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