Unfortunately I don't think that's actually correct, in particular "Rather than watch source files" - the alternatives do not watch source files, they watch externs files. With --editor-mode, either the changes to externs files all come from rebuild commands, or there must be an explicit load of dependencies (almost "report changed source files" but s/source/externs/)

Anyway that's all a bit pedantic, I think you could change it to "Rather than watch externs files, expect an editor to report changed source files" without terribly much loss of information (@kritzcreek ?)

What @nwolverson said. I think we could add a bit of motivation here, saying that file watching has been flaky empirically and polling is resource intensive.

I was wondering if I should switch editor-mode on by default for 0.12? It definitely creates situations which are harder to debug for newcomers, since there's no way they understand that them running pulp build on the console just invalidated their IDE state.

@kritzcreek I didn't want to add too much text to that flag's explanation, as further explanation seems to belong in DESIGN document in this directory. I didn't make a change to that document because it's rather big/unorganized and I couldn't think of a good place in there to put it -- there's no config or options or flags section. Should we find a place for those sections? Or is the README the intended place for explaining the intents and implementation of the config/flags?

Also, I totally forgot that purs ide watches externs instead of source files. I just can't get that into my brain despite repeatedly making that mistake. Thanks for noticing that and fixing it!

Thanks!