import CostCentre
import Module
import Id
-import Name ( localiseName )
import Var ( Var, TyVar )
import VarSet
import Rules
where B is the *non-recursive* binding
fl = fg a b
gl = gg b
- h = h a b
+ h = h a b -- See (b); note shadowing!
Notice (a) g has a different number of type variables to f, so we must
use the mkArbitraryType thing to fill in the gaps.
We use a type-let to do that.
(b) The local variable h isn't in the exports, and rather than
- clone a fresh copy we simply replace h by (h a b).
+ clone a fresh copy we simply replace h by (h a b), where
+ the two h's have different types! Shadowing happens here,
+ which looks confusing but works fine.
(c) The result is *still* quadratic-sized if there are a lot of
small bindings. So if there are more than some small
spec_rhs = Let (NonRec local_poly poly_f_body) ds_spec_expr
poly_f_body = mkLams (tvs ++ dicts) f_body
- extra_dict_bndrs = [localise d
+ extra_dict_bndrs = [localiseId d -- See Note [Constant rule dicts]
| d <- varSetElems (exprFreeVars ds_spec_expr)
, isDictId d]
-- Note [Const rule dicts]
decomp_msg = hang (ptext (sLit "Specialisation too complicated to desugar; ignored"))
2 (ppr spec_expr)
-
- localise d = mkLocalId (localiseName (idName d)) (idType d)
- -- See Note [Constant rule dicts]
+
mkArbitraryTypeEnv :: [TyVar] -> [([TyVar], a, b, c)] -> DsM (TyVarEnv Type)
-- If any of the tyvars is missing from any of the lists in
But be careful! That dInt might be GHC.Base.$fOrdInt, which is an External
Name, and you can't bind them in a lambda or forall without getting things
-confused. Hence the use of 'localise' to make it Internal.
+confused. Hence the use of 'localiseId' to make it Internal.
%************************************************************************