Index: src/natools-s_expressions-interpreters.adb
==================================================================
--- src/natools-s_expressions-interpreters.adb
+++ src/natools-s_expressions-interpreters.adb
@@ -267,6 +267,55 @@
 
       raise Command_Not_Found
         with "Unknown command """ & To_String (Cmd.Current_Atom) & '"';
    end Execute;
 
+
+
+   --------------------------------------
+   -- Interpreter Building Subprograms --
+   --------------------------------------
+
+   function Build (Commands : Command_Array) return Interpreter is
+      Result : Interpreter;
+   begin
+      for I in Commands'Range loop
+         Result.Add_Command
+           (Commands (I).Name.Query.Data.all,
+            Commands (I).Cmd.Query.Data.all);
+      end loop;
+
+      return Result;
+   end Build;
+
+
+   function Build (Commands : Command_Array; Fallback : String)
+     return Interpreter
+   is
+      Result : Interpreter := Build (Commands);
+   begin
+      Result.Set_Fallback (To_Atom (Fallback));
+      return Result;
+   end Build;
+
+
+   function Item (Name : String; Cmd : Command'Class)
+     return Command_Description
+   is
+      function Get_Name return Atom;
+      function Get_Command return Command'Class;
+
+      function Get_Name return Atom is
+      begin
+         return To_Atom (Name);
+      end Get_Name;
+
+      function Get_Command return Command'Class is
+      begin
+         return Cmd;
+      end Get_Command;
+   begin
+      return (Name => Atom_Refs.Create (Get_Name'Access),
+              Cmd => Command_Refs.Create (Get_Command'Access));
+   end Item;
+
 end Natools.S_Expressions.Interpreters;

Index: src/natools-s_expressions-interpreters.ads
==================================================================
--- src/natools-s_expressions-interpreters.ads
+++ src/natools-s_expressions-interpreters.ads
@@ -26,11 +26,13 @@
 ------------------------------------------------------------------------------
 
 with Natools.S_Expressions.Lockable;
 
 private with Ada.Containers.Indefinite_Ordered_Maps;
+private with Natools.References;
 private with Natools.S_Expressions.Atom_Refs;
+private with Natools.Storage_Pools;
 
 generic
    type Shared_State (<>) is limited private;
    type Shared_Context (<>) is limited private;
 
@@ -113,10 +115,18 @@
       State : in out Shared_State;
       Context : in Shared_Context;
       Cmd : in out Lockable.Descriptor'Class);
       --  Execute a single command with arguments
 
+   type Command_Description is private;
+   type Command_Array is array (Positive range <>) of Command_Description;
+
+   function Build (Commands : Command_Array) return Interpreter;
+   function Build (Commands : Command_Array; Fallback : String)
+     return Interpreter;
+   function Item (Name : String; Cmd : Command'Class)
+     return Command_Description;
 
 private
 
    type Exception_Command is new Command with null record;
 
@@ -126,7 +136,17 @@
    type Interpreter is new Command with record
       Commands : Command_Maps.Map;
       Max_Length : Count := 0;
       Fallback_Name : Atom_Refs.Reference;
    end record;
+
+   package Command_Refs is new Natools.References
+     (Command'Class,
+      Storage_Pools.Access_In_Default_Pool'Storage_Pool,
+      Storage_Pools.Access_In_Default_Pool'Storage_Pool);
+
+   type Command_Description is record
+      Name : Atom_Refs.Immutable_Reference;
+      Cmd : Command_Refs.Immutable_Reference;
+   end record;
 
 end Natools.S_Expressions.Interpreters;