'Import the * operator of type level naturals

Follow-up to Import a type family that is an operator in Haskell.

This works:

import GHC.TypeLits (type (+))

This is a parse error in GHC 9.0:

import GHC.TypeLits (type (*))

See for example:

ghci -XTypeOperators
GHCi, version 9.0.2: https://www.haskell.org/ghc/  :? for help
ghci> import GHC.TypeLits (type (+))
ghci> import GHC.TypeLits (type (*))

<interactive>:2:28: error: parse error on input ‘*’

How do I import type level natural number multiplication?

haskellimporttype-level-computation


Solution 1:[1]

It is necessary to activate the language extension NoStarIsType, then it will work. Otherwise, * is going to be interpreted as Type.

Sources

This article follows the attribution requirements of Stack Overflow and is licensed under CC BY-SA 3.0.

Source: Stack Overflow

Solution Source
Solution 1 Turion

Related Questions