Replace Core.Stack with Syntax.Stack.

semantic-core/semantic-core.cabal

@@ -55,7 +55,6 @@ library
     Core.Loc
     Core.Name
     Core.Scope
-    Core.Stack
   build-depends:
       algebraic-graphs            ^>= 0.3
     , base                         >= 4.12 && < 5

semantic-core/src/Core/Core.hs

@@ -40,7 +40,6 @@ import Control.Effect.Carrier
 import Core.Loc
 import Core.Name
 import Core.Scope
-import Core.Stack
 import Data.Bifunctor (Bifunctor (..))
 import Data.Foldable (foldl')
 import Data.List.NonEmpty (NonEmpty (..))
@@ -49,6 +48,7 @@ import Data.Text (Text)
 import GHC.Generics (Generic1)
 import GHC.Stack
 import Source.Span
+import Syntax.Stack
 import Syntax.Module
 import Syntax.Term
 

semantic-core/src/Core/Core/Pretty.hs

@@ -12,11 +12,11 @@ import           Core.Core
 import           Core.File
 import           Core.Name
 import           Core.Scope
-import           Core.Stack
 import           Data.Foldable (toList)
 import           Data.Text.Prettyprint.Doc
 import qualified Data.Text.Prettyprint.Doc.Render.String as Pretty
 import qualified Data.Text.Prettyprint.Doc.Render.Terminal as Pretty
+import           Syntax.Stack
 import           Syntax.Term
 
 showCore :: Term Core Name -> String

semantic-core/src/Core/Scope.hs

@@ -12,15 +12,12 @@ module Core.Scope
 , instantiate1
 , instantiate
 , instantiateEither
-, unprefix
-, unprefixEither
 ) where
 
 import Control.Applicative (liftA2)
 import Control.Effect.Carrier
 import Control.Monad ((>=>), guard)
 import Control.Monad.Trans.Class
-import Core.Stack
 import Data.Function (on)
 import Syntax.Module
 
@@ -108,25 +105,3 @@ instantiate f = instantiateEither (either f pure)
 
 instantiateEither :: Monad f => (Either a b -> f c) -> Scope a f b -> f c
 instantiateEither f = unScope >=> incr (f . Left) (>>= f . Right)
-
-
--- | Unwrap a (possibly-empty) prefix of @a@s wrapping a @t@ using a helper function.
---
---   This allows us to peel a prefix of syntax, typically binders, off of a term, returning a stack of prefixing values (e.g. variables) and the outermost subterm rejected by the function.
-unprefix
-  :: (Int -> t -> Maybe (a, t)) -- ^ A function taking the 0-based index into the prefix & the current term, and optionally returning a pair of the prefixing value and the inner subterm.
-  -> t                          -- ^ The initial term.
-  -> (Stack a, t)               -- ^ A stack of prefixing values & the final subterm.
-unprefix from = unprefixEither (matchMaybe . from)
-
--- | Unwrap a (possibly-empty) prefix of @a@s wrapping a @b@ within a @t@ using a helper function.
---
---   Compared to 'unprefix', this allows the helper function to extract inner terms of a different type, for example when @t@ is a right @b@-module.
-unprefixEither
-  :: (Int -> t -> Either (a, t) b) -- ^ A function taking the 0-based index into the prefix & the current term, and returning either a pair of the prefixing value and the next inner subterm of type @t@, or the final inner subterm of type @b@.
-  -> t                             -- ^ The initial term.
-  -> (Stack a, b)                  -- ^ A stack of prefixing values & the final subterm.
-unprefixEither from = go (0 :: Int) Nil
-  where go i bs t = case from i t of
-          Left (b, t) -> go (succ i) (bs :> b) t
-          Right b     -> (bs, b)

semantic-core/src/Core/Stack.hs

@@ -1,18 +0,0 @@
-{-# LANGUAGE DeriveTraversable #-}
-module Core.Stack
-( Stack(..)
-) where
-
-data Stack a
-  = Nil
-  | Stack a :> a
-  deriving (Eq, Foldable, Functor, Ord, Show, Traversable)
-
-infixl 4 :>
-
-instance Semigroup (Stack a) where
-  xs <> Nil       = xs
-  xs <> (ys :> y) = (xs <> ys) :> y
-
-instance Monoid (Stack a) where
-  mempty = Nil