Initial Commit

Working base grammar, visitor, client, context.
Good test coverage for grammar constructs.

customcmd/lib.py

@@ -0,0 +1,14 @@
+import re
+import regex
+
+
+async def resub_async(pattern, coro, string, flags=0):
+    result = []
+    last_end = 0
+
+    for match in re.finditer(pattern, string, flags=flags):
+        result.append(string[last_end:match.start()])
+        result.append(await coro(string))
+        last_end = match.end()
+
+