The set of options supported by Cascalog, mapped to default values.
(careful-merge l r)
Semigroup that keeps the right value of it's not nil or not equal to the old left value. If these conditions aren't met, the merge will throw an exception.
Accepts a sequence of raw predicates and returns a 2-vector of [option-map, rest-of-preds].
Accepts a sequence of option predicates and generates a map of option -> value.
A predicate is an option if it begins with a keyword.