The effect is the same, but this seems to express the intent more
clearly, and it will make it easier to factor out the shared behavior
with skipBoringSwapUp.
Provide boring-aware versions of 'swapUp' and 'swapDown'.
Note that 'iterate f x' produces a list whose zeroth element is
'x' prior to any application of 'f'. The 'focusUp' and 'focusDown'
operations reject this iteration by checking in the filter predicate
that the focus actually changed:
filter ((`notElem` W.focus st:bs) . W.focus)
We can't do that for swaps, since our focus never changes, so we drop
the zeroth iteration prior to any predicate-based filtering.
The filter predicate checks whether the window immediately below the
our focus is boring. If so, we've performed an uninteresting upwards
swap and should continue swapping until we either swap past a window
that is not boring or wrap around the top of the stack.
It's particularly important that we accept the wrapping case regardless
of any boring neighbor, otherwise we risk missing a legitimate
non-boring swap. Consider, for example, the following stack:
focus: A
up: []
down: [B, boringC]
A swapUp yields:
focus: A
up: [boringC, B]
down: []
This should be considered non-boring, since the non-boring windows
swapped order: A B -> B A. If we were to reject it, we'd swap A up past
boringC and up again past B, putting us back where we started.
Put another way, if our focus was at the top of the stack, then all
other windows were necessarily below it. We want a swapUp to place our
focus below the lowest non-boring window. A wrap around to the bottom of
the stack guarantees that is the case.
Some users like to include type signatures in their configuration. The
Minimize type constructor was not exported, making it impossible to
write a type signature when using minimize.
With this change, a user can write an xmonad.hs like:
import XMonad
import XMonad.Layout.Minimize (Minimize, minimize)
import XMonad.Layout.LayoutModifier
myLayout :: ModifiedLayout
Minimize
(Choose Tall (Choose (Mirror Tall) Full))
Window
myLayout = minimize $ layoutHook def
main :: IO ()
main = xmonad def { layoutHook = myLayout }
Some users like to include type signatures in their configuration. The
HiddenWindows type constructor was not exported, making it impossible to
write a type signature when using hiddenWindows.
With this change, a user can write an xmonad.hs like:
import XMonad
import XMonad.Layout.Hidden (HiddenWindows, hiddenWindows)
import XMonad.Layout.LayoutModifier
myLayout :: ModifiedLayout
HiddenWindows
(Choose Tall (Choose (Mirror Tall) Full))
Window
myLayout = hiddenWindows $ layoutHook def
main :: IO ()
main = xmonad def { layoutHook = myLayout }
The current handle returned by `spawnPipe` doesn't have any encoding
and it uses the function fdToHandle which returns a Binary
Handle. When spawnPipe is used with a program like xmobar, this can
easily lead to errors:
λ> h <- spawnPipe "xmobar"
λ> hPutStrLn h
"\35753Haskell\25110\32773Ghci\33021\27491\30830\26174\31034\27721\23383\24182\19988\35835\21462\27721\23383\21629\21517\30340\25991\26723"
<stdin>: hGetLine: invalid argument (invalid byte sequence)
One workaround, to avoid this is to use `hSetEncoding`. But from
reading GHC's source code - the entire Handle and write operations
seems stateful. So doing something like hPutStr and hSetEncoding can
theoretically lead to an undefined state as the first write will use
latin encoding and the second write will use the new encoding. More
details about it are present here:
* http://hackage.haskell.org/package/base-4.12.0.0/docs/src/GHC.IO.Handle.Internals.html#writeCharBuffer
* http://hackage.haskell.org/package/base-4.12.0.0/docs/src/GHC.IO.Buffer.html#CharBuffer
So having these new functions will ensure that we get the handles in
the proper encoding in the first place.
