Error handling and reporting in Ragel

[Oliver]

Hello,

I'm currently using Ragel to write a parser for an XML-like language.
In
case of a parsing error, I want to be able to provide meaningful
feedback
to the user.

The following is a subset of my machine:
%{{
  machine Test;
  alphtype char;

  NCName = [a-zA-Z] . [a-zA-Z0-9]*;
  Prefix = NCName;
  LocalPart = NCName;
  PrefixedName = Prefix ':' LocalPart;
  UnprefixedName = LocalPart;
  QName = PrefixedName | UnprefixedName;
  LQName = '(' NCName ')' QName;
  AttValue = ('"' [^<&\"]* '"' | "'" [^<&\']* "'");
  Attribute = QName Eq AttValue;
  StartTag = '<' LQName (S Attribute)* S? '>';
  main := StartTag*;
}}%

The following Input (without double quotes) should generate:
  1) "<(l1) test>" -> "Expected QName."
  2) "<l1)test>"   -> "Expected '('."

I have been experimenting with global error state actions. I modified
the
'LQName' rule like this:
  action err1 {
    std::cout << "Expected '('." << std::endl;
  }

  # actions err2 ... err4 are similar to err1

  LQName = '(' @!err1 NCName @!err2 ')' @!err3 QName @!err4;

It this the way to go, or can this be done elegantly in a less verbose
way.
Embedding error actions in all rules looks a litte cumbersome to me.

Best Regards,
Thanks,
Oliver
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