feat[core]: Algebraic Data Types

src/Language/Scalie/Core/AlgebraicDatatype.hs

@@ -0,0 +1,19 @@
+{-# LANGUAGE Trustworthy #-}
+module Language.Scalie.Core.AlgebraicDatatype (AlgebraicDatatype(..)) where
+
+-- meta
+import Data.Kind (Type)
+
+-- data structures
+import Data.Vector (Vector)
+
+-- scalie
+import Language.Scalie.Core.AlgebraicDatatype.TypeName (TypeName)
+import Language.Scalie.Core.AlgebraicDatatype.Constructor (Constructor)
+
+type AlgebraicDatatype :: (Type -> Type) -> Type
+type role AlgebraicDatatype nominal
+data AlgebraicDatatype f = AlgebraicDatatype
+  { name :: f TypeName
+  , constructors :: f (Vector (Constructor f))
+  }

src/Language/Scalie/Core/AlgebraicDatatype/Constructor.hs

@@ -0,0 +1,13 @@
+{-# LANGUAGE Trustworthy #-} -- uses vector operations
+module Language.Scalie.Core.AlgebraicDatatype.Constructor (Constructor(..)) where
+import Data.Kind (Type)
+import Language.Scalie.Core.Expression.ConstructorIdentifier (ConstructorIdentifier)
+import Data.Vector (Vector)
+import Language.Scalie.Core.AlgebraicDatatype.Field (Field)
+
+type Constructor :: (Type -> Type) -> Type
+type role Constructor nominal
+data Constructor f = Constructor
+  { name   :: f ConstructorIdentifier
+  , fields :: f (Vector (Field f))
+  }

src/Language/Scalie/Core/AlgebraicDatatype/Field.hs

@@ -0,0 +1,16 @@
+{-# LANGUAGE Safe #-}
+module Language.Scalie.Core.AlgebraicDatatype.Field (Field(..)) where
+
+-- meta
+import Data.Kind qualified
+
+-- scalie
+import Language.Scalie.Core.AlgebraicDatatype.FieldIdentifier (FieldIdentifier)
+import Language.Scalie.Domain.Type qualified as Scalie.Domain
+
+type Field :: (Data.Kind.Type -> Data.Kind.Type) -> Data.Kind.Type
+type role Field nominal
+data Field f = Field
+  { name :: f FieldIdentifier
+  , typ  :: f Scalie.Domain.Type
+  }

src/Language/Scalie/Core/AlgebraicDatatype/FieldIdentifier.hs

@@ -0,0 +1,8 @@
+{-# LANGUAGE Safe #-}
+module Language.Scalie.Core.AlgebraicDatatype.FieldIdentifier (FieldIdentifier(..)) where
+import Data.Text (Text)
+import Data.Kind (Type)
+
+type FieldIdentifier :: Type
+newtype FieldIdentifier = FieldIdentifier { get :: Text }
+  deriving stock (Show, Read, Eq)

src/Language/Scalie/Core/AlgebraicDatatype/TypeName.hs

@@ -0,0 +1,22 @@
+{-# LANGUAGE Safe #-}
+{-# LANGUAGE InstanceSigs #-}
+module Language.Scalie.Core.AlgebraicDatatype.TypeName (TypeName(..)) where
+
+-- meta
+import Data.Kind (Type)
+
+-- data structures
+import Data.Text (Text)
+import Data.Text qualified as Text
+
+-- library: QuickCheck
+import Test.QuickCheck (Arbitrary (arbitrary), Gen, UnicodeString (getUnicodeString))
+
+type TypeName :: Type
+newtype TypeName = TypeName { get :: Text }
+  deriving stock (Show, Read, Eq)
+
+instance Arbitrary TypeName where
+  arbitrary :: Gen TypeName
+  arbitrary = TypeName . Text.pack . getUnicodeString <$> arbitrary
+