31459
|
1 |
(* Author: Florian Haftmann, TU Muenchen *)
|
29708
|
2 |
|
|
3 |
header {* An abstract view on maps for code generation. *}
|
|
4 |
|
|
5 |
theory Mapping
|
35157
|
6 |
imports Main
|
29708
|
7 |
begin
|
|
8 |
|
|
9 |
subsection {* Type definition and primitive operations *}
|
|
10 |
|
35157
|
11 |
datatype ('a, 'b) mapping = Mapping "'a \<rightharpoonup> 'b"
|
29708
|
12 |
|
35157
|
13 |
definition empty :: "('a, 'b) mapping" where
|
|
14 |
"empty = Mapping (\<lambda>_. None)"
|
29708
|
15 |
|
35157
|
16 |
primrec lookup :: "('a, 'b) mapping \<Rightarrow> 'a \<rightharpoonup> 'b" where
|
|
17 |
"lookup (Mapping f) = f"
|
29708
|
18 |
|
35157
|
19 |
primrec update :: "'a \<Rightarrow> 'b \<Rightarrow> ('a, 'b) mapping \<Rightarrow> ('a, 'b) mapping" where
|
|
20 |
"update k v (Mapping f) = Mapping (f (k \<mapsto> v))"
|
29708
|
21 |
|
35157
|
22 |
primrec delete :: "'a \<Rightarrow> ('a, 'b) mapping \<Rightarrow> ('a, 'b) mapping" where
|
|
23 |
"delete k (Mapping f) = Mapping (f (k := None))"
|
29708
|
24 |
|
|
25 |
|
|
26 |
subsection {* Derived operations *}
|
|
27 |
|
35157
|
28 |
definition keys :: "('a, 'b) mapping \<Rightarrow> 'a set" where
|
|
29 |
"keys m = dom (lookup m)"
|
29708
|
30 |
|
35194
|
31 |
definition ordered_keys :: "('a\<Colon>linorder, 'b) mapping \<Rightarrow> 'a list" where
|
|
32 |
"ordered_keys m = sorted_list_of_set (keys m)"
|
|
33 |
|
35157
|
34 |
definition is_empty :: "('a, 'b) mapping \<Rightarrow> bool" where
|
|
35 |
"is_empty m \<longleftrightarrow> dom (lookup m) = {}"
|
|
36 |
|
|
37 |
definition size :: "('a, 'b) mapping \<Rightarrow> nat" where
|
|
38 |
"size m = (if finite (dom (lookup m)) then card (dom (lookup m)) else 0)"
|
|
39 |
|
|
40 |
definition replace :: "'a \<Rightarrow> 'b \<Rightarrow> ('a, 'b) mapping \<Rightarrow> ('a, 'b) mapping" where
|
29814
|
41 |
"replace k v m = (if lookup m k = None then m else update k v m)"
|
|
42 |
|
35157
|
43 |
definition tabulate :: "'a list \<Rightarrow> ('a \<Rightarrow> 'b) \<Rightarrow> ('a, 'b) mapping" where
|
|
44 |
"tabulate ks f = Mapping (map_of (map (\<lambda>k. (k, f k)) ks))"
|
29708
|
45 |
|
35157
|
46 |
definition bulkload :: "'a list \<Rightarrow> (nat, 'a) mapping" where
|
|
47 |
"bulkload xs = Mapping (\<lambda>k. if k < length xs then Some (xs ! k) else None)"
|
29826
|
48 |
|
29708
|
49 |
|
|
50 |
subsection {* Properties *}
|
|
51 |
|
35157
|
52 |
lemma lookup_inject [simp]:
|
29708
|
53 |
"lookup m = lookup n \<longleftrightarrow> m = n"
|
|
54 |
by (cases m, cases n) simp
|
|
55 |
|
35157
|
56 |
lemma mapping_eqI:
|
|
57 |
assumes "lookup m = lookup n"
|
|
58 |
shows "m = n"
|
|
59 |
using assms by simp
|
|
60 |
|
29708
|
61 |
lemma lookup_empty [simp]:
|
|
62 |
"lookup empty = Map.empty"
|
|
63 |
by (simp add: empty_def)
|
|
64 |
|
|
65 |
lemma lookup_update [simp]:
|
|
66 |
"lookup (update k v m) = (lookup m) (k \<mapsto> v)"
|
|
67 |
by (cases m) simp
|
|
68 |
|
35157
|
69 |
lemma lookup_delete [simp]:
|
|
70 |
"lookup (delete k m) = (lookup m) (k := None)"
|
|
71 |
by (cases m) simp
|
29708
|
72 |
|
35157
|
73 |
lemma lookup_tabulate [simp]:
|
29708
|
74 |
"lookup (tabulate ks f) = (Some o f) |` set ks"
|
|
75 |
by (induct ks) (auto simp add: tabulate_def restrict_map_def expand_fun_eq)
|
|
76 |
|
35157
|
77 |
lemma lookup_bulkload [simp]:
|
29826
|
78 |
"lookup (bulkload xs) = (\<lambda>k. if k < length xs then Some (xs ! k) else None)"
|
35157
|
79 |
by (simp add: bulkload_def)
|
29826
|
80 |
|
29708
|
81 |
lemma update_update:
|
|
82 |
"update k v (update k w m) = update k v m"
|
|
83 |
"k \<noteq> l \<Longrightarrow> update k v (update l w m) = update l w (update k v m)"
|
35157
|
84 |
by (rule mapping_eqI, simp add: fun_upd_twist)+
|
29708
|
85 |
|
35157
|
86 |
lemma update_delete [simp]:
|
|
87 |
"update k v (delete k m) = update k v m"
|
|
88 |
by (rule mapping_eqI) simp
|
29708
|
89 |
|
|
90 |
lemma delete_update:
|
|
91 |
"delete k (update k v m) = delete k m"
|
|
92 |
"k \<noteq> l \<Longrightarrow> delete k (update l v m) = update l v (delete k m)"
|
35157
|
93 |
by (rule mapping_eqI, simp add: fun_upd_twist)+
|
29708
|
94 |
|
35157
|
95 |
lemma delete_empty [simp]:
|
|
96 |
"delete k empty = empty"
|
|
97 |
by (rule mapping_eqI) simp
|
29708
|
98 |
|
35157
|
99 |
lemma replace_update:
|
|
100 |
"k \<notin> dom (lookup m) \<Longrightarrow> replace k v m = m"
|
|
101 |
"k \<in> dom (lookup m) \<Longrightarrow> replace k v m = update k v m"
|
|
102 |
by (rule mapping_eqI, auto simp add: replace_def fun_upd_twist)+
|
29708
|
103 |
|
|
104 |
lemma size_empty [simp]:
|
|
105 |
"size empty = 0"
|
35157
|
106 |
by (simp add: size_def)
|
29708
|
107 |
|
|
108 |
lemma size_update:
|
35157
|
109 |
"finite (dom (lookup m)) \<Longrightarrow> size (update k v m) =
|
|
110 |
(if k \<in> dom (lookup m) then size m else Suc (size m))"
|
|
111 |
by (auto simp add: size_def insert_dom)
|
29708
|
112 |
|
|
113 |
lemma size_delete:
|
35157
|
114 |
"size (delete k m) = (if k \<in> dom (lookup m) then size m - 1 else size m)"
|
|
115 |
by (simp add: size_def)
|
29708
|
116 |
|
|
117 |
lemma size_tabulate:
|
|
118 |
"size (tabulate ks f) = length (remdups ks)"
|
35157
|
119 |
by (simp add: size_def distinct_card [of "remdups ks", symmetric] comp_def)
|
29708
|
120 |
|
29831
|
121 |
lemma bulkload_tabulate:
|
29826
|
122 |
"bulkload xs = tabulate [0..<length xs] (nth xs)"
|
35157
|
123 |
by (rule mapping_eqI) (simp add: expand_fun_eq)
|
29826
|
124 |
|
31459
|
125 |
|
|
126 |
subsection {* Some technical code lemmas *}
|
|
127 |
|
|
128 |
lemma [code]:
|
35157
|
129 |
"mapping_case f m = f (Mapping.lookup m)"
|
31459
|
130 |
by (cases m) simp
|
|
131 |
|
|
132 |
lemma [code]:
|
35157
|
133 |
"mapping_rec f m = f (Mapping.lookup m)"
|
31459
|
134 |
by (cases m) simp
|
|
135 |
|
|
136 |
lemma [code]:
|
35157
|
137 |
"Nat.size (m :: (_, _) mapping) = 0"
|
31459
|
138 |
by (cases m) simp
|
|
139 |
|
|
140 |
lemma [code]:
|
35157
|
141 |
"mapping_size f g m = 0"
|
31459
|
142 |
by (cases m) simp
|
|
143 |
|
35157
|
144 |
|
35194
|
145 |
hide (open) const empty is_empty lookup update delete ordered_keys keys size replace tabulate bulkload
|
35157
|
146 |
|
29708
|
147 |
end |