Comment by munchler

1 day 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 21 hours ago

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