I thought I was making more of an observation than a suggestion. A forum has acyclic relationships that give it structure:
- "___ is a reply to ___" (establishes a forest of stars[1] or shallow trees, depending on whether people can reply to replies)
- "___ was authored after the typically expected period of editing for ___" (establishes a rather dense partial order)
Module systems are sometimes encumbered with the need to resolve cyclic dependencies. On a forum, with its already acyclic structure, it should be possible to avoid that complexity in the common case.
"A dimension has the property that you can start at one well-defined end and travel in one direction and be sure you saw everything. This is a useful property, not because we expect users to do this very often (though some will) but because it hooks into our spatial metaphors for information in an intuitive way."
While I see some value in that kind of pursuit, I'd like to even the field of discussion a bit. Humans may live in a low-dimensional world, but they move around, manage a changing environment, and maintain different levels of human-to-human association even within a single population[citation needed]. I think it's plausible that humans evolved to reason about both spaces and networks.
Maybe an interesting scientific-ish approach would be to look at what parts of the brain are involved in forum use. If there isn't enough activity on the right side of the brain, we could work on spatial metaphors. Once there isn't enough activity on the left side, we can go back to language-like metaphors. :-p
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"Imagine a forum where you can define new dimensions as 2 functions: one to convert a new post to a coordinate, and another to render a neighborhood of coordinates."
I don't think it needs to be formalized that well yet. If the forum software is itself an open source project like Anarki, that should be stable enough for a small, dedicated community to experiment.
I bet once people can browse source code repositories with forum topic annotations on the side, it'll be a while before other features begin to appear necessary. If nothing else, the UI design and module system integration of these annotations would be finicky enough that the developers would have to chew on it for a while before they take on yet another revolutionary change. :-p
In a more secure and seamless model, well, I'd go with David Barbour's vision and say all state (e.g. the state of a project under development or the content of a discussion) would be hooked together using RDP, and individual state models would have continuous, idempotent interfaces that were designed for view composition and concurrent modification in the first place. The issue of designing forums for programming would naturally decompose into designing composition-friendly repository models, composition-friendly discussion models, the discussion of composition-friendly UI state models, and maybe some remaining issues with composing these models over RDP in practice.
