On Tue, May 15, 2012 at 10:49 AM, Leo Alekseyev wrote:

On Tue, May 15, 2012 at 7:20 AM, Norbert Zeh wrote:

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wagnerdm@seas.upenn.edu [2012.05.14 2219 -0400]:

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Quoting Leo Alekseyev :

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On Sun, May 13, 2012 at 8:45 AM, Norbert Zeh wrote:

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myWorkspaces = ["1:terminals", "2:emacs", "3:web", "4", "5", "6", "7","8","9","0"] ++ map (\x -> show x ++ "SCR") ([1..9]++[0]) .....

zeroSub 0 = 10 zeroSub x = x

jumpToMain = gets windowset >>= \W.StackSet { W.current = W.Screen { W.workspace = w } } -> withNthWorkspace W.greedyView (-1+(zeroSub $ read [head(W.tag w)])) jumpToScratch = gets windowset >>= \W.StackSet { W.current = W.Screen { W.workspace = w } } -> withNthWorkspace W.greedyView (9+(zeroSub $ read [head(W.tag w)]))

The math here looks all wrong, and I'm surprised that it worked at all before.

The math looks fine to me, and in fact your suggestion:

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What you want, I think, is the following:

jumpToMain = gets (W.tag . W.workspace . W.current . windowset)         >>= W.greedyView . toMain  where    toMain ws = [head ws]

jumpToScratch = gets (W.tag . W.workspace . W.current . windowset)            >>= W.greedyView . toScratch  where    toScratch ws | length ws == 1 = ws ++ "SCR"                 | otherwise      = ws

is the one that looks dodgy to me. Notice that his main workspace names are things like "3:web", but the SCR-version is just "3SCR"! In fact, I would humbly suggest that this paragraph:

Oops.  I overlooked that the primary workspaces were not just numbered.  My bad. I still don't get the math in the original code snippet.  zeroSub has an effect only when its argument is 0.  So, for any starting workspace except "0" or "0SCR", say its number is x, the above code goes to workspace x-1 or x+9.  It should, however, go to workspace x-10 or x+10 and that conditionally on whether the main/scratch workspace is already visible.  What is it I don't understand here?

My original understanding was this: I have an array of workspaces like so: [1, 2, ...9, 0, 1SCR, 2SCR, ... 0SCR]

When I want to go from e.g. 2 to 2SCR, I want element 11 in this 0-indexed array.  So, I get the head of the tag, I assume /read/ converts it to an integer, and I add 9 to it, and hope that withNthWorkspace on the 11th array element will do the right thing. By that logic, to go from 2SCR back to 2, I need to subtract 11 to get element 1 of the array.  However, when I originally wrote that code, this didn't work right, and I put in random numbers until for some reason putting in 1 worked.  (Yes, programming by coincidence and all.)

Speaking of programming by coincidence, I changed the numbers to +10 and -0, and things started working.  Then I logged in and out, and now I'm back to off-by-one, but in a different direction, i.e. 2 takes me to 3SCR and going back takes me to 4, etc...  I put in my old code, and now things work again, but if history is any indication, it will break some time later today or tomorrow.

I'm clearly misunderstanding something about how workspace switching works...

What I said above about subtracting 11 is of course wrong: by my logic, I read in the head of the tag "2SCR", i.e. "2", get an int, subtract 1, and go to element 1 of the workspace array, which should have workspace 1. So my math is consistent with my mental model of how workspace switching works. (Why do I have to realize this 3 seconds after I hit send? :P)