rasguanabana/function-pattern-matching

Pattern matching and guards for Python functions

function-pattern-matching's Issues

Mixing case and guard raises error

Works:

@fpm.case
@fpm.guard(msg = fpm.eq("Ping"), sender = fpm.isoftype(Actor))
def handle(self, sender, msg, payload):
	sender.tell("Pong", sender=self)

Doesn't work:

@fpm.case(msg = "Ping")
@fpm.guard(sender = fpm.isoftype(Actor))
def handle(self, sender, msg, payload):
	sender.tell("Pong", sender=self)

The second case raises the following error:

Traceback (most recent call last):
  File "./ping_pong.py", line 14, in <module>
    class PingPong(Actor):
  File "./ping_pong.py", line 20, in PingPong
    @fpm.guard(sender = fpm.isoftype(Actor))
  File "/Users/mklemm/compile/python-arago-actors/lib/python3.7/site-packages/function_pattern_matching.py", line 551, in decorator
    decoratee._argument_guards[arg_name] = match & decoratee._argument_guards[arg_name]
  File "/Users/mklemm/compile/python-arago-actors/lib/python3.7/site-packages/function_pattern_matching.py", line 141, in checks
    raise TypeError("The right-hand operand has to be instance of GuardFunc")
TypeError: The right-hand operand has to be instance of GuardFunc

Measure overhead

Module may need some optimisation.

Test different/older Python versions

fpm works under 2.7 and 3.5. Older versions should be checked also, especially pre 3.3

Not sure what about anything different from CPython

Readme and docs

Make complete and accurate.

setup.py and pip release

Doesn't work with methods

Hi,

I'm writing a small actor system based on gevent and I really like your pattern matching library. It allows me keep the functions that handle the various messages that can be sent to an actor rather short because of the multi-dispatch feature.

But there seems to be a problem when decorating methods instead of functions with @guard and @case: Because inspect.signature skips the "self" argument, the signature doesn't match and a MatchError is raised

My current workaround is this:

from function_pattern_matching import MultiFunc

if isinstance(obj.method, MultiFunc):
    obj.method(obj, argument)
else:
    obj.method(argument)

It works and isn't too bad but I wonder if you have an idea howto improve this.

But anyway, thanks for the great work!