Function EvalTransform

engine/transformer.go:29–39

EvalTransform evaluates a transform.

(
	head ast.Atom,
	transform ast.Transform,
	input []ast.ConstSubstList,
	emit func(atom ast.Atom) bool)

// EvalTransform evaluates a transform.
func EvalTransform(
	head ast.Atom,
	transform ast.Transform,
	input []ast.ConstSubstList,
	emit func(atom ast.Atom) bool) error {

	if transform.IsLetTransform() {
		return evalLet(head, transform, input, emit)
	}
	return evalDo(head, transform, input, emit)
}

// evalLet evaluates a let transform. This consists of a number of let statements,
// each acting on a single row.