Add support for extracting RFCs from XML.

Fallback to .txt if the XML file cannot be found.

extractors/rfc_extractor.py

@@ -47,11 +47,21 @@ def __init__(self, rfc_extractor_paths: RFCExtractorPaths, debug_level: int):
         self.__create_ietf_rfcs_list()
 
     def __create_ietf_rfcs_list(self):
-        self.ietf_rfcs = [
-            f
-            for f in os.listdir(self.rfc_extractor_paths.rfc_path)
-            if os.path.isfile(os.path.join(self.rfc_extractor_paths.rfc_path, f))
-        ]
+        for f in os.listdir(self.rfc_extractor_paths.rfc_path):
+            if not f.endswith(".txt"):
+                continue
+
+            (base, _) = os.path.splitext(f)
+            full_path = os.path.join(self.rfc_extractor_paths.rfc_path, f)
+            fname = f
+            xml_file = os.path.join(self.rfc_extractor_paths.rfc_path, base + ".xml")
+            if os.path.isfile(xml_file):
+                full_path = xml_file
+                fname = base + ".xml"
+
+            if os.path.isfile(full_path):
+                self.ietf_rfcs.append(fname)
+
         self.ietf_rfcs.sort()
         print('IETF RFCs list created')
 
@@ -95,6 +105,7 @@ def extract_from_rfc_file(self, rfc_file: str) -> list[str]:
             force_revision_pyang=False,
             force_revision_regexp=True,
             extract_code_snippets=True,
+            rfcxml=(rfc_file.endswith(".xml")),
             code_snippets_dir=os.path.join(self.code_snippets_directory, os.path.splitext(rfc_file)[0]),
         )