3 ms·

> let notAValue: string | null = null When did F# get unions?

• datadeft 2y ago
  It had it since the first version as far as I know.
  • ctenb 2y ago
    You're probably referring to Disciminated unions aka sumtypes? That's not what the parent meant
    • datadeft 2y ago
      I thought those are the same and I realize that there is a difference.
• jfausdfwsdfa 2y ago
  Damn. It's only for nulls: https://github.com/fsharp/fslang-design/blob/main/RFCs/FS-1060-nullable-reference-types.md https://github.com/fsharp/fslang-design/blob/main/RFCs/FS-10... Wonder if they will generalize: https://github.com/fsharp/fslang-design/blob/main/RFCs/FS-1092-anonymous-type-tagged-unions.md https://github.com/fsharp/fslang-design/blob/main/RFCs/FS-10...
  • ctenb 2y ago
    At least they chose a syntax that makes it possible to generalize, which is a smart choice imho :)
    • robertlagrant 2y ago
      Yeah it looks a lot like Python's PEP 604[0]. [0] https://peps.python.org/pep-0604 https://peps.python.org/pep-0604