Merge pull request #148 from yui-knk/error_locations

Include error location to parse error messages
ruby · Oct 21, 2023 · 1de81f0 · 1de81f0
2 parents 374bdcf + c6f4d0b
commit 1de81f0
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diff --git a/lib/lrama/parser.rb b/lib/lrama/parser.rb
diff --git a/parser.y b/parser.y
@@ -409,3 +409,8 @@ end
 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) || '?')
+end
diff --git a/spec/lrama/parser_spec.rb b/spec/lrama/parser_spec.rb
@@ -1316,6 +1316,25 @@ class : keyword_class tSTRING keyword_end { code 1 }
         end
       end
     end
+
+    describe "error messages" do
+      it "contains line number and column" do
+        y = <<~INPUT
+%{
+// Prologue
+%}
+
+%expect invalid
+
+%%
+
+program: /* empty */
+       ;
+        INPUT
+
+        expect { Lrama::Parser.new(y).parse }.to raise_error(/5:14: parse error/)
+      end
+    end
   end
 
   describe "#fill_symbol_number" do