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erasure improvements

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This commit is contained in:
Steve Dunham
2025-02-02 16:33:37 -08:00
parent c83632881d
commit 9586ca96bb
7 changed files with 31 additions and 26 deletions
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25
newt/Prelude.newt
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@@ -114,15 +114,16 @@ join mma = mma >>= id
-- Equality
infixl 1 _≡_
data _≡_ : {A : U} -> A -> A -> U where
Refl : {A : U} -> {a : A} -> a ≡ a
data _≡_ : {0 A : U} -> A -> A -> U where
Refl : {0 A : U} -> {a : A} -> a ≡ a
replace : {A : U} {a b : A} -> (P : A -> U) -> a ≡ b -> P a -> P b
replace : {0 A : U} {0 a b : A} -> (P : A -> U) -> a ≡ b -> P a -> P b
replace p Refl x = x
cong : {A B : U} {a b : A} -> (f : A -> B) -> a ≡ b -> f a ≡ f b
cong : {0 A B : U} {0 a b : A} -> (f : A -> B) -> a ≡ b -> f a ≡ f b
cong f Refl = Refl
sym : {A : U} -> {a b : A} -> a ≡ b -> b ≡ a
sym : {0 A : U} -> {0 a b : A} -> a ≡ b -> b ≡ a
sym Refl = Refl
@@ -130,10 +131,10 @@ sym Refl = Refl
-- Functor
class Functor (m : U → U) where
map : {0 a b} → (a → b) → m a → m b
map : ∀ a b. (a → b) → m a → m b
infixr 4 _<$>_ _<$_
_<$>_ : {0 f} {{Functor f}} {0 a b} → (a → b) → f a → f b
_<$>_ : ∀ f. {{Functor f}} {0 a b} → (a → b) → f a → f b
f <$> ma = map f ma
_<$_ : ∀ f a b. {{Functor f}} → b → f a → f b
@@ -167,8 +168,8 @@ instance Functor SnocList where
infixl 3 _<*>_ _<*_ _*>_
class Applicative (f : U → U) where
-- appIsFunctor : Functor f
return : {0 a} → a → f a
_<*>_ : {0 a b} -> f (a → b) → f a → f b
return : ∀ a. a → f a
_<*>_ : ∀ a b. f (a → b) → f a → f b
_<*_ : ∀ f a b. {{Applicative f}} → f a → f b → f a
@@ -188,10 +189,12 @@ instance Traversable List where
traverse_ : ∀ t f a b. {{Traversable t}} {{Applicative f}} → (a → f b) → t a → f Unit
traverse_ f xs = return (const MkUnit) <*> traverse f xs
for : {t : U → U} {f : U → U} → {{Traversable t}} {{appf : Applicative f}} → {a : U} → {b : U} → t a → (a → f b) → f (t b)
-- FIXME - there is something subtly wrong in erasure here. t gets applied and there is no warning about it.
-- maybe we don't check the head of an application?
for : {0 t : U → U} {0 f : U → U} → {{Traversable t}} {{appf : Applicative f}} → {0 a : U} → {0 b : U} → t a → (a → f b) → f (t b)
for stuff fun = traverse fun stuff
for_ : {t : U → U} {f : U → U} → {{Traversable t}} {{appf : Applicative f}} → {a : U} → {b : U} → t a → (a → f b) → f Unit
for_ : {0 t : U → U} {0 f : U → U} → {{Traversable t}} {{appf : Applicative f}} → {0 a : U} → {0 b : U} → t a → (a → f b) → f Unit
for_ stuff fun = return (const MkUnit) <*> traverse fun stuff
instance Applicative Maybe where