-- | Scott-encoded @unit@ and related functions.

{-# LANGUAGE OverloadedStrings #-}

module PlutusCore.StdLib.Data.ScottUnit
    ( unit
    , unitval
    ) where

import PlutusCore.Core
import PlutusCore.MkPlc
import PlutusCore.Name.Unique
import PlutusCore.Quote

-- | '()' as a PLC type.
--
-- > all (A :: *). A -> A
unit :: Type TyName uni ()
unit :: forall (uni :: * -> *). Type TyName uni ()
unit = Quote (Type TyName uni ()) -> Type TyName uni ()
forall a. Quote a -> a
runQuote (Quote (Type TyName uni ()) -> Type TyName uni ())
-> Quote (Type TyName uni ()) -> Type TyName uni ()
forall a b. (a -> b) -> a -> b
$ do
    TyName
a <- Text -> QuoteT Identity TyName
forall (m :: * -> *). MonadQuote m => Text -> m TyName
freshTyName Text
"a"
    Type TyName uni () -> Quote (Type TyName uni ())
forall a. a -> QuoteT Identity a
forall (m :: * -> *) a. Monad m => a -> m a
return
        (Type TyName uni () -> Quote (Type TyName uni ()))
-> (Type TyName uni () -> Type TyName uni ())
-> Type TyName uni ()
-> Quote (Type TyName uni ())
forall b c a. (b -> c) -> (a -> b) -> a -> c
. () -> TyName -> Kind () -> Type TyName uni () -> Type TyName uni ()
forall tyname (uni :: * -> *) ann.
ann
-> tyname -> Kind ann -> Type tyname uni ann -> Type tyname uni ann
TyForall () TyName
a (() -> Kind ()
forall ann. ann -> Kind ann
Type ())
        (Type TyName uni () -> Type TyName uni ())
-> (Type TyName uni () -> Type TyName uni ())
-> Type TyName uni ()
-> Type TyName uni ()
forall b c a. (b -> c) -> (a -> b) -> a -> c
. ()
-> Type TyName uni () -> Type TyName uni () -> Type TyName uni ()
forall tyname (uni :: * -> *) ann.
ann
-> Type tyname uni ann
-> Type tyname uni ann
-> Type tyname uni ann
TyFun () (() -> TyName -> Type TyName uni ()
forall tyname (uni :: * -> *) ann.
ann -> tyname -> Type tyname uni ann
TyVar () TyName
a)
        (Type TyName uni () -> Quote (Type TyName uni ()))
-> Type TyName uni () -> Quote (Type TyName uni ())
forall a b. (a -> b) -> a -> b
$ () -> TyName -> Type TyName uni ()
forall tyname (uni :: * -> *) ann.
ann -> tyname -> Type tyname uni ann
TyVar () TyName
a

-- | '()' as a PLC term.
--
-- > /\(A :: *) -> \(x : A) -> x
unitval :: TermLike term TyName Name uni fun => term ()
unitval :: forall (term :: * -> *) (uni :: * -> *) fun.
TermLike term TyName Name uni fun =>
term ()
unitval = Quote (term ()) -> term ()
forall a. Quote a -> a
runQuote (Quote (term ()) -> term ()) -> Quote (term ()) -> term ()
forall a b. (a -> b) -> a -> b
$ do
    TyName
a <- Text -> QuoteT Identity TyName
forall (m :: * -> *). MonadQuote m => Text -> m TyName
freshTyName Text
"a"
    Name
x <- Text -> QuoteT Identity Name
forall (m :: * -> *). MonadQuote m => Text -> m Name
freshName Text
"x"
    term () -> Quote (term ())
forall a. a -> QuoteT Identity a
forall (m :: * -> *) a. Monad m => a -> m a
return
        (term () -> Quote (term ()))
-> (term () -> term ()) -> term () -> Quote (term ())
forall b c a. (b -> c) -> (a -> b) -> a -> c
. () -> TyName -> Kind () -> term () -> term ()
forall ann. ann -> TyName -> Kind ann -> term ann -> term ann
forall (term :: * -> *) tyname name (uni :: * -> *) fun ann.
TermLike term tyname name uni fun =>
ann -> tyname -> Kind ann -> term ann -> term ann
tyAbs  () TyName
a (() -> Kind ()
forall ann. ann -> Kind ann
Type ())
        (term () -> term ()) -> (term () -> term ()) -> term () -> term ()
forall b c a. (b -> c) -> (a -> b) -> a -> c
. () -> Name -> Type TyName uni () -> term () -> term ()
forall ann.
ann -> Name -> Type TyName uni ann -> term ann -> term ann
forall (term :: * -> *) tyname name (uni :: * -> *) fun ann.
TermLike term tyname name uni fun =>
ann -> name -> Type tyname uni ann -> term ann -> term ann
lamAbs () Name
x (() -> TyName -> Type TyName uni ()
forall tyname (uni :: * -> *) ann.
ann -> tyname -> Type tyname uni ann
TyVar () TyName
a)
        (term () -> Quote (term ())) -> term () -> Quote (term ())
forall a b. (a -> b) -> a -> b
$ () -> Name -> term ()
forall ann. ann -> Name -> term ann
forall (term :: * -> *) tyname name (uni :: * -> *) fun ann.
TermLike term tyname name uni fun =>
ann -> name -> term ann
var () Name
x