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Diffstat (limited to 'compiler/GHC/Core/Opt/SpecConstr.hs')
| -rw-r--r-- | compiler/GHC/Core/Opt/SpecConstr.hs | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/compiler/GHC/Core/Opt/SpecConstr.hs b/compiler/GHC/Core/Opt/SpecConstr.hs index 6cba93023b..2eb5862039 100644 --- a/compiler/GHC/Core/Opt/SpecConstr.hs +++ b/compiler/GHC/Core/Opt/SpecConstr.hs @@ -1,3 +1,4 @@ +{-# LANGUAGE CPP #-} {- ToDo [Oct 2013] ~~~~~~~~~~~~~~~ @@ -974,6 +975,14 @@ lookupHowBound env id = lookupVarEnv (sc_how_bound env) id scSubstId :: ScEnv -> InId -> OutExpr scSubstId env v = lookupIdSubst (sc_subst env) v + +-- Solo is only defined in base starting from ghc-9.2 +#if !(MIN_VERSION_base(4, 16, 0)) + +data Solo a = Solo a + +#endif + -- The !subst ensures that we force the selection `(sc_subst env)`, which avoids -- retaining all of `env` when we only need `subst`. The `Solo` means that the -- substitution itself is lazy, because that type is often discarded. |