locus: Add an AtLeastOneOccurrence constructor.

The semantics is obviously that it is an error if not at least one
occurrence is found (natural semantics for rewriting for
example).

7 files changed, 19 insertions, 8 deletions

diff --git a/pretyping/evarconv.ml b/pretyping/evarconv.ml
index aa30ed8d2e..f8e5e0759b 100644
--- a/pretyping/evarconv.ml
+++ b/pretyping/evarconv.ml
@@ -1148,7 +1148,7 @@ let second_order_matching ts env_rhs evd (evk,args) argoccs rhs =
   | (id,_,c,cty,evsref,filter,occs)::subst ->
       let set_var k =
         match occs with
-        | Some Locus.AllOccurrences -> mkVar id
+        | Some (Locus.AtLeastOneOccurrence | Locus.AllOccurrences) -> mkVar id
         | Some _ -> user_err Pp.(str "Selection of specific occurrences not supported")
         | None ->
         let evty = set_holes evdref cty subst in
diff --git a/pretyping/find_subterm.ml b/pretyping/find_subterm.ml
index b16087031b..d150f8e1cb 100644
--- a/pretyping/find_subterm.ml
+++ b/pretyping/find_subterm.ml
@@ -125,7 +125,7 @@ let replace_term_occ_gen_modulo sigma occs like_first test bywhat cl occ t =
          end;
          add_subst t subst; incr pos;
          (* Check nested matching subterms *)
-         if occs != Locus.AllOccurrences && occs != Locus.NoOccurrences then
+         if not (Locusops.is_all_occurrences occs) && occs != Locus.NoOccurrences then
            begin nested := true; ignore (subst_below k t); nested := false end;
          (* Do the effective substitution *)
          Vars.lift k (bywhat ()))
diff --git a/pretyping/locus.ml b/pretyping/locus.ml
index 37dd120c1a..087a6b9174 100644
--- a/pretyping/locus.ml
+++ b/pretyping/locus.ml
@@ -20,6 +20,7 @@ type 'a or_var =
 
 type 'a occurrences_gen =
   | AllOccurrences
+  | AtLeastOneOccurrence
   | AllOccurrencesBut of 'a list (** non-empty *)
   | NoOccurrences
   | OnlyOccurrences of 'a list (** non-empty *)
diff --git a/pretyping/locusops.ml b/pretyping/locusops.ml
index 6b6a3f8a9f..aaa4ce684d 100644
--- a/pretyping/locusops.ml
+++ b/pretyping/locusops.ml
@@ -19,15 +19,17 @@ let occurrences_map f = function
   | AllOccurrencesBut l ->
     let l' = f l in
     if l' = [] then AllOccurrences else AllOccurrencesBut l'
-  | (NoOccurrences|AllOccurrences) as o -> o
+  | (NoOccurrences|AllOccurrences|AtLeastOneOccurrence) as o -> o
 
 let convert_occs = function
+  | AtLeastOneOccurrence -> (false,[])
   | AllOccurrences -> (false,[])
   | AllOccurrencesBut l -> (false,l)
   | NoOccurrences -> (true,[])
   | OnlyOccurrences l -> (true,l)
 
 let is_selected occ = function
+  | AtLeastOneOccurrence -> true
   | AllOccurrences -> true
   | AllOccurrencesBut l -> not (Int.List.mem occ l)
   | OnlyOccurrences l -> Int.List.mem occ l
@@ -46,6 +48,11 @@ let is_nowhere = function
 | { onhyps=Some[]; concl_occs=NoOccurrences } -> true
 | _ -> false
 
+let is_all_occurrences = function
+  | AtLeastOneOccurrence
+  | AllOccurrences -> true
+  | _ -> false
+
 (** Clause conversion functions, parametrized by a hyp enumeration function *)
 
 (** From [clause] to [simple_clause] *)
@@ -61,12 +68,12 @@ let simple_clause_of enum_hyps cl =
 	List.map Option.make (enum_hyps ())
     | Some l ->
 	List.map (fun ((occs,id),w) ->
-	  if occs <> AllOccurrences then error_occurrences ();
+          if not (is_all_occurrences occs) then error_occurrences ();
 	  if w = InHypValueOnly then error_body_selection ();
 	  Some id) l in
   if cl.concl_occs = NoOccurrences then hyps
   else
-    if cl.concl_occs <> AllOccurrences then error_occurrences ()
+    if not (is_all_occurrences cl.concl_occs) then error_occurrences ()
     else None :: hyps
 
 (** From [clause] to [concrete_clause] *)
@@ -111,7 +118,7 @@ let clause_with_generic_occurrences cls =
      List.for_all
        (function ((AllOccurrences,_),_) -> true | _ -> false) hyps in
   let concl = match cls.concl_occs with
-  | AllOccurrences | NoOccurrences -> true
+  | AtLeastOneOccurrence | AllOccurrences | NoOccurrences -> true
   | _ -> false in
   hyps && concl
 
@@ -122,6 +129,6 @@ let clause_with_generic_context_selection cls =
      List.for_all
        (function ((AllOccurrences,_),InHyp) -> true | _ -> false) hyps in
   let concl = match cls.concl_occs with
-  | AllOccurrences | NoOccurrences -> true
+  | AtLeastOneOccurrence | AllOccurrences | NoOccurrences -> true
   | _ -> false in
   hyps && concl
diff --git a/pretyping/locusops.mli b/pretyping/locusops.mli
index a07c018c32..ac15fe1018 100644
--- a/pretyping/locusops.mli
+++ b/pretyping/locusops.mli
@@ -21,6 +21,8 @@ val convert_occs : occurrences -> bool * int list
 
 val is_selected : int -> occurrences -> bool
 
+val is_all_occurrences : 'a occurrences_gen -> bool
+
 (** Usual clauses *)
 
 val allHypsAndConcl : 'a clause_expr
diff --git a/pretyping/tacred.ml b/pretyping/tacred.ml
index 2308a541fb..5db571433a 100644
--- a/pretyping/tacred.ml
+++ b/pretyping/tacred.ml
@@ -1105,6 +1105,7 @@ let unfoldoccs env sigma (occs,name) c =
     | AllOccurrences -> unfold env sigma name c
     | OnlyOccurrences l -> unfo true l
     | AllOccurrencesBut l -> unfo false l
+    | AtLeastOneOccurrence -> unfo false []
 
 (* Unfold reduction tactic: *)
 let unfoldn loccname env sigma c =
diff --git a/pretyping/unification.ml b/pretyping/unification.ml
index ac0b58b92b..ce97912b84 100644
--- a/pretyping/unification.ml
+++ b/pretyping/unification.ml
@@ -1649,7 +1649,7 @@ let make_abstraction_core name (test,out) env sigma c ty occs check_occs concl =
     match occurrences_of_hyp hyp occs with
     | NoOccurrences, InHyp ->
         (push_named_context_val d sign,depdecls)
-    | AllOccurrences, InHyp as occ ->
+    | (AllOccurrences | AtLeastOneOccurrence), InHyp as occ ->
         let occ = if likefirst then LikeFirst else AtOccs occ in
         let newdecl = replace_term_occ_decl_modulo sigma occ test mkvarid d in
         if Context.Named.Declaration.equal (EConstr.eq_constr sigma) d newdecl