src/HOL/Tools/Quickcheck/narrowing_generators.ML
author wenzelm
Sun Mar 13 19:27:39 2011 +0100 (2011-03-13)
changeset 41953 994d088fbfbc
parent 41952 c7297638599b
child 41963 d8c3b26b3da4
permissions -rw-r--r--
slightly more robust bash exec, which fails on empty executable;
     1 (*  Title:      HOL/Tools/Quickcheck/narrowing_generators.ML
     2     Author:     Lukas Bulwahn, TU Muenchen
     3 
     4 Narrowing-based counterexample generation.
     5 *)
     6 
     7 signature NARROWING_GENERATORS =
     8 sig
     9   val compile_generator_expr:
    10     Proof.context -> term -> int -> term list option * Quickcheck.report option
    11   val put_counterexample: (unit -> term list option) -> Proof.context -> Proof.context
    12   val setup: theory -> theory
    13 end;
    14 
    15 structure Narrowing_Generators : NARROWING_GENERATORS =
    16 struct
    17 
    18 val target = "Haskell"
    19 
    20 (* invocation of Haskell interpreter *)
    21 
    22 val narrowing_engine = File.read (Path.explode "~~/src/HOL/Tools/Quickcheck/Narrowing_Engine.hs")
    23 
    24 fun exec verbose code =
    25   ML_Context.exec (fn () => Secure.use_text ML_Env.local_context (0, "generated code") verbose code)
    26 
    27 fun value ctxt (get, put, put_ml) (code, value) =
    28   let
    29     val tmp_prefix = "Quickcheck_Narrowing"
    30     fun run in_path = 
    31       let
    32         val code_file = Path.append in_path (Path.basic "Code.hs")
    33         val narrowing_engine_file = Path.append in_path (Path.basic "Narrowing_Engine.hs")
    34         val main_file = Path.append in_path (Path.basic "Main.hs")
    35         val main = "module Main where {\n\n" ^
    36           "import Narrowing_Engine;\n" ^
    37           "import Code;\n\n" ^
    38           "main = Narrowing_Engine.smallCheck 7 (Code.value ())\n\n" ^
    39           "}\n"
    40         val code' = prefix "module Code where {\n\ndata Typerep = Typerep String [Typerep];\n"
    41           (unprefix "module Code where {" code)
    42         val _ = File.write code_file code'
    43         val _ = File.write narrowing_engine_file narrowing_engine
    44         val _ = File.write main_file main
    45         val executable = File.shell_path (Path.append in_path (Path.basic "isa_lsc"))
    46         val cmd = "exec \"$ISABELLE_GHC\" -fglasgow-exts " ^
    47           (space_implode " " (map File.shell_path [code_file, narrowing_engine_file, main_file])) ^
    48           " -o " ^ executable ^ " && " ^ executable
    49       in
    50         bash_output cmd
    51       end
    52     val result = Isabelle_System.with_tmp_dir tmp_prefix run
    53     val output_value = the_default "NONE"
    54       (try (snd o split_last o filter_out (fn s => s = "") o split_lines o fst) result)
    55     val ml_code = "\nval _ = Context.set_thread_data (SOME (Context.map_proof (" ^ put_ml
    56       ^ " (fn () => " ^ output_value ^ ")) (ML_Context.the_generic_context ())))";
    57     val ctxt' = ctxt
    58       |> put (fn () => error ("Bad evaluation for " ^ quote put_ml))
    59       |> Context.proof_map (exec false ml_code);
    60   in get ctxt' () end;
    61 
    62 fun evaluation cookie thy evaluator vs_t args =
    63   let
    64     val ctxt = ProofContext.init_global thy;
    65     val (program_code, value_name) = evaluator vs_t;
    66     val value_code = space_implode " "
    67       (value_name :: "()" :: map (enclose "(" ")") args);
    68   in Exn.interruptible_capture (value ctxt cookie) (program_code, value_code) end;
    69 
    70 fun dynamic_value_strict cookie thy postproc t args =
    71   let
    72     fun evaluator naming program ((_, vs_ty), t) deps =
    73       evaluation cookie thy (Code_Target.evaluator thy target naming program deps) (vs_ty, t) args;
    74   in Exn.release (Code_Thingol.dynamic_value thy (Exn.map_result o postproc) evaluator t) end;
    75 
    76 (* counterexample generator *)
    77   
    78 structure Counterexample = Proof_Data
    79 (
    80   type T = unit -> term list option
    81   fun init _ () = error "Counterexample"
    82 )
    83 
    84 val put_counterexample =  Counterexample.put
    85   
    86 fun compile_generator_expr ctxt t size =
    87   let
    88     val thy = ProofContext.theory_of ctxt
    89     fun ensure_testable t =
    90       Const (@{const_name Quickcheck_Narrowing.ensure_testable}, fastype_of t --> fastype_of t) $ t
    91     val t = dynamic_value_strict
    92       (Counterexample.get, Counterexample.put, "Narrowing_Generators.put_counterexample")
    93       thy (Option.map o map) (ensure_testable t) []
    94   in
    95     (t, NONE)
    96   end;
    97 
    98 
    99 val setup =
   100   Context.theory_map
   101     (Quickcheck.add_generator ("narrowing", compile_generator_expr))
   102     
   103 end;