diff --git a/prototyping/Luau/TypeNormalization.agda b/prototyping/Luau/TypeNormalization.agda new file mode 100644 index 00000000..1a3843e6 --- /dev/null +++ b/prototyping/Luau/TypeNormalization.agda @@ -0,0 +1,78 @@ +module Luau.TypeNormalization where + +open import Luau.Type using (Type; nil; number; string; boolean; never; unknown; _⇒_; _∪_; _∩_; src) + +-- The top non-function type +¬function : Type +¬function = number ∪ (string ∪ (nil ∪ boolean)) + +-- Unions and intersections of normalized types +_∪ᶠ_ : Type → Type → Type +_∩ᶠ_ : Type → Type → Type +_∪ⁿˢ_ : Type → Type → Type +_∩ⁿˢ_ : Type → Type → Type +_∪ⁿ_ : Type → Type → Type +_∩ⁿ_ : Type → Type → Type +_⇒ᶠ_ : Type → Type → Type + +-- Union of function types +(F₁ ∩ F₂) ∪ᶠ G = (F₁ ∪ᶠ G) ∩ᶠ (F₂ ∪ᶠ G) +F ∪ᶠ (G₁ ∩ G₂) = (F ∪ᶠ G₁) ∩ᶠ (F ∪ᶠ G₂) +(R ⇒ S) ∪ᶠ (T ⇒ U) = (R ∩ⁿ T) ⇒ᶠ (S ∪ⁿ U) +F ∪ᶠ G = F ∪ G + +-- Intersection of function types +F ∩ᶠ G = F ∩ G + +-- Union of normalized types +S ∪ⁿ (T₁ ∪ T₂) = (S ∪ⁿ T₁) ∪ T₂ +S ∪ⁿ unknown = unknown +S ∪ⁿ never = S +unknown ∪ⁿ T = unknown +never ∪ⁿ T = T +(S₁ ∪ S₂) ∪ⁿ G = (S₁ ∪ⁿ G) ∪ S₂ +F ∪ⁿ G = F ∪ᶠ G + +-- Intersection of normalized types +S ∩ⁿ (T₁ ∪ T₂) = (S ∩ⁿ T₁) ∪ⁿˢ (S ∩ⁿˢ T₂) +S ∩ⁿ unknown = S +S ∩ⁿ never = never +(S₁ ∪ S₂) ∩ⁿ G = (S₁ ∩ⁿ G) +unknown ∩ⁿ G = G +never ∩ⁿ G = never +F ∩ⁿ G = F ∩ᶠ G + +-- Intersection of normalized types with a scalar +(S₁ ∪ nil) ∩ⁿˢ nil = nil +(S₁ ∪ boolean) ∩ⁿˢ boolean = boolean +(S₁ ∪ number) ∩ⁿˢ number = number +(S₁ ∪ string) ∩ⁿˢ string = string +(S₁ ∪ S₂) ∩ⁿˢ T = S₁ ∩ⁿˢ T +F ∩ⁿˢ T = never + +-- Union of normalized types with an optional scalar +S ∪ⁿˢ never = S +unknown ∪ⁿˢ T = unknown +(S₁ ∪ nil) ∪ⁿˢ nil = S₁ ∪ nil +(S₁ ∪ boolean) ∪ⁿˢ boolean = S₁ ∪ boolean +(S₁ ∪ number) ∪ⁿˢ number = S₁ ∪ number +(S₁ ∪ string) ∪ⁿˢ string = S₁ ∪ string +(S₁ ∪ S₂) ∪ⁿˢ T = (S₁ ∪ⁿˢ T) ∪ S₂ +F ∪ⁿˢ T = F ∪ T + +-- Functions between normalized types +(never ⇒ᶠ T) = (never ⇒ unknown) +(S ⇒ᶠ T) = (S ⇒ T) + +-- Normalize! +normalize : Type → Type +normalize nil = never ∪ nil +normalize (S ⇒ T) = (normalize S ⇒ᶠ normalize T) +normalize never = never +normalize unknown = unknown +normalize boolean = never ∪ boolean +normalize number = never ∪ number +normalize string = never ∪ string +normalize (S ∪ T) = normalize S ∪ⁿ normalize T +normalize (S ∩ T) = normalize S ∩ⁿ normalize T + diff --git a/prototyping/Properties.agda b/prototyping/Properties.agda index 5594812e..cad6ab07 100644 --- a/prototyping/Properties.agda +++ b/prototyping/Properties.agda @@ -11,3 +11,4 @@ import Properties.Step import Properties.StrictMode import Properties.Subtyping import Properties.TypeCheck +import Properties.TypeNormalization diff --git a/prototyping/Properties/TypeNormalization.agda b/prototyping/Properties/TypeNormalization.agda new file mode 100644 index 00000000..84e194a2 --- /dev/null +++ b/prototyping/Properties/TypeNormalization.agda @@ -0,0 +1,161 @@ +{-# OPTIONS --rewriting #-} + +module Properties.TypeNormalization where + +open import Luau.Type using (Type; Scalar; nil; number; string; boolean; never; unknown; _⇒_; _∪_; _∩_; src) +open import Luau.TypeNormalization using (_∪ⁿ_; _∩ⁿ_; _∪ᶠ_; _∩ᶠ_; _∪ⁿˢ_; _∩ⁿˢ_; _⇒ᶠ_; normalize) +open import Luau.Subtyping using (_<:_) +open import Properties.Subtyping using (<:-trans; <:-refl; <:-unknown; <:-never; <:-∪-left; <:-∪-right; <:-∪-lub; <:-∩-left; <:-∩-right; <:-∩-glb; ∪-dist-∩-<:; <:-function; <:-function-∪-∩; <:-everything) + +-- Notmal forms for types +data FunType : Type → Set +data Normal : Type → Set + +data FunType where + _⇒_ : ∀ {S T} → Normal S → Normal T → FunType (S ⇒ T) + _∩_ : ∀ {F G} → FunType F → FunType G → FunType (F ∩ G) + +data Normal where + never : Normal never + unknown : Normal unknown + _⇒_ : ∀ {S T} → Normal S → Normal T → Normal (S ⇒ T) + _∩_ : ∀ {F G} → FunType F → FunType G → Normal (F ∩ G) + _∪_ : ∀ {S T} → Normal S → Scalar T → Normal (S ∪ T) + +data OptScalar : Type → Set where + never : OptScalar never + number : OptScalar number + boolean : OptScalar boolean + string : OptScalar string + nil : OptScalar nil + +-- Normalization produces normal types +normal : ∀ T → Normal (normalize T) +normalᶠ : ∀ {F} → FunType F → Normal F +normal-∪ⁿ : ∀ {S T} → Normal S → Normal T → Normal (S ∪ⁿ T) +normal-∩ⁿ : ∀ {S T} → Normal S → Normal T → Normal (S ∩ⁿ T) +normal-∪ⁿˢ : ∀ {S T} → Normal S → OptScalar T → Normal (S ∪ⁿˢ T) +normal-∩ⁿˢ : ∀ {S T} → Normal S → Scalar T → OptScalar (S ∩ⁿˢ T) +normal-∪ᶠ : ∀ {F G} → FunType F → FunType G → FunType (F ∪ᶠ G) +normal-∩ᶠ : ∀ {F G} → FunType F → FunType G → FunType (F ∩ᶠ G) +normal-⇒ᶠ : ∀ {S T} → Normal S → Normal T → FunType (S ⇒ᶠ T) + +normal nil = never ∪ nil +normal (S ⇒ T) = normalᶠ (normal-⇒ᶠ (normal S) (normal T)) +normal never = never +normal unknown = unknown +normal boolean = never ∪ boolean +normal number = never ∪ number +normal string = never ∪ string +normal (S ∪ T) = normal-∪ⁿ (normal S) (normal T) +normal (S ∩ T) = normal-∩ⁿ (normal S) (normal T) + +normalᶠ (S ⇒ T) = S ⇒ T +normalᶠ (F ∩ G) = F ∩ G + +normal-∪ⁿ S (T₁ ∪ T₂) = (normal-∪ⁿ S T₁) ∪ T₂ +normal-∪ⁿ S never = S +normal-∪ⁿ S unknown = unknown +normal-∪ⁿ never (T ⇒ U) = T ⇒ U +normal-∪ⁿ never (G₁ ∩ G₂) = G₁ ∩ G₂ +normal-∪ⁿ unknown (T ⇒ U) = unknown +normal-∪ⁿ unknown (G₁ ∩ G₂) = unknown +normal-∪ⁿ (R ⇒ S) (T ⇒ U) = normalᶠ (normal-∪ᶠ (R ⇒ S) (T ⇒ U)) +normal-∪ⁿ (R ⇒ S) (G₁ ∩ G₂) = normalᶠ (normal-∪ᶠ (R ⇒ S) (G₁ ∩ G₂)) +normal-∪ⁿ (F₁ ∩ F₂) (T ⇒ U) = normalᶠ (normal-∪ᶠ (F₁ ∩ F₂) (T ⇒ U)) +normal-∪ⁿ (F₁ ∩ F₂) (G₁ ∩ G₂) = normalᶠ (normal-∪ᶠ (F₁ ∩ F₂) (G₁ ∩ G₂)) +normal-∪ⁿ (S₁ ∪ S₂) (T₁ ⇒ T₂) = normal-∪ⁿ S₁ (T₁ ⇒ T₂) ∪ S₂ +normal-∪ⁿ (S₁ ∪ S₂) (G₁ ∩ G₂) = normal-∪ⁿ S₁ (G₁ ∩ G₂) ∪ S₂ + +normal-∩ⁿ S never = never +normal-∩ⁿ S unknown = S +normal-∩ⁿ S (T ∪ U) = normal-∪ⁿˢ (normal-∩ⁿ S T) (normal-∩ⁿˢ S U ) +normal-∩ⁿ never (T ⇒ U) = never +normal-∩ⁿ unknown (T ⇒ U) = T ⇒ U +normal-∩ⁿ (R ⇒ S) (T ⇒ U) = (R ⇒ S) ∩ (T ⇒ U) +normal-∩ⁿ (R ∩ S) (T ⇒ U) = (R ∩ S) ∩ (T ⇒ U) +normal-∩ⁿ (R ∪ S) (T ⇒ U) = normal-∩ⁿ R (T ⇒ U) +normal-∩ⁿ never (T ∩ U) = never +normal-∩ⁿ unknown (T ∩ U) = T ∩ U +normal-∩ⁿ (R ⇒ S) (T ∩ U) = (R ⇒ S) ∩ (T ∩ U) +normal-∩ⁿ (R ∩ S) (T ∩ U) = (R ∩ S) ∩ (T ∩ U) +normal-∩ⁿ (R ∪ S) (T ∩ U) = normal-∩ⁿ R (T ∩ U) + +normal-∪ⁿˢ S never = S +normal-∪ⁿˢ never number = never ∪ number +normal-∪ⁿˢ unknown number = unknown +normal-∪ⁿˢ (R ⇒ S) number = (R ⇒ S) ∪ number +normal-∪ⁿˢ (R ∩ S) number = (R ∩ S) ∪ number +normal-∪ⁿˢ (R ∪ number) number = R ∪ number +normal-∪ⁿˢ (R ∪ boolean) number = normal-∪ⁿˢ R number ∪ boolean +normal-∪ⁿˢ (R ∪ string) number = normal-∪ⁿˢ R number ∪ string +normal-∪ⁿˢ (R ∪ nil) number = normal-∪ⁿˢ R number ∪ nil +normal-∪ⁿˢ never boolean = never ∪ boolean +normal-∪ⁿˢ unknown boolean = unknown +normal-∪ⁿˢ (R ⇒ S) boolean = (R ⇒ S) ∪ boolean +normal-∪ⁿˢ (R ∩ S) boolean = (R ∩ S) ∪ boolean +normal-∪ⁿˢ (R ∪ number) boolean = normal-∪ⁿˢ R boolean ∪ number +normal-∪ⁿˢ (R ∪ boolean) boolean = R ∪ boolean +normal-∪ⁿˢ (R ∪ string) boolean = normal-∪ⁿˢ R boolean ∪ string +normal-∪ⁿˢ (R ∪ nil) boolean = normal-∪ⁿˢ R boolean ∪ nil +normal-∪ⁿˢ never string = never ∪ string +normal-∪ⁿˢ unknown string = unknown +normal-∪ⁿˢ (R ⇒ S) string = (R ⇒ S) ∪ string +normal-∪ⁿˢ (R ∩ S) string = (R ∩ S) ∪ string +normal-∪ⁿˢ (R ∪ number) string = normal-∪ⁿˢ R string ∪ number +normal-∪ⁿˢ (R ∪ boolean) string = normal-∪ⁿˢ R string ∪ boolean +normal-∪ⁿˢ (R ∪ string) string = R ∪ string +normal-∪ⁿˢ (R ∪ nil) string = normal-∪ⁿˢ R string ∪ nil +normal-∪ⁿˢ never nil = never ∪ nil +normal-∪ⁿˢ unknown nil = unknown +normal-∪ⁿˢ (R ⇒ S) nil = (R ⇒ S) ∪ nil +normal-∪ⁿˢ (R ∩ S) nil = (R ∩ S) ∪ nil +normal-∪ⁿˢ (R ∪ number) nil = normal-∪ⁿˢ R nil ∪ number +normal-∪ⁿˢ (R ∪ boolean) nil = normal-∪ⁿˢ R nil ∪ boolean +normal-∪ⁿˢ (R ∪ string) nil = normal-∪ⁿˢ R nil ∪ string +normal-∪ⁿˢ (R ∪ nil) nil = R ∪ nil + +normal-∩ⁿˢ never number = never +normal-∩ⁿˢ never boolean = never +normal-∩ⁿˢ never string = never +normal-∩ⁿˢ never nil = never +normal-∩ⁿˢ unknown number = never +normal-∩ⁿˢ unknown boolean = never +normal-∩ⁿˢ unknown string = never +normal-∩ⁿˢ unknown nil = never +normal-∩ⁿˢ (R ⇒ S) number = never +normal-∩ⁿˢ (R ⇒ S) boolean = never +normal-∩ⁿˢ (R ⇒ S) string = never +normal-∩ⁿˢ (R ⇒ S) nil = never +normal-∩ⁿˢ (R ∩ S) number = never +normal-∩ⁿˢ (R ∩ S) boolean = never +normal-∩ⁿˢ (R ∩ S) string = never +normal-∩ⁿˢ (R ∩ S) nil = never +normal-∩ⁿˢ (R ∪ number) number = number +normal-∩ⁿˢ (R ∪ boolean) number = normal-∩ⁿˢ R number +normal-∩ⁿˢ (R ∪ string) number = normal-∩ⁿˢ R number +normal-∩ⁿˢ (R ∪ nil) number = normal-∩ⁿˢ R number +normal-∩ⁿˢ (R ∪ number) boolean = normal-∩ⁿˢ R boolean +normal-∩ⁿˢ (R ∪ boolean) boolean = boolean +normal-∩ⁿˢ (R ∪ string) boolean = normal-∩ⁿˢ R boolean +normal-∩ⁿˢ (R ∪ nil) boolean = normal-∩ⁿˢ R boolean +normal-∩ⁿˢ (R ∪ number) string = normal-∩ⁿˢ R string +normal-∩ⁿˢ (R ∪ boolean) string = normal-∩ⁿˢ R string +normal-∩ⁿˢ (R ∪ string) string = string +normal-∩ⁿˢ (R ∪ nil) string = normal-∩ⁿˢ R string +normal-∩ⁿˢ (R ∪ number) nil = normal-∩ⁿˢ R nil +normal-∩ⁿˢ (R ∪ boolean) nil = normal-∩ⁿˢ R nil +normal-∩ⁿˢ (R ∪ string) nil = normal-∩ⁿˢ R nil +normal-∩ⁿˢ (R ∪ nil) nil = nil + +normal-⇒ᶠ never T = never ⇒ unknown +normal-⇒ᶠ unknown T = unknown ⇒ T +normal-⇒ᶠ (R ⇒ S) T = (R ⇒ S) ⇒ T +normal-⇒ᶠ (R ∩ S) T = (R ∩ S) ⇒ T +normal-⇒ᶠ (R ∪ S) T = (R ∪ S) ⇒ T + +normal-∩ᶠ F G = F ∩ G + +normal-∪ᶠ (R ⇒ S) (T ⇒ U) = normal-⇒ᶠ (normal-∩ⁿ R T) (normal-∪ⁿ S U) +normal-∪ᶠ (R ⇒ S) (G ∩ H) = normal-∪ᶠ (R ⇒ S) G ∩ normal-∪ᶠ (R ⇒ S) H +normal-∪ᶠ (E ∩ F) G = normal-∪ᶠ E G ∩ normal-∪ᶠ F G