Provide own interfaces since Chameleon will not provide them in a fut…

…ure release

CHANGES.rst

@@ -5,7 +5,8 @@
 4.1 (unreleased)
 ================
 
-- Nothing changed yet.
+- Provide own interfaces, since Chameleon will not provide those in a
+  future release.
 
 
 4.0 (2023-03-27)

src/z3c/pt/configure.zcml

@@ -9,7 +9,7 @@
     <include package="zope.security" file="meta.zcml" />
 
     <class class="chameleon.tal.RepeatItem">
-      <allow interface="chameleon.interfaces.ITALESIterator" />
+      <allow interface=".interfaces.ITALESIterator" />
     </class>
 
     <class class=".pagetemplate.BoundPageTemplate">

src/z3c/pt/interfaces.py

@@ -0,0 +1,86 @@
+from zope.interface import Interface
+
+
+class ITALIterator(Interface):  # pragma: no cover
+    """A TAL iterator
+
+    Not to be confused with a Python iterator.
+    """
+
+    def next():
+        """Advance to the next value in the iteration, if possible
+
+        Return a true value if it was possible to advance and return
+        a false value otherwise.
+        """
+
+
+class ITALESIterator(ITALIterator):  # pragma: no cover
+    """TAL Iterator provided by TALES
+
+    Values of this iterator are assigned to items in the repeat namespace.
+
+    For example, with a TAL statement like: tal:repeat="item items",
+    an iterator will be assigned to "repeat/item".  The iterator
+    provides a number of handy methods useful in writing TAL loops.
+
+    The results are undefined of calling any of the methods except
+    'length' before the first iteration.
+    """
+
+    def index():
+        """Return the position (starting with "0") within the iteration
+        """
+
+    def number():
+        """Return the position (starting with "1") within the iteration
+        """
+
+    def even():
+        """Return whether the current position is even
+        """
+
+    def odd():
+        """Return whether the current position is odd
+        """
+
+    def parity():
+        """Return 'odd' or 'even' depending on the position's parity
+
+        Useful for assigning CSS class names to table rows.
+        """
+
+    def start():
+        """Return whether the current position is the first position
+        """
+
+    def end():
+        """Return whether the current position is the last position
+        """
+
+    def letter():
+        """Return the position (starting with "a") within the iteration
+        """
+
+    def Letter():
+        """Return the position (starting with "A") within the iteration
+        """
+
+    def roman():
+        """Return the position (starting with "i") within the iteration
+        """
+
+    def Roman():
+        """Return the position (starting with "I") within the iteration
+        """
+
+    def item():
+        """Return the item at the current position
+        """
+
+    def length():
+        """Return the length of the sequence
+
+        Note that this may fail if the TAL iterator was created on a Python
+        iterator.
+        """