Define command question

["Dennis L. Doughty" <doughty@SCRC-YUKON.ARPA>]

    Date: 13 Jul 88 17:06 EST
    From: STERRITT%SDEVAX.decnet@ge-crd.arpa


    Hello,
	    I have been trying to get a simple Program Framework put together,
    and have run into an annoying thing.  The problem is that I have a flavor,
    called Scenario-Flavor, that I want to have commands operate on.  So, I
    define a command for my frame that accepts an instance of this flavor, and
    since there is a pane with all of the available ones listed, this works
    fine as long as you do something like:
	Framework Command: Examine Scenario <mouseclick>
    BUT, if you hit two spaces after the word scenario, I get a line below the
    command line that says "End of file for #<window description>", and if I
    hit anything else, it gets into an infinite loop with this text flashing
    below the line.  I'm doing this under 7.1, but 7.2 gives a similar message,
    without the infinite loop.
	    The command definition just asks for an instance of the flavor,
    and I've defined a sys:print-self method for the flavor.
	    Anybody know what I can do to avoid this?  Obviously, it's not an
    error one sees with the regular commands.
	    thanks,
	    chris sterritt
	    sterritt%sdevax.decnet@ge-crd.arpa

Because you have defined no way of parsing a printed representation of
Scenario-Flavor, the system is defaulting to reading an expression.  You
should define a presentation type called Scenario-Flavor whose parser
either

a) if smart knows how to parse a printed representation and turn it into
an object

b) if dumb simply loops doing dw:read-char-for-accept, thereby
guaranteeing that no printed representation can be read, but mouse
clicks will still grab the objects.

You should read the documentation on presentation types.