src/HOL/Imperative_HOL/Array.thy
changeset 37716 271ecd4fb9f9
parent 37713 24bb91462892
child 37751 d0a384c84d69
equal deleted inserted replaced
37715:3046ebbb43c0 37716:271ecd4fb9f9
     6 
     6 
     7 theory Array
     7 theory Array
     8 imports Heap_Monad
     8 imports Heap_Monad
     9 begin
     9 begin
    10 
    10 
       
    11 subsection {* Primitive layer *}
       
    12 
       
    13 definition 
       
    14   array_present :: "'a\<Colon>heap array \<Rightarrow> heap \<Rightarrow> bool" where
       
    15   "array_present a h \<longleftrightarrow> addr_of_array a < lim h"
       
    16 
       
    17 definition
       
    18   get_array :: "'a\<Colon>heap array \<Rightarrow> heap \<Rightarrow> 'a list" where
       
    19   "get_array a h = map from_nat (arrays h (TYPEREP('a)) (addr_of_array a))"
       
    20 
       
    21 definition
       
    22   set_array :: "'a\<Colon>heap array \<Rightarrow> 'a list \<Rightarrow> heap \<Rightarrow> heap" where
       
    23   "set_array a x = 
       
    24   arrays_update (\<lambda>h. h(TYPEREP('a) := ((h(TYPEREP('a))) (addr_of_array a:=map to_nat x))))"
       
    25 
       
    26 definition array :: "'a list \<Rightarrow> heap \<Rightarrow> 'a\<Colon>heap array \<times> heap" where
       
    27   "array xs h = (let
       
    28      l = lim h;
       
    29      r = Array l;
       
    30      h'' = set_array r xs (h\<lparr>lim := l + 1\<rparr>)
       
    31    in (r, h''))"
       
    32 
       
    33 definition length :: "'a\<Colon>heap array \<Rightarrow> heap \<Rightarrow> nat" where
       
    34   "length a h = List.length (get_array a h)"
       
    35   
       
    36 definition change :: "'a\<Colon>heap array \<Rightarrow> nat \<Rightarrow> 'a \<Rightarrow> heap \<Rightarrow> heap" where
       
    37   "change a i x h = set_array a ((get_array a h)[i:=x]) h"
       
    38 
       
    39 text {* Properties of imperative arrays *}
       
    40 
       
    41 text {* FIXME: Does there exist a "canonical" array axiomatisation in
       
    42 the literature?  *}
       
    43 
       
    44 definition noteq_arrs :: "('a\<Colon>heap) array \<Rightarrow> ('b\<Colon>heap) array \<Rightarrow> bool" (infix "=!!=" 70) where
       
    45   "r =!!= s \<longleftrightarrow> TYPEREP('a) \<noteq> TYPEREP('b) \<or> addr_of_array r \<noteq> addr_of_array s"
       
    46 
       
    47 lemma noteq_arrs_sym: "a =!!= b \<Longrightarrow> b =!!= a"
       
    48   and unequal_arrs [simp]: "a \<noteq> a' \<longleftrightarrow> a =!!= a'"
       
    49   unfolding noteq_arrs_def by auto
       
    50 
       
    51 lemma noteq_arrs_irrefl: "r =!!= r \<Longrightarrow> False"
       
    52   unfolding noteq_arrs_def by auto
       
    53 
       
    54 lemma present_new_arr: "array_present a h \<Longrightarrow> a =!!= fst (array xs h)"
       
    55   by (simp add: array_present_def noteq_arrs_def array_def Let_def)
       
    56 
       
    57 lemma array_get_set_eq [simp]: "get_array r (set_array r x h) = x"
       
    58   by (simp add: get_array_def set_array_def o_def)
       
    59 
       
    60 lemma array_get_set_neq [simp]: "r =!!= s \<Longrightarrow> get_array r (set_array s x h) = get_array r h"
       
    61   by (simp add: noteq_arrs_def get_array_def set_array_def)
       
    62 
       
    63 lemma set_array_same [simp]:
       
    64   "set_array r x (set_array r y h) = set_array r x h"
       
    65   by (simp add: set_array_def)
       
    66 
       
    67 lemma array_set_set_swap:
       
    68   "r =!!= r' \<Longrightarrow> set_array r x (set_array r' x' h) = set_array r' x' (set_array r x h)"
       
    69   by (simp add: Let_def expand_fun_eq noteq_arrs_def set_array_def)
       
    70 
       
    71 lemma get_array_change_eq [simp]:
       
    72   "get_array a (change a i v h) = (get_array a h) [i := v]"
       
    73   by (simp add: change_def)
       
    74 
       
    75 lemma nth_change_array_neq_array [simp]:
       
    76   "a =!!= b \<Longrightarrow> get_array a (change b j v h) ! i = get_array a h ! i"
       
    77   by (simp add: change_def noteq_arrs_def)
       
    78 
       
    79 lemma get_arry_array_change_elem_neqIndex [simp]:
       
    80   "i \<noteq> j \<Longrightarrow> get_array a (change a j v h) ! i = get_array a h ! i"
       
    81   by simp
       
    82 
       
    83 lemma length_change [simp]: 
       
    84   "length a (change b i v h) = length a h"
       
    85   by (simp add: change_def length_def set_array_def get_array_def)
       
    86 
       
    87 lemma change_swap_neqArray:
       
    88   "a =!!= a' \<Longrightarrow> 
       
    89   change a i v (change a' i' v' h) 
       
    90   = change a' i' v' (change a i v h)"
       
    91 apply (unfold change_def)
       
    92 apply simp
       
    93 apply (subst array_set_set_swap, assumption)
       
    94 apply (subst array_get_set_neq)
       
    95 apply (erule noteq_arrs_sym)
       
    96 apply (simp)
       
    97 done
       
    98 
       
    99 lemma change_swap_neqIndex:
       
   100   "\<lbrakk> i \<noteq> i' \<rbrakk> \<Longrightarrow> change a i v (change a i' v' h) = change a i' v' (change a i v h)"
       
   101   by (auto simp add: change_def array_set_set_swap list_update_swap)
       
   102 
       
   103 lemma get_array_init_array_list:
       
   104   "get_array (fst (array ls h)) (snd (array ls' h)) = ls'"
       
   105   by (simp add: Let_def split_def array_def)
       
   106 
       
   107 lemma set_array:
       
   108   "set_array (fst (array ls h))
       
   109      new_ls (snd (array ls h))
       
   110        = snd (array new_ls h)"
       
   111   by (simp add: Let_def split_def array_def)
       
   112 
       
   113 lemma array_present_change [simp]: 
       
   114   "array_present a (change b i v h) = array_present a h"
       
   115   by (simp add: change_def array_present_def set_array_def get_array_def)
       
   116 
       
   117 
       
   118 
    11 subsection {* Primitives *}
   119 subsection {* Primitives *}
    12 
   120 
    13 definition
   121 definition
    14   new :: "nat \<Rightarrow> 'a\<Colon>heap \<Rightarrow> 'a array Heap" where
   122   new :: "nat \<Rightarrow> 'a\<Colon>heap \<Rightarrow> 'a array Heap" where
    15   [code del]: "new n x = Heap_Monad.heap (Heap.array (replicate n x))"
   123   [code del]: "new n x = Heap_Monad.heap (Array.array (replicate n x))"
    16 
   124 
    17 definition
   125 definition
    18   of_list :: "'a\<Colon>heap list \<Rightarrow> 'a array Heap" where
   126   of_list :: "'a\<Colon>heap list \<Rightarrow> 'a array Heap" where
    19   [code del]: "of_list xs = Heap_Monad.heap (Heap.array xs)"
   127   [code del]: "of_list xs = Heap_Monad.heap (Array.array xs)"
    20 
   128 
    21 definition
   129 definition
    22   length :: "'a\<Colon>heap array \<Rightarrow> nat Heap" where
   130   len :: "'a\<Colon>heap array \<Rightarrow> nat Heap" where
    23   [code del]: "length arr = Heap_Monad.heap (\<lambda>h. (Heap.length arr h, h))"
   131   [code del]: "len arr = Heap_Monad.heap (\<lambda>h. (Array.length arr h, h))"
    24 
   132 
    25 definition
   133 definition
    26   nth :: "'a\<Colon>heap array \<Rightarrow> nat \<Rightarrow> 'a Heap"
   134   nth :: "'a\<Colon>heap array \<Rightarrow> nat \<Rightarrow> 'a Heap"
    27 where
   135 where
    28   [code del]: "nth a i = (do len \<leftarrow> length a;
   136   [code del]: "nth a i = (do len \<leftarrow> len a;
    29                  (if i < len
   137                  (if i < len
    30                      then Heap_Monad.heap (\<lambda>h. (get_array a h ! i, h))
   138                      then Heap_Monad.heap (\<lambda>h. (get_array a h ! i, h))
    31                      else raise ''array lookup: index out of range'')
   139                      else raise ''array lookup: index out of range'')
    32               done)"
   140               done)"
    33 
   141 
    34 definition
   142 definition
    35   upd :: "nat \<Rightarrow> 'a \<Rightarrow> 'a\<Colon>heap array \<Rightarrow> 'a\<Colon>heap array Heap"
   143   upd :: "nat \<Rightarrow> 'a \<Rightarrow> 'a\<Colon>heap array \<Rightarrow> 'a\<Colon>heap array Heap"
    36 where
   144 where
    37   [code del]: "upd i x a = (do len \<leftarrow> length a;
   145   [code del]: "upd i x a = (do len \<leftarrow> len a;
    38                       (if i < len
   146                       (if i < len
    39                            then Heap_Monad.heap (\<lambda>h. (a, Heap.upd a i x h))
   147                            then Heap_Monad.heap (\<lambda>h. (a, change a i x h))
    40                            else raise ''array update: index out of range'')
   148                            else raise ''array update: index out of range'')
    41                    done)" 
   149                    done)" 
    42 
   150 
    43 lemma upd_return:
   151 lemma upd_return:
    44   "upd i x a \<guillemotright> return a = upd i x a"
   152   "upd i x a \<guillemotright> return a = upd i x a"
    71 
   179 
    72 definition
   180 definition
    73   freeze :: "'a\<Colon>heap array \<Rightarrow> 'a list Heap"
   181   freeze :: "'a\<Colon>heap array \<Rightarrow> 'a list Heap"
    74 where
   182 where
    75   "freeze a = (do
   183   "freeze a = (do
    76      n \<leftarrow> length a;
   184      n \<leftarrow> len a;
    77      mapM (nth a) [0..<n]
   185      mapM (nth a) [0..<n]
    78    done)"
   186    done)"
    79 
   187 
    80 definition
   188 definition
    81    map :: "('a\<Colon>heap \<Rightarrow> 'a) \<Rightarrow> 'a array \<Rightarrow> 'a array Heap"
   189    map :: "('a\<Colon>heap \<Rightarrow> 'a) \<Rightarrow> 'a array \<Rightarrow> 'a array Heap"
    82 where
   190 where
    83   "map f a = (do
   191   "map f a = (do
    84      n \<leftarrow> length a;
   192      n \<leftarrow> len a;
    85      mapM (\<lambda>n. map_entry n f a) [0..<n];
   193      mapM (\<lambda>n. map_entry n f a) [0..<n];
    86      return a
   194      return a
    87    done)"
   195    done)"
    88 
   196 
    89 hide_const (open) new map -- {* avoid clashed with some popular names *}
       
    90 
   197 
    91 
   198 
    92 subsection {* Properties *}
   199 subsection {* Properties *}
    93 
   200 
    94 lemma array_make [code]:
   201 lemma array_make [code]:
   123 hide_const (open) make'
   230 hide_const (open) make'
   124 lemma [code]:
   231 lemma [code]:
   125   "Array.make n f = Array.make' (Code_Numeral.of_nat n) (f o Code_Numeral.nat_of)"
   232   "Array.make n f = Array.make' (Code_Numeral.of_nat n) (f o Code_Numeral.nat_of)"
   126   by (simp add: make'_def o_def)
   233   by (simp add: make'_def o_def)
   127 
   234 
   128 definition length' where
   235 definition len' where
   129   [code del]: "length' a = Array.length a \<guillemotright>= (\<lambda>n. return (Code_Numeral.of_nat n))"
   236   [code del]: "len' a = Array.len a \<guillemotright>= (\<lambda>n. return (Code_Numeral.of_nat n))"
   130 hide_const (open) length'
   237 hide_const (open) len'
   131 lemma [code]:
   238 lemma [code]:
   132   "Array.length a = Array.length' a \<guillemotright>= (\<lambda>i. return (Code_Numeral.nat_of i))"
   239   "Array.len a = Array.len' a \<guillemotright>= (\<lambda>i. return (Code_Numeral.nat_of i))"
   133   by (simp add: length'_def)
   240   by (simp add: len'_def)
   134 
   241 
   135 definition nth' where
   242 definition nth' where
   136   [code del]: "nth' a = Array.nth a o Code_Numeral.nat_of"
   243   [code del]: "nth' a = Array.nth a o Code_Numeral.nat_of"
   137 hide_const (open) nth'
   244 hide_const (open) nth'
   138 lemma [code]:
   245 lemma [code]:
   152 code_type array (SML "_/ array")
   259 code_type array (SML "_/ array")
   153 code_const Array (SML "raise/ (Fail/ \"bare Array\")")
   260 code_const Array (SML "raise/ (Fail/ \"bare Array\")")
   154 code_const Array.new' (SML "(fn/ ()/ =>/ Array.array/ ((_),/ (_)))")
   261 code_const Array.new' (SML "(fn/ ()/ =>/ Array.array/ ((_),/ (_)))")
   155 code_const Array.of_list' (SML "(fn/ ()/ =>/ Array.fromList/ _)")
   262 code_const Array.of_list' (SML "(fn/ ()/ =>/ Array.fromList/ _)")
   156 code_const Array.make' (SML "(fn/ ()/ =>/ Array.tabulate/ ((_),/ (_)))")
   263 code_const Array.make' (SML "(fn/ ()/ =>/ Array.tabulate/ ((_),/ (_)))")
   157 code_const Array.length' (SML "(fn/ ()/ =>/ Array.length/ _)")
   264 code_const Array.len' (SML "(fn/ ()/ =>/ Array.length/ _)")
   158 code_const Array.nth' (SML "(fn/ ()/ =>/ Array.sub/ ((_),/ (_)))")
   265 code_const Array.nth' (SML "(fn/ ()/ =>/ Array.sub/ ((_),/ (_)))")
   159 code_const Array.upd' (SML "(fn/ ()/ =>/ Array.update/ ((_),/ (_),/ (_)))")
   266 code_const Array.upd' (SML "(fn/ ()/ =>/ Array.update/ ((_),/ (_),/ (_)))")
   160 
   267 
   161 code_reserved SML Array
   268 code_reserved SML Array
   162 
   269 
   165 
   272 
   166 code_type array (OCaml "_/ array")
   273 code_type array (OCaml "_/ array")
   167 code_const Array (OCaml "failwith/ \"bare Array\"")
   274 code_const Array (OCaml "failwith/ \"bare Array\"")
   168 code_const Array.new' (OCaml "(fun/ ()/ ->/ Array.make/ (Big'_int.int'_of'_big'_int/ _)/ _)")
   275 code_const Array.new' (OCaml "(fun/ ()/ ->/ Array.make/ (Big'_int.int'_of'_big'_int/ _)/ _)")
   169 code_const Array.of_list' (OCaml "(fun/ ()/ ->/ Array.of'_list/ _)")
   276 code_const Array.of_list' (OCaml "(fun/ ()/ ->/ Array.of'_list/ _)")
   170 code_const Array.length' (OCaml "(fun/ ()/ ->/ Big'_int.big'_int'_of'_int/ (Array.length/ _))")
   277 code_const Array.len' (OCaml "(fun/ ()/ ->/ Big'_int.big'_int'_of'_int/ (Array.length/ _))")
   171 code_const Array.nth' (OCaml "(fun/ ()/ ->/ Array.get/ _/ (Big'_int.int'_of'_big'_int/ _))")
   278 code_const Array.nth' (OCaml "(fun/ ()/ ->/ Array.get/ _/ (Big'_int.int'_of'_big'_int/ _))")
   172 code_const Array.upd' (OCaml "(fun/ ()/ ->/ Array.set/ _/ (Big'_int.int'_of'_big'_int/ _)/ _)")
   279 code_const Array.upd' (OCaml "(fun/ ()/ ->/ Array.set/ _/ (Big'_int.int'_of'_big'_int/ _)/ _)")
   173 
   280 
   174 code_reserved OCaml Array
   281 code_reserved OCaml Array
   175 
   282 
   178 
   285 
   179 code_type array (Haskell "Heap.STArray/ Heap.RealWorld/ _")
   286 code_type array (Haskell "Heap.STArray/ Heap.RealWorld/ _")
   180 code_const Array (Haskell "error/ \"bare Array\"")
   287 code_const Array (Haskell "error/ \"bare Array\"")
   181 code_const Array.new' (Haskell "Heap.newArray/ (0,/ _)")
   288 code_const Array.new' (Haskell "Heap.newArray/ (0,/ _)")
   182 code_const Array.of_list' (Haskell "Heap.newListArray/ (0,/ _)")
   289 code_const Array.of_list' (Haskell "Heap.newListArray/ (0,/ _)")
   183 code_const Array.length' (Haskell "Heap.lengthArray")
   290 code_const Array.len' (Haskell "Heap.lengthArray")
   184 code_const Array.nth' (Haskell "Heap.readArray")
   291 code_const Array.nth' (Haskell "Heap.readArray")
   185 code_const Array.upd' (Haskell "Heap.writeArray")
   292 code_const Array.upd' (Haskell "Heap.writeArray")
   186 
   293 
       
   294 hide_const (open) new map -- {* avoid clashed with some popular names *}
       
   295 
   187 end
   296 end