diff options
Diffstat (limited to 'pretyping')
| -rw-r--r-- | pretyping/pretyping.mllib | 1 | ||||
| -rw-r--r-- | pretyping/proofview.ml | 1204 | ||||
| -rw-r--r-- | pretyping/proofview.mli | 586 |
3 files changed, 1791 insertions, 0 deletions
diff --git a/pretyping/pretyping.mllib b/pretyping/pretyping.mllib index b59589bda2..5dfdd0379a 100644 --- a/pretyping/pretyping.mllib +++ b/pretyping/pretyping.mllib @@ -21,6 +21,7 @@ Constr_matching Tacred Typeclasses_errors Typeclasses +Proofview Classops Program Coercion diff --git a/pretyping/proofview.ml b/pretyping/proofview.ml new file mode 100644 index 0000000000..20be02e76d --- /dev/null +++ b/pretyping/proofview.ml @@ -0,0 +1,1204 @@ +(************************************************************************) +(* v * The Coq Proof Assistant / The Coq Development Team *) +(* <O___,, * INRIA - CNRS - LIX - LRI - PPS - Copyright 1999-2016 *) +(* \VV/ **************************************************************) +(* // * This file is distributed under the terms of the *) +(* * GNU Lesser General Public License Version 2.1 *) +(************************************************************************) + + +(** This files defines the basic mechanism of proofs: the [proofview] + type is the state which tactics manipulate (a global state for + existential variables, together with the list of goals), and the type + ['a tactic] is the (abstract) type of tactics modifying the proof + state and returning a value of type ['a]. *) + +open Pp +open Util +open Proofview_monad +open Sigma.Notations +open Context.Named.Declaration + +(** Main state of tactics *) +type proofview = Proofview_monad.proofview + +type entry = (Term.constr * Term.types) list + +(** Returns a stylised view of a proofview for use by, for instance, + ide-s. *) +(* spiwack: the type of [proofview] 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: returns the list of focused goals together with + the [evar_map] context. *) +let proofview p = + p.comb , p.solution + +let compact el ({ solution } as pv) = + let nf = Evarutil.nf_evar solution in + let size = Evd.fold (fun _ _ i -> 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 = Sigma.Unsafe.of_evar_map sigma in + let Sigma (econstr, sigma, _) = Evarutil.new_evar env sigma ~src ~store typ in + let sigma = Sigma.to_evar_map sigma 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 -> std_ppcmds) ref = ref (fun n -> mt ()) +let set_nosuchgoals_hook f = nosuchgoals_hook := f + + + +(* This uses the hook above *) +let _ = Errors.register_handler begin function + | NoSuchGoals n -> + let suffix = !nosuchgoals_hook n in + Errors.errorlabstrm "" + (str "No such " ++ str (String.plural n "goal") ++ 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] returns the list of unifiable goals 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 None + | 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 + tclUNIT (Some 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 d1 d2 = + match d1, d2 with + | LocalAssum (i1,t1), LocalAssum (i2,t2) -> + Names.Id.equal i1 i2 && eq_constr sigma1 sigma2 t1 t2 + | LocalDef (i1,c1,t1), LocalDef (i2,c2,t2) -> + Names.Id.equal i1 i2 && eq_constr sigma1 sigma2 c1 c2 + && eq_constr sigma1 sigma2 t1 t2 + | _ -> + false + 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 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 advance = advance + +end + +module UnsafeRepr = Proof.Unsafe + +let (>>=) = tclBIND +let (<*>) = tclTHEN +let (<+>) t1 t2 = tclOR t1 (fun _ -> t2) + +(** {6 Goal-dependent tactics} *) + +let goal_env evars gl = + let evi = Evd.find evars gl in + Evd.evar_filtered_env evi + +let goal_nf_evar sigma gl = + let evi = Evd.find sigma gl in + let evi = Evarutil.nf_evar_info sigma evi in + let sigma = Evd.add sigma gl evi in + (gl, sigma) + +let goal_extra evars gl = + let evi = Evd.find evars gl in + evi.Evd.evar_extra + + +let catchable_exception = function + | Logic_monad.Exception _ -> false + | e -> Errors.noncritical e + + +module Goal = struct + + type ('a, 'r) t = { + env : Environ.env; + sigma : Evd.evar_map; + concl : Term.constr ; + self : Evar.t ; (* for compatibility with old-style definitions *) + } + + type ('a, 'b) enter = + { enter : 'r. ('a, 'r) t -> 'b } + + let assume (gl : ('a, 'r) t) = (gl :> ([ `NF ], 'r) t) + + let env { env=env } = env + let sigma { sigma=sigma } = Sigma.Unsafe.of_evar_map sigma + let hyps { env=env } = Environ.named_context env + let concl { concl=concl } = concl + let extra { sigma=sigma; self=self } = goal_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.enter 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.enter 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 + + type ('a, 'b) s_enter = + { s_enter : 'r. ('a, 'r) t -> ('b, 'r) Sigma.sigma } + + let s_enter f = + InfoL.tag (Info.Dispatch) begin + iter_goal begin fun goal -> + Env.get >>= fun env -> + tclEVARMAP >>= fun sigma -> + try + let gl = gmake env sigma goal in + let Sigma (tac, sigma, _) = f.s_enter gl in + let sigma = Sigma.to_evar_map sigma in + tclTHEN (Unsafe.tclEVARS sigma) (InfoL.tag (Info.DBranch) tac) + with e when catchable_exception e -> + let (e, info) = Errors.push e in + tclZERO ~info e + end + end + + let nf_s_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 + let Sigma (tac, sigma, _) = f.s_enter gl in + let sigma = Sigma.to_evar_map sigma in + tclTHEN (Unsafe.tclEVARS sigma) (InfoL.tag (Info.DBranch) tac) + with e when catchable_exception e -> + let (e, info) = Errors.push e in + tclZERO ~info e + end + end + + let goals = + 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 = + Env.get >>= fun env -> + 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 + + let lift (gl : ('a, 'r) t) _ = (gl :> ('a, 's) t) + +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 -> goal_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"<unknown>")) >> + 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 = goal_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 of_tactic t gls = + try + let init = { shelf = []; solution = gls.Evd.sigma ; comb = [gls.Evd.it] } in + let (_,final,_,_) = apply (goal_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 + +(** {7 Notations} *) + +module Notations = struct + let (>>=) = tclBIND + let (<*>) = tclTHEN + let (<+>) t1 t2 = tclOR t1 (fun _ -> t2) + type ('a, 'b) enter = ('a, 'b) Goal.enter = + { enter : 'r. ('a, 'r) Goal.t -> 'b } + type ('a, 'b) s_enter = ('a, 'b) Goal.s_enter = + { s_enter : 'r. ('a, 'r) Goal.t -> ('b, 'r) Sigma.sigma } +end diff --git a/pretyping/proofview.mli b/pretyping/proofview.mli new file mode 100644 index 0000000000..6bc2e9a0ed --- /dev/null +++ b/pretyping/proofview.mli @@ -0,0 +1,586 @@ +(************************************************************************) +(* v * The Coq Proof Assistant / The Coq Development Team *) +(* <O___,, * INRIA - CNRS - LIX - LRI - PPS - Copyright 1999-2016 *) +(* \VV/ **************************************************************) +(* // * This file is distributed under the terms of the *) +(* * GNU Lesser General Public License Version 2.1 *) +(************************************************************************) + +(** This files defines the basic mechanism of proofs: the [proofview] + type is the state which tactics manipulate (a global state for + existential variables, together with the list of goals), and the type + ['a tactic] is the (abstract) type of tactics modifying the proof + state and returning a value of type ['a]. *) + +open Util +open Term + +(** Main state of tactics *) +type proofview + +(** Returns a stylised view of a proofview for use by, for instance, + ide-s. *) +(* spiwack: the type of [proofview] 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: returns the list of focused goals together with + the [evar_map] context. *) +val proofview : proofview -> Goal.goal list * Evd.evar_map + + +(** {6 Starting and querying a proof view} *) + +(** Abstract representation of the initial goals of a proof. *) +type entry + +(** Optimize memory consumption *) +val compact : entry -> proofview -> entry * proofview + +(** Initialises a proofview, the main argument is a list of + environments (including a [named_context] which are used as + hypotheses) pair with conclusion types, creating accordingly many + initial goals. Because a proof does not necessarily starts in an + empty [evar_map] (indeed a proof can be triggered by an incomplete + pretyping), [init] takes an additional argument to represent the + initial [evar_map]. *) +val init : Evd.evar_map -> (Environ.env * Term.types) list -> entry * proofview + +(** A [telescope] is a list of environment and conclusion like in + {!init}, except that each element may depend on the previous + goals. The telescope passes the goals in the form of a + [Term.constr] which represents the goal as an [evar]. The + [evar_map] is threaded in state passing style. *) +type telescope = + | TNil of Evd.evar_map + | TCons of Environ.env * Evd.evar_map * Term.types * (Evd.evar_map -> Term.constr -> telescope) + +(** Like {!init}, but goals are allowed to be dependent on one + another. Dependencies between goals is represented with the type + [telescope] instead of [list]. Note that the first [evar_map] of + the telescope plays the role of the [evar_map] argument in + [init]. *) +val dependent_init : telescope -> entry * proofview + +(** [finished pv] is [true] if and only if [pv] is complete. That is, + if it has an empty list of focused goals. There could still be + unsolved subgoaled, but they would then be out of focus. *) +val finished : proofview -> bool + +(** Returns the current [evar] state. *) +val return : proofview -> Evd.evar_map + +val partial_proof : entry -> proofview -> constr list +val initial_goals : entry -> (constr * types) list + + + +(** {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. *) +type focus_context + +(** 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). *) +val focus_context : focus_context -> Goal.goal list * Goal.goal list + +(** [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. *) +val focus : int -> int -> proofview -> proofview * focus_context + +(** Unfocuses a proofview with respect to a context. *) +val unfocus : focus_context -> proofview -> proofview + + +(** {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. +*) + + +(** The abstract type of tactics *) +type +'a tactic + +(** Applies a tactic to the current proofview. Returns a tuple + [a,pv,(b,sh,gu)] where [a] is the return value of the tactic, [pv] + is the updated proofview, [b] a boolean which is [true] if the + tactic has not done any action considered unsafe (such as + admitting a lemma), [sh] is the list of goals which have been + shelved by the tactic, and [gu] the list of goals on which the + tactic has given up. In case of multiple success the first one is + selected. If there is no success, fails with + {!Logic_monad.TacticFailure}*) +val apply : Environ.env -> 'a tactic -> proofview -> 'a + * proofview + * (bool*Goal.goal list*Goal.goal list) + * Proofview_monad.Info.tree + +(** {7 Monadic primitives} *) + +(** Unit of the tactic monad. *) +val tclUNIT : 'a -> 'a tactic + +(** Bind operation of the tactic monad. *) +val tclBIND : 'a tactic -> ('a -> 'b tactic) -> 'b tactic + +(** Interprets the ";" (semicolon) of Ltac. As a monadic operation, + it's a specialized "bind". *) +val tclTHEN : unit tactic -> 'a tactic -> 'a tactic + +(** [tclIGNORE t] has the same operational content as [t], but drops + the returned value. *) +val tclIGNORE : 'a tactic -> unit tactic + +(** Generic monadic combinators for tactics. *) +module Monad : Monad.S with type +'a t = 'a tactic + +(** {7 Failure and backtracking} *) + +(** [tclZERO e] fails with exception [e]. It has no success. *) +val tclZERO : ?info:Exninfo.info -> exn -> 'a tactic + +(** [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. *) +val tclOR : 'a tactic -> (iexn -> 'a tactic) -> 'a tactic + +(** [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. *) +val tclORELSE : 'a tactic -> (iexn -> 'a tactic) -> 'a tactic + +(** [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]. *) +val tclIFCATCH : 'a tactic -> ('a -> 'b tactic) -> (iexn -> 'b tactic) -> 'b tactic + +(** [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]. *) +val tclONCE : 'a tactic -> 'a tactic + +(** [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}). *) +exception MoreThanOneSuccess +val tclEXACTLY_ONCE : exn -> 'a tactic -> 'a tactic + +(** [tclCASE t] splits [t] into its first success and a + continuation. It is the most general primitive to control + backtracking. *) +type 'a case = + | Fail of iexn + | Next of 'a * (iexn -> 'a tactic) +val tclCASE : 'a tactic -> 'a case tactic + +(** [tclBREAK p t] is a generalization of [tclONCE t]. Instead of + stopping after the first success, it succeeds like [t] until a + failure with an exception [e] such that [p e = Some e'] is raised. At + which point it drops the remaining successes, failing with [e']. + [tclONCE t] is equivalent to [tclBREAK (fun e -> Some e) t]. *) +val tclBREAK : (iexn -> iexn option) -> 'a tactic -> 'a tactic + + +(** {7 Focusing tactics} *) + +(** [tclFOCUS i j t] applies [t] after focusing on the goals number + [i] to [j] (see {!focus}). The rest of the goals is restored after + the tactic action. If the specified range doesn't correspond to + existing goals, fails with [NoSuchGoals] (a user error). this + exception is caught at toplevel with a default message + a hook + message that can be customized by [set_nosuchgoals_hook] below. + This hook is used to add a suggestion about bullets when + applicable. *) +exception NoSuchGoals of int +val set_nosuchgoals_hook: (int -> Pp.std_ppcmds) -> unit + +val tclFOCUS : int -> int -> 'a tactic -> 'a tactic + +(** [tclFOCUSID x t] applies [t] on a (single) focused goal like + {!tclFOCUS}. The goal is found by its name rather than its + number.*) +val tclFOCUSID : Names.Id.t -> 'a tactic -> 'a tactic + +(** [tclTRYFOCUS i j t] behaves like {!tclFOCUS}, except that if the + specified range doesn't correspond to existing goals, behaves like + [tclUNIT ()] instead of failing. *) +val tclTRYFOCUS : int -> int -> unit tactic -> unit tactic + + +(** {7 Dispatching on goals} *) + +(** 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. *) +exception SizeMismatch of int*int +val tclDISPATCH : unit tactic list -> unit tactic +val tclDISPATCHL : 'a tactic list -> 'a list tactic + +(** [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). *) +val tclEXTEND : unit tactic list -> unit tactic -> unit tactic list -> unit tactic + +(** [tclINDEPENDENT tac] runs [tac] on each goal successively, from + the first one to the last one. Backtracking in one goal is + independent of backtracking in another. It is equivalent to + [tclEXTEND [] tac []]. *) +val tclINDEPENDENT : unit tactic -> unit tactic + + +(** {7 Goal manipulation} *) + +(** Shelves all the goals under focus. The goals are placed on the + shelf for later use (or being solved by side-effects). *) +val shelve : unit tactic + +(** Shelves the unifiable goals under focus, i.e. the goals which + appear in other goals under focus (the unfocused goals are not + considered). *) +val shelve_unifiable : unit tactic + +(** [guard_no_unifiable] returns the list of unifiable goals if some + goals are unifiable (see {!shelve_unifiable}) in the current focus. *) +val guard_no_unifiable : Names.Name.t list option tactic + +(** [unshelve l p] adds all the goals in [l] at the end of the focused + goals of p *) +val unshelve : Goal.goal list -> proofview -> proofview + +(** [with_shelf tac] executes [tac] and returns its result together with the set + of goals shelved by [tac]. The current shelf is unchanged. *) +val with_shelf : 'a tactic -> (Goal.goal list * 'a) tactic + +(** If [n] is positive, [cycle n] puts the [n] first goal last. If [n] + is negative, then it puts the [n] last goals first.*) +val cycle : int -> unit tactic + +(** [swap i j] swaps the position of goals number [i] and [j] + (negative numbers can be used to address goals from the end. Goals + are indexed from [1]. For simplicity index [0] corresponds to goal + [1] as well, rather than raising an error. *) +val swap : int -> int -> unit tactic + +(** [revgoals] reverses the list of focused goals. *) +val revgoals : unit tactic + +(** [numgoals] returns the number of goals under focus. *) +val numgoals : int tactic + + +(** {7 Access primitives} *) + +(** [tclEVARMAP] doesn't affect the proof, it returns the current + [evar_map]. *) +val tclEVARMAP : Evd.evar_map tactic + +(** [tclENV] doesn't affect the proof, it returns the current + environment. It is not the environment of a particular goal, + rather the "global" environment of the proof. The goal-wise + environment is obtained via {!Proofview.Goal.env}. *) +val tclENV : Environ.env tactic + + +(** {7 Put-like primitives} *) + +(** [tclEFFECTS eff] add the effects [eff] to the current state. *) +val tclEFFECTS : Safe_typing.private_constants -> unit tactic + +(** [mark_as_unsafe] declares the current tactic is unsafe. *) +val mark_as_unsafe : unit tactic + +(** Gives up on the goal under focus. Reports an unsafe status. Proofs + with given up goals cannot be closed. *) +val give_up : unit tactic + + +(** {7 Control primitives} *) + +(** [tclPROGRESS t] checks the state of the proof after [t]. It it is + identical to the state before, then [tclePROGRESS t] fails, otherwise + it succeeds like [t]. *) +val tclPROGRESS : 'a tactic -> 'a tactic + +(** Checks for interrupts *) +val tclCHECKINTERRUPT : unit tactic + +exception Timeout +(** [tclTIMEOUT n t] can have only one success. + In case of timeout if fails with [tclZERO Timeout]. *) +val tclTIMEOUT : int -> 'a tactic -> 'a tactic + +(** [tclTIME s t] displays time for each atomic call to t, using s as an + identifying annotation if present *) +val tclTIME : string option -> 'a tactic -> 'a tactic + +(** {7 Unsafe primitives} *) + +(** The primitives in the [Unsafe] module should be avoided as much as + possible, since they can make the proof state inconsistent. They are + nevertheless helpful, in particular when interfacing the pretyping and + the proof engine. *) +module Unsafe : sig + + (** [tclEVARS sigma] replaces the current [evar_map] by [sigma]. If + [sigma] has new unresolved [evar]-s they will not appear as + goal. If goals have been solved in [sigma] they will still + appear as unsolved goals. *) + val tclEVARS : Evd.evar_map -> unit tactic + + (** Like {!tclEVARS} but also checks whether goals have been solved. *) + val tclEVARSADVANCE : Evd.evar_map -> unit tactic + + (** [tclNEWGOALS gls] adds the goals [gls] to the ones currently + being proved, appending them to the list of focused goals. If a + goal is already solved, it is not added. *) + val tclNEWGOALS : Goal.goal list -> unit tactic + + (** [tclSETGOALS gls] sets goals [gls] as the goals being under focus. If a + goal is already solved, it is not set. *) + val tclSETGOALS : Goal.goal list -> unit tactic + + (** [tclGETGOALS] returns the list of goals under focus. *) + val tclGETGOALS : Goal.goal list tactic + + (** Sets the evar universe context. *) + val tclEVARUNIVCONTEXT : Evd.evar_universe_context -> unit tactic + + (** Clears the future goals store in the proof view. *) + val reset_future_goals : proofview -> proofview + + (** Give an evar the status of a goal (changes its source location + and makes it unresolvable for type classes. *) + val mark_as_goal : Evd.evar_map -> Evar.t -> Evd.evar_map + + (** [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. *) + val advance : Evd.evar_map -> Evar.t -> Evar.t option +end + +(** This module gives access to the innards of the monad. Its use is + restricted to very specific cases. *) +module UnsafeRepr : +sig + type state = Proofview_monad.Logical.Unsafe.state + val repr : 'a tactic -> ('a, state, state, iexn) Logic_monad.BackState.t + val make : ('a, state, state, iexn) Logic_monad.BackState.t -> 'a tactic +end + +(** {6 Goal-dependent tactics} *) + +module Goal : sig + + (** Type of goals. + + The first parameter type is a phantom argument indicating whether the data + contained in the goal has been normalized w.r.t. the current sigma. If it + is the case, it is flagged [ `NF ]. You may still access the un-normalized + data using {!assume} if you known you do not rely on the assumption of + being normalized, at your own risk. + + The second parameter is a stage indicating where the goal belongs. See + module {!Sigma}. + *) + type ('a, 'r) t + + (** Assume that you do not need the goal to be normalized. *) + val assume : ('a, 'r) t -> ([ `NF ], 'r) t + + (** Normalises the argument goal. *) + val normalize : ('a, 'r) t -> ([ `NF ], 'r) t tactic + + (** [concl], [hyps], [env] and [sigma] given a goal [gl] return + respectively the conclusion of [gl], the hypotheses of [gl], the + environment of [gl] (i.e. the global environment and the + hypotheses) and the current evar map. *) + val concl : ([ `NF ], 'r) t -> Term.constr + val hyps : ([ `NF ], 'r) t -> Context.Named.t + val env : ('a, 'r) t -> Environ.env + val sigma : ('a, 'r) t -> 'r Sigma.t + val extra : ('a, 'r) t -> Evd.Store.t + + (** Returns the goal's conclusion even if the goal is not + normalised. *) + val raw_concl : ('a, 'r) t -> Term.constr + + type ('a, 'b) enter = + { enter : 'r. ('a, 'r) t -> 'b } + + (** [nf_enter t] applies the goal-dependent tactic [t] in each goal + independently, in the manner of {!tclINDEPENDENT} except that + the current goal is also given as an argument to [t]. The goal + is normalised with respect to evars. *) + val nf_enter : ([ `NF ], unit tactic) enter -> unit tactic + + (** Like {!nf_enter}, but does not normalize the goal beforehand. *) + val enter : ([ `LZ ], unit tactic) enter -> unit tactic + + type ('a, 'b) s_enter = + { s_enter : 'r. ('a, 'r) t -> ('b, 'r) Sigma.sigma } + + (** A variant of {!enter} allows to work with a monotonic state. The evarmap + returned by the argument is put back into the current state before firing + the returned tactic. *) + val s_enter : ([ `LZ ], unit tactic) s_enter -> unit tactic + + (** Like {!s_enter}, but normalizes the goal beforehand. *) + val nf_s_enter : ([ `NF ], unit tactic) s_enter -> unit tactic + + (** Recover the list of current goals under focus, without evar-normalization. + FIXME: encapsulate the level in an existential type. *) + val goals : ([ `LZ ], 'r) t tactic list tactic + + (** Compatibility: avoid if possible *) + val goal : ([ `NF ], 'r) t -> Evar.t + + (** Every goal is valid at a later stage. FIXME: take a later evarmap *) + val lift : ('a, 'r) t -> ('r, 's) Sigma.le -> ('a, 's) t + +end + + +(** {6 Trace} *) + +module Trace : sig + + (** [record_info_trace t] behaves like [t] except the [info] trace + is stored. *) + val record_info_trace : 'a tactic -> 'a tactic + + val log : Proofview_monad.lazy_msg -> unit tactic + val name_tactic : Proofview_monad.lazy_msg -> 'a tactic -> 'a tactic + + val pr_info : ?lvl:int -> Proofview_monad.Info.tree -> Pp.std_ppcmds + +end + + +(** {6 Non-logical state} *) + +(** The [NonLogical] module allows the execution of effects (including + I/O) in tactics (non-logical side-effects are not discarded at + failures). *) +module NonLogical : module type of Logic_monad.NonLogical + +(** [tclLIFT c] is a tactic which behaves exactly as [c]. *) +val tclLIFT : 'a NonLogical.t -> 'a tactic + + +(**/**) + +(*** Compatibility layer with <= 8.2 tactics ***) +module V82 : sig + type tac = Evar.t Evd.sigma -> Evar.t list Evd.sigma + val tactic : tac -> unit tactic + + (* normalises the evars in the goals, and stores the result in + solution. *) + val nf_evar_goals : unit tactic + + val has_unresolved_evar : proofview -> bool + + (* Main function in the implementation of Grab Existential Variables. + Resets the proofview's goals so that it contains all unresolved evars + (in chronological order of insertion). *) + val grab : proofview -> proofview + + (* Returns the open goals of the proofview together with the evar_map to + interpret them. *) + val goals : proofview -> Evar.t list Evd.sigma + + val top_goals : entry -> proofview -> Evar.t list Evd.sigma + + (* returns the existential variable used to start the proof *) + val top_evars : entry -> Evd.evar list + + (* Caution: this function loses quite a bit of information. It + should be avoided as much as possible. It should work as + expected for a tactic obtained from {!V82.tactic} though. *) + val of_tactic : 'a tactic -> tac + + (* marks as unsafe if the argument is [false] *) + val put_status : bool -> unit tactic + + (* exception for which it is deemed to be safe to transmute into + tactic failure. *) + val catchable_exception : exn -> bool + + (* transforms every Ocaml (catchable) exception into a failure in + the monad. *) + val wrap_exceptions : (unit -> 'a tactic) -> 'a tactic +end + +(** {7 Notations} *) + +module Notations : sig + + (** {!tclBIND} *) + val (>>=) : 'a tactic -> ('a -> 'b tactic) -> 'b tactic + (** {!tclTHEN} *) + val (<*>) : unit tactic -> 'a tactic -> 'a tactic + (** {!tclOR}: [t1+t2] = [tclOR t1 (fun _ -> t2)]. *) + val (<+>) : 'a tactic -> 'a tactic -> 'a tactic + + type ('a, 'b) enter = ('a, 'b) Goal.enter = + { enter : 'r. ('a, 'r) Goal.t -> 'b } + type ('a, 'b) s_enter = ('a, 'b) Goal.s_enter = + { s_enter : 'r. ('a, 'r) Goal.t -> ('b, 'r) Sigma.sigma } +end |