This provides a class which works as a command registry. Functions are added to
the registry through a method on the class `add`. Add acts as a decorator
taking in the name of the command and optionally type converters for arguments.
When handling requests, we can now tokenize the line, and then just pass the
arguments to our commands helper. It will lookup the correct handler and apply
any validation before calling the original function.
For the sake of testing the original function is not wrapped. This the
functions, and anything testing them directly can simply assume pre-converted
data as long as type annotations are in place.
A sample usage would be:
@protocol.commands.add('addid', position=protocol.integer)
def addid(context, uri, position=None)
pass
def handle_request(line):
tokens = protocol.tokenizer(line)
context = ...
result = protocol.commands.call(tokens, context=context)