[xmonad] Changes to XPrompt

[wagnerdm at seas.upenn.edu]

Quoting Carlos López Camey <c.lopez at kmels.net>:

> provide it to mkPrompt, instead of both the explicit completion and
> action functions, i.e. replace
>
> mkXPrompt t conf compl action
>
> with
>
> mkXPrompt t conf myMode
>    where myMode = XPMode {
>      complFunction = ..
>      action = ..
>    }

I'm not sure I understand. Why is providing a data structure that  
stores two values better than supplying the two values? What can the  
internal code do with an XPMode that it couldn't do with a completion  
function and an action? (...and even if there is an answer to this,  
why can't the API wrap its two arguments in an XPMode before doing  
whatever it is it's doing?)

~d