-haddock does not collect documentation on family instances
Summary
Documentation added to type family instances declarations doesn't appear in the .hi
file when -haddock
is enabled. It looks like it may be related to https://github.com/haskell/haddock/pull/867
Steps to reproduce
Given the file
{-# LANGUAGE TypeFamilies #-}
module TFDocBug where
-- | This is my family
type family F a
-- | Hello world
type instance F Int = Bool
Run ghc -haddock TFDocBug.hs -ddump-hi
Expected behavior
The output of -ddump-hi
should contain something near the bottom like
module header:
Nothing
declaration docs:
TFDocBug.F:
" This is my family"
TFDocBug.$fmangledNameForF.Int
" Hello world"
arg docs:
The actual output is just
module header:
Nothing
declaration docs:
TFDocBug.F:
" This is my family"
arg docs:
Environment
- GHC version used: ghc-HEAD
Optional:
- Operating System: Darwin