The meaning of XEvent is different on the left and right sides of the
newtype declaration. On the left, it's a type; on the right, it's a data
constructor. The constructor wraps a value which refers to the type, but
not recursively back to the constructor itself.
On Tue, Nov 6, 2018, 8:36 AM Guru Devanla Hello Haskell-Cafe, I have been recently studying the XMonad code and some related types
available in the X11 bindings library. I came across this type: newtype XEvent = XEvent XEventPtr type XEventPtr = Ptr
http://hackage.haskell.org/package/base-4.10.1.0/docs/Foreign-Ptr.html#t:Ptr
XEvent
http://hackage.haskell.org/package/X11-1.9/docs/Graphics-X11-Xlib-Event.html... Available here: http://hackage.haskell.org/package/X11-1.9/docs/Graphics-X11-Xlib-Event.html... It seems that this type is circular here. how does one use this type? Is
it possible to create a value out of this type? What is the use of this
type? Please could someone help me wrap my head around this? Thanks _______________________________________________
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