The Bit Bang You Are Completed package is Yet Another Completion method. Say you have a Lisp variable named this-is-a-very-long-variable-for-example, in the buffer in which this name is already typed, you can type tvvf and then press M-g to complete it. You can type tvx or even tx for the same effect, if you like. There are also other completing methods, for e.g., to complete arbitrary strings, whole lines, sexp and paragraphs. The last two is not as useful as the others. For more information see the readme at: https://github.com/baohaojun/bbyac