src/Pure/Tools/find_consts.ML

refer directly to structure Keyword and Parse;
eliminated old-style structure aliases K and P;

(*  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 Find_Consts : FIND_CONSTS =
struct

(* search criteria *)

datatype criterion =
    Strict of string
  | Loose of string
  | Name of string;


(* matching types/consts *)

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)) =
      (case f c of
        NONE => NONE
      | SOME i => SOME (c, Int.min (r, i)));


(* 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_global 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 user_visible consts (nm, _) =
      if Consts.is_concealed consts nm 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 (fn (_, (_, t)) => fn n => Term.size_of_typ t + n) tye 0;
              in SOME sub_size end handle Type.TYPE_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 (Consts.dest consts);
    fun eval_entry c =
      fold filter_const (user_visible 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 (#cpu (end_timing start)) ^ " secs";
  in
    Pretty.big_list "searched for:" (map pretty_criterion raw_criteria)
      :: Pretty.str ""
      :: (Pretty.str o implode)
           (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);

val criterion =
  Parse.reserved "strict" |-- Parse.!!! (Parse.$$$ ":" |-- Parse.xname) >> Strict ||
  Parse.reserved "name" |-- Parse.!!! (Parse.$$$ ":" |-- Parse.xname) >> Name ||
  Parse.xname >> Loose;

val _ =
  OuterSyntax.improper_command "find_consts" "search constants by type pattern" Keyword.diag
    (Scan.repeat ((Scan.option Parse.minus >> is_none) -- criterion)
      >> (Toplevel.no_timing oo find_consts_cmd));

end;