another attempt
start on monadic (for labeling) ant builder

this is still a bit messy and very much a work in progress
move search (random walking) to separate function
second iteration (incomplete)
use 'reader' instead of (<$> ask)
work in progress…
starting to look like something...
minor
changed type of Closed again…
compile function (and it works!)
fixed flip
fixed flip again
compile and example ant fixes
changed example a bit
Change types again, uses RWS monad and supports scopes
switch using foldr
rename labelled to goto (probably clearer)
simplified labelling function
Open newtype and Monoid interface
a couple more combinators
use Dual Seq for teh performance!!
removed Open newtype and Monoid instance
simplified combinators a bit