[xmonad] Re: Compile-time verification of keymaps

Spencer Janssen spencerjanssen at gmail.com
Sun Mar 28 02:25:37 EDT 2010

On Wed, Mar 24, 2010 at 02:53:36AM -0400, wagnerdm at seas.upenn.edu wrote:
> Quoting Adam Vogt <vogt.adam at gmail.com>:
> >I don't quite understand how -fwarn-overlapping-patterns can be used to
> >avoid overlapping keybinds: you suggest replacing the (Map Key (X ()))
> >with a function   (Key -> Maybe (X ())) (with the maybe possibly added
> >by catching pattern match failures)?  Performance probably doesn't
> >matter here, but I believe pattern matches are tried one after the
> >other, as compared to Data.Map which is a bit smarter than that.
> Something like that, yes, though changing the interface to core
> functionality has historically been a hard sell. Rather, I would
> suggest writing keybindings as a function, then reifying the
> function as a Data.Map in the configuration value both for
> backwards-compatibility and (as you say) for performance reasons.
> This shouldn't be too hard, assuming there's a reasonably short
> range of possible keys, which seems pretty likely.
> ~d

KeySym is a 29 bit value, and you've also got to consider modifiers.
Functions are not workable unless you can accept extending xmonad's
startup time by several hours.

Spencer Janssen

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