DisallowedExtensions.md

Disallowed Extensions

The following extensions are not compatible with the minimum version of GHC (currently 8.10) that we support:

Syntax

• LexicalNegation (9.0)
• QualifiedDo (9.0)

Types

• LinearTypes (9.0)
• ImpredicativeTypes (9.2)
• TypeData (9.6)

Records

• FieldSelectors (9.2)
• OverloadedRecordDot (9.2): this will be really fun when we can use it!
• OverloadedRecordUpdate (9.2 and experimental)

Unboxed Types and Primitive Operations

• UnliftedDatatypes (9.2)

  This one is a bit annoying to lose, as it would be good to be able to unbox some of the state threaded through the parser; in general there is a lot we want to ensure is never lazy -- including state and defunctionalised errors.

  In practice, I think we could probably use this under a CPP guard. Worth considering!