Expose the function [number] in the incremental API.

CHANGES

@@ -4,6 +4,7 @@ A [supplier] is a function that produces tokens on demand.
 [lexer_lexbuf_to_supplier] turns a lexer and a lexbuf into a supplier.
 [loop] is a ready-made made main parsing loop.
 [loop_handle] is a variant of [loop] that lets the user do her own error handling.
+[number] maps a state of the LR(1) automaton to its number.
 
 2015/10/16:
 Incompatible change of the incremental API: renamed the type ['a result]

TODO

@@ -88,7 +88,7 @@
 
 * Suite des patchs de Frédéric Bour.
     API d'inspection complète.
-      Exposer le nombre d'états (pour la mémoisation) et une conversion état -> entier.
+      Exposer le nombre d'états (pour la mémoisation).
       Idem pour les productions.
       Fonctions d'affichage pour les types terminal, nonterminal, etc.?
       Fonctions d'isomorphisme entre token et 'a terminal * 'a?

doc/main.tex

@@ -2149,6 +2149,14 @@ The index \verb+'a+ is the type of the semantic values associated with $A$.
 The role played by \verb+'a+ is clarified in the definition of the
 type \verb+element+, which follows.
 
+%% val number
+
+\begin{verbatim}
+  val number: _ lr1state -> int
+\end{verbatim}
+
+The states of the LR(1) automaton are numbered (from 0 and up).
+
 %% type element
 
 \begin{verbatim}

src/IncrementalEngine.ml

@@ -113,6 +113,10 @@ module type INCREMENTAL_ENGINE = sig
 
   type 'a lr1state
 
+  (* The states of the LR(1) automaton are numbered (from 0 and up). *)
+
+  val number: _ lr1state -> int
+
   (* An element is a pair of a non-initial state [s] and a semantic value [v]
      associated with the incoming symbol of this state. The idea is, the value
      [v] was pushed onto the stack just before the state [s] was entered. Thus,

src/engineTypes.ml

@@ -84,6 +84,10 @@ module type TABLE = sig
 
   type state
 
+  (* States are numbered. *)
+
+  val number: state -> int
+
   (* The type of tokens. These can be thought of as real tokens, that is,
      tokens returned by the lexer. They carry a semantic value. This type
      does not include the [error] pseudo-token. *)

src/referenceInterpreter.ml

@@ -9,6 +9,9 @@ module T = struct
   type state =
       Lr1.node
 
+  let number =
+    Lr1.number
+   
   type token =
       Terminal.t
 

src/tableInterpreter.ml

@@ -5,6 +5,8 @@ module Make (T : TableFormat.TABLES)
   type state =
       int
 
+  let number s = s
+
   type token =
       T.token