Data.OverloadedLabels

This module defines the IsLabel class is used by the OverloadedLabels extension. See the wiki page for more details.

The key idea is that when GHC sees an occurrence of the new overloaded label syntax #foo, it is replaced with

fromLabel (proxy# :: Proxy# "foo") :: alpha

plus a wanted constraint IsLabel "foo" alpha.

Oveloaded Labels

class IsLabel l a where

Methods

fromLabel :: Proxy# l -> a

Instances

(SetField l s b, (~) * (UpdateType l s b) t) => IsLabel l (Setter s t b)