Added comparison functions for productions and items.

src/IncrementalEngine.ml

@@ -134,13 +134,6 @@ module type INSPECTION = sig
 
   include SYMBOLS
 
-  (* Ordering functions. *)
-
-  val compare_terminals: _ terminal -> _ terminal -> int
-  val compare_nonterminals: _ nonterminal -> _ nonterminal -> int
-  val compare_symbols: xsymbol -> xsymbol -> int
-  val compare_words: xsymbol list -> xsymbol list -> int
-
   (* The type ['a lr1state] is meant to be the same as in [INCREMENTAL_ENGINE]. *)
 
   type 'a lr1state
@@ -158,6 +151,15 @@ module type INSPECTION = sig
   type item =
       production * int
 
+  (* Ordering functions. *)
+
+  val compare_terminals: _ terminal -> _ terminal -> int
+  val compare_nonterminals: _ nonterminal -> _ nonterminal -> int
+  val compare_symbols: xsymbol -> xsymbol -> int
+  val compare_words: xsymbol list -> xsymbol list -> int
+  val compare_productions: production -> production -> int
+  val compare_items: item -> item -> int
+
   (* [incoming_symbol s] is the incoming symbol of the state [s], that is,
      the symbol that the parser must recognize before (has recognized when)
      it enters the state [s]. This function gives access to the semantic

src/inspectionTableInterpreter.ml

@@ -104,6 +104,15 @@ module Make
   let compare_words w1 w2 =
     General.compare compare_symbols w1 w2
 
+  let compare_productions prod1 prod2 =
+    (* Subtraction is safe because overflow is impossible. *)
+    prod1 - prod2
+
+  let compare_items (prod1, index1) (prod2, index2) =
+    let c = compare_productions prod1 prod2 in
+    (* Subtraction is safe because overflow is impossible. *)
+    if c <> 0 then c else index1 - index2
+
   (* The function [incoming_symbol] goes through the tables [T.lr0_core] and
      [T.lr0_incoming]. This yields a representation of type [xsymbol], out of
      which we strip the [X] quantifier, so as to get a naked symbol. This last