diff options
Diffstat (limited to 'compiler/GHC/Rename/Expr.hs')
| -rw-r--r-- | compiler/GHC/Rename/Expr.hs | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/compiler/GHC/Rename/Expr.hs b/compiler/GHC/Rename/Expr.hs index aff3ce3dbd..a85103d8ed 100644 --- a/compiler/GHC/Rename/Expr.hs +++ b/compiler/GHC/Rename/Expr.hs @@ -130,7 +130,7 @@ but several have a little bit of special treatment: * SectionL and SectionR (left and right sections) (`op` e) ==> rightSection op e (e `op`) ==> leftSection (op e) - where `leftSection` and `rightSection` are levity-polymorphic + where `leftSection` and `rightSection` are representation-polymorphic wired-in Ids. See Note [Left and right sections] * It's a bit painful to transform `OpApp e1 op e2` to a `HsExpansion` @@ -613,19 +613,19 @@ Note the wrinkles: sections , but only to eliminate special-purpose code paths in the renamer and desugarer. -* leftSection and rightSection must be levity-polymorphic, to allow +* leftSection and rightSection must be representation-polymorphic, to allow (+# 4#) and (4# +#) to work. See GHC.Types.Id.Make. Note [Wired-in Ids for rebindable syntax] in * leftSection and rightSection must be multiplicity-polymorphic. (Test linear/should_compile/OldList showed this up.) -* Because they are levity-polymorphic, we have to define them +* Because they are representation-polymorphic, we have to define them as wired-in Ids, with compulsory inlining. See GHC.Types.Id.Make.leftSectionId, rightSectionId. * leftSection is just ($) really; but unlike ($) it is - levity polymorphic in the result type, so we can write + representation-polymorphic in the result type, so we can write `(x +#)`, say. * The type of leftSection must have an arrow in its first argument, |