I'm reading The Great Gatsby by F.Scott Fitzgerald and there's one part of the book where Jordan Baker goes to sleep and says:
'Good-night' she said softly. 'Wake me at eight, won't you?'
If you'll get up
I will. Good-night, Mr Carraway. See you anon.
If you will mean in this context?
Could be the sentence written as
If you get up?