.

cylc · Apr 25, 2022 · 38e20ac · 38e20ac
1 parent 2825025
commit 38e20ac
Showing 1 changed file with 10 additions and 5 deletions.
diff --git a/cylc/rose/jinja2_parser.py b/cylc/rose/jinja2_parser.py
@@ -35,18 +35,23 @@
 
 
 def _lexer_wrap(fcn):
+    """Helper for patch_jinja2_leading_zeros.
+
+    Patches the jinja2.lexer.Lexer.wrap method.
+    """
     instances = set()
 
     def _stream(stream):
-        nonlocal instances
+        """Patch the token stream to strip the leading zero where necessary."""
+        nonlocal instances  # record of uses of deprecated syntax
         for lineno, token, value_str in stream:
             if (
                 token == jinja2.lexer.TOKEN_INTEGER
                 and len(value_str) > 1
                 and value_str[0] == '0'
             ):
                 instances.add(value_str)
-                value_str = value_str[1:]
+                value_str = value_str[1:]  # strip the leading zero
             yield (lineno, token, value_str)
 
     def _inner(
@@ -58,8 +63,8 @@ def _inner(
         nonlocal fcn
         return fcn(self, _stream(stream), name, filename)
 
-    _inner.__wrapped__ = fcn
-    _inner._instances = instances
+    _inner.__wrapped__ = fcn  # save the un-patched function
+    _inner._instances = instances  # save the set of uses of deprecated syntax
 
     return _inner
 
@@ -115,7 +120,7 @@ def patch_jinja2_leading_zeros():
             'Support for integers with leading zeros was dropped'
             ' in Jinja2 v3.'
             ' Rose will extend support until a future version.'
-            '\nPlease amend your configuration e.g:'
+            '\nPlease amend your Rose configuration files e.g:'
             '\n * '
             + (
                 '\n * '.join(