From f224e2392dc5f8ccf5791703acd77cd800f077f5 Mon Sep 17 00:00:00 2001
From: Japheth Lim <Japheth.Lim@data61.csiro.au>
Date: Fri, 27 Apr 2018 16:42:47 +1000
Subject: [PATCH] lib: add time_methods method for comparing proof tactic
 speeds

---
 lib/NICTATools.thy       |   1 +
 lib/Time_Methods_Cmd.thy | 131 +++++++++++++++++++++++++++++++++++++++
 2 files changed, 132 insertions(+)
 create mode 100644 lib/Time_Methods_Cmd.thy

diff --git a/lib/NICTATools.thy b/lib/NICTATools.thy
index 2c50a74f5..dcfb4bb2d 100644
--- a/lib/NICTATools.thy
+++ b/lib/NICTATools.thy
@@ -17,6 +17,7 @@ imports
   (* Solves_Tac *)
   Rule_By_Method
   Eisbach_Methods
+  Time_Methods_Cmd
   Insulin
   ShowTypes
   AutoLevity_Hooks
diff --git a/lib/Time_Methods_Cmd.thy b/lib/Time_Methods_Cmd.thy
new file mode 100644
index 000000000..2f50120d3
--- /dev/null
+++ b/lib/Time_Methods_Cmd.thy
@@ -0,0 +1,131 @@
+(*
+ *
+ * Copyright 2018, Data61, CSIRO
+ *
+ * This software may be distributed and modified according to the terms of
+ * the BSD 2-Clause license. Note that NO WARRANTY is provided.
+ * See "LICENSE_BSD2.txt" for details.
+ *
+ * @TAG(DATA61_BSD)
+ *)
+
+theory Time_Methods_Cmd imports
+  Eisbach_Methods
+begin
+
+text \<open>
+  Utility that runs several methods on the same proof goal, printing the
+  running time of each one.
+
+  Usage:
+
+    apply (time_methods [(no_check)]
+        [name1:] \<open>method1\<close>
+        [name2:] \<open>method2\<close>
+        ...)
+
+  See the examples at the end of this theory.
+\<close>
+
+ML {*
+*}
+method_setup time_methods =
+ \<open>
+let
+  (* Work around Isabelle running every apply method on an empty proof state *)
+  fun skip_dummy_state tactic = fn st =>
+      case Thm.prop_of st of
+          Const ("Pure.prop", _) $ (Const ("Pure.term", _) $ Const ("Pure.dummy_pattern", _)) =>
+            Seq.succeed st
+        | _ => tactic st;
+in
+  Scan.lift (Scan.optional (Args.parens (Parse.reserved "no_check") >> K true) false) --
+  Scan.repeat1 (Scan.option (Scan.lift (Parse.liberal_name --| Parse.$$$ ":")) -- Method.text_closure) >>
+  (fn (no_check, maybe_named_methods) => fn ctxt => fn facts => let
+        val named_methods = tag_list 1 maybe_named_methods
+                |> map (fn (i, (maybe_name, method)) =>
+                        case maybe_name of SOME name => (name, method)
+                                         | NONE => ("[method " ^ string_of_int i ^ "]", method))
+        fun tac st = let
+            fun run name method =
+                  Timing.timing (fn () => case method_evaluate method ctxt facts st |> Seq.pull of
+                        NONE => (NONE, Seq.empty)
+                      | SOME (st', sts') => (SOME st', Seq.cons st' sts')) ()
+            val results = named_methods |> map (fn (name, method) =>
+                  let val (time, (st', results)) = run name method
+                      val _ = warning (name ^ ": " ^ Timing.message time)
+                  in {name = name, state = st', results = results} end)
+            val canonical_result = hd results
+            val other_results = tl results
+          in
+            if no_check then #results canonical_result else
+            case other_results |> filter (fn result =>
+                      Option.map Thm.full_prop_of (#state result) <>
+                      Option.map Thm.full_prop_of (#state canonical_result)) of
+                [] => #results canonical_result
+              | (bad::_) => raise THM ("methods \"" ^ #name canonical_result ^
+                                       "\" and \"" ^ #name bad ^ "\" have different results",
+                                       1, the_list (#state canonical_result) @ the_list (#state bad))
+          end
+     in SIMPLE_METHOD (skip_dummy_state tac) [] end)
+end
+\<close>
+
+text \<open>Examples\<close>
+experiment begin
+  lemma
+    "a = b \<Longrightarrow> b = c \<Longrightarrow> a = c"
+    apply (time_methods
+            \<open>rule back_subst[where P="op= a"], assumption+\<close>
+            \<open>rule trans, assumption+\<close>)
+    done
+
+  lemma
+    "a = b \<Longrightarrow> b = c \<Longrightarrow> a = c"
+    apply (time_methods (no_check)
+            \<open>rule back_subst[where P="op= a"]\<close>
+            \<open>rule trans\<close>)
+     text \<open>no_check prevents failing even though the method results differ\<close>
+     apply assumption+
+    done
+
+  text \<open>
+    Fast and slow list reversals
+  \<close>
+  lemma list_eval_rev_append:
+    "rev xs = rev xs @ []"
+    "rev [] @ ys = ys"
+    "rev (x # xs) @ ys = rev xs @ (x # ys)"
+    by auto
+
+  lemma "rev [10..90] = map (op- 100) [10..90]"
+        "rev [10..290] = map (op- 300) [10..290]"
+    text \<open>evaluate everything but @{term rev}\<close>
+    apply (all \<open>match conclusion in "rev x = y" for x y \<Rightarrow>
+                  \<open>rule subst[where t = x], simp\<close>\<close>)
+    apply (all \<open>match conclusion in "rev x = y" for x y \<Rightarrow>
+                  \<open>rule subst[where t = y], simp\<close>\<close>)
+
+    text \<open>evaluate @{term rev}\<close>
+    apply (time_methods
+            simp: \<open>simp\<close>
+            slow: \<open>simp only: rev.simps append.simps\<close>
+            fast: \<open>subst list_eval_rev_append(1), simp only: list_eval_rev_append(2-3)\<close>
+          )
+    apply (time_methods
+            simp: \<open>simp\<close>
+            slow: \<open>simp only: rev.simps append.simps\<close>
+            fast: \<open>subst list_eval_rev_append(1), simp only: list_eval_rev_append(2-3)\<close>
+          )
+    done
+
+
+  text \<open>Other tests\<close>
+
+  lemma "A"
+    -- "simp should fail and time_methods should propagate the failure"
+    apply (fails \<open>time_methods \<open>simp\<close>\<close>)
+    oops
+end
+
+end