src/Pure/name.ML
author wenzelm
Thu Jun 09 20:22:22 2011 +0200 (2011-06-09)
changeset 43329 84472e198515
parent 43326 47cf4bc789aa
child 43683 b5d1873449fb
permissions -rw-r--r--
tuned signature: Name.invent and Name.invent_names;
wenzelm@20089
     1
(*  Title:      Pure/name.ML
wenzelm@20089
     2
    Author:     Makarius
wenzelm@20089
     3
haftmann@28965
     4
Names of basic logical entities (variables etc.).
wenzelm@20089
     5
*)
wenzelm@20089
     6
wenzelm@20089
     7
signature NAME =
wenzelm@20089
     8
sig
wenzelm@24849
     9
  val uu: string
wenzelm@24849
    10
  val aT: string
wenzelm@20089
    11
  val bound: int -> string
wenzelm@20089
    12
  val is_bound: string -> bool
wenzelm@20089
    13
  val internal: string -> string
wenzelm@20089
    14
  val dest_internal: string -> string
wenzelm@20089
    15
  val skolem: string -> string
wenzelm@20089
    16
  val dest_skolem: string -> string
wenzelm@20089
    17
  val clean_index: string * int -> string * int
wenzelm@20089
    18
  val clean: string -> string
wenzelm@20089
    19
  type context
wenzelm@20089
    20
  val context: context
wenzelm@20158
    21
  val make_context: string list -> context
wenzelm@20089
    22
  val declare: string -> context -> context
wenzelm@20158
    23
  val is_declared: context -> string -> bool
wenzelm@43329
    24
  val invent: context -> string -> int -> string list
wenzelm@43329
    25
  val invent_names: context -> string -> 'a list -> (string * 'a) list
wenzelm@20089
    26
  val invent_list: string list -> string -> int -> string list
wenzelm@43326
    27
  val variant: string -> context -> string * context
wenzelm@20089
    28
  val variant_list: string list -> string list -> string list
haftmann@31035
    29
  val desymbolize: bool -> string -> string
wenzelm@20089
    30
end;
wenzelm@20089
    31
wenzelm@20089
    32
structure Name: NAME =
wenzelm@20089
    33
struct
wenzelm@20089
    34
wenzelm@24849
    35
(** common defaults **)
wenzelm@24849
    36
wenzelm@24849
    37
val uu = "uu";
wenzelm@24849
    38
val aT = "'a";
wenzelm@24849
    39
wenzelm@24849
    40
wenzelm@20089
    41
wenzelm@20089
    42
(** special variable names **)
wenzelm@20089
    43
wenzelm@20089
    44
(* encoded bounds *)
wenzelm@20089
    45
wenzelm@20089
    46
(*names for numbered variables --
wenzelm@20089
    47
  preserves order wrt. int_ord vs. string_ord, avoids allocating new strings*)
wenzelm@20089
    48
wenzelm@20089
    49
val small_int = Vector.tabulate (1000, fn i =>
wenzelm@20089
    50
  let val leading = if i < 10 then "00" else if i < 100 then "0" else ""
wenzelm@20089
    51
  in ":" ^ leading ^ string_of_int i end);
wenzelm@20089
    52
wenzelm@20089
    53
fun bound n =
wenzelm@20089
    54
  if n < 1000 then Vector.sub (small_int, n)
wenzelm@20089
    55
  else ":" ^ bound (n div 1000) ^ Vector.sub (small_int, n mod 1000);
wenzelm@20089
    56
wenzelm@20089
    57
val is_bound = String.isPrefix ":";
wenzelm@20089
    58
wenzelm@20089
    59
wenzelm@20089
    60
(* internal names *)
wenzelm@20089
    61
wenzelm@20089
    62
val internal = suffix "_";
wenzelm@20089
    63
val dest_internal = unsuffix "_";
wenzelm@20089
    64
wenzelm@20089
    65
val skolem = suffix "__";
wenzelm@20089
    66
val dest_skolem = unsuffix "__";
wenzelm@20089
    67
wenzelm@20099
    68
fun clean_index (x, i) =
wenzelm@20099
    69
  (case try dest_internal x of
wenzelm@20099
    70
    NONE => (x, i)
wenzelm@20099
    71
  | SOME x' => clean_index (x', i + 1));
wenzelm@20089
    72
wenzelm@20089
    73
fun clean x = #1 (clean_index (x, 0));
wenzelm@20089
    74
wenzelm@20089
    75
wenzelm@20089
    76
wenzelm@20089
    77
(** generating fresh names **)
wenzelm@20089
    78
wenzelm@20089
    79
(* context *)
wenzelm@20089
    80
wenzelm@20089
    81
datatype context =
wenzelm@20089
    82
  Context of string option Symtab.table;    (*declared names with latest renaming*)
wenzelm@20089
    83
wenzelm@20099
    84
fun declare x (Context tab) =
wenzelm@20099
    85
  Context (Symtab.default (clean x, NONE) tab);
wenzelm@20099
    86
wenzelm@20099
    87
fun declare_renaming (x, x') (Context tab) =
wenzelm@20099
    88
  Context (Symtab.update (clean x, SOME (clean x')) tab);
wenzelm@20089
    89
wenzelm@20158
    90
fun is_declared (Context tab) = Symtab.defined tab;
wenzelm@20089
    91
fun declared (Context tab) = Symtab.lookup tab;
wenzelm@20089
    92
wenzelm@20121
    93
val context = Context Symtab.empty |> fold declare ["", "'"];
wenzelm@20089
    94
fun make_context used = fold declare used context;
wenzelm@20089
    95
wenzelm@20089
    96
wenzelm@43329
    97
(* invent names *)
wenzelm@20089
    98
wenzelm@43329
    99
fun invent ctxt =
wenzelm@20089
   100
  let
wenzelm@20089
   101
    fun invs _ 0 = []
wenzelm@20089
   102
      | invs x n =
wenzelm@43329
   103
          let val x' = Symbol.bump_string x
wenzelm@43329
   104
          in if is_declared ctxt x then invs x' n else x :: invs x' (n - 1) end;
wenzelm@20099
   105
  in invs o clean end;
wenzelm@20089
   106
wenzelm@43329
   107
fun invent_names ctxt x xs = invent ctxt x (length xs) ~~ xs;
wenzelm@20198
   108
wenzelm@43329
   109
val invent_list = invent o make_context;
wenzelm@20089
   110
wenzelm@20089
   111
wenzelm@20089
   112
(* variants *)
wenzelm@20089
   113
wenzelm@20089
   114
(*makes a variant of a name distinct from already used names in a
wenzelm@20089
   115
  context; preserves a suffix of underscores "_"*)
wenzelm@43326
   116
fun variant name ctxt =
wenzelm@20089
   117
  let
wenzelm@20089
   118
    fun vary x =
wenzelm@20089
   119
      (case declared ctxt x of
wenzelm@20089
   120
        NONE => x
wenzelm@20089
   121
      | SOME x' => vary (Symbol.bump_string (the_default x x')));
wenzelm@20089
   122
wenzelm@20121
   123
    val (x, n) = clean_index (name, 0);
wenzelm@20089
   124
    val (x', ctxt') =
wenzelm@20158
   125
      if not (is_declared ctxt x) then (x, declare x ctxt)
wenzelm@20089
   126
      else
wenzelm@20089
   127
        let
wenzelm@20089
   128
          val x0 = Symbol.bump_init x;
wenzelm@20089
   129
          val x' = vary x0;
wenzelm@20089
   130
          val ctxt' = ctxt
wenzelm@21565
   131
            |> x0 <> x' ? declare_renaming (x0, x')
wenzelm@20089
   132
            |> declare x';
wenzelm@20089
   133
        in (x', ctxt') end;
wenzelm@43326
   134
  in (x' ^ replicate_string n "_", ctxt') end;
wenzelm@20089
   135
wenzelm@43326
   136
fun variant_list used names = #1 (make_context used |> fold_map variant names);
wenzelm@20089
   137
haftmann@31013
   138
haftmann@31035
   139
(* names conforming to typical requirements of identifiers in the world outside *)
haftmann@31013
   140
haftmann@31035
   141
fun desymbolize upper "" = if upper then "X" else "x"
haftmann@31035
   142
  | desymbolize upper s =
haftmann@31013
   143
      let
haftmann@31035
   144
        val xs as (x :: _) = Symbol.explode s;
wenzelm@33547
   145
        val ys =
wenzelm@33547
   146
          if Symbol.is_ascii_letter x orelse Symbol.is_symbolic x then xs
haftmann@31013
   147
          else "x" :: xs;
haftmann@31013
   148
        fun is_valid x =
haftmann@34307
   149
          Symbol.is_ascii_letter x orelse Symbol.is_ascii_digit x;
haftmann@31013
   150
        fun sep [] = []
haftmann@31013
   151
          | sep (xs as "_" :: _) = xs
haftmann@31013
   152
          | sep xs = "_" :: xs;
haftmann@31035
   153
        fun desep ("_" :: xs) = xs
haftmann@31035
   154
          | desep xs = xs;
wenzelm@33547
   155
        fun desymb x xs =
wenzelm@33547
   156
          if is_valid x then x :: xs
haftmann@31013
   157
          else
wenzelm@33547
   158
            (case Symbol.decode x of
wenzelm@40627
   159
              Symbol.Sym name => "_" :: raw_explode name @ sep xs
wenzelm@33547
   160
            | _ => sep xs);
wenzelm@33547
   161
        fun upper_lower cs =
wenzelm@33547
   162
          if upper then nth_map 0 Symbol.to_ascii_upper cs
wenzelm@33547
   163
          else
wenzelm@33547
   164
            (if forall Symbol.is_ascii_upper cs then map else nth_map 0)
wenzelm@33547
   165
              Symbol.to_ascii_lower cs;
haftmann@31035
   166
      in fold_rev desymb ys [] |> desep |> upper_lower |> implode end;
haftmann@31013
   167
wenzelm@20089
   168
end;