-(*
- ||M|| This file is part of HELM, an Hypertextual, Electronic
- ||A|| Library of Mathematics, developed at the Computer Science
- ||T|| Department, University of Bologna, Italy.
- ||I||
- ||T|| HELM is free software; you can redistribute it and/or
- ||A|| modify it under the terms of the GNU General Public License
- \ / version 2 or (at your option) any later version.
- \ / This software is distributed as is, NO WARRANTY.
- V_______________________________________________________________ *)
-
-(* $Id$ *)
-
-module DiscriminationTreeIndexing =
- functor (A:Set.S) ->
- struct
-
- type path_string_elem =
- | Constant of NUri.uri
- | Bound of int | Variable | Proposition | Datatype | Dead;;
- type path_string = path_string_elem list;;
-
-
- (* needed by the retrieve_* functions, to know the arities of the
- * "functions" *)
-
- let ppelem = function
- | Constant uri -> NUri.name_of_uri uri
- | Bound i -> string_of_int i
- | Variable -> "?"
- | Proposition -> "Prop"
- | Datatype -> "Type"
- | Dead -> "DEAD"
- ;;
- let pppath l = String.concat "::" (List.map ppelem l) ;;
- let elem_of_cic = function
- | NCic.Meta _ | NCic.Implicit _ -> Variable
- | NCic.Rel i -> Bound i
- | NCic.Sort (NCic.Prop) -> Proposition
- | NCic.Sort _ -> Datatype
- | NCic.Const _ | NCic.Var _ | NCic.MutInd _ | NCic.MutConstruct _ as t ->
- (try Constant (CicUtil.uri_of_term t)
- with Invalid_argument _ -> assert false)
- | NCic.Appl _ ->
- assert false (* should not happen *)
- | NCic.LetIn _ | NCic.Lambda _ | NCic.Prod _ | NCic.Cast _
- | NCic.MutCase _ | NCic.Fix _ | NCic.CoFix _ ->
- HLog.debug "FIXME: the trie receives an invalid term";
- Dead
- (* assert false universe.ml removes these *)
- ;;
- let path_string_of_term arities =
- let set_arity arities k n =
- (assert (k<>Variable || n=0);
- if k = Dead then arities else (k,n)::(List.remove_assoc k arities))
- in
- let rec aux arities = function
- | NCic.Appl ((hd::tl) as l) ->
- let arities =
- set_arity arities (elem_of_cic hd) (List.length tl) in
- List.fold_left
- (fun (arities,path) t ->
- let arities,tpath = aux arities t in
- arities,path@tpath)
- (arities,[]) l
- | t -> arities, [elem_of_cic t]
- in
- aux arities
- ;;
- let compare_elem e1 e2 =
- match e1,e2 with
- | Constant u1,Constant u2 -> NUri.compare u1 u2
- | e1,e2 -> Pervasives.compare e1 e2
- ;;
-
- module OrderedPathStringElement = struct
- type t = path_string_elem
- let compare = compare_elem
- end
-
- module PSMap = Map.Make(OrderedPathStringElement);;
-
- type key = PSMap.key
-
- module DiscriminationTree = Trie.Make(PSMap);;
-
- type t = A.t DiscriminationTree.t * (path_string_elem*int) list
- let empty = DiscriminationTree.empty, [] ;;
-
- let iter (dt, _ ) f =
- DiscriminationTree.iter (fun _ x -> f x) dt
- ;;
-
- let index (tree,arity) term info =
- let arity,ps = path_string_of_term arity term in
- let ps_set =
- try DiscriminationTree.find ps tree
- with Not_found -> A.empty in
- let tree = DiscriminationTree.add ps (A.add info ps_set) tree in
- tree,arity
- ;;
-
- let remove_index (tree,arity) term info =
- let arity,ps = path_string_of_term arity term in
- try
- let ps_set = A.remove info (DiscriminationTree.find ps tree) in
- if A.is_empty ps_set then
- DiscriminationTree.remove ps tree,arity
- else
- DiscriminationTree.add ps ps_set tree,arity
- with Not_found ->
- tree,arity
- ;;
-
- let in_index (tree,arity) term test =
- let arity,ps = path_string_of_term arity term in
- try
- let ps_set = DiscriminationTree.find ps tree in
- A.exists test ps_set
- with Not_found ->
- false
- ;;
-
- let head_of_term = function
- | NCic.Appl (hd::tl) -> hd
- | term -> term
- ;;
-
- let rec skip_prods = function
- | NCic.Prod (_,_,t) -> skip_prods t
- | term -> term
- ;;
-
- let rec subterm_at_pos pos term =
- match pos with
- | [] -> term
- | index::pos ->
- match term with
- | NCic.Appl l ->
- (try subterm_at_pos pos (List.nth l index)
- with Failure _ -> raise Not_found)
- | _ -> raise Not_found
- ;;
-
-
- let rec after_t pos term =
- let pos' =
- match pos with
- | [] -> raise Not_found
- | pos ->
- List.fold_right
- (fun i r -> if r = [] then [i+1] else i::r) pos []
- in
- try
- ignore(subterm_at_pos pos' term ); pos'
- with Not_found ->
- let pos, _ =
- List.fold_right
- (fun i (r, b) -> if b then (i::r, true) else (r, true))
- pos ([], false)
- in
- after_t pos term
- ;;
-
-
- let next_t pos term =
- let t = subterm_at_pos pos term in
- try
- let _ = subterm_at_pos [1] t in
- pos @ [1]
- with Not_found ->
- match pos with
- | [] -> [1]
- | pos -> after_t pos term
- ;;
-
- let retrieve_generalizations (tree,arity) term =
- let term = skip_prods term in
- let rec retrieve tree term pos =
- match tree with
- | DiscriminationTree.Node (Some s, _) when pos = [] -> s
- | DiscriminationTree.Node (_, map) ->
- let res =
- let hd_term =
- elem_of_cic (head_of_term (subterm_at_pos pos term))
- in
- if hd_term = Variable then A.empty else
- try
- let n = PSMap.find hd_term map in
- match n with
- | DiscriminationTree.Node (Some s, _) -> s
- | DiscriminationTree.Node (None, _) ->
- let newpos =
- try next_t pos term
- with Not_found -> []
- in
- retrieve n term newpos
- with Not_found ->
- A.empty
- in
- try
- let n = PSMap.find Variable map in
- let newpos = try after_t pos term with Not_found -> [-1] in
- if newpos = [-1] then
- match n with
- | DiscriminationTree.Node (Some s, _) -> A.union s res
- | _ -> res
- else
- A.union res (retrieve n term newpos)
- with Not_found ->
- res
- in
- retrieve tree term []
- ;;
-
-
- let jump_list arities = function
- | DiscriminationTree.Node (value, map) ->
- let rec get n tree =
- match tree with
- | DiscriminationTree.Node (v, m) ->
- if n = 0 then
- [tree]
- else
- PSMap.fold
- (fun k v res ->
- let a =
- try List.assoc k arities
- with Not_found -> 0
- in
- (get (n-1 + a) v) @ res) m []
- in
- PSMap.fold
- (fun k v res ->
- let arity =
- try
- List.assoc k arities
- with Not_found -> 0 in
- (get arity v) @ res)
- map []
- ;;
-
-
- let retrieve_unifiables (tree,arities) term =
- let term = skip_prods term in
- let rec retrieve tree term pos =
- match tree with
- | DiscriminationTree.Node (Some s, _) when pos = [] -> s
- | DiscriminationTree.Node (_, map) ->
- let subterm =
- try Some (subterm_at_pos pos term) with Not_found -> None
- in
- match subterm with
- | None -> A.empty
- | Some (NCic.Meta _) ->
- let newpos = try next_t pos term with Not_found -> [] in
- let jl = jump_list arities tree in
- List.fold_left
- (fun r s -> A.union r s)
- A.empty
- (List.map (fun t -> retrieve t term newpos) jl)
- | Some subterm ->
- let res =
- let hd_term = elem_of_cic (head_of_term subterm) in
- if hd_term = Variable then
- A.empty else
- try
- let n = PSMap.find hd_term map in
- match n with
- | DiscriminationTree.Node (Some s, _) -> s
- | DiscriminationTree.Node (None, _) ->
- retrieve n term (next_t pos term)
- with Not_found ->
- A.empty
- in
- try
- let n = PSMap.find Variable map in
- let newpos =
- try after_t pos term
- with Not_found -> [-1]
- in
- if newpos = [-1] then
- match n with
- | DiscriminationTree.Node (Some s, _) ->
- A.union s res
- | _ -> res
- else
- A.union res (retrieve n term newpos)
- with Not_found ->
- res
- in
- retrieve tree term []
- end
-;;
-