GHC.Types.Avail

A collection of AvailInfo - several things that are "available"

Records what things are "available", i.e. in scope

Does this AvailInfo export the parent decl? This depends on the invariant that the parent is first if it appears at all.

Just the main name made available, i.e. not the available pieces of type or class brought into scope by the AvailInfo

Names and fields made available by the availability information.

Names and fields made available by the availability information, other than the main decl itself.

Compare lexicographically

trims an AvailInfo to keep only a single name

filters an AvailInfo by the given predicate

filters AvailInfos by the given predicate

Combines AvailInfos from the same family avails may have several items with the same availName E.g import Ix( Ix(..), index ) will give Ix(Ix,index,range) and Ix(index) We want to combine these; plusAvail does that

Sort Avails/AvailInfos

Occurrences of Avails in interface files must be deterministically ordered to guarantee interface file determinism.

We guarantee a deterministic order by either using the order explicitly given by the user (e.g. in an explicit constructor export list) or instead by sorting the avails with sortAvails.

It's always safe to match on DetOrdAvails

Create an empty DetOrdAvails