Using ASDF as part of an interactive app framework - storing components in memory?

[Faré]

If you are indeed using files for all your dependency nodes, I suppose
you could use ASDF for this kind of things. In that case,
package-inferred-system would be a good template to start from, in
terms of letting ASDF dynamically build a model from your files.

However, if any of your nodes does not correspond to files, then maybe
you should consider cells, or computed-class, or some reactive
functional programming system.

—♯ƒ • François-René ÐVB Rideau •Reflection&Cybernethics• http://fare.tunes.org
To stay young requires unceasing cultivation of the ability to
unlearn old falsehoods. — Robert Heinlein, "Time Enough For Love"


On Tue, Jul 19, 2016 at 5:38 AM, Andrew Sengul <ml at imagegardenphoto.com> wrote:
> I'm interested in using ASDF to build interactive applications. Here's
> an example of the kind of thing I'd like to do. Imagine creating a
> Web-based multiple choice poll. When someone submits an entry to the
> poll, a data file containing all the responses is updated with the new
> entry. Two SVG graphics, a bar chart and a pie chart of the answers, are
> also updated according to the updated data set.
>
> If I wanted to implement something like this in Common Lisp, ASDF seems
> like a good foundation to build on, since it allows me to create a
> complex dependency graph of code and data files. In the example above,
> the SVG visualizations are dependent on the answers data set, and they
> get updated when the answer data is updated.
>
> However, I don't know how well this approach would scale because in
> order to use ASDF this way, a file needs to be written to disk and other
> files must be loaded from disk and compiled each time an entry is made
> to the poll. Would it make sense to create a new component type that
> represents a quoted piece of code stored as a variable in a running
> program rather than a file? If the poll is implemented with a persistent
> Web server, it could keep the answer data and the graphics in its memory
> instead of on disk, and use some means to periodically back up the
> contents of those variables to disk.
>
> I'm still new to ASDF so I'm not sure if there's a simple way I could
> add in this functionality or if it's a good idea. I know that the Web
> poll example I gave above would work better if the graphics generation
> and answer storage was just written into the Web server instead of using
> ASDF, but the poll is just an example; my goal is to develop a system
> that can handle much more complex code/data graphs.
>
> Any feedback appreciated. Thanks,
>
> Andrew
>