From a52a2d2110fcf20d532a2005c1957cba0d2c4043 Mon Sep 17 00:00:00 2001 From: Gaëtan Gilbert Date: Fri, 11 May 2018 14:43:44 +0200 Subject: Fix restrict_universe_context --- engine/univops.ml | 85 +++++++----------------------------------------------- engine/univops.mli | 5 +++- kernel/uGraph.ml | 54 ++++++++++++++++++++++++++++++---- kernel/uGraph.mli | 10 ++++++- 4 files changed, 71 insertions(+), 83 deletions(-) diff --git a/engine/univops.ml b/engine/univops.ml index 76dbaa250..3fd518490 100644 --- a/engine/univops.ml +++ b/engine/univops.ml @@ -35,79 +35,14 @@ let universes_of_constr env c = | _ -> Constr.fold aux s c in aux LSet.empty c -type graphnode = { - mutable up : constraint_type LMap.t; - mutable visited : bool -} - -let merge_types d d0 = - match d, d0 with - | _, Lt | Lt, _ -> Lt - | Le, _ | _, Le -> Le - | Eq, Eq -> Eq - -let merge_up d b up = - let find = try Some (LMap.find b up) with Not_found -> None in - match find with - | Some d0 -> - let d = merge_types d d0 in - if d == d0 then up else LMap.add b d up - | None -> LMap.add b d up - -let add_up a d b graph = - let node, graph = - try LMap.find a graph, graph - with Not_found -> - let node = { up = LMap.empty; visited = false } in - node, LMap.add a node graph - in - node.up <- merge_up d b node.up; - graph - -(* for each node transitive close until you find a non removable, discard the rest *) -let transitive_close removable graph = - let rec do_node a node = - if not node.visited - then - let keepup = - LMap.fold (fun b d keepup -> - if not (LSet.mem b removable) - then merge_up d b keepup - else - begin - match LMap.find b graph with - | bnode -> - do_node b bnode; - LMap.fold (fun k d' keepup -> - merge_up (merge_types d d') k keepup) - bnode.up keepup - | exception Not_found -> keepup - end - ) - node.up LMap.empty - in - node.up <- keepup; - node.visited <- true - in - LMap.iter do_node graph - -let restrict_universe_context (univs,csts) keep = - let removable = LSet.diff univs keep in - let (csts, rem) = - Constraint.fold (fun (a,d,b as cst) (csts, rem) -> - if LSet.mem a removable || LSet.mem b removable - then (csts, add_up a d b rem) - else (Constraint.add cst csts, rem)) - csts (Constraint.empty, LMap.empty) - in - transitive_close removable rem; - let csts = - LMap.fold (fun a node csts -> - if LSet.mem a removable - then csts - else - LMap.fold (fun b d csts -> Constraint.add (a,d,b) csts) - node.up csts) - rem csts - in +let restrict_universe_context (univs, csts) keep = + let removed = LSet.diff univs keep in + if LSet.is_empty removed then univs, csts + else + let allunivs = Constraint.fold (fun (u,_,v) all -> LSet.add u (LSet.add v all)) csts univs in + let g = UGraph.empty_universes in + let g = LSet.fold UGraph.add_universe_unconstrained allunivs g in + let g = UGraph.merge_constraints csts g in + let allkept = LSet.diff allunivs removed in + let csts = UGraph.constraints_for ~kept:allkept g in (LSet.inter univs keep, csts) diff --git a/engine/univops.mli b/engine/univops.mli index d1585414c..0b37ab975 100644 --- a/engine/univops.mli +++ b/engine/univops.mli @@ -14,5 +14,8 @@ open Univ (** The universes of monomorphic constants appear. *) val universes_of_constr : Environ.env -> constr -> LSet.t -(** Shrink a universe context to a restricted set of variables *) +(** [restrict_universe_context (univs,csts) keep] restricts [univs] to + the universes in [keep]. The constraints [csts] are adjusted so + that transitive constraints between remaining universes (those in + [keep] and those not in [univs]) are preserved. *) val restrict_universe_context : ContextSet.t -> LSet.t -> ContextSet.t diff --git a/kernel/uGraph.ml b/kernel/uGraph.ml index e6b27077b..4a9467de5 100644 --- a/kernel/uGraph.ml +++ b/kernel/uGraph.ml @@ -503,7 +503,7 @@ let insert_edge strict ucan vcan g = let () = cleanup_universes g in raise e -let add_universe vlev strict g = +let add_universe_gen vlev g = try let _arcv = UMap.find vlev g.entries in raise AlreadyDeclared @@ -520,8 +520,14 @@ let add_universe vlev strict g = } in let entries = UMap.add vlev (Canonical v) g.entries in - let g = { entries; index = g.index - 1; n_nodes = g.n_nodes + 1; n_edges = g.n_edges } in - insert_edge strict (get_set_arc g) v g + { entries; index = g.index - 1; n_nodes = g.n_nodes + 1; n_edges = g.n_edges }, v + +let add_universe vlev strict g = + let g, v = add_universe_gen vlev g in + insert_edge strict (get_set_arc g) v g + +let add_universe_unconstrained vlev g = + fst (add_universe_gen vlev g) exception Found_explanation of explanation @@ -696,6 +702,9 @@ let enforce_univ_lt u v g = error_inconsistency Lt u v (get_explanation false v u g) let empty_universes = + { entries = UMap.empty; index = 0; n_nodes = 0; n_edges = 0 } + +let initial_universes = let set_arc = Canonical { univ = Level.set; ltle = LMap.empty; @@ -718,9 +727,6 @@ let empty_universes = let empty = { entries; index = (-2); n_nodes = 2; n_edges = 0 } in enforce_univ_lt Level.prop Level.set empty -(* Prop = Set is forbidden here. *) -let initial_universes = empty_universes - let is_initial_universes g = UMap.equal (==) g.entries initial_universes.entries let enforce_constraint cst g = @@ -780,6 +786,42 @@ let constraints_of_universes g = let csts = UMap.fold constraints_of g.entries Constraint.empty in csts, UF.partition uf +(* domain g.entries = kept + removed *) +let constraints_for ~kept g = + (* rmap: partial map from canonical universes to kept universes *) + let rmap, csts = LSet.fold (fun u (rmap,csts) -> + let arcu = repr g u in + if LSet.mem arcu.univ kept then + LMap.add arcu.univ arcu.univ rmap, enforce_eq_level u arcu.univ csts + else + match LMap.find arcu.univ rmap with + | v -> rmap, enforce_eq_level u v csts + | exception Not_found -> LMap.add arcu.univ u rmap, csts) + kept (LMap.empty,Constraint.empty) + in + let rec add_from u csts todo = match todo with + | [] -> csts + | (v,strict)::todo -> + let v = repr g v in + (match LMap.find v.univ rmap with + | v -> + let d = if strict then Lt else Le in + let csts = Constraint.add (u,d,v) csts in + add_from u csts todo + | exception Not_found -> + (* v is not equal to any kept universe *) + let todo = LMap.fold (fun v' strict' todo -> + (v',strict || strict') :: todo) + v.ltle todo + in + add_from u csts todo) + in + LSet.fold (fun u csts -> + let arc = repr g u in + LMap.fold (fun v strict csts -> add_from u csts [v,strict]) + arc.ltle csts) + kept csts + (** [sort_universes g] builds a totally ordered universe graph. The output graph should imply the input graph (and the implication will be strict most of the time), but is not necessarily minimal. diff --git a/kernel/uGraph.mli b/kernel/uGraph.mli index cca2eb472..e6dd629e4 100644 --- a/kernel/uGraph.mli +++ b/kernel/uGraph.mli @@ -49,13 +49,15 @@ exception AlreadyDeclared val add_universe : Level.t -> bool -> t -> t +(** Add a universe without (Prop,Set) <= u *) +val add_universe_unconstrained : Level.t -> t -> t + (** {6 Pretty-printing of universes. } *) val pr_universes : (Level.t -> Pp.t) -> t -> Pp.t (** The empty graph of universes *) val empty_universes : t -[@@ocaml.deprecated "Use UGraph.initial_universes"] val sort_universes : t -> t @@ -64,6 +66,12 @@ val sort_universes : t -> t of the universes into equivalence classes. *) val constraints_of_universes : t -> Constraint.t * LSet.t list +(** [constraints_for ~kept g] returns the constraints about the + universes [kept] in [g] up to transitivity. + + eg if [g] is [a <= b <= c] then [constraints_for ~kept:{a, c} g] is [a <= c]. *) +val constraints_for : kept:LSet.t -> t -> Constraint.t + val check_subtype : AUContext.t check_function (** [check_subtype univ ctx1 ctx2] checks whether [ctx2] is an instance of [ctx1]. *) -- cgit v1.2.3