Comment by munchler

21 hours ago

Unions are simpler than subclasses and more powerful than enums, so the use cases are plentiful. This should reduce the proliferation of verbose class hierarchies in C#. Algebraic data types (i.e. records and unions) can usually express domain models much more succinctly than traditional OO.

6 comments

munchler

Quarrelsome 21 hours ago

> so the use cases are plentiful

such as?

> This should reduce the proliferation of verbose class hierarchies in C#

So just as an alternative for class hierarchies? I mean good people already balance that by having a preference for composition.

munchler 21 hours ago

Simple example:

   type Expr =
       | Primitive of int
       | Addition of (Expr * Expr)
       | Subtraction of (Expr * Expr)
       | Negation of Expr

Quarrelsome 21 hours ago

Isn't that just Func<int> ?

2 replies →

LeFantome 20 hours ago

“Compoision”. A typo I know but it would be a word describing what goes wrong with class hierarchies.