diff options
Diffstat (limited to 'compiler/specialise')
| -rw-r--r-- | compiler/specialise/Rules.hs | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/compiler/specialise/Rules.hs b/compiler/specialise/Rules.hs index bdf196a163..4233980ea4 100644 --- a/compiler/specialise/Rules.hs +++ b/compiler/specialise/Rules.hs @@ -41,7 +41,8 @@ import CoreUtils ( exprType, eqExpr, mkTick, mkTicks, isJoinBind ) import PprCore ( pprRules ) import Type ( Type, TCvSubst, extendTvSubst, extendCvSubst - , mkEmptyTCvSubst, substTy ) + , mkEmptyTCvSubst, substTy, tyConAppTyCon_maybe ) +import TyCon ( isClassTyCon ) import TcType ( tcSplitTyConApp_maybe ) import TysWiredIn ( anyTypeOfKind ) import Coercion @@ -519,8 +520,8 @@ matchRule _ in_scope is_active _ args rough_args | not (is_active act) = Left [] | ruleCantMatch tpl_tops rough_args = Left [] | not rule_auto - , [] /= tpl_vars - , [] /= nonAffineOrDictArgs = Left nonAffineOrDictArgs + , not (null tpl_vars) + , not (null nonAffineOrDictArgs) = Left nonAffineOrDictArgs | otherwise = case matchN in_scope rule_name tpl_vars tpl_args args rhs of Just match -> Right match Nothing -> Left [] |