(* Title: HOL/Tools/Sledgehammer/sledgehammer_util.ML
Author: Jasmin Blanchette, TU Muenchen
General-purpose functions used by the Sledgehammer modules.
*)
signature SLEDGEHAMMER_UTIL =
sig
val find_first_in_list_vector : (''a * 'b) list vector -> ''a -> 'b option
val plural_s : int -> string
val serial_commas : string -> string list -> string list
val simplify_spaces : string -> string
val strip_spaces_except_between_ident_chars : string -> string
val parse_bool_option : bool -> string -> string -> bool option
val parse_time_option : string -> string -> Time.time option
val scan_integer : string list -> int * string list
val nat_subscript : int -> string
val unyxml : string -> string
val maybe_quote : string -> string
val monomorphic_term : Type.tyenv -> term -> term
val eta_expand : typ list -> term -> int -> term
val transform_elim_term : term -> term
val specialize_type : theory -> (string * typ) -> term -> term
val subgoal_count : Proof.state -> int
val strip_subgoal : thm -> int -> (string * typ) list * term list * term
val reserved_isar_keyword_table : unit -> unit Symtab.table
end;
structure Sledgehammer_Util : SLEDGEHAMMER_UTIL =
struct
fun find_first_in_list_vector vec key =
Vector.foldl (fn (ps, NONE) => AList.lookup (op =) ps key
| (_, value) => value) NONE vec
fun plural_s n = if n = 1 then "" else "s"
fun serial_commas _ [] = ["??"]
| serial_commas _ [s] = [s]
| serial_commas conj [s1, s2] = [s1, conj, s2]
| serial_commas conj [s1, s2, s3] = [s1 ^ ",", s2 ^ ",", conj, s3]
| serial_commas conj (s :: ss) = s ^ "," :: serial_commas conj ss
fun strip_spaces_in_list _ [] = []
| strip_spaces_in_list _ [c1] = if Char.isSpace c1 then [] else [str c1]
| strip_spaces_in_list is_evil [c1, c2] =
strip_spaces_in_list is_evil [c1] @ strip_spaces_in_list is_evil [c2]
| strip_spaces_in_list is_evil (c1 :: c2 :: c3 :: cs) =
if Char.isSpace c1 then
strip_spaces_in_list is_evil (c2 :: c3 :: cs)
else if Char.isSpace c2 then
if Char.isSpace c3 then
strip_spaces_in_list is_evil (c1 :: c3 :: cs)
else
str c1 :: (if forall is_evil [c1, c3] then [" "] else []) @
strip_spaces_in_list is_evil (c3 :: cs)
else
str c1 :: strip_spaces_in_list is_evil (c2 :: c3 :: cs)
fun strip_spaces is_evil =
implode o strip_spaces_in_list is_evil o String.explode
val simplify_spaces = strip_spaces (K true)
fun is_ident_char c = Char.isAlphaNum c orelse c = #"_"
val strip_spaces_except_between_ident_chars = strip_spaces is_ident_char
fun parse_bool_option option name s =
(case s of
"smart" => if option then NONE else raise Option
| "false" => SOME false
| "true" => SOME true
| "" => SOME true
| _ => raise Option)
handle Option.Option =>
let val ss = map quote ((option ? cons "smart") ["true", "false"]) in
error ("Parameter " ^ quote name ^ " must be assigned " ^
space_implode " " (serial_commas "or" ss) ^ ".")
end
fun parse_time_option _ "none" = NONE
| parse_time_option name s =
let
val msecs =
case space_explode " " s of
[s1, "min"] => 60000 * the (Int.fromString s1)
| [s1, "s"] => 1000 * the (Int.fromString s1)
| [s1, "ms"] => the (Int.fromString s1)
| _ => 0
in
if msecs <= 0 then
error ("Parameter " ^ quote name ^ " must be assigned a positive time \
\value (e.g., \"60 s\", \"200 ms\") or \"none\".")
else
SOME (Time.fromMilliseconds msecs)
end
fun is_head_digit s = Char.isDigit (String.sub (s, 0))
val scan_integer = Scan.many1 is_head_digit >> (the o Int.fromString o implode)
val subscript = implode o map (prefix "\<^isub>") o explode
fun nat_subscript n =
n |> string_of_int |> print_mode_active Symbol.xsymbolsN ? subscript
fun plain_string_from_xml_tree t =
Buffer.empty |> XML.add_content t |> Buffer.content
val unyxml = plain_string_from_xml_tree o YXML.parse
val is_long_identifier = forall Syntax.is_identifier o space_explode "."
fun maybe_quote y =
let val s = unyxml y in
y |> ((not (is_long_identifier (perhaps (try (unprefix "'")) s)) andalso
not (is_long_identifier (perhaps (try (unprefix "?")) s))) orelse
Keyword.is_keyword s) ? quote
end
fun monomorphic_term subst t =
map_types (map_type_tvar (fn v =>
case Type.lookup subst v of
SOME typ => typ
| NONE => raise TERM ("monomorphic_term: uninstanitated schematic type \
\variable", [t]))) t
fun eta_expand _ t 0 = t
| eta_expand Ts (Abs (s, T, t')) n =
Abs (s, T, eta_expand (T :: Ts) t' (n - 1))
| eta_expand Ts t n =
fold_rev (fn T => fn t' => Abs ("x" ^ nat_subscript n, T, t'))
(List.take (binder_types (fastype_of1 (Ts, t)), n))
(list_comb (incr_boundvars n t, map Bound (n - 1 downto 0)))
(* Converts an elim-rule into an equivalent theorem that does not have the
predicate variable. Leaves other theorems unchanged. We simply instantiate
the conclusion variable to False. (Cf. "transform_elim_theorem" in
"Clausifier".) *)
fun transform_elim_term t =
case Logic.strip_imp_concl t of
@{const Trueprop} $ Var (z, @{typ bool}) =>
subst_Vars [(z, @{const False})] t
| Var (z, @{typ prop}) => subst_Vars [(z, @{prop False})] t
| _ => t
fun specialize_type thy (s, T) t =
let
fun subst_for (Const (s', T')) =
if s = s' then
SOME (Sign.typ_match thy (T', T) Vartab.empty)
handle Type.TYPE_MATCH => NONE
else
NONE
| subst_for (t1 $ t2) =
(case subst_for t1 of SOME x => SOME x | NONE => subst_for t2)
| subst_for (Abs (_, _, t')) = subst_for t'
| subst_for _ = NONE
in
case subst_for t of
SOME subst => monomorphic_term subst t
| NONE => raise Type.TYPE_MATCH
end
val subgoal_count = Logic.count_prems o prop_of o #goal o Proof.goal
fun strip_subgoal goal i =
let
val (t, frees) = Logic.goal_params (prop_of goal) i
val hyp_ts = t |> Logic.strip_assums_hyp |> map (curry subst_bounds frees)
val concl_t = t |> Logic.strip_assums_concl |> curry subst_bounds frees
in (rev (map dest_Free frees), hyp_ts, concl_t) end
fun reserved_isar_keyword_table () =
union (op =) (Keyword.dest_keywords ()) (Keyword.dest_commands ())
|> map (rpair ()) |> Symtab.make
end;