Removed [Production.used], since it now always returns [true].

src/codeBackend.ml

@@ -710,19 +710,12 @@ let runcellparams var holds_state symbol =
    symbol this stack cell is associated with. *)
 
 let reducecellparams prod i holds_state symbol =
-  let ids = Production.identifiers prod
-  and used = Production.used prod in
+  let ids = Production.identifiers prod in
 
-  (* If the semantic value is used in the semantic action, then it is
-     bound to the variable [ids.(i)]. If the semantic value is not
-     used in the semantic action, then it is dropped using a wildcard
-     pattern. *)
+  (* The semantic value is bound to the variable [ids.(i)]. *)
 
   let semvpat _t =
-    if used.(i) then
-      PVar ids.(i)
-    else
-      PWildcard
+    PVar ids.(i)
   in
 
   elementif holds_state (if i = 0 then PVar state else PWildcard) @
@@ -1137,7 +1130,6 @@ let reducebody prod =
 
   let nt, rhs = Production.def prod
   and ids = Production.identifiers prod
-  and used = Production.used prod
   and length = Production.length prod in
 
   (* Build a pattern that represents the shape of the stack. Out of
@@ -1167,14 +1159,11 @@ let reducebody prod =
 
   let unitbindings =
     Misc.foldi length (fun i unitbindings ->
-      if used.(i) then
-	match semvtype rhs.(i) with
-	| [] ->
-	    (PVar ids.(i), EUnit) :: unitbindings
-	| _ ->
-	    unitbindings
-      else
-	unitbindings
+      match semvtype rhs.(i) with
+      | [] ->
+  	  (PVar ids.(i), EUnit) :: unitbindings
+      | _ ->
+	  unitbindings
     ) []
   in
 

src/grammar.ml

@@ -432,9 +432,6 @@ module Production = struct
   let identifiers : identifier array array =
     Array.make n [||]
 
-  let used : bool array array =
-    Array.make n [||]
-
   let actions : action option array =
     Array.make n None
 
@@ -451,7 +448,6 @@ module Production = struct
       and nt' = Nonterminal.lookup (nonterminal ^ "'") in
       table.(k) <- (nt', [| Symbol.N nt |]);
       identifiers.(k) <- [| "_1" |];
-      used.(k) <- [| true |];
       ntprods.(nt') <- (k, k+1);
       positions.(k) <- Nonterminal.positions nt;
       k+1,
@@ -473,8 +469,6 @@ module Production = struct
       let symbols = Array.of_list branch.producers in
       table.(k) <- (nt, Array.map (fun (v, _) -> Symbol.lookup v) symbols);
       identifiers.(k) <- Array.map snd symbols;
-      (* TEMPORARY: [used] is useless since all arguments are named now. Should we remove it? *)
-      used.(k) <- Array.map (fun _ -> true) symbols; 
       actions.(k) <- Some action;
       reduce_precedence.(k) <- rprec;
       prec_decl.(k) <- sprec;
@@ -535,9 +529,6 @@ module Production = struct
   let identifiers prod =
     identifiers.(prod)
 
-  let used prod =
-    used.(prod)
-
   let is_start prod =
     prod < start
 

src/grammar.mli

@@ -266,14 +266,6 @@ module Production : sig
 
   val identifiers: index -> Syntax.identifier array
 
-  (* This maps a production index to an array of Boolean flag. Each
-     flag tells whether the semantic value of the corresponding symbol
-     is used in the semantic action. This is a conservative
-     approximation: [true] means maybe, while [false] means certainly
-     not. *)
-
-  val used: index -> bool array  
-
   (* This maps a production index to the production's semantic action.
      This function is not applicable to a start production. *)
 

src/tableBackend.ml

@@ -144,12 +144,11 @@ let define_and_measure (x, e) =
 
 let reducecellparams prod i _symbol (next : pattern) : pattern =
 
-  let ids = Production.identifiers prod
-  and used = Production.used prod in
+  let ids = Production.identifiers prod in
 
   PRecord [
     fstate, (if i = 0 then PVar state else PWildcard);
-    fsemv, (if used.(i) then PVar ids.(i) else PWildcard);
+    fsemv, PVar ids.(i);
     fstartp, PVar (Printf.sprintf "_startpos_%s_" ids.(i));
     fendp, PVar (Printf.sprintf "_endpos_%s_" ids.(i));
     fnext, next;
@@ -162,27 +161,22 @@ let reducecellparams prod i _symbol (next : pattern) : pattern =
 
 let reducecellcasts prod i symbol casts =
 
-  let ids = Production.identifiers prod
-  and used = Production.used prod in
-
-  if used.(i) then
-    let id = ids.(i) in
-    let t : typ =
-      match semvtype symbol with
-      | [] ->
-	  tunit
-      | [ t ] ->
-	  t
-      | _ ->
-	  assert false
-    in
-    (* Cast: [let id = ((Obj.magic id) : t) in ...]. *)
-    (
-      PVar id,
-      EAnnot (EMagic (EVar id), type2scheme t)
-    ) :: casts
-  else
-    casts
+  let ids = Production.identifiers prod in
+  let id = ids.(i) in
+  let t : typ =
+    match semvtype symbol with
+    | [] ->
+        tunit
+    | [ t ] ->
+        t
+    | _ ->
+        assert false
+  in
+  (* Cast: [let id = ((Obj.magic id) : t) in ...]. *)
+  (
+    PVar id,
+    EAnnot (EMagic (EVar id), type2scheme t)
+  ) :: casts
 
 (* This is the body of the [reduce] function associated with
    production [prod]. It assumes that the variables [env] and [stack]