diff options
| author | letouzey | 2008-11-06 12:19:41 +0000 |
|---|---|---|
| committer | letouzey | 2008-11-06 12:19:41 +0000 |
| commit | b626be96132d2dc65be5acb054d343a9eeffc826 (patch) | |
| tree | c55b521fbd9f615e9fca4a9a05a0bcf2f6d0cae0 /contrib/extraction/mlutil.ml | |
| parent | 80881f5f94597fc31734f5e439d5fda01a834fc4 (diff) | |
Cosmetic: no more whitespace at end of lines in extraction files
(diff says it's a big commit, whereas diff -w says it's an empty one ;-)
git-svn-id: svn+ssh://scm.gforge.inria.fr/svn/coq/trunk@11547 85f007b7-540e-0410-9357-904b9bb8a0f7
Diffstat (limited to 'contrib/extraction/mlutil.ml')
| -rw-r--r-- | contrib/extraction/mlutil.ml | 880 |
1 files changed, 440 insertions, 440 deletions
diff --git a/contrib/extraction/mlutil.ml b/contrib/extraction/mlutil.ml index 06185875f9..213df31e6e 100644 --- a/contrib/extraction/mlutil.ml +++ b/contrib/extraction/mlutil.ml @@ -31,34 +31,34 @@ let dummy_name = id_of_string "_" let id_of_name = function | Anonymous -> anonymous | Name id when id = dummy_name -> anonymous - | Name id -> id + | Name id -> id (*S Operations upon ML types (with meta). *) -let meta_count = ref 0 - +let meta_count = ref 0 + let reset_meta_count () = meta_count := 0 - -let new_meta _ = - incr meta_count; + +let new_meta _ = + incr meta_count; Tmeta {id = !meta_count; contents = None} (*s Sustitution of [Tvar i] by [t] in a ML type. *) -let type_subst i t0 t = +let type_subst i t0 t = let rec subst t = match t with | Tvar j when i = j -> t0 - | Tmeta {contents=None} -> t + | Tmeta {contents=None} -> t | Tmeta {contents=Some u} -> subst u | Tarr (a,b) -> Tarr (subst a, subst b) | Tglob (r, l) -> Tglob (r, List.map subst l) - | a -> a + | a -> a in subst t - + (* Simultaneous substitution of [[Tvar 1; ... ; Tvar n]] by [l] in a ML type. *) -let type_subst_list l t = - let rec subst t = match t with +let type_subst_list l t = + let rec subst t = match t with | Tvar j -> List.nth l (j-1) | Tmeta {contents=None} -> t | Tmeta {contents=Some u} -> subst u @@ -69,8 +69,8 @@ let type_subst_list l t = (* Simultaneous substitution of [[|Tvar 1; ... ; Tvar n|]] by [v] in a ML type. *) -let type_subst_vect v t = - let rec subst t = match t with +let type_subst_vect v t = + let rec subst t = match t with | Tvar j -> v.(j-1) | Tmeta {contents=None} -> t | Tmeta {contents=Some u} -> subst u @@ -90,17 +90,17 @@ let rec type_occurs alpha t = | Tmeta {id=beta; contents=None} -> alpha = beta | Tmeta {contents=Some u} -> type_occurs alpha u | Tarr (t1, t2) -> type_occurs alpha t1 || type_occurs alpha t2 - | Tglob (r,l) -> List.exists (type_occurs alpha) l + | Tglob (r,l) -> List.exists (type_occurs alpha) l | _ -> false (*s Most General Unificator *) let rec mgu = function | Tmeta m, Tmeta m' when m.id = m'.id -> () - | Tmeta m, t when m.contents=None -> + | Tmeta m, t when m.contents=None -> if type_occurs m.id t then raise Impossible else m.contents <- Some t - | t, Tmeta m when m.contents=None -> + | t, Tmeta m when m.contents=None -> if type_occurs m.id t then raise Impossible else m.contents <- Some t | Tmeta {contents=Some u}, t -> mgu (u, t) @@ -124,12 +124,12 @@ let put_magic p a = if needs_magic p && lang () <> Scheme then MLmagic a else a (*S ML type env. *) -module Mlenv = struct - - let meta_cmp m m' = compare m.id m'.id +module Mlenv = struct + + let meta_cmp m m' = compare m.id m'.id module Metaset = Set.Make(struct type t = ml_meta let compare = meta_cmp end) - (* Main MLenv type. [env] is the real environment, whereas [free] + (* Main MLenv type. [env] is the real environment, whereas [free] (tries to) record the free meta variables occurring in [env]. *) type t = { env : ml_schema list; mutable free : Metaset.t} @@ -138,68 +138,68 @@ module Mlenv = struct let empty = { env = []; free = Metaset.empty } - (* [get] returns a instantiated copy of the n-th most recently added + (* [get] returns a instantiated copy of the n-th most recently added type in the environment. *) - let get mle n = - assert (List.length mle.env >= n); + let get mle n = + assert (List.length mle.env >= n); instantiation (List.nth mle.env (n-1)) - (* [find_free] finds the free meta in a type. *) + (* [find_free] finds the free meta in a type. *) - let rec find_free set = function + let rec find_free set = function | Tmeta m when m.contents = None -> Metaset.add m set | Tmeta {contents = Some t} -> find_free set t | Tarr (a,b) -> find_free (find_free set a) b | Tglob (_,l) -> List.fold_left find_free set l | _ -> set - (* The [free] set of an environment can be outdate after - some unifications. [clean_free] takes care of that. *) - - let clean_free mle = - let rem = ref Metaset.empty - and add = ref Metaset.empty in - let clean m = match m.contents with - | None -> () + (* The [free] set of an environment can be outdate after + some unifications. [clean_free] takes care of that. *) + + let clean_free mle = + let rem = ref Metaset.empty + and add = ref Metaset.empty in + let clean m = match m.contents with + | None -> () | Some u -> rem := Metaset.add m !rem; add := find_free !add u - in - Metaset.iter clean mle.free; + in + Metaset.iter clean mle.free; mle.free <- Metaset.union (Metaset.diff mle.free !rem) !add (* From a type to a type schema. If a [Tmeta] is still uninstantiated and does appears in the [mle], then it becomes a [Tvar]. *) - let generalization mle t = - let c = ref 0 in - let map = ref (Intmap.empty : int Intmap.t) in - let add_new i = incr c; map := Intmap.add i !c !map; !c in - let rec meta2var t = match t with - | Tmeta {contents=Some u} -> meta2var u - | Tmeta ({id=i} as m) -> - (try Tvar (Intmap.find i !map) - with Not_found -> - if Metaset.mem m mle.free then t + let generalization mle t = + let c = ref 0 in + let map = ref (Intmap.empty : int Intmap.t) in + let add_new i = incr c; map := Intmap.add i !c !map; !c in + let rec meta2var t = match t with + | Tmeta {contents=Some u} -> meta2var u + | Tmeta ({id=i} as m) -> + (try Tvar (Intmap.find i !map) + with Not_found -> + if Metaset.mem m mle.free then t else Tvar (add_new i)) | Tarr (t1,t2) -> Tarr (meta2var t1, meta2var t2) - | Tglob (r,l) -> Tglob (r, List.map meta2var l) - | t -> t + | Tglob (r,l) -> Tglob (r, List.map meta2var l) + | t -> t in !c, meta2var t - + (* Adding a type in an environment, after generalizing. *) - let push_gen mle t = - clean_free mle; + let push_gen mle t = + clean_free mle; { env = generalization mle t :: mle.env; free = mle.free } (* Adding a type with no [Tvar], hence no generalization needed. *) - let push_type {env=e;free=f} t = - { env = (0,t) :: e; free = find_free f t} - + let push_type {env=e;free=f} t = + { env = (0,t) :: e; free = find_free f t} + (* Adding a type with no [Tvar] nor [Tmeta]. *) - let push_std_type {env=e;free=f} t = + let push_std_type {env=e;free=f} t = { env = (0,t) :: e; free = f} end @@ -208,7 +208,7 @@ end (*s Does a section path occur in a ML type ? *) -let rec type_mem_kn kn = function +let rec type_mem_kn kn = function | Tmeta {contents = Some t} -> type_mem_kn kn t | Tglob (r,l) -> occur_kn_in_ref kn r || List.exists (type_mem_kn kn) l | Tarr (a,b) -> (type_mem_kn kn a) || (type_mem_kn kn b) @@ -216,31 +216,31 @@ let rec type_mem_kn kn = function (*s Greatest variable occurring in [t]. *) -let type_maxvar t = - let rec parse n = function +let type_maxvar t = + let rec parse n = function | Tmeta {contents = Some t} -> parse n t - | Tvar i -> max i n + | Tvar i -> max i n | Tarr (a,b) -> parse (parse n a) b - | Tglob (_,l) -> List.fold_left parse n l - | _ -> n + | Tglob (_,l) -> List.fold_left parse n l + | _ -> n in parse 0 t -(*s From [a -> b -> c] to [[a;b],c]. *) +(*s From [a -> b -> c] to [[a;b],c]. *) -let rec type_decomp = function - | Tmeta {contents = Some t} -> type_decomp t - | Tarr (a,b) -> let l,h = type_decomp b in a::l, h +let rec type_decomp = function + | Tmeta {contents = Some t} -> type_decomp t + | Tarr (a,b) -> let l,h = type_decomp b in a::l, h | a -> [],a (*s The converse: From [[a;b],c] to [a -> b -> c]. *) -let rec type_recomp (l,t) = match l with - | [] -> t +let rec type_recomp (l,t) = match l with + | [] -> t | a::l -> Tarr (a, type_recomp (l,t)) (*s Translating [Tvar] to [Tvar'] to avoid clash. *) -let rec var2var' = function +let rec var2var' = function | Tmeta {contents = Some t} -> var2var' t | Tvar i -> Tvar' i | Tarr (a,b) -> Tarr (var2var' a, var2var' b) @@ -252,12 +252,12 @@ type abbrev_map = global_reference -> ml_type option (*s Delta-reduction of type constants everywhere in a ML type [t]. [env] is a function of type [ml_type_env]. *) -let type_expand env t = +let type_expand env t = let rec expand = function | Tmeta {contents = Some t} -> expand t - | Tglob (r,l) -> - (match env r with - | Some mlt -> expand (type_subst_list l mlt) + | Tglob (r,l) -> + (match env r with + | Some mlt -> expand (type_subst_list l mlt) | None -> Tglob (r, List.map expand l)) | Tarr (a,b) -> Tarr (expand a, expand b) | a -> a @@ -267,13 +267,13 @@ let type_expand env t = let is_arrow = function Tarr _ -> true | _ -> false -let type_weak_expand env t = +let type_weak_expand env t = let rec expand = function | Tmeta {contents = Some t} -> expand t - | Tglob (r,l) as t -> - (match env r with - | Some mlt -> - let u = expand (type_subst_list l mlt) in + | Tglob (r,l) as t -> + (match env r with + | Some mlt -> + let u = expand (type_subst_list l mlt) in if is_arrow u then u else t | None -> t) | Tarr (a,b) -> Tarr (a, expand b) @@ -282,16 +282,16 @@ let type_weak_expand env t = (*s Generating a signature from a ML type. *) -let type_to_sign env t = match type_expand env t with - | Tdummy d -> Kill d +let type_to_sign env t = match type_expand env t with + | Tdummy d -> Kill d | _ -> Keep -let type_to_signature env t = - let rec f = function - | Tmeta {contents = Some t} -> f t +let type_to_signature env t = + let rec f = function + | Tmeta {contents = Some t} -> f t | Tarr (Tdummy d, b) -> Kill d :: f b | Tarr (_, b) -> Keep :: f b - | _ -> [] + | _ -> [] in f (type_expand env t) let isKill = function Kill _ -> true | _ -> false @@ -302,34 +302,34 @@ let sign_of_id i = if i = dummy_name then Kill Kother else Keep (*s Removing [Tdummy] from the top level of a ML type. *) -let type_expunge env t = - let s = type_to_signature env t in - if s = [] then t - else if List.mem Keep s then - let rec f t s = - if List.exists isKill s then - match t with +let type_expunge env t = + let s = type_to_signature env t in + if s = [] then t + else if List.mem Keep s then + let rec f t s = + if List.exists isKill s then + match t with | Tmeta {contents = Some t} -> f t s - | Tarr (a,b) -> - let t = f b (List.tl s) in - if List.hd s = Keep then Tarr (a, t) else t + | Tarr (a,b) -> + let t = f b (List.tl s) in + if List.hd s = Keep then Tarr (a, t) else t | Tglob (r,l) -> - (match env r with + (match env r with | Some mlt -> f (type_subst_list l mlt) s | None -> assert false) | _ -> assert false - else t - in f t s - else if List.mem (Kill Kother) s then - Tarr (Tdummy Kother, snd (type_decomp (type_weak_expand env t))) + else t + in f t s + else if List.mem (Kill Kother) s then + Tarr (Tdummy Kother, snd (type_decomp (type_weak_expand env t))) else snd (type_decomp (type_weak_expand env t)) (*S Generic functions over ML ast terms. *) -(*s [ast_iter_rel f t] applies [f] on every [MLrel] in t. It takes care +(*s [ast_iter_rel f t] applies [f] on every [MLrel] in t. It takes care of the number of bingings crossed before reaching the [MLrel]. *) -let ast_iter_rel f = +let ast_iter_rel f = let rec iter n = function | MLrel i -> f (i-n) | MLlam (_,a) -> iter (n+1) a @@ -341,7 +341,7 @@ let ast_iter_rel f = | MLcons (_,_,l) -> List.iter (iter n) l | MLmagic a -> iter n a | MLglob _ | MLexn _ | MLdummy | MLaxiom -> () - in iter 0 + in iter 0 (*s Map over asts. *) @@ -361,18 +361,18 @@ let ast_map f = function let ast_map_lift_case f n (c,ids,a) = (c,ids, f (n+(List.length ids)) a) -let ast_map_lift f n = function +let ast_map_lift f n = function | MLlam (i,a) -> MLlam (i, f (n+1) a) | MLletin (i,a,b) -> MLletin (i, f n a, f (n+1) b) | MLcase (i,a,v) -> MLcase (i,f n a,Array.map (ast_map_lift_case f n) v) - | MLfix (i,ids,v) -> + | MLfix (i,ids,v) -> let k = Array.length ids in MLfix (i,ids,Array.map (f (k+n)) v) | MLapp (a,l) -> MLapp (f n a, List.map (f n) l) | MLcons (i,c,l) -> MLcons (i,c, List.map (f n) l) | MLmagic a -> MLmagic (f n a) - | MLrel _ | MLglob _ | MLexn _ | MLdummy | MLaxiom as a -> a + | MLrel _ | MLglob _ | MLexn _ | MLdummy | MLaxiom as a -> a -(*s Iter over asts. *) +(*s Iter over asts. *) let ast_iter_case f (c,ids,a) = f a @@ -390,23 +390,23 @@ let ast_iter f = function (*s [ast_occurs k t] returns [true] if [(Rel k)] occurs in [t]. *) -let ast_occurs k t = - try - ast_iter_rel (fun i -> if i = k then raise Found) t; false +let ast_occurs k t = + try + ast_iter_rel (fun i -> if i = k then raise Found) t; false with Found -> true -(*s [occurs_itvl k k' t] returns [true] if there is a [(Rel i)] +(*s [occurs_itvl k k' t] returns [true] if there is a [(Rel i)] in [t] with [k<=i<=k'] *) -let ast_occurs_itvl k k' t = - try - ast_iter_rel (fun i -> if (k <= i) && (i <= k') then raise Found) t; false +let ast_occurs_itvl k k' t = + try + ast_iter_rel (fun i -> if (k <= i) && (i <= k') then raise Found) t; false with Found -> true (*s Number of occurences of [Rel k] and [Rel 1] in [t]. *) let nb_occur_k k t = - let cpt = ref 0 in + let cpt = ref 0 in ast_iter_rel (fun i -> if i = k then incr cpt) t; !cpt @@ -415,19 +415,19 @@ let nb_occur t = nb_occur_k 1 t (* Number of occurences of [Rel 1] in [t], with special treatment of match: occurences in different branches aren't added, but we rather use max. *) -let nb_occur_match = - let rec nb k = function +let nb_occur_match = + let rec nb k = function | MLrel i -> if i = k then 1 else 0 - | MLcase(_,a,v) -> + | MLcase(_,a,v) -> (nb k a) + - Array.fold_left + Array.fold_left (fun r (_,ids,a) -> max r (nb (k+(List.length ids)) a)) 0 v - | MLletin (_,a,b) -> (nb k a) + (nb (k+1) b) - | MLfix (_,ids,v) -> let k = k+(Array.length ids) in + | MLletin (_,a,b) -> (nb k a) + (nb (k+1) b) + | MLfix (_,ids,v) -> let k = k+(Array.length ids) in Array.fold_left (fun r a -> r+(nb k a)) 0 v | MLlam (_,a) -> nb (k+1) a | MLapp (a,l) -> List.fold_left (fun r a -> r+(nb k a)) (nb k a) l - | MLcons (_,_,l) -> List.fold_left (fun r a -> r+(nb k a)) 0 l + | MLcons (_,_,l) -> List.fold_left (fun r a -> r+(nb k a)) 0 l | MLmagic a -> nb k a | MLglob _ | MLexn _ | MLdummy | MLaxiom -> 0 in nb 1 @@ -435,7 +435,7 @@ let nb_occur_match = (*s Lifting on terms. [ast_lift k t] lifts the binding depth of [t] across [k] bindings. *) -let ast_lift k t = +let ast_lift k t = let rec liftrec n = function | MLrel i as a -> if i-n < 1 then a else MLrel (i+k) | a -> ast_map_lift liftrec n a @@ -443,45 +443,45 @@ let ast_lift k t = let ast_pop t = ast_lift (-1) t -(*s [permut_rels k k' c] translates [Rel 1 ... Rel k] to [Rel (k'+1) ... +(*s [permut_rels k k' c] translates [Rel 1 ... Rel k] to [Rel (k'+1) ... Rel (k'+k)] and [Rel (k+1) ... Rel (k+k')] to [Rel 1 ... Rel k'] *) -let permut_rels k k' = +let permut_rels k k' = let rec permut n = function | MLrel i as a -> let i' = i-n in - if i'<1 || i'>k+k' then a + if i'<1 || i'>k+k' then a else if i'<=k then MLrel (i+k') else MLrel (i-k) | a -> ast_map_lift permut n a - in permut 0 + in permut 0 -(*s Substitution. [ml_subst e t] substitutes [e] for [Rel 1] in [t]. +(*s Substitution. [ml_subst e t] substitutes [e] for [Rel 1] in [t]. Lifting (of one binder) is done at the same time. *) let ast_subst e = let rec subst n = function | MLrel i as a -> - let i' = i-n in + let i' = i-n in if i'=1 then ast_lift n e - else if i'<1 then a + else if i'<1 then a else MLrel (i-1) | a -> ast_map_lift subst n a in subst 0 -(*s Generalized substitution. - [gen_subst v d t] applies to [t] the substitution coded in the - [v] array: [(Rel i)] becomes [v.(i-1)]. [d] is the correction applies +(*s Generalized substitution. + [gen_subst v d t] applies to [t] the substitution coded in the + [v] array: [(Rel i)] becomes [v.(i-1)]. [d] is the correction applies to [Rel] greater than [Array.length v]. *) -let gen_subst v d t = +let gen_subst v d t = let rec subst n = function - | MLrel i as a -> - let i'= i-n in - if i' < 1 then a - else if i' <= Array.length v then - ast_lift n v.(i'-1) - else MLrel (i+d) + | MLrel i as a -> + let i'= i-n in + if i' < 1 then a + else if i' <= Array.length v then + ast_lift n v.(i'-1) + else MLrel (i+d) | a -> ast_map_lift subst n a in subst 0 t @@ -490,7 +490,7 @@ let gen_subst v d t = (*s [collect_lams MLlam(id1,...MLlam(idn,t)...)] returns [[idn;...;id1]] and the term [t]. *) -let collect_lams = +let collect_lams = let rec collect acc = function | MLlam(id,t) -> collect (id::acc) t | x -> acc,x @@ -498,50 +498,50 @@ let collect_lams = (*s [collect_n_lams] does the same for a precise number of [MLlam]. *) -let collect_n_lams = - let rec collect acc n t = - if n = 0 then acc,t - else match t with +let collect_n_lams = + let rec collect acc n t = + if n = 0 then acc,t + else match t with | MLlam(id,t) -> collect (id::acc) (n-1) t | _ -> assert false - in collect [] + in collect [] (*s [remove_n_lams] just removes some [MLlam]. *) -let rec remove_n_lams n t = - if n = 0 then t - else match t with +let rec remove_n_lams n t = + if n = 0 then t + else match t with | MLlam(_,t) -> remove_n_lams (n-1) t | _ -> assert false (*s [nb_lams] gives the number of head [MLlam]. *) -let rec nb_lams = function +let rec nb_lams = function | MLlam(_,t) -> succ (nb_lams t) - | _ -> 0 + | _ -> 0 (*s [named_lams] does the converse of [collect_lams]. *) -let rec named_lams ids a = match ids with - | [] -> a +let rec named_lams ids a = match ids with + | [] -> a | id :: ids -> named_lams ids (MLlam (id,a)) (*s The same in anonymous version. *) -let rec anonym_lams a = function - | 0 -> a +let rec anonym_lams a = function + | 0 -> a | n -> anonym_lams (MLlam (anonymous,a)) (pred n) (*s Idem for [dummy_name]. *) -let rec dummy_lams a = function - | 0 -> a +let rec dummy_lams a = function + | 0 -> a | n -> dummy_lams (MLlam (dummy_name,a)) (pred n) (*s mixed according to a signature. *) -let rec anonym_or_dummy_lams a = function - | [] -> a +let rec anonym_or_dummy_lams a = function + | [] -> a | Keep :: s -> MLlam(anonymous, anonym_or_dummy_lams a s) | Kill _ :: s -> MLlam(dummy_name, anonym_or_dummy_lams a s) @@ -549,41 +549,41 @@ let rec anonym_or_dummy_lams a = function (*s The following function creates [MLrel n;...;MLrel 1] *) -let rec eta_args n = +let rec eta_args n = if n = 0 then [] else (MLrel n)::(eta_args (pred n)) (*s Same, but filtered by a signature. *) -let rec eta_args_sign n = function - | [] -> [] - | Keep :: s -> (MLrel n) :: (eta_args_sign (n-1) s) +let rec eta_args_sign n = function + | [] -> [] + | Keep :: s -> (MLrel n) :: (eta_args_sign (n-1) s) | Kill _ :: s -> eta_args_sign (n-1) s (*s This one tests [MLrel (n+k); ... ;MLrel (1+k)] *) -let rec test_eta_args_lift k n = function +let rec test_eta_args_lift k n = function | [] -> n=0 | a :: q -> (a = (MLrel (k+n))) && (test_eta_args_lift k (pred n) q) (*s Computes an eta-reduction. *) -let eta_red e = - let ids,t = collect_lams e in +let eta_red e = + let ids,t = collect_lams e in let n = List.length ids in - if n = 0 then e - else match t with - | MLapp (f,a) -> - let m = List.length a in - let ids,body,args = - if m = n then + if n = 0 then e + else match t with + | MLapp (f,a) -> + let m = List.length a in + let ids,body,args = + if m = n then [], f, a - else if m < n then - snd (list_chop (n-m) ids), f, a + else if m < n then + snd (list_chop (n-m) ids), f, a else (* m > n *) - let a1,a2 = list_chop (m-n) a in + let a1,a2 = list_chop (m-n) a in [], MLapp (f,a1), a2 - in - let p = List.length args in + in + let p = List.length args in if test_eta_args_lift 0 p args && not (ast_occurs_itvl 1 p body) then named_lams ids (ast_lift (-p) body) else e @@ -592,24 +592,24 @@ let eta_red e = (*s Computes all head linear beta-reductions possible in [(t a)]. Non-linear head beta-redex become let-in. *) -let rec linear_beta_red a t = match a,t with - | [], _ -> t +let rec linear_beta_red a t = match a,t with + | [], _ -> t | a0::a, MLlam (id,t) -> (match nb_occur_match t with | 0 -> linear_beta_red a (ast_pop t) | 1 -> linear_beta_red a (ast_subst a0 t) - | _ -> - let a = List.map (ast_lift 1) a in + | _ -> + let a = List.map (ast_lift 1) a in MLletin (id, a0, linear_beta_red a t)) | _ -> MLapp (t, a) -(*s Applies a substitution [s] of constants by their body, plus - linear beta reductions at modified positions. *) +(*s Applies a substitution [s] of constants by their body, plus + linear beta reductions at modified positions. *) -let rec ast_glob_subst s t = match t with - | MLapp ((MLglob ((ConstRef kn) as refe)) as f, a) -> - let a = List.map (ast_glob_subst s) a in - (try linear_beta_red a (Refmap.find refe s) +let rec ast_glob_subst s t = match t with + | MLapp ((MLglob ((ConstRef kn) as refe)) as f, a) -> + let a = List.map (ast_glob_subst s) a in + (try linear_beta_red a (Refmap.find refe s) with Not_found -> MLapp (f, a)) | MLglob ((ConstRef kn) as refe) -> (try Refmap.find refe s with Not_found -> t) @@ -619,114 +619,114 @@ let rec ast_glob_subst s t = match t with (*S Auxiliary functions used in simplification of ML cases. *) (*s [check_and_generalize (r0,l,c)] transforms any [MLcons(r0,l)] in [MLrel 1] - and raises [Impossible] if any variable in [l] occurs outside such a + and raises [Impossible] if any variable in [l] occurs outside such a [MLcons] *) -let check_and_generalize (r0,l,c) = - let nargs = List.length l in - let rec genrec n = function - | MLrel i as c -> - let i' = i-n in - if i'<1 then c - else if i'>nargs then MLrel (i-nargs+1) +let check_and_generalize (r0,l,c) = + let nargs = List.length l in + let rec genrec n = function + | MLrel i as c -> + let i' = i-n in + if i'<1 then c + else if i'>nargs then MLrel (i-nargs+1) else raise Impossible - | MLcons(_,r,args) when r=r0 && (test_eta_args_lift n nargs args) -> - MLrel (n+1) + | MLcons(_,r,args) when r=r0 && (test_eta_args_lift n nargs args) -> + MLrel (n+1) | a -> ast_map_lift genrec n a - in genrec 0 c + in genrec 0 c -(*s [check_generalizable_case] checks if all branches can be seen as the - same function [f] applied to the term matched. It is a generalized version +(*s [check_generalizable_case] checks if all branches can be seen as the + same function [f] applied to the term matched. It is a generalized version of the identity case optimization. *) -(* CAVEAT: this optimization breaks typing in some special case. example: +(* CAVEAT: this optimization breaks typing in some special case. example: [type 'x a = A]. Then [let f = function A -> A] has type ['x a -> 'y a], which is incompatible with the type of [let f x = x]. - By default, we brutally disable this optim except for some known types: + By default, we brutally disable this optim except for some known types: [bool], [sumbool], [sumor] *) -let generalizable_list = +let generalizable_list = let datatypes = MPfile (dirpath_of_string "Coq.Init.Datatypes") and specif = MPfile (dirpath_of_string "Coq.Init.Specif") - in - [ make_kn datatypes empty_dirpath (mk_label "bool"); + in + [ make_kn datatypes empty_dirpath (mk_label "bool"); make_kn specif empty_dirpath (mk_label "sumbool"); make_kn specif empty_dirpath (mk_label "sumor") ] -let check_generalizable_case unsafe br = - if not unsafe then - (match br.(0) with +let check_generalizable_case unsafe br = + if not unsafe then + (match br.(0) with | ConstructRef ((kn,_),_), _, _ -> if not (List.mem kn generalizable_list) then raise Impossible - | _ -> assert false); - let f = check_and_generalize br.(0) in - for i = 1 to Array.length br - 1 do - if check_and_generalize br.(i) <> f then raise Impossible + | _ -> assert false); + let f = check_and_generalize br.(0) in + for i = 1 to Array.length br - 1 do + if check_and_generalize br.(i) <> f then raise Impossible done; f (*s Detecting similar branches of a match *) -(* If several branches of a match are equal (and independent from their - patterns) we will print them using a _ pattern. If _all_ branches +(* If several branches of a match are equal (and independent from their + patterns) we will print them using a _ pattern. If _all_ branches are equal, we remove the match. *) -let common_branches br = - let tab = Hashtbl.create 13 in - for i = 0 to Array.length br - 1 do - let (r,ids,t) = br.(i) in - let n = List.length ids in - if not (ast_occurs_itvl 1 n t) then - let t = ast_lift (-n) t in - let l = try Hashtbl.find tab t with Not_found -> [] in +let common_branches br = + let tab = Hashtbl.create 13 in + for i = 0 to Array.length br - 1 do + let (r,ids,t) = br.(i) in + let n = List.length ids in + if not (ast_occurs_itvl 1 n t) then + let t = ast_lift (-n) t in + let l = try Hashtbl.find tab t with Not_found -> [] in Hashtbl.replace tab t (i::l) - done; - let best = ref [] in - Hashtbl.iter - (fun _ l -> if List.length l > List.length !best then best := l) tab; + done; + let best = ref [] in + Hashtbl.iter + (fun _ l -> if List.length l > List.length !best then best := l) tab; if List.length !best < 2 then [] else !best (*s If all branches are functions, try to permut the case and the functions. *) -let rec merge_ids ids ids' = match ids,ids' with - | [],l -> l +let rec merge_ids ids ids' = match ids,ids' with + | [],l -> l | l,[] -> l - | i::ids, i'::ids' -> + | i::ids, i'::ids' -> (if i = dummy_name then i' else i) :: (merge_ids ids ids') let is_exn = function MLexn _ -> true | _ -> false -let rec permut_case_fun br acc = - let nb = ref max_int in - Array.iter (fun (_,_,t) -> - let ids, c = collect_lams t in - let n = List.length ids in - if (n < !nb) && (not (is_exn c)) then nb := n) br; - if !nb = max_int || !nb = 0 then ([],br) +let rec permut_case_fun br acc = + let nb = ref max_int in + Array.iter (fun (_,_,t) -> + let ids, c = collect_lams t in + let n = List.length ids in + if (n < !nb) && (not (is_exn c)) then nb := n) br; + if !nb = max_int || !nb = 0 then ([],br) else begin - let br = Array.copy br in - let ids = ref [] in - for i = 0 to Array.length br - 1 do - let (r,l,t) = br.(i) in - let local_nb = nb_lams t in + let br = Array.copy br in + let ids = ref [] in + for i = 0 to Array.length br - 1 do + let (r,l,t) = br.(i) in + let local_nb = nb_lams t in if local_nb < !nb then (* t = MLexn ... *) br.(i) <- (r,l,remove_n_lams local_nb t) else begin - let local_ids,t = collect_n_lams !nb t in - ids := merge_ids !ids local_ids; + let local_ids,t = collect_n_lams !nb t in + ids := merge_ids !ids local_ids; br.(i) <- (r,l,permut_rels !nb (List.length l) t) end - done; + done; (!ids,br) end - + (*S Generalized iota-reduction. *) -(* Definition of a generalized iota-redex: it's a [MLcase(e,_)] - with [(is_iota_gen e)=true]. Any generalized iota-redex is +(* Definition of a generalized iota-redex: it's a [MLcase(e,_)] + with [(is_iota_gen e)=true]. Any generalized iota-redex is transformed into beta-redexes. *) -let rec is_iota_gen = function +let rec is_iota_gen = function | MLcons _ -> true | MLcase(_,_,br)-> array_for_all (fun (_,_,t)->is_iota_gen t) br | _ -> false @@ -735,21 +735,21 @@ let constructor_index = function | ConstructRef (_,j) -> pred j | _ -> assert false -let iota_gen br = - let rec iota k = function +let iota_gen br = + let rec iota k = function | MLcons (i,r,a) -> let (_,ids,c) = br.(constructor_index r) in let c = List.fold_right (fun id t -> MLlam (id,t)) ids c in - let c = ast_lift k c in + let c = ast_lift k c in MLapp (c,a) - | MLcase(i,e,br') -> - let new_br = + | MLcase(i,e,br') -> + let new_br = Array.map (fun (n,i,c)->(n,i,iota (k+(List.length i)) c)) br' in MLcase(i,e, new_br) | _ -> assert false - in iota 0 + in iota 0 -let is_atomic = function +let is_atomic = function | MLrel _ | MLglob _ | MLexn _ | MLdummy -> true | _ -> false @@ -760,131 +760,131 @@ let is_atomic = function let rec simpl o = function | MLapp (f, []) -> simpl o f - | MLapp (f, a) -> + | MLapp (f, a) -> simpl_app o (List.map (simpl o) a) (simpl o f) | MLcase (i,e,br) -> - let br = Array.map (fun (n,l,t) -> (n,l,simpl o t)) br in - simpl_case o i br (simpl o e) - | MLletin(id,c,e) -> - let e = (simpl o e) in - if + let br = Array.map (fun (n,l,t) -> (n,l,simpl o t)) br in + simpl_case o i br (simpl o e) + | MLletin(id,c,e) -> + let e = (simpl o e) in + if (id = dummy_name) || (is_atomic c) || (is_atomic e) || (let n = nb_occur_match e in n = 0 || (n=1 && o.opt_lin_let)) - then + then simpl o (ast_subst c e) - else + else MLletin(id, simpl o c, e) - | MLfix(i,ids,c) -> - let n = Array.length ids in - if ast_occurs_itvl 1 n c.(i) then + | MLfix(i,ids,c) -> + let n = Array.length ids in + if ast_occurs_itvl 1 n c.(i) then MLfix (i, ids, Array.map (simpl o) c) else simpl o (ast_lift (-n) c.(i)) (* Dummy fixpoint *) - | a -> ast_map (simpl o) a + | a -> ast_map (simpl o) a -and simpl_app o a = function +and simpl_app o a = function | MLapp (f',a') -> simpl_app o (a'@a) f' - | MLlam (id,t) when id = dummy_name -> + | MLlam (id,t) when id = dummy_name -> simpl o (MLapp (ast_pop t, List.tl a)) | MLlam (id,t) -> (* Beta redex *) (match nb_occur_match t with | 0 -> simpl o (MLapp (ast_pop t, List.tl a)) - | 1 when o.opt_lin_beta -> + | 1 when o.opt_lin_beta -> simpl o (MLapp (ast_subst (List.hd a) t, List.tl a)) - | _ -> + | _ -> let a' = List.map (ast_lift 1) (List.tl a) in simpl o (MLletin (id, List.hd a, MLapp (t, a')))) - | MLletin (id,e1,e2) when o.opt_let_app -> + | MLletin (id,e1,e2) when o.opt_let_app -> (* Application of a letin: we push arguments inside *) MLletin (id, e1, simpl o (MLapp (e2, List.map (ast_lift 1) a))) - | MLcase (i,e,br) when o.opt_case_app -> + | MLcase (i,e,br) when o.opt_case_app -> (* Application of a case: we push arguments inside *) - let br' = - Array.map - (fun (n,l,t) -> + let br' = + Array.map + (fun (n,l,t) -> let k = List.length l in let a' = List.map (ast_lift k) a in - (n, l, simpl o (MLapp (t,a')))) br - in simpl o (MLcase (i,e,br')) - | (MLdummy | MLexn _) as e -> e + (n, l, simpl o (MLapp (t,a')))) br + in simpl o (MLcase (i,e,br')) + | (MLdummy | MLexn _) as e -> e (* We just discard arguments in those cases. *) | f -> MLapp (f,a) -and simpl_case o i br e = +and simpl_case o i br e = if o.opt_case_iot && (is_iota_gen e) then (* Generalized iota-redex *) simpl o (iota_gen br e) - else + else try (* Does a term [f] exist such that each branch is [(f e)] ? *) if not o.opt_case_idr then raise Impossible; - let f = check_generalizable_case o.opt_case_idg br in + let f = check_generalizable_case o.opt_case_idg br in simpl o (MLapp (MLlam (anonymous,f),[e])) - with Impossible -> + with Impossible -> (* Detect common branches *) let common_br = if not o.opt_case_cst then [] else common_branches br in - if List.length common_br = Array.length br && br <> [||] then + if List.length common_br = Array.length br && br <> [||] then let (_,ids,t) = br.(0) in ast_lift (-List.length ids) t - else - let new_i = (fst i, common_br) in + else + let new_i = (fst i, common_br) in (* Swap the case and the lam if possible *) - if o.opt_case_fun - then - let ids,br = permut_case_fun br [] in - let n = List.length ids in + if o.opt_case_fun + then + let ids,br = permut_case_fun br [] in + let n = List.length ids in if n <> 0 then named_lams ids (MLcase (new_i,ast_lift n e, br)) - else MLcase (new_i,e,br) + else MLcase (new_i,e,br) else MLcase (new_i,e,br) -let rec post_simpl = function - | MLletin(_,c,e) when (is_atomic (eta_red c)) -> +let rec post_simpl = function + | MLletin(_,c,e) when (is_atomic (eta_red c)) -> post_simpl (ast_subst (eta_red c) e) - | a -> ast_map post_simpl a + | a -> ast_map post_simpl a -(*S Local prop elimination. *) +(*S Local prop elimination. *) (* We try to eliminate as many [prop] as possible inside an [ml_ast]. *) -(*s In a list, it selects only the elements corresponding to a [Keep] +(*s In a list, it selects only the elements corresponding to a [Keep] in the boolean list [l]. *) -let rec select_via_bl l args = match l,args with +let rec select_via_bl l args = match l,args with | [],_ -> args | Keep::l,a::args -> a :: (select_via_bl l args) | Kill _::l,a::args -> select_via_bl l args - | _ -> assert false + | _ -> assert false (*s [kill_some_lams] removes some head lambdas according to the signature [bl]. This list is build on the identifier list model: outermost lambda - is on the right. - [Rels] corresponding to removed lambdas are supposed not to occur, and + is on the right. + [Rels] corresponding to removed lambdas are supposed not to occur, and the other [Rels] are made correct via a [gen_subst]. Output is not directly a [ml_ast], compose with [named_lams] if needed. *) let kill_some_lams bl (ids,c) = let n = List.length bl in - let n' = List.fold_left (fun n b -> if b=Keep then (n+1) else n) 0 bl in + let n' = List.fold_left (fun n b -> if b=Keep then (n+1) else n) 0 bl in if n = n' then ids,c - else if n' = 0 then [],ast_lift (-n) c + else if n' = 0 then [],ast_lift (-n) c else begin - let v = Array.make n MLdummy in - let rec parse_ids i j = function + let v = Array.make n MLdummy in + let rec parse_ids i j = function | [] -> () | Keep :: l -> v.(i) <- MLrel j; parse_ids (i+1) (j+1) l | Kill _ :: l -> parse_ids (i+1) j l - in parse_ids 0 1 bl ; + in parse_ids 0 1 bl ; select_via_bl bl ids, gen_subst v (n'-n) c end -(*s [kill_dummy_lams] uses the last function to kill the lambdas corresponding - to a [dummy_name]. It can raise [Impossible] if there is nothing to do, or +(*s [kill_dummy_lams] uses the last function to kill the lambdas corresponding + to a [dummy_name]. It can raise [Impossible] if there is nothing to do, or if there is no lambda left at all. *) -let kill_dummy_lams c = - let ids,c = collect_lams c in +let kill_dummy_lams c = + let ids,c = collect_lams c in let bl = List.map sign_of_id ids in - if (List.mem Keep bl) && (List.exists isKill bl) then - let ids',c = kill_some_lams bl (ids,c) in + if (List.mem Keep bl) && (List.exists isKill bl) then + let ids',c = kill_some_lams bl (ids,c) in ids, named_lams ids' c else raise Impossible -(*s [eta_expansion_sign] takes a function [fun idn ... id1 -> c] +(*s [eta_expansion_sign] takes a function [fun idn ... id1 -> c] and a signature [s] and builds a eta-long version. *) (* For example, if [s = [Keep;Keep;Kill Prop;Keep]] then the output is : @@ -892,137 +892,137 @@ let kill_dummy_lams c = let eta_expansion_sign s (ids,c) = let rec abs ids rels i = function - | [] -> + | [] -> let a = List.rev_map (function MLrel x -> MLrel (i-x) | a -> a) rels - in ids, MLapp (ast_lift (i-1) c, a) - | Keep :: l -> abs (anonymous :: ids) (MLrel i :: rels) (i+1) l + in ids, MLapp (ast_lift (i-1) c, a) + | Keep :: l -> abs (anonymous :: ids) (MLrel i :: rels) (i+1) l | Kill _ :: l -> abs (dummy_name :: ids) (MLdummy :: rels) (i+1) l in abs ids [] 1 s -(*s If [s = [b1; ... ; bn]] then [case_expunge] decomposes [e] - in [n] lambdas (with eta-expansion if needed) and removes all dummy lambdas +(*s If [s = [b1; ... ; bn]] then [case_expunge] decomposes [e] + in [n] lambdas (with eta-expansion if needed) and removes all dummy lambdas corresponding to [Del] in [s]. *) -let case_expunge s e = - let m = List.length s in - let n = nb_lams e in - let p = if m <= n then collect_n_lams m e - else eta_expansion_sign (list_skipn n s) (collect_lams e) in +let case_expunge s e = + let m = List.length s in + let n = nb_lams e in + let p = if m <= n then collect_n_lams m e + else eta_expansion_sign (list_skipn n s) (collect_lams e) in kill_some_lams (List.rev s) p -(*s [term_expunge] takes a function [fun idn ... id1 -> c] - and a signature [s] and remove dummy lams. The difference - with [case_expunge] is that we here leave one dummy lambda +(*s [term_expunge] takes a function [fun idn ... id1 -> c] + and a signature [s] and remove dummy lams. The difference + with [case_expunge] is that we here leave one dummy lambda if all lambdas are logical dummy. *) let term_expunge s (ids,c) = - if s = [] then c - else - let ids,c = kill_some_lams (List.rev s) (ids,c) in - if ids = [] && List.mem (Kill Kother) s then + if s = [] then c + else + let ids,c = kill_some_lams (List.rev s) (ids,c) in + if ids = [] && List.mem (Kill Kother) s then MLlam (dummy_name, ast_lift 1 c) else named_lams ids c -(*s [kill_dummy_args ids t0 t] looks for occurences of [t0] in [t] and - purge the args of [t0] corresponding to a [dummy_name]. - It makes eta-expansion if needed. *) +(*s [kill_dummy_args ids t0 t] looks for occurences of [t0] in [t] and + purge the args of [t0] corresponding to a [dummy_name]. + It makes eta-expansion if needed. *) let kill_dummy_args ids t0 t = - let m = List.length ids in + let m = List.length ids in let bl = List.rev_map sign_of_id ids in - let rec killrec n = function - | MLapp(e, a) when e = ast_lift n t0 -> - let k = max 0 (m - (List.length a)) in - let a = List.map (killrec n) a in - let a = List.map (ast_lift k) a in - let a = select_via_bl bl (a @ (eta_args k)) in - named_lams (list_firstn k ids) (MLapp (ast_lift k e, a)) - | e when e = ast_lift n t0 -> - let a = select_via_bl bl (eta_args m) in + let rec killrec n = function + | MLapp(e, a) when e = ast_lift n t0 -> + let k = max 0 (m - (List.length a)) in + let a = List.map (killrec n) a in + let a = List.map (ast_lift k) a in + let a = select_via_bl bl (a @ (eta_args k)) in + named_lams (list_firstn k ids) (MLapp (ast_lift k e, a)) + | e when e = ast_lift n t0 -> + let a = select_via_bl bl (eta_args m) in named_lams ids (MLapp (ast_lift m e, a)) - | e -> ast_map_lift killrec n e - in killrec 0 t + | e -> ast_map_lift killrec n e + in killrec 0 t (*s The main function for local [dummy] elimination. *) -let rec kill_dummy = function - | MLfix(i,fi,c) -> - (try - let ids,c = kill_dummy_fix i fi c in +let rec kill_dummy = function + | MLfix(i,fi,c) -> + (try + let ids,c = kill_dummy_fix i fi c in ast_subst (MLfix (i,fi,c)) (kill_dummy_args ids (MLrel 1) (MLrel 1)) with Impossible -> MLfix (i,fi,Array.map kill_dummy c)) - | MLapp (MLfix (i,fi,c),a) -> - (try - let ids,c = kill_dummy_fix i fi c in - let a = List.map (fun t -> ast_lift 1 (kill_dummy t)) a in + | MLapp (MLfix (i,fi,c),a) -> + (try + let ids,c = kill_dummy_fix i fi c in + let a = List.map (fun t -> ast_lift 1 (kill_dummy t)) a in let e = kill_dummy_args ids (MLrel 1) (MLapp (MLrel 1,a)) in - ast_subst (MLfix (i,fi,c)) e - with Impossible -> + ast_subst (MLfix (i,fi,c)) e + with Impossible -> MLapp(MLfix(i,fi,Array.map kill_dummy c),List.map kill_dummy a)) - | MLletin(id, MLfix (i,fi,c),e) -> - (try + | MLletin(id, MLfix (i,fi,c),e) -> + (try let ids,c = kill_dummy_fix i fi c in - let e = kill_dummy (kill_dummy_args ids (MLrel 1) e) in + let e = kill_dummy (kill_dummy_args ids (MLrel 1) e) in MLletin(id, MLfix(i,fi,c),e) - with Impossible -> + with Impossible -> MLletin(id, MLfix(i,fi,Array.map kill_dummy c),kill_dummy e)) - | MLletin(id,c,e) -> - (try - let ids,c = kill_dummy_lams c in - let e = kill_dummy_args ids (MLrel 1) e in - MLletin (id, kill_dummy c,kill_dummy e) + | MLletin(id,c,e) -> + (try + let ids,c = kill_dummy_lams c in + let e = kill_dummy_args ids (MLrel 1) e in + MLletin (id, kill_dummy c,kill_dummy e) with Impossible -> MLletin(id,kill_dummy c,kill_dummy e)) | a -> ast_map kill_dummy a -and kill_dummy_fix i fi c = - let n = Array.length fi in - let ids,ci = kill_dummy_lams c.(i) in - let c = Array.copy c in c.(i) <- ci; - for j = 0 to (n-1) do - c.(j) <- kill_dummy (kill_dummy_args ids (MLrel (n-i)) c.(j)) +and kill_dummy_fix i fi c = + let n = Array.length fi in + let ids,ci = kill_dummy_lams c.(i) in + let c = Array.copy c in c.(i) <- ci; + for j = 0 to (n-1) do + c.(j) <- kill_dummy (kill_dummy_args ids (MLrel (n-i)) c.(j)) done; ids,c (*s Putting things together. *) -let normalize a = - let o = optims () in - let a = simpl o a in +let normalize a = + let o = optims () in + let a = simpl o a in if o.opt_kill_dum then post_simpl (kill_dummy a) else a (*S Special treatment of fixpoint for pretty-printing purpose. *) -let general_optimize_fix f ids n args m c = - let v = Array.make n 0 in +let general_optimize_fix f ids n args m c = + let v = Array.make n 0 in for i=0 to (n-1) do v.(i)<-i done; - let aux i = function - | MLrel j when v.(j-1)>=0 -> + let aux i = function + | MLrel j when v.(j-1)>=0 -> if ast_occurs (j+1) c then raise Impossible else v.(j-1)<-(-i-1) | _ -> raise Impossible - in list_iter_i aux args; + in list_iter_i aux args; let args_f = List.rev_map (fun i -> MLrel (i+m+1)) (Array.to_list v) in - let new_f = anonym_lams (MLapp (MLrel (n+m+1),args_f)) m in + let new_f = anonym_lams (MLapp (MLrel (n+m+1),args_f)) m in let new_c = named_lams ids (normalize (MLapp ((ast_subst new_f c),args))) in MLfix(0,[|f|],[|new_c|]) -let optimize_fix a = - if not (optims()).opt_fix_fun then a +let optimize_fix a = + if not (optims()).opt_fix_fun then a else - let ids,a' = collect_lams a in - let n = List.length ids in - if n = 0 then a - else match a' with + let ids,a' = collect_lams a in + let n = List.length ids in + if n = 0 then a + else match a' with | MLfix(_,[|f|],[|c|]) -> - let new_f = MLapp (MLrel (n+1),eta_args n) in + let new_f = MLapp (MLrel (n+1),eta_args n) in let new_c = named_lams ids (normalize (ast_subst new_f c)) in MLfix(0,[|f|],[|new_c|]) | MLapp(a',args) -> - let m = List.length args in - (match a' with - | MLfix(_,_,_) when - (test_eta_args_lift 0 n args) && not (ast_occurs_itvl 1 m a') + let m = List.length args in + (match a' with + | MLfix(_,_,_) when + (test_eta_args_lift 0 n args) && not (ast_occurs_itvl 1 m a') -> a' - | MLfix(_,[|f|],[|c|]) -> + | MLfix(_,[|f|],[|c|]) -> (try general_optimize_fix f ids n args m c with Impossible -> a) | _ -> a) @@ -1036,7 +1036,7 @@ let rec ml_size = function | MLapp(t,l) -> List.length l + ml_size t + ml_size_list l | MLlam(_,t) -> 1 + ml_size t | MLcons(_,_,l) -> ml_size_list l - | MLcase(_,t,pv) -> + | MLcase(_,t,pv) -> 1 + ml_size t + (Array.fold_right (fun (_,_,t) a -> a + ml_size t) pv 0) | MLfix(_,_,f) -> ml_size_array f | MLletin (_,_,t) -> ml_size t @@ -1057,111 +1057,111 @@ let rec is_constr = function (*s Strictness *) (* A variable is strict if the evaluation of the whole term implies - the evaluation of this variable. Non-strict variables can be found - behind Match, for example. Expanding a term [t] is a good idea when - it begins by at least one non-strict lambda, since the corresponding + the evaluation of this variable. Non-strict variables can be found + behind Match, for example. Expanding a term [t] is a good idea when + it begins by at least one non-strict lambda, since the corresponding argument to [t] might be unevaluated in the expanded code. *) exception Toplevel let lift n l = List.map ((+) n) l -let pop n l = List.map (fun x -> if x<=n then raise Toplevel else x-n) l +let pop n l = List.map (fun x -> if x<=n then raise Toplevel else x-n) l (* This function returns a list of de Bruijn indices of non-strict variables, - or raises [Toplevel] if it has an internal non-strict variable. - In fact, not all variables are checked for strictness, only the ones which - de Bruijn index is in the candidates list [cand]. The flag [add] controls - the behaviour when going through a lambda: should we add the corresponding - variable to the candidates? We use this flag to check only the external + or raises [Toplevel] if it has an internal non-strict variable. + In fact, not all variables are checked for strictness, only the ones which + de Bruijn index is in the candidates list [cand]. The flag [add] controls + the behaviour when going through a lambda: should we add the corresponding + variable to the candidates? We use this flag to check only the external lambdas, those that will correspond to arguments. *) -let rec non_stricts add cand = function - | MLlam (id,t) -> +let rec non_stricts add cand = function + | MLlam (id,t) -> let cand = lift 1 cand in let cand = if add then 1::cand else cand in pop 1 (non_stricts add cand t) - | MLrel n -> - List.filter ((<>) n) cand - | MLapp (MLrel n, _) -> + | MLrel n -> + List.filter ((<>) n) cand + | MLapp (MLrel n, _) -> List.filter ((<>) n) cand (* In [(x y)] we say that only x is strict. Cf [sig_rec]. We may *) (* gain something if x is replaced by a function like a projection *) - | MLapp (t,l)-> - let cand = non_stricts false cand t in - List.fold_left (non_stricts false) cand l - | MLcons (_,_,l) -> + | MLapp (t,l)-> + let cand = non_stricts false cand t in + List.fold_left (non_stricts false) cand l + | MLcons (_,_,l) -> List.fold_left (non_stricts false) cand l - | MLletin (_,t1,t2) -> - let cand = non_stricts false cand t1 in + | MLletin (_,t1,t2) -> + let cand = non_stricts false cand t1 in pop 1 (non_stricts add (lift 1 cand) t2) - | MLfix (_,i,f)-> + | MLfix (_,i,f)-> let n = Array.length i in - let cand = lift n cand in - let cand = Array.fold_left (non_stricts false) cand f in + let cand = lift n cand in + let cand = Array.fold_left (non_stricts false) cand f in pop n cand - | MLcase (_,t,v) -> + | MLcase (_,t,v) -> (* The only interesting case: for a variable to be non-strict, *) (* it is sufficient that it appears non-strict in at least one branch, *) (* so we make an union (in fact a merge). *) - let cand = non_stricts false cand t in - Array.fold_left - (fun c (_,i,t)-> - let n = List.length i in - let cand = lift n cand in + let cand = non_stricts false cand t in + Array.fold_left + (fun c (_,i,t)-> + let n = List.length i in + let cand = lift n cand in let cand = pop n (non_stricts add cand t) in Sort.merge (<=) cand c) [] v (* [merge] may duplicates some indices, but I don't mind. *) - | MLmagic t -> + | MLmagic t -> non_stricts add cand t - | _ -> + | _ -> cand (* The real test: we are looking for internal non-strict variables, so we start - with no candidates, and the only positive answer is via the [Toplevel] + with no candidates, and the only positive answer is via the [Toplevel] exception. *) -let is_not_strict t = +let is_not_strict t = try let _ = non_stricts true [] t in false with Toplevel -> true (*s Inlining decision *) -(* [inline_test] answers the following question: - If we could inline [t] (the user said nothing special), - should we inline ? - - We expand small terms with at least one non-strict +(* [inline_test] answers the following question: + If we could inline [t] (the user said nothing special), + should we inline ? + + We expand small terms with at least one non-strict variable (i.e. a variable that may not be evaluated). - + Futhermore we don't expand fixpoints. *) -let inline_test t = - let t1 = eta_red t in +let inline_test t = + let t1 = eta_red t in let t2 = snd (collect_lams t1) in not (is_fix t2) && ml_size t < 12 && is_not_strict t -let manual_inline_list = - let mp = MPfile (dirpath_of_string "Coq.Init.Wf") in +let manual_inline_list = + let mp = MPfile (dirpath_of_string "Coq.Init.Wf") in List.map (fun s -> (make_con mp empty_dirpath (mk_label s))) - [ "well_founded_induction_type"; "well_founded_induction"; + [ "well_founded_induction_type"; "well_founded_induction"; "Acc_rect"; "Acc_rec" ; "Acc_iter" ; "Fix" ] -let manual_inline = function +let manual_inline = function | ConstRef c -> List.mem c manual_inline_list - | _ -> false + | _ -> false (* If the user doesn't say he wants to keep [t], we inline in two cases: \begin{itemize} - \item the user explicitly requests it - \item [expansion_test] answers that the inlining is a good idea, and + \item the user explicitly requests it + \item [expansion_test] answers that the inlining is a good idea, and we are free to act (AutoInline is set) \end{itemize} *) -let inline r t = +let inline r t = not (to_keep r) (* The user DOES want to keep it *) - && not (is_inline_custom r) - && (to_inline r (* The user DOES want to inline it *) + && not (is_inline_custom r) + && (to_inline r (* The user DOES want to inline it *) || (auto_inline () && lang () <> Haskell && not (is_projection r) && (is_recursor r || manual_inline r || inline_test t))) |
