(* Title: HOL/Tools/Quickcheck/narrowing_generators.ML
Author: Lukas Bulwahn, TU Muenchen
Narrowing-based counterexample generation
*)
signature NARROWING_GENERATORS =
sig
val compile_generator_expr:
Proof.context -> term -> int -> term list option * Quickcheck.report option
val put_counterexample: (unit -> term list option) -> Proof.context -> Proof.context
val setup: theory -> theory
end;
structure Narrowing_Generators : NARROWING_GENERATORS =
struct
val target = "Haskell"
(* invocation of Haskell interpreter *)
val narrowing_engine = File.read (Path.explode "~~/src/HOL/Tools/Quickcheck/Narrowing_Engine.hs")
fun exec verbose code =
ML_Context.exec (fn () => Secure.use_text ML_Env.local_context (0, "generated code") verbose code)
fun value ctxt (get, put, put_ml) (code, value) =
let
val tmp_prefix = "Quickcheck_Narrowing"
fun run in_path =
let
val code_file = Path.append in_path (Path.basic "Code.hs")
val narrowing_engine_file = Path.append in_path (Path.basic "Narrowing_Engine.hs")
val main_file = Path.append in_path (Path.basic "Main.hs")
val main = "module Main where {\n\n" ^
"import Narrowing_Engine;\n" ^
"import Code;\n\n" ^
"main = Narrowing_Engine.smallCheck 7 (Code.value ())\n\n" ^
"}\n"
val code' = prefix "module Code where {\n\ndata Typerep = Typerep String [Typerep];\n"
(unprefix "module Code where {" code)
val _ = File.write code_file code'
val _ = File.write narrowing_engine_file narrowing_engine
val _ = File.write main_file main
val executable = Path.implode (Path.append in_path (Path.basic "isa_lsc"))
val cmd = getenv "EXEC_GHC" ^ " -fglasgow-exts " ^
(space_implode " " (map Path.implode [code_file, narrowing_engine_file, main_file])) ^
" -o " ^ executable ^ " && " ^ executable
in
bash_output cmd
end
val result = Isabelle_System.with_tmp_dir tmp_prefix run
val output_value = the_default "NONE"
(try (snd o split_last o filter_out (fn s => s = "") o split_lines o fst) result)
val ml_code = "\nval _ = Context.set_thread_data (SOME (Context.map_proof (" ^ put_ml
^ " (fn () => " ^ output_value ^ ")) (ML_Context.the_generic_context ())))";
val ctxt' = ctxt
|> put (fn () => error ("Bad evaluation for " ^ quote put_ml))
|> Context.proof_map (exec false ml_code);
in get ctxt' () end;
fun evaluation cookie thy evaluator vs_t args =
let
val ctxt = ProofContext.init_global thy;
val (program_code, value_name) = evaluator vs_t;
val value_code = space_implode " "
(value_name :: "()" :: map (enclose "(" ")") args);
in Exn.interruptible_capture (value ctxt cookie) (program_code, value_code) end;
fun dynamic_value_strict cookie thy postproc t args =
let
fun evaluator naming program ((_, vs_ty), t) deps =
evaluation cookie thy (Code_Target.evaluator thy target naming program deps) (vs_ty, t) args;
in Exn.release (Code_Thingol.dynamic_value thy (Exn.map_result o postproc) evaluator t) end;
(* counterexample generator *)
structure Counterexample = Proof_Data
(
type T = unit -> term list option
fun init _ () = error "Counterexample"
)
val put_counterexample = Counterexample.put
fun compile_generator_expr ctxt t size =
let
val thy = ProofContext.theory_of ctxt
fun ensure_testable t =
Const (@{const_name Quickcheck_Narrowing.ensure_testable}, fastype_of t --> fastype_of t) $ t
val t = dynamic_value_strict
(Counterexample.get, Counterexample.put, "Narrowing_Generators.put_counterexample")
thy (Option.map o map) (ensure_testable t) []
in
(t, NONE)
end;
val setup =
Context.theory_map
(Quickcheck.add_generator ("narrowing", compile_generator_expr))
end;