Hi all, I have amended the plan [1] as a result of the ongoing discussion, including leaving the syntax alone for the time being, so record projections are written prefix. Regarding Barney's suggestion of field declarations: On 01/07/13 10:50, Barney Hilken wrote:
All this extra syntax, whether it's ., #, or {} seems very heavy for a problem described as very rare. Why not simply use a declaration
field name
whose effect is to declare
name :: r {name ::t} => r -> t name = getFld
unless name is already in scope as a field name, in which case the declaration does nothing?
This makes sense. I guess the question is whether a new declaration form is justified. The implementation is slightly more subtle than you suggest, because we don't know whether `name` will be brought into scope as a field later, in which case the definition would clash with the actual field. It should be equivalent to defining data Unused { name :: () } data Unused2 { name :: () } (twice so that there is always ambiguity about a use of `name`). Adam [1] http://hackage.haskell.org/trac/ghc/wiki/Records/OverloadedRecordFields/Plan