Improve error message when finding a comma in a macro expression. Fixes

#3048
crystal-lang · Jul 26, 2016 · e592bc8 · e592bc8
1 parent 84ae5cd
commit e592bc8
Showing 1 changed file with 12 additions and 0 deletions.
diff --git a/src/compiler/crystal/syntax/parser.cr b/src/compiler/crystal/syntax/parser.cr
@@ -2792,6 +2792,18 @@ module Crystal
     end
 
     def check_macro_expression_end
+      if @token.type == :","
+        raise <<-MSG
+          expecting token ',', not '}'
+
+          If you are nesting tuples or hashes you must write them like this:
+
+              { {x, y}, {z, w} } # Note the space after the first curly brace
+
+          because {{...}} is parsed as a macro expression.
+          MSG
+      end
+
       check :"}"
 
       next_token