When a command prompts for input in the echo area, the keys
Tab
,
?
and
Space
can invoke completion, depending on the context.
In the Editor tool, a variety of completion commands are available. For example, in Emacs emulation
Tab
invokes the command
Indent Selection or Complete Symbol
. See the
LispWorks Editor User Guide
for details of this and other editor commands.
In the Shell tool,
Tab
expands filenames.
In the Listener tool using Emacs emulation,
Escape
Tab
expands filenames.
In many text input panes such as the
Class:
field of a Class Browser tool,
Up
and
Down
invoke in-place completion while pressing the button raises a completion dialog.
Also, clicking the 
button to the right of a text input pane raises a modal completion dialog, as described in Completion dialog.
LispWorks IDE User Guide (Windows version) - 25 Nov 2011