XXX TODO: description of the role of scalar evaluators and the connection to Heuristic
g-value evaluator
Returns the current g-value of the search.
g()
Preference evaluator
Returns 0 if preferred is true and 1 otherwise.
pref()
Sum evaluator
Calculates the sum of the sub-evaluators.
sum(evals)
evals (list of ScalarEvaluator): at least one scalar evaluator
Weighted evaluator
Multiplies the value of the scalar evaluator with the given weight.
weight(eval, weight)
eval (ScalarEvaluator): scalar evaluator
weight (int): weight