field_list

field_list ::= [ ( ident { "," ident } ":" type ) | 
      ( "CASE" [ ident ":" ] qualident "OF" 
      variant { "|" variant } 
      [ "ELSE" field_list { ";" field_list } ] 
      "END" ) ] 

This rule is called by

-> field_list
-> record_type
-> variant