parser.y in lrama-0.5.7 vs parser.y in lrama-0.5.8

@@ -1,6 +1,7 @@
 class Lrama::Parser
+  token C_DECLARATION CHARACTER IDENT_COLON IDENTIFIER INTEGER STRING TAG
 rule
   input: prologue_declarations bison_declarations "%%" grammar epilogue_opt
 
   prologue_declarations: # empty
                        | prologue_declarations prologue_declaration
@@ -296,11 +297,11 @@
            @code_after_prec = false
          }
      | rhs symbol named_ref_opt
          {
            token = val[1]
-           val[1].alias = val[2]
+           token.alias = val[2]
            result = val[0].append(token)
          }
      | rhs "{"
          {
            if @prec_seen
@@ -385,12 +386,13 @@
 
 ---- inner
 
 include Lrama::Report::Duration
 
-def initialize(text)
+def initialize(text, path)
   @text = text
+  @path = path
 end
 
 def parse
   report_duration(:parse) do
     @lexer = Lrama::Lexer.new(@text)
@@ -409,8 +411,12 @@
 def next_token
   @lexer.next_token
 end
 
 def on_error(error_token_id, error_value, value_stack)
-  raise ParseError, sprintf("\n%d:%d: parse error on value %s (%s)",
-                            @lexer.line, @lexer.column, error_value.inspect, token_to_str(error_token_id) || '?')
+  source = @text.split("\n")[error_value.line - 1]
+  raise ParseError, <<~ERROR
+    #{@path}:#{@lexer.line}:#{@lexer.column}: parse error on value #{error_value.inspect} (#{token_to_str(error_token_id) || '?'})
+    #{source}
+    #{' ' * @lexer.column}^
+  ERROR
 end