allow for own matcher function

[call-me-matt]

Hello,

I would like to add my own mqttMatcher. How can I add my own function to the enforcer with casbin-mesh?

Thanks

Originally posted by @call-me-matt in #71

[casbin-bot]

@WenyXu @nodece @noneback

[nodece]

This is hard to generate a function at runtime and register that to casbin.

Do you know how to generate a function at runtime?

[call-me-matt]

Well, to be honest, I know how to add my own matcher function with python-casbin but I do not know where to start with casbin as a service. It would be sufficient to generate the function statically before runtime.