luau/prototyping/FFI/Data/Vector.agda

54 lines
2.2 KiB
Agda

{-# OPTIONS --rewriting #-}
module FFI.Data.Vector where
open import Agda.Builtin.Equality using (_≡_)
open import Agda.Builtin.Equality.Rewrite using ()
open import Agda.Builtin.Int using (Int; pos; negsuc)
open import Agda.Builtin.Nat using (Nat)
open import Agda.Builtin.Bool using (Bool; false; true)
open import FFI.Data.HaskellInt using (HaskellInt; haskellIntToInt; intToHaskellInt)
open import FFI.Data.Maybe using (Maybe; just; nothing)
open import Properties.Equality using (_≢_)
{-# FOREIGN GHC import qualified Data.Vector #-}
postulate Vector : Set Set
{-# POLARITY Vector ++ #-}
{-# COMPILE GHC Vector = type Data.Vector.Vector #-}
postulate
empty : {A} (Vector A)
null : {A} (Vector A) Bool
unsafeHead : {A} (Vector A) A
unsafeTail : {A} (Vector A) (Vector A)
length : {A} (Vector A) Nat
lookup : {A} (Vector A) Nat (Maybe A)
snoc : {A} (Vector A) A (Vector A)
{-# COMPILE GHC empty = \_ -> Data.Vector.empty #-}
{-# COMPILE GHC null = \_ -> Data.Vector.null #-}
{-# COMPILE GHC unsafeHead = \_ -> Data.Vector.unsafeHead #-}
{-# COMPILE GHC unsafeTail = \_ -> Data.Vector.unsafeTail #-}
{-# COMPILE GHC length = \_ -> (fromIntegral . Data.Vector.length) #-}
{-# COMPILE GHC lookup = \_ v -> ((v Data.Vector.!?) . fromIntegral) #-}
{-# COMPILE GHC snoc = \_ -> Data.Vector.snoc #-}
postulate length-empty : {A} (length (empty {A}) 0)
postulate lookup-empty : {A} n (lookup (empty {A}) n nothing)
postulate lookup-snoc : {A} (x : A) (v : Vector A) (lookup (snoc v x) (length v) just x)
postulate lookup-length : {A} (v : Vector A) (lookup v (length v) nothing)
postulate lookup-snoc-empty : {A} (x : A) (lookup (snoc empty x) 0 just x)
postulate lookup-snoc-not : {A n} (x : A) (v : Vector A) (n length v) (lookup v n lookup (snoc v x) n)
{-# REWRITE length-empty lookup-snoc lookup-length lookup-snoc-empty lookup-empty #-}
head : {A} (Vector A) (Maybe A)
head vec with null vec
head vec | false = just (unsafeHead vec)
head vec | true = nothing
tail : {A} (Vector A) Vector A
tail vec with null vec
tail vec | false = unsafeTail vec
tail vec | true = empty