Select an available options from a set of possibilities

Select an available options from a set of possibilities

.findAvailable(possibilities, option_set, fall_back = NULL)

Arguments

possibilities	possible legal values of a variable
option_set	set of values that includes one of the possibilities
fall_back	if there is none of the possibilities in option_set, or there are multiple hits, default to fall_back

Value

same as option_set, usually character