(*  Title:      Pure/Tools/find_consts.ML
    Author:     Timothy Bourke and Gerwin Klein, NICTA
Hoogle-like (http://www-users.cs.york.ac.uk/~ndm/hoogle) searching by
type over constants, but matching is not fuzzy.
*)
signature FIND_CONSTS =
sig
  datatype criterion =
      Strict of string
    | Loose of string
    | Name of string
  val find_consts : Proof.context -> (bool * criterion) list -> unit
end;
structure FindConsts : FIND_CONSTS =
struct
(* search criteria *)
datatype criterion =
    Strict of string
  | Loose of string
  | Name of string;
(* matching types/consts *)
fun add_tye (_, (_, t)) n = Term.size_of_typ t + n;
fun matches_subtype thy typat =
  let
    val p = can (fn ty => Sign.typ_match thy (typat, ty) Vartab.empty);
    fun fs [] = false
      | fs (t :: ts) = f t orelse fs ts
    and f (t as Type (_, ars)) = p t orelse fs ars
      | f t = p t;
  in f end;
fun check_const p (nm, (ty, _)) =
  if p (nm, ty)
  then SOME (Term.size_of_typ ty)
  else NONE;
fun opt_not f (c as (_, (ty, _))) =
  if is_some (f c)
  then NONE else SOME (Term.size_of_typ ty);
fun filter_const _ NONE = NONE
  | filter_const f (SOME (c, r)) =
      Option.map (pair c o (curry Int.min r)) (f c);
(* pretty results *)
fun pretty_criterion (b, c) =
  let
    fun prfx s = if b then s else "-" ^ s;
  in
    (case c of
      Strict pat => Pretty.str (prfx "strict: " ^ quote pat)
    | Loose pat => Pretty.str (prfx (quote pat))
    | Name name => Pretty.str (prfx "name: " ^ quote name))
  end;
fun pretty_const ctxt (nm, ty) =
  let
    val ty' = Logic.unvarifyT ty;
  in
    Pretty.block
     [Pretty.quote (Pretty.str nm), Pretty.fbrk,
      Pretty.str "::", Pretty.brk 1,
      Pretty.quote (Syntax.pretty_typ ctxt ty')]
  end;
(* find_consts *)
fun find_consts ctxt raw_criteria =
  let
    val start = start_timing ();
    val thy = ProofContext.theory_of ctxt;
    val low_ranking = 10000;
    fun not_internal consts (nm, _) = 
      if member (op =) (Consts.the_tags consts nm) Markup.property_internal
      then NONE else SOME low_ranking;
    fun make_pattern crit =
      let
        val raw_T = Syntax.parse_typ ctxt crit;
        val t = Syntax.check_term
                  (ProofContext.set_mode ProofContext.mode_pattern ctxt)
                  (Term.dummy_pattern raw_T);
      in Term.type_of t end;
    fun make_match (Strict arg) =
          let val qty = make_pattern arg; in
            fn (_, (ty, _)) =>
              let
                val tye = Sign.typ_match thy (qty, ty) Vartab.empty;
                val sub_size = Vartab.fold add_tye tye 0;
              in SOME sub_size end handle MATCH => NONE
          end
      | make_match (Loose arg) =
          check_const (matches_subtype thy (make_pattern arg) o snd)
      
      | make_match (Name arg) = check_const (match_string arg o fst);
    fun make_criterion (b, crit) = (if b then I else opt_not) (make_match crit);
    val criteria = map make_criterion raw_criteria;
    val consts = Sign.consts_of thy;
    val (_, consts_tab) = (#constants o Consts.dest) consts;
    fun eval_entry c = fold filter_const (not_internal consts::criteria)
                                         (SOME (c, low_ranking));
    val matches =
      Symtab.fold (cons o eval_entry) consts_tab []
      |> map_filter I
      |> sort (rev_order o int_ord o pairself snd)
      |> map ((apsnd fst) o fst);
    val end_msg = " in " ^ Time.toString (#all (end_timing start)) ^ " secs";
  in
    Pretty.big_list "searched for:" (map pretty_criterion raw_criteria)
      :: Pretty.str ""
      :: (Pretty.str o concat)
           (if null matches
            then ["nothing found", end_msg]
            else ["found ", (string_of_int o length) matches,
                  " constants", end_msg, ":"])
      :: Pretty.str ""
      :: map (pretty_const ctxt) matches
    |> Pretty.chunks
    |> Pretty.writeln
  end;
(* command syntax *)
fun find_consts_cmd spec =
  Toplevel.unknown_theory o Toplevel.keep (fn state =>
    find_consts (Proof.context_of (Toplevel.enter_proof_body state)) spec);
local
structure P = OuterParse and K = OuterKeyword;
val criterion =
  P.reserved "strict" |-- P.!!! (P.$$$ ":" |-- P.xname) >> Strict ||
  P.reserved "name" |-- P.!!! (P.$$$ ":" |-- P.xname) >> Name ||
  P.xname >> Loose;
in
val _ =
  OuterSyntax.improper_command "find_consts" "search constants by type pattern" K.diag
    (Scan.repeat (((Scan.option P.minus >> is_none) -- criterion))
      >> (Toplevel.no_timing oo find_consts_cmd));
end;
end;