src/Tools/quickcheck.ML
changeset 28952 15a4b2cf8c34
parent 28336 a8edf4c69a79
child 29266 4a478f9d2847
equal deleted inserted replaced
28948:1860f016886d 28952:15a4b2cf8c34
       
     1 (*  Title:      Pure/Tools/quickcheck.ML
       
     2     Author:     Stefan Berghofer, Florian Haftmann, TU Muenchen
       
     3 
       
     4 Generic counterexample search engine.
       
     5 *)
       
     6 
       
     7 signature QUICKCHECK =
       
     8 sig
       
     9   val test_term: Proof.context -> bool -> string option -> int -> int -> term -> (string * term) list option;
       
    10   val add_generator: string * (Proof.context -> term -> int -> term list option) -> theory -> theory
       
    11   val auto: bool ref
       
    12   val auto_time_limit: int ref
       
    13 end;
       
    14 
       
    15 structure Quickcheck : QUICKCHECK =
       
    16 struct
       
    17 
       
    18 (* quickcheck configuration -- default parameters, test generators *)
       
    19 
       
    20 datatype test_params = Test_Params of
       
    21   { size: int, iterations: int, default_type: typ option };
       
    22 
       
    23 fun dest_test_params (Test_Params { size, iterations, default_type}) =
       
    24   ((size, iterations), default_type);
       
    25 fun mk_test_params ((size, iterations), default_type) =
       
    26   Test_Params { size = size, iterations = iterations, default_type = default_type };
       
    27 fun map_test_params f (Test_Params { size, iterations, default_type}) =
       
    28   mk_test_params (f ((size, iterations), default_type));
       
    29 fun merge_test_params (Test_Params {size = size1, iterations = iterations1, default_type = default_type1},
       
    30   Test_Params {size = size2, iterations = iterations2, default_type = default_type2}) =
       
    31   mk_test_params ((Int.max (size1, size2), Int.max (iterations1, iterations2)),
       
    32     case default_type1 of NONE => default_type2 | _ => default_type1);
       
    33 
       
    34 structure Data = TheoryDataFun(
       
    35   type T = (string * (Proof.context -> term -> int -> term list option)) list
       
    36     * test_params;
       
    37   val empty = ([], Test_Params { size = 10, iterations = 100, default_type = NONE });
       
    38   val copy = I;
       
    39   val extend = I;
       
    40   fun merge pp ((generators1, params1), (generators2, params2)) =
       
    41     (AList.merge (op = : string * string -> bool) (K true) (generators1, generators2),
       
    42       merge_test_params (params1, params2));
       
    43 )
       
    44 
       
    45 val add_generator = Data.map o apfst o AList.update (op =);
       
    46 
       
    47 
       
    48 (* generating tests *)
       
    49 
       
    50 fun mk_tester_select name ctxt =
       
    51   case AList.lookup (op =) ((fst o Data.get o ProofContext.theory_of) ctxt) name
       
    52    of NONE => error ("No such quickcheck generator: " ^ name)
       
    53     | SOME generator => generator ctxt;
       
    54 
       
    55 fun mk_testers ctxt t =
       
    56   (map snd o fst o Data.get o ProofContext.theory_of) ctxt
       
    57   |> map_filter (fn generator => try (generator ctxt) t);
       
    58 
       
    59 fun mk_testers_strict ctxt t =
       
    60   let
       
    61     val generators = ((map snd o fst o Data.get o ProofContext.theory_of) ctxt)
       
    62     val testers = map (fn generator => Exn.capture (generator ctxt) t) generators;
       
    63   in if forall (is_none o Exn.get_result) testers
       
    64     then [(Exn.release o snd o split_last) testers]
       
    65     else map_filter Exn.get_result testers
       
    66   end;
       
    67 
       
    68 
       
    69 (* testing propositions *)
       
    70 
       
    71 fun prep_test_term t =
       
    72   let
       
    73     val _ = (null (term_tvars t) andalso null (term_tfrees t)) orelse
       
    74       error "Term to be tested contains type variables";
       
    75     val _ = null (term_vars t) orelse
       
    76       error "Term to be tested contains schematic variables";
       
    77     val frees = map dest_Free (term_frees t);
       
    78   in (map fst frees, list_abs_free (frees, t)) end
       
    79 
       
    80 fun test_term ctxt quiet generator_name size i t =
       
    81   let
       
    82     val (names, t') = prep_test_term t;
       
    83     val testers = case generator_name
       
    84      of NONE => if quiet then mk_testers ctxt t' else mk_testers_strict ctxt t'
       
    85       | SOME name => [mk_tester_select name ctxt t'];
       
    86     fun iterate f 0 = NONE
       
    87       | iterate f k = case f () handle Match => (if quiet then ()
       
    88              else warning "Exception Match raised during quickcheck"; NONE)
       
    89           of NONE => iterate f (k - 1) | SOME q => SOME q;
       
    90     fun with_testers k [] = NONE
       
    91       | with_testers k (tester :: testers) =
       
    92           case iterate (fn () => tester k) i
       
    93            of NONE => with_testers k testers
       
    94             | SOME q => SOME q;
       
    95     fun with_size k = if k > size then NONE
       
    96       else (if quiet then () else priority ("Test data size: " ^ string_of_int k);
       
    97         case with_testers k testers
       
    98          of NONE => with_size (k + 1) | SOME q => SOME q);
       
    99   in case with_size 1
       
   100    of NONE => NONE
       
   101     | SOME ts => SOME (names ~~ ts)
       
   102   end;
       
   103 
       
   104 fun monomorphic_term thy insts default_T = 
       
   105   let
       
   106     fun subst (T as TFree (v, S)) =
       
   107           let
       
   108             val T' = AList.lookup (op =) insts v
       
   109               |> the_default (the_default T default_T)
       
   110           in if Sign.of_sort thy (T, S) then T'
       
   111             else error ("Type " ^ Syntax.string_of_typ_global thy T ^
       
   112               " to be substituted for variable " ^
       
   113               Syntax.string_of_typ_global thy T ^ "\ndoes not have sort " ^
       
   114               Syntax.string_of_sort_global thy S)
       
   115           end
       
   116       | subst T = T;
       
   117   in (map_types o map_atyps) subst end;
       
   118 
       
   119 fun test_goal quiet generator_name size iterations default_T insts i assms state =
       
   120   let
       
   121     val ctxt = Proof.context_of state;
       
   122     val thy = Proof.theory_of state;
       
   123     fun strip (Const ("all", _) $ Abs (_, _, t)) = strip t
       
   124       | strip t = t;
       
   125     val (_, (_, st)) = Proof.get_goal state;
       
   126     val (gi, frees) = Logic.goal_params (prop_of st) i;
       
   127     val gi' = Logic.list_implies (assms, subst_bounds (frees, strip gi))
       
   128       |> monomorphic_term thy insts default_T
       
   129       |> ObjectLogic.atomize_term thy;
       
   130   in test_term ctxt quiet generator_name size iterations gi' end;
       
   131 
       
   132 fun pretty_counterex ctxt NONE = Pretty.str "No counterexamples found."
       
   133   | pretty_counterex ctxt (SOME cex) =
       
   134       Pretty.chunks (Pretty.str "Counterexample found:\n" ::
       
   135         map (fn (s, t) =>
       
   136           Pretty.block [Pretty.str (s ^ " ="), Pretty.brk 1, Syntax.pretty_term ctxt t]) cex);
       
   137 
       
   138 
       
   139 (* automatic testing *)
       
   140 
       
   141 val auto = ref false;
       
   142 val auto_time_limit = ref 5000;
       
   143 
       
   144 fun test_goal_auto int state =
       
   145   let
       
   146     val ctxt = Proof.context_of state;
       
   147     val assms = map term_of (Assumption.assms_of ctxt);
       
   148     val Test_Params { size, iterations, default_type } =
       
   149       (snd o Data.get o Proof.theory_of) state;
       
   150     fun test () =
       
   151       let
       
   152         val res = TimeLimit.timeLimit (Time.fromMilliseconds (!auto_time_limit))
       
   153           (try (test_goal true NONE size iterations default_type [] 1 assms)) state;
       
   154       in
       
   155         case res of
       
   156           NONE => state
       
   157         | SOME NONE => state
       
   158         | SOME cex => Proof.goal_message (fn () => Pretty.chunks [Pretty.str "",
       
   159             Pretty.mark Markup.hilite (pretty_counterex ctxt cex)]) state
       
   160       end handle TimeLimit.TimeOut => (warning "Auto quickcheck: timeout."; state);
       
   161   in
       
   162     if int andalso !auto andalso not (!Toplevel.quiet)
       
   163     then test ()
       
   164     else state
       
   165   end;
       
   166 
       
   167 val _ = Context.>> (Specification.add_theorem_hook test_goal_auto);
       
   168 
       
   169 
       
   170 (* Isar interfaces *)
       
   171 
       
   172 fun read_nat s = case (Library.read_int o Symbol.explode) s
       
   173  of (k, []) => if k >= 0 then k
       
   174       else error ("Not a natural number: " ^ s)
       
   175   | (_, _ :: _) => error ("Not a natural number: " ^ s);
       
   176 
       
   177 fun parse_test_param ctxt ("size", arg) =
       
   178       (apfst o apfst o K) (read_nat arg)
       
   179   | parse_test_param ctxt ("iterations", arg) =
       
   180       (apfst o apsnd o K) (read_nat arg)
       
   181   | parse_test_param ctxt ("default_type", arg) =
       
   182       (apsnd o K o SOME) (ProofContext.read_typ ctxt arg)
       
   183   | parse_test_param ctxt (name, _) =
       
   184       error ("Bad test parameter: " ^ name);
       
   185 
       
   186 fun parse_test_param_inst ctxt ("generator", arg) =
       
   187       (apsnd o apfst o K o SOME) arg
       
   188   | parse_test_param_inst ctxt (name, arg) =
       
   189       case try (ProofContext.read_typ ctxt) name
       
   190        of SOME (TFree (v, _)) => (apsnd o apsnd o AList.update (op =))
       
   191               (v, ProofContext.read_typ ctxt arg)
       
   192         | _ => (apfst o parse_test_param ctxt) (name, arg);
       
   193 
       
   194 fun quickcheck_params_cmd args thy =
       
   195   let
       
   196     val ctxt = ProofContext.init thy;
       
   197     val f = fold (parse_test_param ctxt) args;
       
   198   in
       
   199     thy
       
   200     |> (Data.map o apsnd o map_test_params) f
       
   201   end;
       
   202 
       
   203 fun quickcheck_cmd args i state =
       
   204   let
       
   205     val prf = Toplevel.proof_of state;
       
   206     val thy = Toplevel.theory_of state;
       
   207     val ctxt = Toplevel.context_of state;
       
   208     val default_params = (dest_test_params o snd o Data.get) thy;
       
   209     val f = fold (parse_test_param_inst ctxt) args;
       
   210     val (((size, iterations), default_type), (generator_name, insts)) =
       
   211       f (default_params, (NONE, []));
       
   212     val counterex = test_goal false generator_name size iterations
       
   213       default_type insts i [] prf;
       
   214   in (Pretty.writeln o pretty_counterex ctxt) counterex end;
       
   215 
       
   216 local structure P = OuterParse and K = OuterKeyword in
       
   217 
       
   218 val parse_arg = P.name --| P.$$$ "=" -- P.name;
       
   219 val parse_args = P.$$$ "[" |-- P.list1 parse_arg --| P.$$$ "]"
       
   220   || Scan.succeed [];
       
   221 
       
   222 val _ = OuterSyntax.command "quickcheck_params" "set parameters for random testing" K.thy_decl
       
   223   (parse_args >> (fn args => Toplevel.theory (quickcheck_params_cmd args)));
       
   224 
       
   225 val _ = OuterSyntax.improper_command "quickcheck" "try to find counterexample for subgoal" K.diag
       
   226   (parse_args -- Scan.optional P.nat 1
       
   227     >> (fn (args, i) => Toplevel.no_timing o Toplevel.keep (quickcheck_cmd args i)));
       
   228 
       
   229 end; (*local*)
       
   230 
       
   231 end;
       
   232 
       
   233 
       
   234 val auto_quickcheck = Quickcheck.auto;
       
   235 val auto_quickcheck_time_limit = Quickcheck.auto_time_limit;