(* Title: HOL/Library/AList_Mapping.thy Author: Florian Haftmann, TU Muenchen *) section ‹Implementation of mappings with Association Lists› theory AList_Mapping imports AList Mapping begin lift_definition Mapping :: "('a × 'b) list ⇒ ('a, 'b) mapping" is map_of . code_datatype Mapping lemma lookup_Mapping [simp, code]: "Mapping.lookup (Mapping xs) = map_of xs" by transfer rule lemma keys_Mapping [simp, code]: "Mapping.keys (Mapping xs) = set (map fst xs)" by transfer (simp add: dom_map_of_conv_image_fst) lemma empty_Mapping [code]: "Mapping.empty = Mapping []" by transfer simp lemma is_empty_Mapping [code]: "Mapping.is_empty (Mapping xs) ⟷ List.null xs" by (cases xs) (simp_all add: is_empty_def null_def) lemma update_Mapping [code]: "Mapping.update k v (Mapping xs) = Mapping (AList.update k v xs)" by transfer (simp add: update_conv') lemma delete_Mapping [code]: "Mapping.delete k (Mapping xs) = Mapping (AList.delete k xs)" by transfer (simp add: delete_conv') lemma ordered_keys_Mapping [code]: "Mapping.ordered_keys (Mapping xs) = sort (remdups (map fst xs))" by (simp only: ordered_keys_def keys_Mapping sorted_list_of_set_sort_remdups) simp lemma size_Mapping [code]: "Mapping.size (Mapping xs) = length (remdups (map fst xs))" by (simp add: size_def length_remdups_card_conv dom_map_of_conv_image_fst) lemma tabulate_Mapping [code]: "Mapping.tabulate ks f = Mapping (map (λk. (k, f k)) ks)" by transfer (simp add: map_of_map_restrict) lemma bulkload_Mapping [code]: "Mapping.bulkload vs = Mapping (map (λn. (n, vs ! n)) [0..<length vs])" by transfer (simp add: map_of_map_restrict fun_eq_iff) lemma equal_Mapping [code]: "HOL.equal (Mapping xs) (Mapping ys) ⟷ (let ks = map fst xs; ls = map fst ys in (∀l∈set ls. l ∈ set ks) ∧ (∀k∈set ks. k ∈ set ls ∧ map_of xs k = map_of ys k))" proof - have *: "(a, b) ∈ set xs ⟹ a ∈ fst ` set xs" for a b xs by (auto simp add: image_def intro!: bexI) show ?thesis apply transfer apply (auto intro!: map_of_eqI) apply (auto dest!: map_of_eq_dom intro: *) done qed lemma map_values_Mapping [code]: "Mapping.map_values f (Mapping xs) = Mapping (map (λ(x,y). (x, f x y)) xs)" for f :: "'c ⇒ 'a ⇒ 'b" and xs :: "('c × 'a) list" apply transfer apply (rule ext) subgoal for f xs x by (induct xs) auto done lemma combine_with_key_code [code]: "Mapping.combine_with_key f (Mapping xs) (Mapping ys) = Mapping.tabulate (remdups (map fst xs @ map fst ys)) (λx. the (combine_options (f x) (map_of xs x) (map_of ys x)))" apply transfer apply (rule ext) apply (rule sym) subgoal for f xs ys x apply (cases "map_of xs x"; cases "map_of ys x"; simp) apply (force simp: map_of_eq_None_iff combine_options_def option.the_def o_def image_iff dest: map_of_SomeD split: option.splits)+ done done lemma combine_code [code]: "Mapping.combine f (Mapping xs) (Mapping ys) = Mapping.tabulate (remdups (map fst xs @ map fst ys)) (λx. the (combine_options f (map_of xs x) (map_of ys x)))" apply transfer apply (rule ext) apply (rule sym) subgoal for f xs ys x apply (cases "map_of xs x"; cases "map_of ys x"; simp) apply (force simp: map_of_eq_None_iff combine_options_def option.the_def o_def image_iff dest: map_of_SomeD split: option.splits)+ done done lemma map_of_filter_distinct: (* TODO: move? *) assumes "distinct (map fst xs)" shows "map_of (filter P xs) x = (case map_of xs x of None ⇒ None | Some y ⇒ if P (x,y) then Some y else None)" using assms by (auto simp: map_of_eq_None_iff filter_map distinct_map_filter dest: map_of_SomeD simp del: map_of_eq_Some_iff intro!: map_of_is_SomeI split: option.splits) lemma filter_Mapping [code]: "Mapping.filter P (Mapping xs) = Mapping (filter (λ(k,v). P k v) (AList.clearjunk xs))" apply transfer apply (rule ext) apply (subst map_of_filter_distinct) apply (simp_all add: map_of_clearjunk split: option.split) done lemma [code nbe]: "HOL.equal (x :: ('a, 'b) mapping) x ⟷ True" by (fact equal_refl) end