This sort of thing is really determined by what the top-level loop of the application does rather than any property of the interactor pane. If you look at the top-level function in the listener, it simply peeks at the first character typed and then decides whether to read a command or a lisp form based on that. Unfortunately this is a rather low-level way of doing things and at timess undermine some of the nice features that McCLIM would normally provide (keyboard accelerator gestures, completion, etc). I don't mind working around this to retain absolute control, but I'd recommend a different approach.

CLIM contains an "or" presentation type which allows you to accept one of a number of types. The default accept method for this type attempts to read the first type in the list textually. If the accept method for the first type in the list signals a parse error, it tries to read as the next type, and so on. What might work for you is to define a presentation type for elements and one for whatever else as "12g C H4", with accept methods for each type which call your parser. Then you can write a top-level loop that accepts '(or command element whatever-else..) and examines second value returned (presentation type of input) to decide what to do (call execute-frame-command, inpect element, etc).

I haven't made much use of this technique, but it seems like right way to do it. I'm concerned that the command parser may continue reading and block you from entering things such as "Krypton". Things that don't resemble command names, such as "12 g C H4", should work. If this is indeed a problem, I'm sure we can find a way to make it work.

On Thu, 27 Jan 2005 13:52:25 -0700, Peter Scott sketerpot@gmail.com wrote:

I'm writing a GUI for a chemistry program with McCLIM. My problem is that I want the user to be able to type commands into the interactor pane in a special syntax, which I have written a parser for. For example, typing "Krypton" should call the Inspect Element command on the element called "Krypton". Typing "12 g C H4" should display how many moles of methane there are in 12 g. There's more like that, but I have the code to handle it all written---except for the code that hooks it into an interactor pane.

There's a way of getting an interactor pane to differentiate between commands and s-expressions, for use in a listener, so I think that what I want is possible. Can anybody tell me how?