block = type name ['(' {attributes} ')'] '{' {data_fields} '}';
type = 'map' | 'class' | 'module' | 'vartab';

attributes = name ':' name [','];
data_fields = data_name ',' data_value [':' depend_macro] '\n';

(* regular expression *)
name = [_a-zA-Z]\w*;
data_name = [\._a-zA-Z]\w*;
data_value = [\w\()]+;
depend_macro = [_a-zA-Z]\w*;