Re: "Dynamic" Imenu

[Scott Frazer <frazer.scott@gmail.com>]

Eric wrote:
> I am trying to write a major mode for language that's used at my
> workplace. Function-type blocks take the form
>    METHOD [methodName]
> Obviously, it's easy to write an imenu regexp for that line. However,
> "functions" associated with a certain window take the form
>    WINDOW [windowName] (windowObjectAssociatedWith)
> Two windows could have identically named windowObjects. I would like
> an imenu that looks something like this:
> Imenu
>   FunctionFoo1
>   FunctionFoo2
>   Window >
>     Window1 >
>       windowFunctionFoo1
>       windowFunctionFoo2
>    Window2 >
>       windowFunctionFoo1
>       windowFunctionFoo2
> So that the Window submenu has submenus, where each submenu is the
> name of a window.
> Alternatively, the imenu could simply contain submenus that are the
> name of the window. So
> Imenu
>   FunctionFoo1
>   FunctionFoo2
>   Window1 >
>     windowFunctionFoo1
>     windowFunctionFoo2
>   Window2 >
>     windowFunctionFoo1
>     windowFunctionFoo2
> 
> I've wrestled with the lisp for a while, but I can't think of a way to
> do this with the imenu-generic-expression variable. Any suggestions?
> Is this even possible with an imenu?

Use the imenu-create-index-function variable.  You set it to a function
(you would create) to scan the current buffer and build an alist with the
function tree you want.  That var will point you to imenu--index-alist
that has the format you need to create, and so on.

Scott