On 18 août 2015, at 08:16, Richard A. O'Keefe
If you want to argue about the grammar of 'data' declarations, go right ahead. I myself was a little confused by them at the beginning, because the declare a new type and some constructors, but do not declare 'data' in the sense that a DATA statement in BASIC or Fortran or the DATA DIVISION in COBOL does. The word 'data' is so very far from conveying the idea "introduce a new type" that it's not funny.
Ok, then, just hypothetically (i do not want to argue about actually introducing it), how about type Name = String type Date ::= Date Int Int Int type Anniversary ::= Birthday Name Date | Wedding Name Name Date instead of type Name = String data Date = Date Int Int Int data Anniversary = Birthday Name Date | Wedding Name Name Date ? Alexey.