Alternative, more composable config.

This means the config can be assembled using pieces that encode:

• correct composition when config options don't commute: a (b conf) works, but b (a (conf) is nonsense (ex. respecting layout hints and other layout modifiers).
• features that must be enabled once-only
• bundling multiple features in a single function: Config captures IO
• collect warnings (nothing uses this feature yet)

For examples, refer to sources:

• XMonad.Config.Alt.Sample

Implementation

• XMonad.Config.Alt.Internal