Others have advised not to do this in a macro and I agree with that - but as you asked for one, here:

/ac Continuation
/ac Gnashing Fang
/ac Savage Claw
/ac Wicked Talon
/micon Gnashing Fang

Whenever Gnashing Fang comes off CD you can just jam this button over and over and it will execute everything in the proper order. You probably won’t be able to double-weave very effectively and you will lose GCDs over a sustained period of time. You might want more SS.

It’s better not to do it on a macro but play with it and find that out for yourself. GL!