
 true for later versions of Lemon

---
 src/parser.lemon     | 13 +------------
 src/tokenprocessor.h | 19 ++-----------------
 2 files changed, 3 insertions(+), 29 deletions(-)

diff --git a/src/parser.lemon b/src/parser.lemon
index 0d2fb17..ae65c45 100644
--- a/src/parser.lemon
+++ b/src/parser.lemon
@@ -50,18 +50,7 @@
 
 %syntax_error
 {
-    // Build up a vector of expected tokens
-    // Mostly based on the following SO post, but we instead put it in a std::vector
-    // https://stackoverflow.com/questions/11705737/expected-token-using-lemon-parser-generator/13010096#13010096
-    std::vector<std::string> expectedTokens;
-
-    // we loop over all known tokens, if we exceed our defined tokens we exit
-    // our last defined token is TOKEN_STRING, so we halt when we go past it
-    for (int i = 0; i <= TOKEN_STRING; ++i) {
-        int a = yy_find_shift_action(yypParser, (YYCODETYPE)i);
-        if (a < YYNSTATE + YYNRULE) expectedTokens.emplace_back(yyTokenName[i]);
-    }
-    parent->syntaxError(expectedTokens);
+    parent->syntaxError();
 }
 
 %stack_overflow
diff --git a/src/tokenprocessor.h b/src/tokenprocessor.h
index 8ac6931..7b56355 100644
--- a/src/tokenprocessor.h
+++ b/src/tokenprocessor.h
@@ -88,25 +88,10 @@ class TokenProcessor
     /**
      *  This will get called by lemon in case of a syntax error
      */
-    void syntaxError(const std::vector<std::string> &expectedTokens)
+    void syntaxError()
     {
+        // remember that we're in syntax error state
         _error.append("Syntax error");
-
-        // If we have any expected tokens append them to the error
-        if (expectedTokens.empty() == false)
-        {
-            _error.append(", expected one of the following tokens [");
-
-            for (auto iter = expectedTokens.begin(); iter != expectedTokens.end(); ++iter)
-            {
-                _error.append(*iter);
-
-                // for every token that is not our last token (end iter - 1) we append a space for readability
-                if (iter != expectedTokens.end() - 1) _error.push_back(' ');
-            }
-
-            _error.push_back(']');
-        }
     }
 
     /**