{-# OPTIONS --without-K --safe #-}
module Category.Monad.Indexed where
open import Category.Applicative.Indexed
open import Function
open import Level
private
variable
a b c i f : Level
A : Set a
B : Set b
C : Set c
I : Set i
record RawIMonad {I : Set i} (M : IFun I f) : Set (i ⊔ suc f) where
infixl 1 _>>=_ _>>_ _>=>_
infixr 1 _=<<_ _<=<_
field
return : ∀ {i} → A → M i i A
_>>=_ : ∀ {i j k} → M i j A → (A → M j k B) → M i k B
_>>_ : ∀ {i j k} → M i j A → M j k B → M i k B
m₁ >> m₂ = m₁ >>= λ _ → m₂
_=<<_ : ∀ {i j k} → (A → M j k B) → M i j A → M i k B
f =<< c = c >>= f
_>=>_ : ∀ {i j k} → (A → M i j B) → (B → M j k C) → (A → M i k C)
f >=> g = _=<<_ g ∘ f
_<=<_ : ∀ {i j k} → (B → M j k C) → (A → M i j B) → (A → M i k C)
g <=< f = f >=> g
join : ∀ {i j k} → M i j (M j k A) → M i k A
join m = m >>= id
rawIApplicative : RawIApplicative M
rawIApplicative = record
{ pure = return
; _⊛_ = λ f x → f >>= λ f' → x >>= λ x' → return (f' x')
}
open RawIApplicative rawIApplicative public
RawIMonadT : {I : Set i} (T : IFun I f → IFun I f) → Set (i ⊔ suc f)
RawIMonadT T = ∀ {M} → RawIMonad M → RawIMonad (T M)
record RawIMonadZero {I : Set i} (M : IFun I f) : Set (i ⊔ suc f) where
field
monad : RawIMonad M
applicativeZero : RawIApplicativeZero M
open RawIMonad monad public
open RawIApplicativeZero applicativeZero using (∅) public
record RawIMonadPlus {I : Set i} (M : IFun I f) : Set (i ⊔ suc f) where
field
monad : RawIMonad M
alternative : RawIAlternative M
open RawIMonad monad public
open RawIAlternative alternative using (∅; _∣_) public
monadZero : RawIMonadZero M
monadZero = record
{ monad = monad
; applicativeZero = RawIAlternative.applicativeZero alternative
}