(************************************************************************) (* v * The Coq Proof Assistant / The Coq Development Team *) (* i+1) solution 0 in let new_el = List.map (fun (t,ty) -> nf t, nf ty) el in let pruned_solution = Evd.drop_all_defined solution in let apply_subst_einfo _ ei = Evd.({ ei with evar_concl = nf ei.evar_concl; evar_hyps = Environ.map_named_val nf ei.evar_hyps; evar_candidates = Option.map (List.map nf) ei.evar_candidates }) in let new_solution = Evd.raw_map_undefined apply_subst_einfo pruned_solution in let new_size = Evd.fold (fun _ _ i -> i+1) new_solution 0 in msg_info (Pp.str (Printf.sprintf "Evars: %d -> %d\n" size new_size)); new_el, { pv with solution = new_solution; } (** {6 Starting and querying a proof view} *) type telescope = | TNil of Evd.evar_map | TCons of Environ.env * Evd.evar_map * Term.types * (Evd.evar_map -> Term.constr -> telescope) let dependent_init = (* Goals are created with a store which marks them as unresolvable for type classes. *) let store = Typeclasses.set_resolvable Evd.Store.empty false in (* Goals don't have a source location. *) let src = (Loc.ghost,Evar_kinds.GoalEvar) in (* Main routine *) let rec aux = function | TNil sigma -> [], { solution = sigma; comb = []; shelf = [] } | TCons (env, sigma, typ, t) -> let (sigma, econstr ) = Evarutil.new_evar env sigma ~src ~store typ in let ret, { solution = sol; comb = comb } = aux (t sigma econstr) in let (gl, _) = Term.destEvar econstr in let entry = (econstr, typ) :: ret in entry, { solution = sol; comb = gl :: comb; shelf = [] } in fun t -> let entry, v = aux t in (* The created goal are not to be shelved. *) let solution = Evd.reset_future_goals v.solution in entry, { v with solution } let init = let rec aux sigma = function | [] -> TNil sigma | (env,g)::l -> TCons (env,sigma,g,(fun sigma _ -> aux sigma l)) in fun sigma l -> dependent_init (aux sigma l) let initial_goals initial = initial let finished = function | {comb = []} -> true | _ -> false let return { solution=defs } = defs let return_constr { solution = defs } c = Evarutil.nf_evar defs c let partial_proof entry pv = CList.map (return_constr pv) (CList.map fst entry) (** {6 Focusing commands} *) (** A [focus_context] represents the part of the proof view which has been removed by a focusing action, it can be used to unfocus later on. *) (* First component is a reverse list of the goals which come before and second component is the list of the goals which go after (in the expected order). *) type focus_context = Evar.t list * Evar.t list (** Returns a stylised view of a focus_context for use by, for instance, ide-s. *) (* spiwack: the type of [focus_context] will change as we push more refined functions to ide-s. This would be better than spawning a new nearly identical function everytime. Hence the generic name. *) (* In this version: the goals in the context, as a "zipper" (the first list is in reversed order). *) let focus_context f = f (** This (internal) function extracts a sublist between two indices, and returns this sublist together with its context: if it returns [(a,(b,c))] then [a] is the sublist and (rev b)@a@c is the original list. The focused list has lenght [j-i-1] and contains the goals from number [i] to number [j] (both included) the first goal of the list being numbered [1]. [focus_sublist i j l] raises [IndexOutOfRange] if [i > length l], or [j > length l] or [j < i]. *) let focus_sublist i j l = let (left,sub_right) = CList.goto (i-1) l in let (sub, right) = try CList.chop (j-i+1) sub_right with Failure _ -> raise CList.IndexOutOfRange in (sub, (left,right)) (** Inverse operation to the previous one. *) let unfocus_sublist (left,right) s = CList.rev_append left (s@right) (** [focus i j] focuses a proofview on the goals from index [i] to index [j] (inclusive, goals are indexed from [1]). I.e. goals number [i] to [j] become the only focused goals of the returned proofview. It returns the focused proofview, and a context for the focus stack. *) let focus i j sp = let (new_comb, context) = focus_sublist i j sp.comb in ( { sp with comb = new_comb } , context ) (** [advance sigma g] returns [Some g'] if [g'] is undefined and is the current avatar of [g] (for instance [g] was changed by [clear] into [g']). It returns [None] if [g] has been (partially) solved. *) (* spiwack: [advance] is probably performance critical, and the good behaviour of its definition may depend sensitively to the actual definition of [Evd.find]. Currently, [Evd.find] starts looking for a value in the heap of undefined variable, which is small. Hence in the most common case, where [advance] is applied to an unsolved goal ([advance] is used to figure if a side effect has modified the goal) it terminates quickly. *) let rec advance sigma g = let open Evd in let evi = Evd.find sigma g in match evi.evar_body with | Evar_empty -> Some g | Evar_defined v -> if Option.default false (Store.get evi.evar_extra Evarutil.cleared) then let (e,_) = Term.destEvar v in advance sigma e else None (** [undefined defs l] is the list of goals in [l] which are still unsolved (after advancing cleared goals). *) let undefined defs l = CList.map_filter (advance defs) l (** Unfocuses a proofview with respect to a context. *) let unfocus c sp = { sp with comb = undefined sp.solution (unfocus_sublist c sp.comb) } (** {6 The tactic monad} *) (** - Tactics are objects which apply a transformation to all the subgoals of the current view at the same time. By opposition to the old vision of applying it to a single goal. It allows tactics such as [shelve_unifiable], tactics to reorder the focused goals, or global automation tactic for dependent subgoals (instantiating an evar has influences on the other goals of the proof in progress, not being able to take that into account causes the current eauto tactic to fail on some instances where it could succeed). Another benefit is that it is possible to write tactics that can be executed even if there are no focused goals. - Tactics form a monad ['a tactic], in a sense a tactic can be seen as a function (without argument) which returns a value of type 'a and modifies the environment (in our case: the view). Tactics of course have arguments, but these are given at the meta-level as OCaml functions. Most tactics in the sense we are used to return [()], that is no really interesting values. But some might pass information around. The tactics seen in Coq's Ltac are (for now at least) only [unit tactic], the return values are kept for the OCaml toolkit. The operation or the monad are [Proofview.tclUNIT] (which is the "return" of the tactic monad) [Proofview.tclBIND] (which is the "bind") and [Proofview.tclTHEN] (which is a specialized bind on unit-returning tactics). - Tactics have support for full-backtracking. Tactics can be seen having multiple success: if after returning the first success a failure is encountered, the tactic can backtrack and use a second success if available. The state is backtracked to its previous value, except the non-logical state defined in the {!NonLogical} module below. *) (* spiwack: as far as I'm aware this doesn't really relate to F. Kirchner and C. Muñoz. *) module Proof = Logical (** type of tactics: tactics can - access the environment, - report unsafe status, shelved goals and given up goals - access and change the current [proofview] - backtrack on previous changes of the proofview *) type +'a tactic = 'a Proof.t (** Applies a tactic to the current proofview. *) let apply env t sp = let open Logic_monad in let ans = Proof.repr (Proof.run t false (sp,env)) in let ans = Logic_monad.NonLogical.run ans in match ans with | Nil (e, info) -> iraise (TacticFailure e, info) | Cons ((r, (state, _), status, info), _) -> let (status, gaveup) = status in let status = (status, state.shelf, gaveup) in let state = { state with shelf = [] } in r, state, status, Trace.to_tree info (** {7 Monadic primitives} *) (** Unit of the tactic monad. *) let tclUNIT = Proof.return (** Bind operation of the tactic monad. *) let tclBIND = Proof.(>>=) (** Interpretes the ";" (semicolon) of Ltac. As a monadic operation, it's a specialized "bind". *) let tclTHEN = Proof.(>>) (** [tclIGNORE t] has the same operational content as [t], but drops the returned value. *) let tclIGNORE = Proof.ignore module Monad = Proof (** {7 Failure and backtracking} *) (** [tclZERO e] fails with exception [e]. It has no success. *) let tclZERO ?info e = let info = match info with | None -> Exninfo.null | Some info -> info in Proof.zero (e, info) (** [tclOR t1 t2] behaves like [t1] as long as [t1] succeeds. Whenever the successes of [t1] have been depleted and it failed with [e], then it behaves as [t2 e]. In other words, [tclOR] inserts a backtracking point. *) let tclOR = Proof.plus (** [tclORELSE t1 t2] is equal to [t1] if [t1] has at least one success or [t2 e] if [t1] fails with [e]. It is analogous to [try/with] handler of exception in that it is not a backtracking point. *) let tclORELSE t1 t2 = let open Logic_monad in let open Proof in split t1 >>= function | Nil e -> t2 e | Cons (a,t1') -> plus (return a) t1' (** [tclIFCATCH a s f] is a generalisation of {!tclORELSE}: if [a] succeeds at least once then it behaves as [tclBIND a s] otherwise, if [a] fails with [e], then it behaves as [f e]. *) let tclIFCATCH a s f = let open Logic_monad in let open Proof in split a >>= function | Nil e -> f e | Cons (x,a') -> plus (s x) (fun e -> (a' e) >>= fun x' -> (s x')) (** [tclONCE t] behave like [t] except it has at most one success: [tclONCE t] stops after the first success of [t]. If [t] fails with [e], [tclONCE t] also fails with [e]. *) let tclONCE = Proof.once exception MoreThanOneSuccess let _ = Errors.register_handler begin function | MoreThanOneSuccess -> Errors.error "This tactic has more than one success." | _ -> raise Errors.Unhandled end (** [tclEXACTLY_ONCE e t] succeeds as [t] if [t] has exactly one success. Otherwise it fails. The tactic [t] is run until its first success, then a failure with exception [e] is simulated. It [t] yields another success, then [tclEXACTLY_ONCE e t] fails with [MoreThanOneSuccess] (it is a user error). Otherwise, [tclEXACTLY_ONCE e t] succeeds with the first success of [t]. Notice that the choice of [e] is relevant, as the presence of further successes may depend on [e] (see {!tclOR}). *) let tclEXACTLY_ONCE e t = let open Logic_monad in let open Proof in split t >>= function | Nil (e, info) -> tclZERO ~info e | Cons (x,k) -> Proof.split (k (e, Exninfo.null)) >>= function | Nil _ -> tclUNIT x | _ -> tclZERO MoreThanOneSuccess (** [tclCASE t] wraps the {!Proofview_monad.Logical.split} primitive. *) type 'a case = | Fail of iexn | Next of 'a * (iexn -> 'a tactic) let tclCASE t = let open Logic_monad in let map = function | Nil e -> Fail e | Cons (x, t) -> Next (x, t) in Proof.map map (Proof.split t) let tclBREAK = Proof.break (** {7 Focusing tactics} *) exception NoSuchGoals of int (* This hook returns a string to be appended to the usual message. Primarily used to add a suggestion about the right bullet to use to focus the next goal, if applicable. *) let nosuchgoals_hook:(int -> string option) ref = ref ((fun n -> None)) let set_nosuchgoals_hook f = nosuchgoals_hook := f (* This uses the hook above *) let _ = Errors.register_handler begin function | NoSuchGoals n -> let suffix:string option = (!nosuchgoals_hook) n in Errors.errorlabstrm "" (str "No such " ++ str (String.plural n "goal") ++ str "." ++ pr_opt str suffix) | _ -> raise Errors.Unhandled end (** [tclFOCUS_gen nosuchgoal i j t] applies [t] in a context where only the goals numbered [i] to [j] are focused (the rest of the goals is restored at the end of the tactic). If the range [i]-[j] is not valid, then it [tclFOCUS_gen nosuchgoal i j t] is [nosuchgoal]. *) let tclFOCUS_gen nosuchgoal i j t = let open Proof in Pv.get >>= fun initial -> try let (focused,context) = focus i j initial in Pv.set focused >> t >>= fun result -> Pv.modify (fun next -> unfocus context next) >> return result with CList.IndexOutOfRange -> nosuchgoal let tclFOCUS i j t = tclFOCUS_gen (tclZERO (NoSuchGoals (j+1-i))) i j t let tclTRYFOCUS i j t = tclFOCUS_gen (tclUNIT ()) i j t (** Like {!tclFOCUS} but selects a single goal by name. *) let tclFOCUSID id t = let open Proof in Pv.get >>= fun initial -> try let ev = Evd.evar_key id initial.solution in try let n = CList.index Evar.equal ev initial.comb in (* goal is already under focus *) let (focused,context) = focus n n initial in Pv.set focused >> t >>= fun result -> Pv.modify (fun next -> unfocus context next) >> return result with Not_found -> (* otherwise, save current focus and work purely on the shelve *) Comb.set [ev] >> t >>= fun result -> Comb.set initial.comb >> return result with Not_found -> tclZERO (NoSuchGoals 1) (** {7 Dispatching on goals} *) exception SizeMismatch of int*int let _ = Errors.register_handler begin function | SizeMismatch (i,_) -> let open Pp in let errmsg = str"Incorrect number of goals" ++ spc() ++ str"(expected "++int i++str(String.plural i " tactic") ++ str")." in Errors.errorlabstrm "" errmsg | _ -> raise Errors.Unhandled end (** A variant of [Monad.List.iter] where we iter over the focused list of goals. The argument tactic is executed in a focus comprising only of the current goal, a goal which has been solved by side effect is skipped. The generated subgoals are concatenated in order. *) let iter_goal i = let open Proof in Comb.get >>= fun initial -> Proof.List.fold_left begin fun (subgoals as cur) goal -> Solution.get >>= fun step -> match advance step goal with | None -> return cur | Some goal -> Comb.set [goal] >> i goal >> Proof.map (fun comb -> comb :: subgoals) Comb.get end [] initial >>= fun subgoals -> Solution.get >>= fun evd -> Comb.set CList.(undefined evd (flatten (rev subgoals))) (** A variant of [Monad.List.fold_left2] where the first list is the list of focused goals. The argument tactic is executed in a focus comprising only of the current goal, a goal which has been solved by side effect is skipped. The generated subgoals are concatenated in order. *) let fold_left2_goal i s l = let open Proof in Pv.get >>= fun initial -> let err = return () >>= fun () -> (* Delay the computation of list lengths. *) tclZERO (SizeMismatch (CList.length initial.comb,CList.length l)) in Proof.List.fold_left2 err begin fun ((r,subgoals) as cur) goal a -> Solution.get >>= fun step -> match advance step goal with | None -> return cur | Some goal -> Comb.set [goal] >> i goal a r >>= fun r -> Proof.map (fun comb -> (r, comb :: subgoals)) Comb.get end (s,[]) initial.comb l >>= fun (r,subgoals) -> Solution.get >>= fun evd -> Comb.set CList.(undefined evd (flatten (rev subgoals))) >> return r (** Dispatch tacticals are used to apply a different tactic to each goal under focus. They come in two flavours: [tclDISPATCH] takes a list of [unit tactic]-s and build a [unit tactic]. [tclDISPATCHL] takes a list of ['a tactic] and returns an ['a list tactic]. They both work by applying each of the tactic in a focus restricted to the corresponding goal (starting with the first goal). In the case of [tclDISPATCHL], the tactic returns a list of the same size as the argument list (of tactics), each element being the result of the tactic executed in the corresponding goal. When the length of the tactic list is not the number of goal, raises [SizeMismatch (g,t)] where [g] is the number of available goals, and [t] the number of tactics passed. [tclDISPATCHGEN join tacs] generalises both functions as the successive results of [tacs] are stored in reverse order in a list, and [join] is used to convert the result into the expected form. *) let tclDISPATCHGEN0 join tacs = match tacs with | [] -> begin let open Proof in Comb.get >>= function | [] -> tclUNIT (join []) | comb -> tclZERO (SizeMismatch (CList.length comb,0)) end | [tac] -> begin let open Proof in Pv.get >>= function | { comb=[goal] ; solution } -> begin match advance solution goal with | None -> tclUNIT (join []) | Some _ -> Proof.map (fun res -> join [res]) tac end | {comb} -> tclZERO (SizeMismatch(CList.length comb,1)) end | _ -> let iter _ t cur = Proof.map (fun y -> y :: cur) t in let ans = fold_left2_goal iter [] tacs in Proof.map join ans let tclDISPATCHGEN join tacs = let branch t = InfoL.tag (Info.DBranch) t in let tacs = CList.map branch tacs in InfoL.tag (Info.Dispatch) (tclDISPATCHGEN0 join tacs) let tclDISPATCH tacs = tclDISPATCHGEN Pervasives.ignore tacs let tclDISPATCHL tacs = tclDISPATCHGEN CList.rev tacs (** [extend_to_list startxs rx endxs l] builds a list [startxs@[rx,...,rx]@endxs] of the same length as [l]. Raises [SizeMismatch] if [startxs@endxs] is already longer than [l]. *) let extend_to_list startxs rx endxs l = (* spiwack: I use [l] essentially as a natural number *) let rec duplicate acc = function | [] -> acc | _::rest -> duplicate (rx::acc) rest in let rec tail to_match rest = match rest, to_match with | [] , _::_ -> raise (SizeMismatch(0,0)) (* placeholder *) | _::rest , _::to_match -> tail to_match rest | _ , [] -> duplicate endxs rest in let rec copy pref rest = match rest,pref with | [] , _::_ -> raise (SizeMismatch(0,0)) (* placeholder *) | _::rest, a::pref -> a::(copy pref rest) | _ , [] -> tail endxs rest in copy startxs l (** [tclEXTEND b r e] is a variant of {!tclDISPATCH}, where the [r] tactic is "repeated" enough time such that every goal has a tactic assigned to it ([b] is the list of tactics applied to the first goals, [e] to the last goals, and [r] is applied to every goal in between). *) let tclEXTEND tacs1 rtac tacs2 = let open Proof in Comb.get >>= fun comb -> try let tacs = extend_to_list tacs1 rtac tacs2 comb in tclDISPATCH tacs with SizeMismatch _ -> tclZERO (SizeMismatch( CList.length comb, (CList.length tacs1)+(CList.length tacs2))) (* spiwack: failure occurs only when the number of goals is too small. Hence we can assume that [rtac] is replicated 0 times for any error message. *) (** [tclEXTEND [] tac []]. *) let tclINDEPENDENT tac = let open Proof in Pv.get >>= fun initial -> match initial.comb with | [] -> tclUNIT () | [_] -> tac | _ -> let tac = InfoL.tag (Info.DBranch) tac in InfoL.tag (Info.Dispatch) (iter_goal (fun _ -> tac)) (** {7 Goal manipulation} *) (** Shelves all the goals under focus. *) let shelve = let open Proof in Comb.get >>= fun initial -> Comb.set [] >> InfoL.leaf (Info.Tactic (fun () -> Pp.str"shelve")) >> Shelf.modify (fun gls -> gls @ initial) (** [contained_in_info e evi] checks whether the evar [e] appears in the hypotheses, the conclusion or the body of the evar_info [evi]. Note: since we want to use it on goals, the body is actually supposed to be empty. *) let contained_in_info sigma e evi = Evar.Set.mem e (Evd.evars_of_filtered_evar_info (Evarutil.nf_evar_info sigma evi)) (** [depends_on sigma src tgt] checks whether the goal [src] appears as an existential variable in the definition of the goal [tgt] in [sigma]. *) let depends_on sigma src tgt = let evi = Evd.find sigma tgt in contained_in_info sigma src evi (** [unifiable sigma g l] checks whether [g] appears in another subgoal of [l]. The list [l] may contain [g], but it does not affect the result. *) let unifiable sigma g l = CList.exists (fun tgt -> not (Evar.equal g tgt) && depends_on sigma g tgt) l (** [partition_unifiable sigma l] partitions [l] into a pair [(u,n)] where [u] is composed of the unifiable goals, i.e. the goals on whose definition other goals of [l] depend, and [n] are the non-unifiable goals. *) let partition_unifiable sigma l = CList.partition (fun g -> unifiable sigma g l) l (** Shelves the unifiable goals under focus, i.e. the goals which appear in other goals under focus (the unfocused goals are not considered). *) let shelve_unifiable = let open Proof in Pv.get >>= fun initial -> let (u,n) = partition_unifiable initial.solution initial.comb in Comb.set n >> InfoL.leaf (Info.Tactic (fun () -> Pp.str"shelve_unifiable")) >> Shelf.modify (fun gls -> gls @ u) (** [guard_no_unifiable] fails with error [UnresolvedBindings] if some goals are unifiable (see {!shelve_unifiable}) in the current focus. *) let guard_no_unifiable = let open Proof in Pv.get >>= fun initial -> let (u,n) = partition_unifiable initial.solution initial.comb in match u with | [] -> tclUNIT () | gls -> let l = CList.map (fun g -> Evd.dependent_evar_ident g initial.solution) gls in let l = CList.map (fun id -> Names.Name id) l in tclZERO (Logic.RefinerError (Logic.UnresolvedBindings l)) (** [unshelve l p] adds all the goals in [l] at the end of the focused goals of p *) let unshelve l p = (* advance the goals in case of clear *) let l = undefined p.solution l in { p with comb = p.comb@l } let with_shelf tac = let open Proof in Pv.get >>= fun pv -> let { shelf; solution } = pv in Pv.set { pv with shelf = []; solution = Evd.reset_future_goals solution } >> tac >>= fun ans -> Pv.get >>= fun npv -> let { shelf = gls; solution = sigma } = npv in let gls' = Evd.future_goals sigma in let fgoals = Evd.future_goals solution in let pgoal = Evd.principal_future_goal solution in let sigma = Evd.restore_future_goals sigma fgoals pgoal in Pv.set { npv with shelf; solution = sigma } >> tclUNIT (CList.rev_append gls' gls, ans) (** [goodmod p m] computes the representative of [p] modulo [m] in the interval [[0,m-1]].*) let goodmod p m = let p' = p mod m in (* if [n] is negative [n mod l] is negative of absolute value less than [l], so [(n mod l)+l] is the representative of [n] in the interval [[0,l-1]].*) if p' < 0 then p'+m else p' let cycle n = let open Proof in InfoL.leaf (Info.Tactic (fun () -> Pp.(str"cycle "++int n))) >> Comb.modify begin fun initial -> let l = CList.length initial in let n' = goodmod n l in let (front,rear) = CList.chop n' initial in rear@front end let swap i j = let open Proof in InfoL.leaf (Info.Tactic (fun () -> Pp.(hov 2 (str"swap"++spc()++int i++spc()++int j)))) >> Comb.modify begin fun initial -> let l = CList.length initial in let i = if i>0 then i-1 else i and j = if j>0 then j-1 else j in let i = goodmod i l and j = goodmod j l in CList.map_i begin fun k x -> match k with | k when Int.equal k i -> CList.nth initial j | k when Int.equal k j -> CList.nth initial i | _ -> x end 0 initial end let revgoals = let open Proof in InfoL.leaf (Info.Tactic (fun () -> Pp.str"revgoals")) >> Comb.modify CList.rev let numgoals = let open Proof in Comb.get >>= fun comb -> return (CList.length comb) (** {7 Access primitives} *) let tclEVARMAP = Solution.get let tclENV = Env.get (** {7 Put-like primitives} *) let emit_side_effects eff x = { x with solution = Evd.emit_side_effects eff x.solution } let tclEFFECTS eff = let open Proof in return () >>= fun () -> (* The Global.env should be taken at exec time *) Env.set (Global.env ()) >> Pv.modify (fun initial -> emit_side_effects eff initial) let mark_as_unsafe = Status.put false (** Gives up on the goal under focus. Reports an unsafe status. Proofs with given up goals cannot be closed. *) let give_up = let open Proof in Comb.get >>= fun initial -> Comb.set [] >> mark_as_unsafe >> InfoL.leaf (Info.Tactic (fun () -> Pp.str"give_up")) >> Giveup.put initial (** {7 Control primitives} *) module Progress = struct let eq_constr = Evarutil.eq_constr_univs_test (** equality function on hypothesis contexts *) let eq_named_context_val sigma1 sigma2 ctx1 ctx2 = let open Environ in let c1 = named_context_of_val ctx1 and c2 = named_context_of_val ctx2 in let eq_named_declaration (i1, c1, t1) (i2, c2, t2) = Names.Id.equal i1 i2 && Option.equal (eq_constr sigma1 sigma2) c1 c2 && (eq_constr sigma1 sigma2) t1 t2 in List.equal eq_named_declaration c1 c2 let eq_evar_body sigma1 sigma2 b1 b2 = let open Evd in match b1, b2 with | Evar_empty, Evar_empty -> true | Evar_defined t1, Evar_defined t2 -> eq_constr sigma1 sigma2 t1 t2 | _ -> false let eq_evar_info sigma1 sigma2 ei1 ei2 = let open Evd in eq_constr sigma1 sigma2 ei1.evar_concl ei2.evar_concl && eq_named_context_val sigma1 sigma2 (ei1.evar_hyps) (ei2.evar_hyps) && eq_evar_body sigma1 sigma2 ei1.evar_body ei2.evar_body (** Equality function on goals *) let goal_equal evars1 gl1 evars2 gl2 = let evi1 = Evd.find evars1 gl1 in let evi2 = Evd.find evars2 gl2 in eq_evar_info evars1 evars2 evi1 evi2 end let tclPROGRESS t = let open Proof in Pv.get >>= fun initial -> t >>= fun res -> Pv.get >>= fun final -> (* [*_test] test absence of progress. [quick_test] is approximate whereas [exhaustive_test] is complete. *) let quick_test = initial.solution == final.solution && initial.comb == final.comb in let exhaustive_test = Util.List.for_all2eq begin fun i f -> Progress.goal_equal initial.solution i final.solution f end initial.comb final.comb in let test = quick_test || exhaustive_test in if not test then tclUNIT res else tclZERO (Errors.UserError ("Proofview.tclPROGRESS" , Pp.str"Failed to progress.")) exception Timeout let _ = Errors.register_handler begin function | Timeout -> Errors.errorlabstrm "Proofview.tclTIMEOUT" (Pp.str"Tactic timeout!") | _ -> Pervasives.raise Errors.Unhandled end let tclTIMEOUT n t = let open Proof in (* spiwack: as one of the monad is a continuation passing monad, it doesn't force the computation to be threaded inside the underlying (IO) monad. Hence I force it myself by asking for the evaluation of a dummy value first, lest [timeout] be called when everything has already been computed. *) let t = Proof.lift (Logic_monad.NonLogical.return ()) >> t in Proof.get >>= fun initial -> Proof.current >>= fun envvar -> Proof.lift begin Logic_monad.NonLogical.catch begin let open Logic_monad.NonLogical in timeout n (Proof.repr (Proof.run t envvar initial)) >>= fun r -> match r with | Logic_monad.Nil e -> return (Util.Inr e) | Logic_monad.Cons (r, _) -> return (Util.Inl r) end begin let open Logic_monad.NonLogical in function (e, info) -> match e with | Logic_monad.Timeout -> return (Util.Inr (Timeout, info)) | Logic_monad.TacticFailure e -> return (Util.Inr (e, info)) | e -> Logic_monad.NonLogical.raise ~info e end end >>= function | Util.Inl (res,s,m,i) -> Proof.set s >> Proof.put m >> Proof.update (fun _ -> i) >> return res | Util.Inr (e, info) -> tclZERO ~info e let tclTIME s t = let pr_time t1 t2 n msg = let msg = if n = 0 then str msg else str (msg ^ " after ") ++ int n ++ str (String.plural n " backtracking") in msg_info(str "Tactic call" ++ pr_opt str s ++ str " ran for " ++ System.fmt_time_difference t1 t2 ++ str " " ++ surround msg) in let rec aux n t = let open Proof in tclUNIT () >>= fun () -> let tstart = System.get_time() in Proof.split t >>= let open Logic_monad in function | Nil (e, info) -> begin let tend = System.get_time() in pr_time tstart tend n "failure"; tclZERO ~info e end | Cons (x,k) -> let tend = System.get_time() in pr_time tstart tend n "success"; tclOR (tclUNIT x) (fun e -> aux (n+1) (k e)) in aux 0 t (** {7 Unsafe primitives} *) module Unsafe = struct let tclEVARS evd = Pv.modify (fun ps -> { ps with solution = evd }) let tclNEWGOALS gls = Pv.modify begin fun step -> let gls = undefined step.solution gls in { step with comb = step.comb @ gls } end let tclGETGOALS = Comb.get let tclSETGOALS = Comb.set let tclEVARSADVANCE evd = Pv.modify (fun ps -> { ps with solution = evd; comb = undefined evd ps.comb }) let tclEVARUNIVCONTEXT ctx = Pv.modify (fun ps -> { ps with solution = Evd.set_universe_context ps.solution ctx }) let reset_future_goals p = { p with solution = Evd.reset_future_goals p.solution } let mark_as_goal_evm evd content = let info = Evd.find evd content in let info = { info with Evd.evar_source = match info.Evd.evar_source with | _, (Evar_kinds.VarInstance _ | Evar_kinds.GoalEvar) as x -> x | loc,_ -> loc,Evar_kinds.GoalEvar } in let info = Typeclasses.mark_unresolvable info in Evd.add evd content info let mark_as_goal p gl = { p with solution = mark_as_goal_evm p.solution gl } end (** {7 Notations} *) module Notations = struct let (>>=) = tclBIND let (<*>) = tclTHEN let (<+>) t1 t2 = tclOR t1 (fun _ -> t2) end open Notations (** {6 Goal-dependent tactics} *) (* To avoid shadowing by the local [Goal] module *) module GoalV82 = Goal.V82 let catchable_exception = function | Logic_monad.Exception _ -> false | e -> Errors.noncritical e module Goal = struct type 'a t = { env : Environ.env; sigma : Evd.evar_map; concl : Term.constr ; self : Evar.t ; (* for compatibility with old-style definitions *) } let assume (gl : 'a t) = (gl :> [ `NF ] t) let env { env=env } = env let sigma { sigma=sigma } = sigma let hyps { env=env } = Environ.named_context env let concl { concl=concl } = concl let extra { sigma=sigma; self=self } = Goal.V82.extra sigma self let raw_concl { concl=concl } = concl let gmake_with info env sigma goal = { env = Environ.reset_with_named_context (Evd.evar_filtered_hyps info) env ; sigma = sigma ; concl = Evd.evar_concl info ; self = goal } let nf_gmake env sigma goal = let info = Evarutil.nf_evar_info sigma (Evd.find sigma goal) in let sigma = Evd.add sigma goal info in gmake_with info env sigma goal , sigma let nf_enter f = InfoL.tag (Info.Dispatch) begin iter_goal begin fun goal -> Env.get >>= fun env -> tclEVARMAP >>= fun sigma -> try let (gl, sigma) = nf_gmake env sigma goal in tclTHEN (Unsafe.tclEVARS sigma) (InfoL.tag (Info.DBranch) (f gl)) with e when catchable_exception e -> let (e, info) = Errors.push e in tclZERO ~info e end end let normalize { self } = Env.get >>= fun env -> tclEVARMAP >>= fun sigma -> let (gl,sigma) = nf_gmake env sigma self in tclTHEN (Unsafe.tclEVARS sigma) (tclUNIT gl) let gmake env sigma goal = let info = Evd.find sigma goal in gmake_with info env sigma goal let enter f = let f gl = InfoL.tag (Info.DBranch) (f gl) in InfoL.tag (Info.Dispatch) begin iter_goal begin fun goal -> Env.get >>= fun env -> tclEVARMAP >>= fun sigma -> try f (gmake env sigma goal) with e when catchable_exception e -> let (e, info) = Errors.push e in tclZERO ~info e end end let goals = Env.get >>= fun env -> Pv.get >>= fun step -> let sigma = step.solution in let map goal = match advance sigma goal with | None -> None (** ppedrot: Is this check really necessary? *) | Some goal -> let gl = tclEVARMAP >>= fun sigma -> tclUNIT (gmake env sigma goal) in Some gl in tclUNIT (CList.map_filter map step.comb) (* compatibility *) let goal { self=self } = self end (** {6 The refine tactic} *) module Refine = struct let extract_prefix env info = let ctx1 = List.rev (Environ.named_context env) in let ctx2 = List.rev (Evd.evar_context info) in let rec share l1 l2 accu = match l1, l2 with | d1 :: l1, d2 :: l2 -> if d1 == d2 then share l1 l2 (d1 :: accu) else (accu, d2 :: l2) | _ -> (accu, l2) in share ctx1 ctx2 [] let typecheck_evar ev env sigma = let info = Evd.find sigma ev in (** Typecheck the hypotheses. *) let type_hyp (sigma, env) (na, body, t as decl) = let evdref = ref sigma in let _ = Typing.sort_of env evdref t in let () = match body with | None -> () | Some body -> Typing.check env evdref body t in (!evdref, Environ.push_named decl env) in let (common, changed) = extract_prefix env info in let env = Environ.reset_with_named_context (Environ.val_of_named_context common) env in let (sigma, env) = List.fold_left type_hyp (sigma, env) changed in (** Typecheck the conclusion *) let evdref = ref sigma in let _ = Typing.sort_of env evdref (Evd.evar_concl info) in !evdref let typecheck_proof c concl env sigma = let evdref = ref sigma in let () = Typing.check env evdref c concl in !evdref let (pr_constrv,pr_constr) = Hook.make ~default:(fun _env _sigma _c -> Pp.str"") () let refine ?(unsafe = true) f = Goal.enter begin fun gl -> let sigma = Goal.sigma gl in let env = Goal.env gl in let concl = Goal.concl gl in (** Save the [future_goals] state to restore them after the refinement. *) let prev_future_goals = Evd.future_goals sigma in let prev_principal_goal = Evd.principal_future_goal sigma in (** Create the refinement term *) let (sigma, c) = f (Evd.reset_future_goals sigma) in let evs = Evd.future_goals sigma in let evkmain = Evd.principal_future_goal sigma in (** Check that the introduced evars are well-typed *) let fold accu ev = typecheck_evar ev env accu in let sigma = if unsafe then sigma else CList.fold_left fold sigma evs in (** Check that the refined term is typesafe *) let sigma = if unsafe then sigma else typecheck_proof c concl env sigma in (** Check that the goal itself does not appear in the refined term *) let _ = if not (Evarutil.occur_evar_upto sigma gl.Goal.self c) then () else Pretype_errors.error_occur_check env sigma gl.Goal.self c in (** Proceed to the refinement *) let sigma = match evkmain with | None -> Evd.define gl.Goal.self c sigma | Some evk -> let id = Evd.evar_ident gl.Goal.self sigma in Evd.rename evk id (Evd.define gl.Goal.self c sigma) in (** Restore the [future goals] state. *) let sigma = Evd.restore_future_goals sigma prev_future_goals prev_principal_goal in (** Select the goals *) let comb = undefined sigma (CList.rev evs) in let sigma = CList.fold_left Unsafe.mark_as_goal_evm sigma comb in let open Proof in InfoL.leaf (Info.Tactic (fun () -> Pp.(hov 2 (str"refine"++spc()++ Hook.get pr_constrv env sigma c)))) >> Pv.modify (fun ps -> { ps with solution = sigma; comb; }) end (** Useful definitions *) let with_type env evd c t = let my_type = Retyping.get_type_of env evd c in let j = Environ.make_judge c my_type in let (evd,j') = Coercion.inh_conv_coerce_to true (Loc.ghost) env evd j t in evd , j'.Environ.uj_val let refine_casted ?unsafe f = Goal.enter begin fun gl -> let concl = Goal.concl gl in let env = Goal.env gl in let f h = let (h, c) = f h in with_type env h c concl in refine ?unsafe f end end (** {6 Trace} *) module Trace = struct let record_info_trace = InfoL.record_trace let log m = InfoL.leaf (Info.Msg m) let name_tactic m t = InfoL.tag (Info.Tactic m) t let pr_info ?(lvl=0) info = assert (lvl >= 0); Info.(print (collapse lvl info)) end (** {6 Non-logical state} *) module NonLogical = Logic_monad.NonLogical let tclLIFT = Proof.lift let tclCHECKINTERRUPT = tclLIFT (NonLogical.make Control.check_for_interrupt) (*** Compatibility layer with <= 8.2 tactics ***) module V82 = struct type tac = Evar.t Evd.sigma -> Evar.t list Evd.sigma let tactic tac = (* spiwack: we ignore the dependencies between goals here, expectingly preserving the semantics of <= 8.2 tactics *) (* spiwack: convenience notations, waiting for ocaml 3.12 *) let open Proof in Pv.get >>= fun ps -> try let tac gl evd = let glsigma = tac { Evd.it = gl ; sigma = evd; } in let sigma = glsigma.Evd.sigma in let g = glsigma.Evd.it in ( g, sigma ) in (* Old style tactics expect the goals normalized with respect to evars. *) let (initgoals,initevd) = Evd.Monad.List.map (fun g s -> GoalV82.nf_evar s g) ps.comb ps.solution in let (goalss,evd) = Evd.Monad.List.map tac initgoals initevd in let sgs = CList.flatten goalss in let sgs = undefined evd sgs in InfoL.leaf (Info.Tactic (fun () -> Pp.str"")) >> Pv.set { ps with solution = evd; comb = sgs; } with e when catchable_exception e -> let (e, info) = Errors.push e in tclZERO ~info e (* normalises the evars in the goals, and stores the result in solution. *) let nf_evar_goals = Pv.modify begin fun ps -> let map g s = GoalV82.nf_evar s g in let (goals,evd) = Evd.Monad.List.map map ps.comb ps.solution in { ps with solution = evd; comb = goals; } end let has_unresolved_evar pv = Evd.has_undefined pv.solution (* Main function in the implementation of Grab Existential Variables.*) let grab pv = let undef = Evd.undefined_map pv.solution in let goals = CList.rev_map fst (Evar.Map.bindings undef) in { pv with comb = goals } (* Returns the open goals of the proofview together with the evar_map to interpret them. *) let goals { comb = comb ; solution = solution; } = { Evd.it = comb ; sigma = solution } let top_goals initial { solution=solution; } = let goals = CList.map (fun (t,_) -> fst (Term.destEvar t)) initial in { Evd.it = goals ; sigma=solution; } let top_evars initial = let evars_of_initial (c,_) = Evar.Set.elements (Evd.evars_of_term c) in CList.flatten (CList.map evars_of_initial initial) let instantiate_evar n com pv = let (evk,_) = let evl = Evarutil.non_instantiated pv.solution in let evl = Evar.Map.bindings evl in if (n <= 0) then Errors.error "incorrect existential variable index" else if CList.length evl < n then Errors.error "not so many uninstantiated existential variables" else CList.nth evl (n-1) in { pv with solution = Evar_refiner.instantiate_pf_com evk com pv.solution } let of_tactic t gls = try let init = { shelf = []; solution = gls.Evd.sigma ; comb = [gls.Evd.it] } in let (_,final,_,_) = apply (GoalV82.env gls.Evd.sigma gls.Evd.it) t init in { Evd.sigma = final.solution ; it = final.comb } with Logic_monad.TacticFailure e as src -> let (_, info) = Errors.push src in iraise (e, info) let put_status = Status.put let catchable_exception = catchable_exception let wrap_exceptions f = try f () with e when catchable_exception e -> let (e, info) = Errors.push e in tclZERO ~info e end