From a511dceb455975ded324c14c10f3cb6f85b95c3d Mon Sep 17 00:00:00 2001 From: Helmut Grohne Date: Sat, 21 Jan 2012 12:22:34 +0100 Subject: rewrite generate using zip and fromAscList This way matches the usage in lemma-1 more closely since zip actually is something similar to assoc. --- Bidir.agda | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/Bidir.agda b/Bidir.agda index 84d3b73..28534a2 100644 --- a/Bidir.agda +++ b/Bidir.agda @@ -25,6 +25,10 @@ module FinMap where empty : {A : Set} {n : ℕ} → FinMapMaybe n A empty = replicate nothing + fromAscList : {A : Set} {n : ℕ} → List (Fin n × A) → FinMapMaybe n A + fromAscList [] = empty + fromAscList ((f , a) ∷ xs) = insert f a (fromAscList xs) + FinMap : ℕ → Set → Set FinMap n A = Vec A n @@ -52,8 +56,7 @@ assoc eq (i ∷ is) (b ∷ bs) = maybe′ (checkInsert eq i b) nothing (assoc eq assoc _ _ _ = nothing generate : {A : Set} {n : ℕ} → (Fin n → A) → List (Fin n) → FinMapMaybe n A -generate f [] = empty -generate f (n ∷ ns) = insert n (f n) (generate f ns) +generate f is = fromAscList (zip is (map f is)) lemma-1 : {τ : Set} {n : ℕ} → (eq : (x y : τ) → Dec (x ≡ y)) → (f : Fin n → τ) → (is : List (Fin n)) → assoc eq is (map f is) ≡ just (generate f is) lemma-1 eq f [] = refl -- cgit v1.2.3