1 files changed, 91 insertions, 0 deletions
diff --git a/src/change_vectors.ads b/src/change_vectors.ads
new file mode 100644
index 0000000..b2b74b7
--- /dev/null
+++ b/src/change_vectors.ads
@@ -0,0 +1,91 @@
+
+
+with FLTK.Text_Buffers;
+with Ada.Strings.Unbounded; use Ada.Strings.Unbounded;
+private with Ada.Containers.Vectors;
+
+
+package Change_Vectors is
+
+
+    type Change_Vector is tagged private;
+
+
+    type Change is
+        record
+            Action : FLTK.Text_Buffers.Modification;
+            Place  : FLTK.Text_Buffers.Position;
+            Length : Natural;
+            Text   : Unbounded_String;
+        end record;
+
+
+    Empty_Vector : constant Change_Vector;
+
+
+    procedure Push
+           (This : in out Change_Vector;
+            Item : in     Change);
+
+
+    function Pop
+           (This : in out Change_Vector)
+        return Boolean;
+
+
+    procedure Pop
+           (This : in out Change_Vector);
+
+
+    function Peek
+           (This : in     Change_Vector;
+            Item :    out Change)
+        return Boolean;
+
+
+    procedure Peek
+           (This : in     Change_Vector;
+            Item :    out Change);
+
+
+    function Re_Push
+           (This : in out Change_Vector)
+        return Boolean;
+
+
+    procedure Re_Push
+           (This : in out Change_Vector);
+
+
+    function At_Start
+           (This : in Change_Vector)
+        return Boolean;
+
+
+    function At_End
+           (This : in Change_Vector)
+        return Boolean;
+
+
+private
+
+
+    package Internal_Vectors is new Ada.Containers.Vectors
+           (Index_Type => Positive, Element_Type => Change);
+
+
+    type Change_Vector is tagged
+        record
+            Near, Far : Natural;
+            List      : Internal_Vectors.Vector;
+        end record;
+
+
+    Empty_Vector : constant Change_Vector :=
+           (Near => 0,
+            Far => 0,
+            List => Internal_Vectors.Empty_Vector);
+
+
+end Change_Vectors;
+