try-expand-dabbrev-visible
try-expand-dabbrev-visible is a compiled Lisp function in `hippie-exp.el
'.
(try-expand-dabbrev-visible OLD)
Try to expand word "dynamically", searching visible window parts.
The argument OLD has to be nil the first call of this function, and t
for subsequent calls (for further possible expansions of the same
string). It returns t if a new expansion is found, nil otherwise.