Idris2-boot/libs/base/System/FFI.idr
Edwin Brady a5c356f998 Basic support for struct in FFI
Just in the Chez backend for now, and not allowing strings or functions
due to limitations of Chez.
2020-03-01 23:23:21 +00:00

36 lines
1.2 KiB
Idris

-- Additional FFI help for more interesting C types
-- Some assumptions are made about the existence of this module in
-- Compiler.CompileExpr
module System.FFI
export
data Struct : String -> -- C struct name
List (String, Type) -> -- field names and types
Type where
public export
data FieldType : String -> Type -> List (String, Type) -> Type where
First : FieldType n t ((n, t) :: ts)
Later : FieldType n t ts -> FieldType n t (f :: ts)
%extern
prim__getField : {s : _} -> forall fs, ty .
Struct s fs -> (n : String) ->
FieldType n ty fs -> ty
%extern
prim__setField : {s : _} -> forall fs, ty .
Struct s fs -> (n : String) ->
FieldType n ty fs -> ty -> PrimIO ()
public export %inline
getField : {s : _} -> Struct s fs -> (n : String) ->
{auto fieldok : FieldType n ty fs} -> ty
getField s n = prim__getField s n fieldok
public export %inline
setField : {s : _} -> Struct s fs -> (n : String) ->
{auto fieldok : FieldType n ty fs} -> ty -> IO ()
setField s n val = primIO (prim__setField s n fieldok val)