pro.ometa

ometa PrologTranslator : Parser {
  variable     ::= <spaces> <firstAndRest #upper #letterOrDigit>:name           => [Var new: (name join: '')].
  symbol       ::= <spaces> <firstAndRest #lower #letterOrDigit>:name           => [Sym new: (name join: '')].
  clause       ::= <symbol>:sym <token '('> <listOf #expr ','>:args <token ')'> => [Clause new: sym : args].
  expr         ::= <clause> | <variable> | <symbol>.
  clauses      ::= <listOf #clause ','>.
  rule         ::= <clause>:head <token ':-'> <clauses>:body <token '.'>        => [Rule new: head : body]
                 | <clause>:head                             <token '.'>        => [Rule new: head : {}].
  rules        ::= <rule>*:rs <spaces> <end>                                    => [rs].
  query        ::= <clause>:c <spaces> <end>                                    => [c].
}.

What's the host language? I thought at first it was Smalltalk (which wouldn't be surprising, given that that was Ometa's first host language), but Clause new: sym : args is not valid Smalltalk syntax. It would need to be something like Clause new: sym args: args (note the characters prior to the :).