CallBack for commands

CallBack for each commands can be of types

• Functions

• Generators

• Asynchronous Functions

• Asynchronous Generators

Function type

Functions can’t be a better since we can’t call asynchronous functions (including msg.channel.send) from non asynchronous functions so we can reply only once.

Example:

@key(re.compile(r"^!repeat (\d*) (.*)$"))
def repeat(msg, times, string):
    times = int(times)
    return '\n'.join([string]*times)

Generator type

With Generators we can reply multiple times even though it is non asynchronous.

Example:

@key(re.compile(r"^!repeat (\d*) (.*)$"))
def repeat(msg, times, string):
    times = int(times)
    for i in range(times):
        yield string

Asynchronous Function type

Asynchronous Functions is recommended since we can call both asynchronous functions and non asynchronous functions. Also most of the discord.py methods are asynchronous.

Example:

@key(re.compile(r"^!repeat (\d*) (.*)$"))
async def repeat(msg, times, string):
    times = int(times)
    for i in range(times):
        await msg.channel.send(string)

Asynchronous Generator type

Asynchronous Generators has a benefit of reply multiple times. (Asynchronous Functions also can using msg.channel.send)

Example:

@key(re.compile(r"^!repeat (\d*) (.*)$"))
async def repeat(msg, times, string):
    times = int(times)
    for i in range(times):
        yield string

Updating callback at runtime

It supports updating callbacks at runtime, since it is literally changing value of key(s) in python dictionary.

@key(re.compile(r"^repeat (.*)$"), re.compile(r"^twice (.*)$"))
def twice(msg, string):
    return string * 2


@key("upgrade-to-thrice")
def upgrade(msg):
    thrice = lambda msg, x: x * 3
    key(re.compile(r"^repeat (.*)$"))(thrice)
    return "repeat is upgrade to thrice the string"


"""
'repeat hello' -> "hellohello"
'twice world' -> "worldworld"
'upgrade-to-thrice' -> "repeat is upgrade to thrice the string"
'repeat hello' -> "hellohellohello"
'twice world' -> "worldworld"
"""