Deprecated feature section

John Hughes
Fri, 26 Oct 2001 09:05:39 +0200 (MET DST)

	George Russel proposed a search for things which should be deprecated.
	I have a very distinct unfondness for contexts in algebraic data type
	declarations. They make absolutely no difference except move type
	errors to a different part of a program (or rather, they add type 
	errors). In that sense they could be said to be quite harmless, but
	they dramatically complicate the typing rules for everything involving
	algebraic data types, especially when combined with labelled fields.



Seconded! There is a sensible meaning for contexts on data-type declarations,
but Haskell ones don't have it. (See my paper "Restricted Data Types" in the
Haskell workshop a couple of years ago). At present they are simply useless.