As the linear type proposal is underway, and the specifics of how linear types should be exposed in Haskell are being debated, you may wonder: but how is it implemented? Is it easy? Is it hard? Is it small? Is it big? As a GHC developer what would it change for me in practice?

This talk will describe our implementation in progress of the linear type feature. How we changed the linear arrow constructor, how type checking is performed, what changes are necessary in Core to account for linearity, etc…