Merge pull request #230 from purescript/addProxy

Ports `purescript-proxy` into this repo

Author: hdgarrood

src/Control/Applicative.purs

@@ -10,6 +10,7 @@ import Control.Apply (class Apply, apply, (*>), (<*), (<*>))
 
 import Data.Functor (class Functor, map, void, ($>), (<#>), (<$), (<$>))
 import Data.Unit (Unit, unit)
+import Type.Proxy (Proxy(..))
 
 -- | The `Applicative` type class extends the [`Apply`](#apply) type class
 -- | with a `pure` function, which can be used to create values of type `f a`
@@ -38,6 +39,9 @@ instance applicativeFn :: Applicative ((->) r) where
 instance applicativeArray :: Applicative Array where
   pure x = [x]
 
+instance applicativeProxy :: Applicative Proxy where
+  pure _ = Proxy
+
 -- | `liftA1` provides a default implementation of `(<$>)` for any
 -- | [`Applicative`](#applicative) functor, without using `(<$>)` as provided
 -- | by the [`Functor`](#functor)-[`Applicative`](#applicative) superclass

src/Control/Apply.purs

@@ -9,6 +9,7 @@ module Control.Apply
 import Data.Functor (class Functor, map, void, ($>), (<#>), (<$), (<$>))
 import Data.Function (const)
 import Control.Category (identity)
+import Type.Proxy (Proxy(..))
 
 -- | The `Apply` class provides the `(<*>)` which is used to apply a function
 -- | to an argument under a type constructor.
@@ -54,6 +55,9 @@ instance applyArray :: Apply Array where
 
 foreign import arrayApply :: forall a b. Array (a -> b) -> Array a -> Array b
 
+instance applyProxy :: Apply Proxy where
+  apply _ _ = Proxy
+
 -- | Combine two effectful actions, keeping only the result of the first.
 applyFirst :: forall a b f. Apply f => f a -> f b -> f a
 applyFirst a b = const <$> a <*> b

src/Control/Bind.purs

@@ -19,6 +19,7 @@ import Control.Category (identity)
 import Data.Function (flip)
 import Data.Functor (class Functor, map, void, ($>), (<#>), (<$), (<$>))
 import Data.Unit (Unit)
+import Type.Proxy (Proxy(..), Proxy2, Proxy3)
 
 -- | The `Bind` type class extends the [`Apply`](#apply) type class with a
 -- | "bind" operation `(>>=)` which composes computations in sequence, using
@@ -90,6 +91,9 @@ instance bindArray :: Bind Array where
 
 foreign import arrayBind :: forall a b. Array a -> (a -> Array b) -> Array b
 
+instance bindProxy :: Bind Proxy where
+  bind _ _ = Proxy
+
 -- | A class for types whose values can safely be discarded
 -- | in a `do` notation block.
 -- |
@@ -101,6 +105,15 @@ class Discard a where
 instance discardUnit :: Discard Unit where
   discard = bind
 
+instance discardProxy :: Discard (Proxy a) where
+  discard = bind
+
+instance discardProxy2 :: Discard (Proxy2 a) where
+  discard = bind
+
+instance discardProxy3 :: Discard (Proxy3 a) where
+  discard = bind
+
 -- | Collapse two applications of a monadic type constructor into one.
 join :: forall a m. Bind m => m (m a) -> m a
 join m = m >>= identity

src/Control/Monad.purs

@@ -15,6 +15,7 @@ import Control.Bind (class Bind, bind, ap, ifM, join, (<=<), (=<<), (>=>), (>>=)
 
 import Data.Functor (class Functor, map, void, ($>), (<#>), (<$), (<$>))
 import Data.Unit (Unit)
+import Type.Proxy (Proxy)
 
 -- | The `Monad` type class combines the operations of the `Bind` and
 -- | `Applicative` type classes. Therefore, `Monad` instances represent type
@@ -32,6 +33,8 @@ instance monadFn :: Monad ((->) r)
 
 instance monadArray :: Monad Array
 
+instance monadProxy :: Monad Proxy
+
 -- | `liftM1` provides a default implementation of `(<$>)` for any
 -- | [`Monad`](#monad), without using `(<$>)` as provided by the
 -- | [`Functor`](#functor)-[`Monad`](#monad) superclass relationship.

src/Data/BooleanAlgebra.purs

@@ -9,6 +9,7 @@ import Data.Symbol (class IsSymbol)
 import Data.Unit (Unit)
 import Prim.Row as Row
 import Prim.RowList as RL
+import Type.Proxy (Proxy, Proxy2, Proxy3)
 
 -- | The `BooleanAlgebra` type class represents types that behave like boolean
 -- | values.
@@ -24,9 +25,13 @@ instance booleanAlgebraBoolean :: BooleanAlgebra Boolean
 instance booleanAlgebraUnit :: BooleanAlgebra Unit
 instance booleanAlgebraFn :: BooleanAlgebra b => BooleanAlgebra (a -> b)
 instance booleanAlgebraRecord :: (RL.RowToList row list, BooleanAlgebraRecord list row row) => BooleanAlgebra (Record row)
+instance booleanAlgebraProxy :: BooleanAlgebra (Proxy a)
+instance booleanAlgebraProxy2 :: BooleanAlgebra (Proxy2 a)
+instance booleanAlgebraProxy3 :: BooleanAlgebra (Proxy3 a)
 
 -- | A class for records where all fields have `BooleanAlgebra` instances, used
 -- | to implement the `BooleanAlgebra` instance for records.
+class BooleanAlgebraRecord :: RL.RowList Type -> Row Type -> Row Type -> Constraint
 class HeytingAlgebraRecord rowlist row subrow <= BooleanAlgebraRecord rowlist row subrow | rowlist -> subrow
 
 instance booleanAlgebraRecordNil :: BooleanAlgebraRecord RL.Nil row ()

src/Data/Bounded.purs

@@ -7,13 +7,12 @@ module Data.Bounded
   ) where
 
 import Data.Ord (class Ord, class OrdRecord, Ordering(..), compare, (<), (<=), (>), (>=))
-import Data.Symbol (class IsSymbol, SProxy(..), reflectSymbol)
+import Data.Symbol (class IsSymbol, reflectSymbol)
 import Data.Unit (Unit, unit)
 import Prim.Row as Row
 import Prim.RowList as RL
 import Record.Unsafe (unsafeSet)
-import Type.Data.Row (RProxy(..))
-import Type.Data.RowList (RLProxy(..))
+import Type.Proxy (Proxy(..), Proxy2(..), Proxy3(..))
 
 -- | The `Bounded` type class represents totally ordered types that have an
 -- | upper and lower boundary.
@@ -62,9 +61,22 @@ instance boundedNumber :: Bounded Number where
   top = topNumber
   bottom = bottomNumber
 
+instance boundedProxy :: Bounded (Proxy a) where
+  bottom = Proxy
+  top = Proxy
+
+instance boundedProxy2 :: Bounded (Proxy2 a) where
+  bottom = Proxy2
+  top = Proxy2
+
+instance boundedProxy3 :: Bounded (Proxy3 a) where
+  bottom = Proxy3
+  top = Proxy3
+
+class BoundedRecord :: RL.RowList Type -> Row Type -> Row Type -> Constraint
 class OrdRecord rowlist row <= BoundedRecord rowlist row subrow | rowlist -> subrow where
-  topRecord :: RLProxy rowlist -> RProxy row -> Record subrow
-  bottomRecord :: RLProxy rowlist -> RProxy row -> Record subrow
+  topRecord :: forall rlproxy rproxy. rlproxy rowlist -> rproxy row -> Record subrow
+  bottomRecord :: forall rlproxy rproxy. rlproxy rowlist -> rproxy row -> Record subrow
 
 instance boundedRecordNil :: BoundedRecord RL.Nil row () where
   topRecord _ _ = {}
@@ -81,21 +93,21 @@ instance boundedRecordCons
   topRecord _ rowProxy
     = insert top tail
     where
-      key = reflectSymbol (SProxy :: SProxy key)
+      key = reflectSymbol (Proxy :: Proxy key)
       insert = unsafeSet key :: focus -> Record subrowTail -> Record subrow
-      tail = topRecord (RLProxy :: RLProxy rowlistTail) rowProxy
+      tail = topRecord (Proxy :: Proxy rowlistTail) rowProxy
 
   bottomRecord _ rowProxy
     = insert bottom tail
     where
-      key = reflectSymbol (SProxy :: SProxy key)
+      key = reflectSymbol (Proxy :: Proxy key)
       insert = unsafeSet key :: focus -> Record subrowTail -> Record subrow
-      tail = bottomRecord (RLProxy :: RLProxy rowlistTail) rowProxy
+      tail = bottomRecord (Proxy :: Proxy rowlistTail) rowProxy
 
 instance boundedRecord
     :: ( RL.RowToList row list
        , BoundedRecord list row row
        )
     => Bounded (Record row) where
-  top = topRecord (RLProxy :: RLProxy list) (RProxy :: RProxy row)
-  bottom = bottomRecord (RLProxy :: RLProxy list) (RProxy :: RProxy row)
+  top = topRecord (Proxy :: Proxy list) (Proxy :: Proxy row)
+  bottom = bottomRecord (Proxy :: Proxy list) (Proxy :: Proxy row)

src/Data/CommutativeRing.purs

@@ -11,6 +11,7 @@ import Data.Symbol (class IsSymbol)
 import Data.Unit (Unit)
 import Prim.Row as Row
 import Prim.RowList as RL
+import Type.Proxy (Proxy, Proxy2, Proxy3)
 
 -- | The `CommutativeRing` class is for rings where multiplication is
 -- | commutative.
@@ -26,6 +27,9 @@ instance commutativeRingNumber :: CommutativeRing Number
 instance commutativeRingUnit :: CommutativeRing Unit
 instance commutativeRingFn :: CommutativeRing b => CommutativeRing (a -> b)
 instance commutativeRingRecord :: (RL.RowToList row list, CommutativeRingRecord list row row) => CommutativeRing (Record row)
+instance commutativeRingProxy :: CommutativeRing (Proxy a)
+instance commutativeRingProxy2 :: CommutativeRing (Proxy2 a)
+instance commutativeRingProxy3 :: CommutativeRing (Proxy3 a)
 
 -- | A class for records where all fields have `CommutativeRing` instances, used
 -- | to implement the `CommutativeRing` instance for records.

src/Data/Eq.purs

@@ -5,13 +5,13 @@ module Data.Eq
   ) where
 
 import Data.HeytingAlgebra ((&&))
-import Data.Symbol (class IsSymbol, SProxy(..), reflectSymbol)
+import Data.Symbol (class IsSymbol, reflectSymbol)
 import Data.Unit (Unit)
 import Data.Void (Void)
 import Prim.Row as Row
 import Prim.RowList as RL
 import Record.Unsafe (unsafeGet)
-import Type.Data.RowList (RLProxy(..))
+import Type.Proxy (Proxy(..), Proxy2, Proxy3)
 
 -- | The `Eq` type class represents types which support decidable equality.
 -- |
@@ -62,7 +62,16 @@ instance eqArray :: Eq a => Eq (Array a) where
   eq = eqArrayImpl eq
 
 instance eqRec :: (RL.RowToList row list, EqRecord list row) => Eq (Record row) where
-  eq = eqRecord (RLProxy :: RLProxy list)
+  eq = eqRecord (Proxy :: Proxy list)
+
+instance eqProxy :: Eq (Proxy a) where
+  eq _ _ = true
+
+instance eqProxy2 :: Eq (Proxy2 a) where
+  eq _ _ = true
+
+instance eqProxy3 :: Eq (Proxy3 a) where
+  eq _ _ = true
 
 foreign import eqBooleanImpl :: Boolean -> Boolean -> Boolean
 foreign import eqIntImpl :: Int -> Int -> Boolean
@@ -84,8 +93,9 @@ notEq1 x y = (x `eq1` y) == false
 
 -- | A class for records where all fields have `Eq` instances, used to implement
 -- | the `Eq` instance for records.
+class EqRecord :: RL.RowList Type -> Row Type -> Constraint
 class EqRecord rowlist row where
-  eqRecord :: RLProxy rowlist -> Record row -> Record row -> Boolean
+  eqRecord :: forall rlproxy. rlproxy rowlist -> Record row -> Record row -> Boolean
 
 instance eqRowNil :: EqRecord RL.Nil row where
   eqRecord _ _ _ = true
@@ -99,6 +109,6 @@ instance eqRowCons
     => EqRecord (RL.Cons key focus rowlistTail) row where
   eqRecord _ ra rb = (get ra == get rb) && tail
     where
-      key = reflectSymbol (SProxy :: SProxy key)
+      key = reflectSymbol (Proxy :: Proxy key)
       get = unsafeGet key :: Record row -> focus
-      tail = eqRecord (RLProxy :: RLProxy rowlistTail) ra rb
+      tail = eqRecord (Proxy :: Proxy rowlistTail) ra rb

src/Data/Functor.purs

@@ -9,6 +9,7 @@ module Data.Functor
 
 import Data.Function (const, compose)
 import Data.Unit (Unit, unit)
+import Type.Proxy (Proxy(..))
 
 -- | A `Functor` is a type constructor which supports a mapping operation
 -- | `map`.
@@ -42,6 +43,9 @@ instance functorFn :: Functor ((->) r) where
 instance functorArray :: Functor Array where
   map = arrayMap
 
+instance functorProxy :: Functor Proxy where
+  map _ _ = Proxy
+
 foreign import arrayMap :: forall a b. (a -> b) -> Array a -> Array b
 
 -- | The `void` function is used to ignore the type wrapped by a