class IDL::AST::Leaf

def prefix=(pfx)
  unless pfx.to_s.empty?
    raise 'ID prefix should not start or end with \'/\'' if pfx[0, 1] == '/' or pfx[-1, 1] == '/'
    raise "ID prefix should not start with one of '#{REPO_ID_XCHARS.join("', '")}'" if REPO_ID_XCHARS.include?(pfx[0, 1])
    raise 'Invalid ID prefix! Only a..z, A..Z, 0..9, \'.\', \'-\', \'_\' or \'\/\' allowed' unless REPO_ID_RE =~ pfx
  end
  self.set_prefix(pfx)
end