(*  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 plural_s : int -> string

  val serial_commas : string -> string list -> string list

  val simplify_spaces : string -> string

  val parse_bool_option : bool -> string -> string -> bool option

  val parse_time_option : string -> string -> Time.time option

  val subgoal_count : Proof.state -> int

  val normalize_chained_theorems : thm list -> thm list

  val reserved_isar_keyword_table : unit -> unit Symtab.table

end;

structure Sledgehammer_Util : SLEDGEHAMMER_UTIL =

struct

open ATP_Util

fun plural_s n = if n = 1 then "" else "s"

val serial_commas = Try.serial_commas

val simplify_spaces = strip_spaces false (K true)

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

val has_junk =

  exists (fn s => not (Symbol.is_digit s) andalso s <> ".") o raw_explode (* FIXME Symbol.explode (?) *)

fun parse_time_option _ "none" = NONE

  | parse_time_option name s =

    let val secs = if has_junk s then NONE else Real.fromString s in

      if is_none secs orelse Real.< (the secs, 0.0) then

        error ("Parameter " ^ quote name ^ " must be assigned a nonnegative \

               \number of seconds (e.g., \"60\", \"0.5\") or \"none\".")

      else

        SOME (seconds (the secs))

    end

val subgoal_count = Try.subgoal_count

val normalize_chained_theorems =

  maps (fn th => insert Thm.eq_thm_prop (zero_var_indexes th) [th])

fun reserved_isar_keyword_table () =

  Keyword.dest () |-> union (op =)

  |> map (rpair ()) |> Symtab.make

end;