attribute{Attribute=Datatype}:
  match /$(IDENT)/
equal{Normal}:
  symbol =
value{Value=String}:
  from " to "
  from ' to '
  string.entity{Entity}:
    match /&[A-Za-z]+;/
    match /&#[0-9]+;/
value.unquoted{Value}:
  match /[^"'`=<>\s]+/
