Index: src/natools-smaz_implementations-base_64_tools.adb
==================================================================
--- src/natools-smaz_implementations-base_64_tools.adb
+++ src/natools-smaz_implementations-base_64_tools.adb
@@ -1,7 +1,7 @@
 ------------------------------------------------------------------------------
--- Copyright (c) 2016, Natacha Porté                                        --
+-- Copyright (c) 2016-2017, Natacha Porté                                   --
 --                                                                          --
 -- Permission to use, copy, modify, and distribute this software for any    --
 -- purpose with or without fee is hereby granted, provided that the above   --
 -- copyright notice and this permission notice appear in all copies.        --
 --                                                                          --
@@ -226,10 +226,33 @@
 
       Digit := Value (Input (Offset));
       Offset := Offset + 1;
    end Next_Digit;
 
+
+   procedure Next_Digit_Or_End
+     (Input : in Ada.Streams.Stream_Element_Array;
+      Offset : in out Ada.Streams.Stream_Element_Offset;
+      Digit : out Base_64_Digit;
+      Finished : out Boolean) is
+   begin
+      loop
+         if Offset not in Input'Range then
+            Finished := True;
+            return;
+         end if;
+
+         exit when Input (Offset) in Base_64_Symbol;
+
+         Offset := Offset + 1;
+      end loop;
+
+      Digit := Value (Input (Offset));
+      Finished := False;
+      Offset := Offset + 1;
+   end Next_Digit_Or_End;
+
 
    function Symbol_Count (Input : Ada.Streams.Stream_Element_Array)
      return Ada.Streams.Stream_Element_Count
    is
       Result : Ada.Streams.Stream_Element_Count := 0;

Index: src/natools-smaz_implementations-base_64_tools.ads
==================================================================
--- src/natools-smaz_implementations-base_64_tools.ads
+++ src/natools-smaz_implementations-base_64_tools.ads
@@ -1,7 +1,7 @@
 ------------------------------------------------------------------------------
--- Copyright (c) 2016, Natacha Porté                                        --
+-- Copyright (c) 2016-2017, Natacha Porté                                   --
 --                                                                          --
 -- Permission to use, copy, modify, and distribute this software for any    --
 -- purpose with or without fee is hereby granted, provided that the above   --
 -- copyright notice and this permission notice appear in all copies.        --
 --                                                                          --
@@ -140,8 +140,13 @@
 
    procedure Next_Digit
      (Input : in Ada.Streams.Stream_Element_Array;
       Offset : in out Ada.Streams.Stream_Element_Offset;
       Digit : out Base_64_Digit);
+   procedure Next_Digit_Or_End
+     (Input : in Ada.Streams.Stream_Element_Array;
+      Offset : in out Ada.Streams.Stream_Element_Offset;
+      Digit : out Base_64_Digit;
+      Finished : out Boolean);
       --  Look for the first valid symbol in Input from Offset, and decode it
 
 end Natools.Smaz_Implementations.Base_64_Tools;