lh-l4v/tools/autocorres/record_utils.ML

119 lines
3.3 KiB
Standard ML

(*
* Copyright 2020, Data61, CSIRO (ABN 41 687 119 230)
*
* SPDX-License-Identifier: BSD-2-Clause
*)
(*
* Utiltites for working with HOL records.
*)
structure RecordUtils =
struct
(* Fetch information about a record from the record package. *)
fun get_record_info thy T =
Record.dest_recTs T
|> hd
|> fst
|> Long_Name.explode
|> split_last
|> fst
|> Long_Name.implode
|> Record.the_info thy
(*
* Get the constructor for the given record type; i.e., the constant
* which is used to construct records of this type.
*
* We instantiate the "more" component of the record type to unit.
*
* HACK: This doesn't seem to be the best way of doing this, because we
* rely on the ordering of the "#defs" field of the record_info
* structure.
*)
fun get_record_constructor thy T =
get_record_info thy T |> #ext_def |> Thm.prop_of |> Utils.lhs_of |> head_of
|> Term_Subst.instantiate ([((("'z", 0), @{sort "type"}), @{typ unit})], [])
(*
* Given a record "bar" (assumed to have fields "a", "b", "c" and a
* definition of the form:
*
* foo x y s == bar_ext (f x y s) (f' x y s) (f'' x y s)
*
* generate simps of the form:
*
* a (foo x y s) = f x y s
* b (foo x y s) = f' x y s
* c (foo x y s) = f'' x y s
*
* This allows certain simplifications to occur on the definition
* "foo" without having to expand it.
*)
fun generate_ext_simps name def_thm ctxt =
let
val thy = Proof_Context.theory_of ctxt
(* Determine record type. *)
val T = Thm.prop_of def_thm |> Utils.rhs_of |> head_of |> fastype_of |> body_type
(* Fetch components that make up the new record. *)
val components = Thm.prop_of def_thm |> Utils.rhs_of |> strip_comb |> snd
(* Fetch fields of the record type T. *)
val fields = let
val (a, b) = Record.get_recT_fields thy T
in
a @ [b]
end
(* Generate theorems. *)
fun gen_simp_proof ((field_name, field_type), defn) =
HOLogic.mk_Trueprop (
HOLogic.mk_eq (
Const (field_name, T --> field_type) $ (Thm.prop_of def_thm |> Utils.lhs_of), defn))
|> Thm.cterm_of ctxt
|> Goal.init
|> Utils.apply_tac "solve simple record proof"
(simp_tac (ctxt addsimps [def_thm]) 1)
|> Goal.finish ctxt
val thms = map gen_simp_proof (fields ~~ components)
(* Define the theorem. *)
val lthy = Utils.define_lemmas name thms ctxt |> snd
(* Add new rules to the simpset. *)
val lthy = Local_Theory.map_contexts
(fn _ => Context.proof_map (Simplifier.map_ss (fn x => x addsimps thms))) lthy
in
(thms, lthy)
end
(* Get a record setter from its getter name and type. *)
fun get_record_getter recT (name, T) =
Const (name, recT --> T)
fun get_record_setter recT (name, T) =
Const (name ^ "_update", (T --> T) --> recT --> recT)
(* Get the simpset including all record-based theorems, including simprocs. *)
fun get_record_simpset ctxt =
let
val thy = Proof_Context.theory_of ctxt
val record_ss_1 = Record.get_simpset thy
val record_ss_2 = RecursiveRecordPackage.get_simpset thy
val record_ss = merge_ss (record_ss_1, record_ss_2)
in
(put_simpset record_ss ctxt)
addsimprocs ([
Record.simproc,
Record.upd_simproc,
Record.eq_simproc,
Record.ex_sel_eq_simproc,
Record.split_simproc (K ~1)
])
addsimps (Record.get_extinjects thy)
|> simpset_of
end
end