Remove old error recovery code

src/compiler/build_tables/build_lex_table.cc

@@ -65,9 +65,7 @@ class LexTableBuilder {
     LexItemSet result;
     for (const Symbol &symbol : symbols) {
       vector<rule_ptr> rules;
-      if (symbol == rules::ERROR()) {
-        continue;
-      } else if (symbol == rules::END_OF_INPUT()) {
+      if (symbol == rules::END_OF_INPUT()) {
         rules.push_back(CharacterSet().include(0).copy());
       } else if (symbol.is_token) {
         rule_ptr rule = lex_grammar.variables[symbol.index].rule;

src/compiler/build_tables/build_parse_table.cc

@@ -80,8 +80,6 @@ class ParseTableBuilder {
     mark_fragile_actions();
     remove_duplicate_parse_states();
 
-    parse_table.symbols.insert({ rules::ERROR(), { true } });
-
     return { parse_table, CompileError::none() };
   }
 
@@ -400,9 +398,7 @@ class ParseTableBuilder {
 
   string symbol_name(const rules::Symbol &symbol) const {
     if (symbol.is_built_in()) {
-      if (symbol == rules::ERROR())
-        return "ERROR";
-      else if (symbol == rules::END_OF_INPUT())
+      if (symbol == rules::END_OF_INPUT())
         return "END_OF_INPUT";
       else
         return "";

src/compiler/generate_code/c_code.cc

@@ -23,7 +23,6 @@ using std::to_string;
 using std::vector;
 using util::escape_char;
 
-static Variable ERROR_ENTRY("error", VariableTypeNamed, rule_ptr());
 static Variable EOF_ENTRY("end", VariableTypeNamed, rule_ptr());
 
 static const map<char, string> REPLACEMENTS({
@@ -465,8 +464,6 @@ class CCodeGenerator {
   // Helper functions
 
   string symbol_id(const rules::Symbol &symbol) {
-    if (symbol == rules::ERROR())
-      return "ts_builtin_sym_error";
     if (symbol == rules::END_OF_INPUT())
       return "ts_builtin_sym_end";
 
@@ -484,16 +481,12 @@ class CCodeGenerator {
   }
 
   string symbol_name(const rules::Symbol &symbol) {
-    if (symbol == rules::ERROR())
-      return "ERROR";
     if (symbol == rules::END_OF_INPUT())
       return "END";
     return entry_for_symbol(symbol).first;
   }
 
   VariableType symbol_type(const rules::Symbol &symbol) {
-    if (symbol == rules::ERROR())
-      return VariableTypeNamed;
     if (symbol == rules::END_OF_INPUT())
       return VariableTypeHidden;
     return entry_for_symbol(symbol).second;

src/compiler/parse_grammar.cc

@@ -90,7 +90,7 @@ ParseRuleResult parse_rule(json_value *rule_json) {
     json_value content_json = rule_json->operator[]("content");
     ParseRuleResult content = parse_rule(&content_json);
     if (content.rule.get()) {
-      return { err(content.rule), "" };
+      return { content.rule, "" };
     } else {
       error_message = "Invalid error content: " + content.error_message;
       goto error;

src/compiler/rules.h

@@ -16,7 +16,6 @@ rule_ptr seq(const std::vector<rule_ptr> &);
 rule_ptr sym(const std::string &);
 rule_ptr pattern(const std::string &);
 rule_ptr str(const std::string &);
-rule_ptr err(const rule_ptr &);
 rule_ptr prec(int precedence, const rule_ptr &);
 rule_ptr prec_left(const rule_ptr &);
 rule_ptr prec_left(int precedence, const rule_ptr &);

src/compiler/rules/built_in_symbols.cc

@@ -7,16 +7,12 @@ Symbol END_OF_INPUT() {
   return Symbol(-1, true);
 }
 
-Symbol ERROR() {
-  return Symbol(-2, true);
-}
-
 Symbol START() {
-  return Symbol(-3);
+  return Symbol(-2);
 }
 
 Symbol NONE() {
-  return Symbol(-4);
+  return Symbol(-3);
 }
 
 }  // namespace rules

src/compiler/rules/built_in_symbols.h

@@ -6,7 +6,6 @@
 namespace tree_sitter {
 namespace rules {
 
-Symbol ERROR();
 Symbol END_OF_INPUT();
 Symbol START();
 Symbol NONE();

src/compiler/rules/rules.cc

@@ -59,10 +59,6 @@ rule_ptr str(const string &value) {
   return make_shared<rules::String>(value);
 }
 
-rule_ptr err(const rule_ptr &rule) {
-  return choice({ rule, rules::ERROR().copy() });
-}
-
 rule_ptr prec_left(const rule_ptr &rule) {
   return metadata(rule, { { rules::ASSOCIATIVITY, rules::AssociativityLeft } });
 }