From: Stefano Zacchiroli <zack@upsilon.cc>
Date: Tue, 11 Jan 2005 16:01:46 +0000 (+0000)
Subject: - added support for contexts (terms with holes)
X-Git-Tag: V_0_1_0~150
X-Git-Url: http://matita.cs.unibo.it/gitweb/?a=commitdiff_plain;h=b24d13c4dcc96a204951857ddfa18c5ded4cecd0;p=helm.git

- added support for contexts (terms with holes)
- added CicUtil.pack/unpack to pack/unpack several terms in a single term
- added CicUtil.strip_prods to removed a given number of head prods from a term
- added CicUtil.context_of/select to create contexts/select a subterm
  matching a context
---

diff --git a/helm/ocaml/cic/cic.ml b/helm/ocaml/cic/cic.ml
index c997d99ca..4f7051688 100644
--- a/helm/ocaml/cic/cic.ml
+++ b/helm/ocaml/cic/cic.ml
@@ -39,7 +39,7 @@
 type id = string  (* the abstract type of the (annotated) node identifiers *)
 type 'term explicit_named_substitution = (UriManager.uri * 'term) list
 
-type implicit_annotation = [ `Closed | `Type ]
+type implicit_annotation = [ `Closed | `Type | `Hole ]
 
 type anntarget =
    Object of annobj         (* if annobj is a Constant, this is its type *)
@@ -58,7 +58,7 @@ and name =
    Name of string
  | Anonymous
 and term =
-   Rel of int                                       (* DeBrujin index *)
+   Rel of int                                       (* DeBrujin index, 1 based*)
  | Var of UriManager.uri *                          (* uri,                   *)
      term explicit_named_substitution               (*  explicit named subst. *)
  | Meta of int * (term option) list                 (* numeric id,    *)
@@ -94,7 +94,7 @@ and obj =
  | CurrentProof of string * metasenv *            (* name, conjectures,       *)
     term * term * UriManager.uri list             (*  value, type, parameters *)
  | InductiveDefinition of inductiveType list *    (* inductive types,         *)
-    UriManager.uri list * int                     (*  parameters, n ind. pars *)
+    UriManager.uri list * int                     (*  params, left params no  *)
 and inductiveType = 
  string * bool * term *                       (* typename, inductive, arity *)
   constructor list                            (*  constructors              *)
diff --git a/helm/ocaml/cic/cicUtil.ml b/helm/ocaml/cic/cicUtil.ml
index 1c5d603ca..5e0d6d4a9 100644
--- a/helm/ocaml/cic/cicUtil.ml
+++ b/helm/ocaml/cic/cicUtil.ml
@@ -160,3 +160,96 @@ let term_of_uri s =
   | Failure _
   | Not_found -> raise (UriManager.IllFormedUri s)
 
+let select ~term ~context =
+  let rec aux context term =
+    match (context, term) with
+    | Cic.Implicit (Some `Hole), t -> [t]
+    | Cic.Meta (_, ctxt1), Cic.Meta (_, ctxt2) ->
+        List.concat
+          (List.map2
+            (fun t1 t2 ->
+              (match (t1, t2) with Some t1, Some t2 -> aux t1 t2 | _ -> []))
+            ctxt1 ctxt2)
+    | Cic.Cast (te1, ty1), Cic.Cast (te2, ty2) -> aux te1 te2 @ aux ty1 ty2
+    | Cic.Prod (_, s1, t1), Cic.Prod (_, s2, t2)
+    | Cic.Lambda (_, s1, t1), Cic.Lambda (_, s2, t2)
+    | Cic.LetIn (_, s1, t1), Cic.LetIn (_, s2, t2) -> aux s1 s2 @ aux t1 t2
+    | Cic.Appl terms1, Cic.Appl terms2 -> auxs terms1 terms2
+    | Cic.Var (_, subst1), Cic.Var (_, subst2)
+    | Cic.Const (_, subst1), Cic.Const (_, subst2)
+    | Cic.MutInd (_, _, subst1), Cic.MutInd (_, _, subst2)
+    | Cic.MutConstruct (_, _, _, subst1), Cic.MutConstruct (_, _, _, subst2) ->
+        auxs (List.map snd subst1) (List.map snd subst2)
+    | Cic.MutCase (_, _, out1, t1, pat1), Cic.MutCase (_ , _, out2, t2, pat2) ->
+        aux out1 out2 @ aux t1 t2 @ auxs pat1 pat2
+    | Cic.Fix (_, funs1), Cic.Fix (_, funs2) ->
+        List.concat
+          (List.map2
+            (fun (_, _, ty1, bo1) (_, _, ty2, bo2) -> aux ty1 ty2 @ aux bo1 bo2)
+            funs1 funs2)
+    | Cic.CoFix (_, funs1), Cic.CoFix (_, funs2) ->
+        List.concat
+          (List.map2
+            (fun (_, ty1, bo1) (_, ty2, bo2) -> aux ty1 ty2 @ aux bo1 bo2)
+            funs1 funs2)
+    | _ -> assert false
+  and auxs terms1 terms2 =  (* as aux for list of terms *)
+    List.concat (List.map2 aux terms1 terms2)
+  in
+  aux context term
+
+let context_of ?(equality=(==)) ~term terms =
+  let (===) x y = equality x y in
+  let rec aux t =
+    match t with
+    | t when List.exists (fun t' -> t === t') terms -> Cic.Implicit (Some `Hole)
+    | Cic.Var (uri, subst) -> Cic.Var (uri, aux_subst subst)
+    | Cic.Meta (i, ctxt) ->
+        let ctxt =
+          List.map (function None -> None | Some t -> Some (aux t)) ctxt
+        in
+        Cic.Meta (i, ctxt)
+    | Cic.Cast (t, ty) -> Cic.Cast (aux t, aux ty)
+    | Cic.Prod (name, s, t) -> Cic.Prod (name, aux s, aux t)
+    | Cic.Lambda (name, s, t) -> Cic.Lambda (name, aux s, aux t)
+    | Cic.LetIn (name, s, t) -> Cic.LetIn (name, aux s, aux t)
+    | Cic.Appl terms -> Cic.Appl (List.map aux terms)
+    | Cic.Const (uri, subst) -> Cic.Const (uri, aux_subst subst)
+    | Cic.MutInd (uri, tyno, subst) -> Cic.MutInd (uri, tyno, aux_subst subst)
+    | Cic.MutConstruct (uri, tyno, consno, subst) ->
+        Cic.MutConstruct (uri, tyno, consno, aux_subst subst)
+    | Cic.MutCase (uri, tyno, outty, t, pat) ->
+        Cic.MutCase (uri, tyno, aux outty, aux t, List.map aux pat)
+    | Cic.Fix (funno, funs) ->
+        let funs =
+          List.map (fun (name, i, ty, bo) -> (name, i, aux ty, aux bo)) funs
+        in
+        Cic.Fix (funno, funs)
+    | Cic.CoFix (funno, funs) ->
+        let funs =
+          List.map (fun (name, ty, bo) -> (name, aux ty, aux bo)) funs
+        in
+        Cic.CoFix (funno, funs)
+    | Cic.Rel _
+    | Cic.Sort _
+    | Cic.Implicit _ -> t
+  and aux_subst subst =
+    List.map (fun (uri, t) -> (uri, aux t)) subst
+  in
+  aux term
+
+let pack terms =
+  List.fold_right
+    (fun term acc -> Cic.Prod (Cic.Anonymous, term, acc))
+    terms (Cic.Sort (Cic.Type (CicUniv.fresh ())))
+
+let rec unpack = function
+  | Cic.Prod (Cic.Anonymous, term, Cic.Sort (Cic.Type _)) -> [term]
+  | Cic.Prod (Cic.Anonymous, term, tgt) -> term :: unpack tgt
+  | _ -> assert false
+
+let rec strip_prods n = function
+  | t when n = 0 -> t
+  | Cic.Prod (_, _, tgt) when n > 0 -> strip_prods (n-1) tgt
+  | _ -> failwith "not enough prods"
+
diff --git a/helm/ocaml/cic/cicUtil.mli b/helm/ocaml/cic/cicUtil.mli
index ba9bab63d..cfd2d813a 100644
--- a/helm/ocaml/cic/cicUtil.mli
+++ b/helm/ocaml/cic/cicUtil.mli
@@ -39,3 +39,25 @@ val is_meta_closed : Cic.term -> bool
   (** @raise UriManager.IllFormedUri *)
 val term_of_uri: string -> Cic.term
 
+  (** packing/unpacking of several terms into a single one *)
+val pack: Cic.term list -> Cic.term
+val unpack: Cic.term -> Cic.term list
+
+  (** @raise Failure "not enough prods" *)
+val strip_prods: int -> Cic.term -> Cic.term
+
+(** {2 Contexts}
+ * A context is a Cic term in which Cic.Implicit terms annotated with `Hole
+ * appears *)
+
+(** create a context from a term and a list of subterm.
+* @param equality equality function used while walking the term. Defaults to
+* physical equality (==) *)
+val context_of:
+  ?equality:(Cic.term -> Cic.term -> bool) -> term:Cic.term -> Cic.term list ->
+    Cic.term
+
+(** select all subterms of a given term matching a given context (i.e. subtrees
+* rooted at context's holes *)
+val select: term:Cic.term -> context:Cic.term -> Cic.term list
+