#12550: Inconsistent unicode display for kinds ---------------------------------+-------------------------------------- Reporter: johnleo | Owner: johnleo Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.0.1 Resolution: | Keywords: Operating System: MacOS X | Architecture: x86_64 (amd64) Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | ---------------------------------+-------------------------------------- Description changed by johnleo: @@ -54,0 +54,4 @@ + + :t (:*:) + (:*:) ∷ ∀ {g ∷ ★ → *} {p} {f ∷ ★ → *}. f p → g p → (:*:) ★ f g p + -- Note that ★ and * are reversed from what :i displays! New description: With `:set -fprint-unicode-syntax`, the kind `*` should always be printed as `★`. However the output is extremely inconsistent. Here are a few examples from ghci, and I will add more as I run across them. {{{ :t fmap fmap ∷ ∀ {f ∷ ★ → ★} {a} {b}. Functor f ⇒ (a → b) → f a → f b :i fmap class Functor (f ∷ * → *) where fmap ∷ forall a b. (a → b) → f a → f b -- (note that forall is also not displayed properly as ∀ here) :k Functor Functor ∷ (★ → ★) → Constraint :m + GHC.Generics :i Functor -- (among other output) instance ∀ (f ∷ * → ★). Functor f ⇒ Functor (Rec1 f) -- Defined in ‘GHC.Generics’ instance Functor Par1 -- Defined in ‘GHC.Generics’ instance ∀ i (c ∷ Meta) (f ∷ * → ★). Functor f ⇒ Functor (M1 i c f) -- Defined in ‘GHC.Generics’ instance ∀ i c. Functor (K1 i c) -- Defined in ‘GHC.Generics’ instance ∀ (f ∷ * → ★) (g ∷ * → *). (Functor f, Functor g) ⇒ Functor (f :.: g) -- Defined in ‘GHC.Generics’ instance ∀ (f ∷ * → ★) (g ∷ * → ★). (Functor f, Functor g) ⇒ Functor (f :+: g) -- Defined in ‘GHC.Generics’ instance ∀ (f ∷ * → ★) (g ∷ * → ★). (Functor f, Functor g) ⇒ Functor (f :*: g) -- Defined in ‘GHC.Generics’ :t datatypeName datatypeName ∷ ∀ {d} {t ∷ ★ → (* → *) → ★ → ★} {f ∷ * → *} {a}. Datatype ★ d ⇒ t d f a → [Char] :i datatypeName class Datatype k (d ∷ k) where datatypeName ∷ forall {k1} (t ∷ k → (* → *) → k1 → *) (f ∷ * → *) (a ∷ k1). t d f a → [Char] ... -- Defined in ‘GHC.Generics’ :t (:*:) (:*:) ∷ ∀ {g ∷ ★ → *} {p} {f ∷ ★ → *}. f p → g p → (:*:) ★ f g p -- Note that ★ and * are reversed from what :i displays! }}} Note that `:t datatypeName` causes a panic in 8.1; I have filed a separate bug [https://ghc.haskell.org/trac/ghc/ticket/12549] -- -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/12550#comment:3 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler