wlhs

This project aims to develop a set of Haskell bindings for wlroots (and some parts of libwayland) At the moment it focusses on low-level bindings, in the wlhs-bindings package.

Warning: this project has just begun! Currently, the bindings are highly incomplete. Please feel free to help us expand them!

Development

We currently target wlroots version 0.17.1.

There is a Nix development flake available, which may be accessed via nix develop. For direnv users, an .envrc file is also provided.

hsc2hs extensions

wlhs-bindings contains a custom Setup.hs, which extends hsc2hs files with some custom syntax. This is probably best illustrated by example:

Macro call	Equivalent to
{{ struct include.h, wl_type_name }}	data {-# CTYPE "include.h" "struct wl_type_name" #-} WL_type_name deriving (Show) (Note: requires {-# LANGUAGE EmptyDataDeriving #-})
{{ struct include.h, wl_type_name, field1, Type1, field2, Type2, nested field, Type2, arrayfield, [3]Type3 }}	data {-# CTYPE "include.h" "struct wl_type_name" #-} WL_type_name = WL_type_name { wl_type_name_field1 :: Type1 , wl_type_name_field2 :: Type2 , wl_type_name_nested_field :: Type2 , wl_type_name_arrayfield :: [Type3] } deriving (Show) instance Storable WL_type_name where alignment _ = #alignment struct wl_type_name sizeOf _ = #size struct wl_type_name peek ptr = WL_type_name <$> (#peek struct wl_type_name, field1) ptr <*> (#peek struct wl_type_name, field2) ptr <*> (#peek struct wl_type_name, nested.field) ptr <*> peekArray 3 ((#ptr struct wl_type_name, arrayfield) ptr) poke ptr t = do (#poke struct wl_type_name, field1) ptr (wl_type_name_field1 t) (#poke struct wl_type_name, field2) ptr (wl_type_name_field2 t) (#poke struct wl_type_name, nested.field) ptr (wl_type_name_nested_field t) pokeArray ((#ptr struct wl_type_name, nested.field) ptr) (wl_type_name_nested_field t)
{{ enum WL_type_name, WLR_ENUM_VALUE_1, WLR_ENUM_VALUE_2 }}	type WL_type_name = CInt pattern WLR_ENUM_VALUE_1 :: (Eq a, Num a) => a pattern WLR_ENUM_VALUE_1 = #const WLR_ENUM_VALUE_1 pattern WLR_ENUM_VALUE_2 :: (Eq a, Num a) => a pattern WLR_ENUM_VALUE_2 = #const WLR_ENUM_VALUE_2