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Diffstat (limited to 'proofs/proof_bullet.ml')
| -rw-r--r-- | proofs/proof_bullet.ml | 248 |
1 files changed, 248 insertions, 0 deletions
diff --git a/proofs/proof_bullet.ml b/proofs/proof_bullet.ml new file mode 100644 index 000000000..f80cb7cc6 --- /dev/null +++ b/proofs/proof_bullet.ml @@ -0,0 +1,248 @@ +(************************************************************************) +(* v * The Coq Proof Assistant / The Coq Development Team *) +(* <O___,, * INRIA - CNRS - LIX - LRI - PPS - Copyright 1999-2017 *) +(* \VV/ **************************************************************) +(* // * This file is distributed under the terms of the *) +(* * GNU Lesser General Public License Version 2.1 *) +(************************************************************************) + +open Proof + +type t = Vernacexpr.bullet + +let bullet_eq b1 b2 = match b1, b2 with +| Vernacexpr.Dash n1, Vernacexpr.Dash n2 -> n1 = n2 +| Vernacexpr.Star n1, Vernacexpr.Star n2 -> n1 = n2 +| Vernacexpr.Plus n1, Vernacexpr.Plus n2 -> n1 = n2 +| _ -> false + +let pr_bullet b = + match b with + | Vernacexpr.Dash n -> Pp.(str (String.make n '-')) + | Vernacexpr.Star n -> Pp.(str (String.make n '*')) + | Vernacexpr.Plus n -> Pp.(str (String.make n '+')) + + +type behavior = { + name : string; + put : proof -> t -> proof; + suggest: proof -> Pp.t +} + +let behaviors = Hashtbl.create 4 +let register_behavior b = Hashtbl.add behaviors b.name b + +(*** initial modes ***) +let none = { + name = "None"; + put = (fun x _ -> x); + suggest = (fun _ -> Pp.mt ()) +} +let _ = register_behavior none + +module Strict = struct + type suggestion = + | Suggest of t (* this bullet is mandatory here *) + | Unfinished of t (* no mandatory bullet here, but this bullet is unfinished *) + | NoBulletInUse (* No mandatory bullet (or brace) here, no bullet pending, + some focused goals exists. *) + | NeedClosingBrace (* Some unfocussed goal exists "{" needed to focus them *) + | ProofFinished (* No more goal anywhere *) + + (* give a message only if more informative than the standard coq message *) + let suggest_on_solved_goal sugg = + match sugg with + | NeedClosingBrace -> Pp.(str"Try unfocusing with \"}\".") + | NoBulletInUse -> Pp.mt () + | ProofFinished -> Pp.mt () + | Suggest b -> Pp.(str"Focus next goal with bullet " ++ pr_bullet b ++ str".") + | Unfinished b -> Pp.(str"The current bullet " ++ pr_bullet b ++ str" is unfinished.") + + (* give always a message. *) + let suggest_on_error sugg = + match sugg with + | NeedClosingBrace -> Pp.(str"Try unfocusing with \"}\".") + | NoBulletInUse -> assert false (* This should never raise an error. *) + | ProofFinished -> Pp.(str"No more subgoals.") + | Suggest b -> Pp.(str"Expecting " ++ pr_bullet b ++ str".") + | Unfinished b -> Pp.(str"Current bullet " ++ pr_bullet b ++ str" is not finished.") + + exception FailedBullet of t * suggestion + + let _ = + CErrors.register_handler + (function + | FailedBullet (b,sugg) -> + let prefix = Pp.(str"Wrong bullet " ++ pr_bullet b ++ str": ") in + CErrors.user_err ~hdr:"Focus" Pp.(prefix ++ suggest_on_error sugg) + | _ -> raise CErrors.Unhandled) + + + (* spiwack: we need only one focus kind as we keep a stack of (distinct!) bullets *) + let bullet_kind = (new_focus_kind () : t list focus_kind) + let bullet_cond = done_cond ~loose_end:true bullet_kind + + (* spiwack: as it is bullets are reset (locally) by *any* non-bullet focusing command + experience will tell if this is the right discipline of if we want to be finer and + reset them only for a choice of bullets. *) + let get_bullets pr = + if is_last_focus bullet_kind pr then + get_at_focus bullet_kind pr + else + [] + + let has_bullet bul pr = + let rec has_bullet = function + | b'::_ when bullet_eq bul b' -> true + | _::l -> has_bullet l + | [] -> false + in + has_bullet (get_bullets pr) + + (* pop a bullet from proof [pr]. There should be at least one + bullet in use. If pop impossible (pending proofs on this level + of bullet or higher) then raise [Proof.CannotUnfocusThisWay]. *) + let pop pr = + match get_bullets pr with + | b::_ -> unfocus bullet_kind pr () , b + | _ -> assert false + + let push (b:t) pr = + focus bullet_cond (b::get_bullets pr) 1 pr + + (* Used only in the next function. + TODO: use a recursive function instead? *) + exception SuggestFound of t + + let suggest_bullet (prf : proof): suggestion = + if is_done prf then ProofFinished + else if not (no_focused_goal prf) + then (* No suggestion if a bullet is not mandatory, look for an unfinished bullet *) + match get_bullets prf with + | b::_ -> Unfinished b + | _ -> NoBulletInUse + else (* There is no goal under focus but some are unfocussed, + let us look at the bullet needed. If no *) + let pcobaye = ref prf in + try + while true do + let pcobaye', b = pop !pcobaye in + (* pop went well, this means that there are no more goals + *under this* bullet b, see if a new b can be pushed. *) + (try let _ = push b pcobaye' in (* push didn't fail so a new b can be pushed. *) + raise (SuggestFound b) + with SuggestFound _ as e -> raise e + | _ -> ()); (* b could not be pushed, so we must look for a outer bullet *) + pcobaye := pcobaye' + done; + assert false + with SuggestFound b -> Suggest b + | _ -> NeedClosingBrace (* No push was possible, but there are still + subgoals somewhere: there must be a "}" to use. *) + + + let rec pop_until (prf : proof) bul : proof = + let prf', b = pop prf in + if bullet_eq bul b then prf' + else pop_until prf' bul + + let put p bul = + try + if not (has_bullet bul p) then + (* bullet is not in use, so pushing it is always ok unless + no goal under focus. *) + push bul p + else + match suggest_bullet p with + | Suggest suggested_bullet when bullet_eq bul suggested_bullet + -> (* suggested_bullet is mandatory and you gave the right one *) + let p' = pop_until p bul in + push bul p' + (* the bullet you gave is in use but not the right one *) + | sugg -> raise (FailedBullet (bul,sugg)) + with NoSuchGoals _ -> (* push went bad *) + raise (FailedBullet (bul,suggest_bullet p)) + + let strict = { + name = "Strict Subproofs"; + put = put; + suggest = (fun prf -> suggest_on_solved_goal (suggest_bullet prf)) + + } + let _ = register_behavior strict +end + +(* Current bullet behavior, controlled by the option *) +let current_behavior = ref Strict.strict + +let _ = + Goptions.(declare_string_option { + optdepr = false; + optname = "bullet behavior"; + optkey = ["Bullet";"Behavior"]; + optread = begin fun () -> + (!current_behavior).name + end; + optwrite = begin fun n -> + current_behavior := + try Hashtbl.find behaviors n + with Not_found -> + CErrors.user_err Pp.(str ("Unknown bullet behavior: \"" ^ n ^ "\".")) + end + }) + +let put p b = + (!current_behavior).put p b + +let suggest p = + (!current_behavior).suggest p + +(**********************************************************) +(* *) +(* Default goal selector *) +(* *) +(**********************************************************) + + +(* Default goal selector: selector chosen when a tactic is applied + without an explicit selector. *) +let default_goal_selector = ref (Vernacexpr.SelectNth 1) +let get_default_goal_selector () = !default_goal_selector + +let pr_range_selector (i, j) = + if i = j then Pp.int i + else Pp.(int i ++ str "-" ++ int j) + +let pr_goal_selector = function + | Vernacexpr.SelectAll -> Pp.str "all" + | Vernacexpr.SelectNth i -> Pp.int i + | Vernacexpr.SelectList l -> + Pp.(str "[" + ++ prlist_with_sep pr_comma pr_range_selector l + ++ str "]") + | Vernacexpr.SelectId id -> Names.Id.print id + +let parse_goal_selector = function + | "all" -> Vernacexpr.SelectAll + | i -> + let err_msg = "The default selector must be \"all\" or a natural number." in + begin try + let i = int_of_string i in + if i < 0 then CErrors.user_err Pp.(str err_msg); + Vernacexpr.SelectNth i + with Failure _ -> CErrors.user_err Pp.(str err_msg) + end + +let _ = + Goptions.(declare_string_option{optdepr = false; + optname = "default goal selector" ; + optkey = ["Default";"Goal";"Selector"] ; + optread = begin fun () -> + Pp.string_of_ppcmds + (pr_goal_selector !default_goal_selector) + end; + optwrite = begin fun n -> + default_goal_selector := parse_goal_selector n + end + }) + |