package net.fortytwo.ripple.libs.stack;
import net.fortytwo.flow.Sink;
import net.fortytwo.ripple.RippleException;
import net.fortytwo.ripple.model.ModelConnection;
import net.fortytwo.ripple.model.PrimitiveStackMapping;
import net.fortytwo.ripple.model.RippleList;
import net.fortytwo.ripple.model.RippleValue;
/**
* A primitive which permutes the second, third and fourth items on the stack
* such that (... x y z ...) becomes (... z y x ...).
*
* @author Joshua Shinavier (http://fortytwo.net)
*/
public class Rotated extends PrimitiveStackMapping {
private static final String[] IDENTIFIERS = {
StackLibrary.NS_2013_03 + "rotated",
StackLibrary.NS_2008_08 + "rotated",
StackLibrary.NS_2007_08 + "rotated",
StackLibrary.NS_2007_05 + "rotated"};
public String[] getIdentifiers() {
return IDENTIFIERS;
}
public Rotated()
throws RippleException {
super();
}
public Parameter[] getParameters() {
return new Parameter[]{
new Parameter("x", null, true),
new Parameter("y", null, true),
new Parameter("z", null, true),
new Parameter("a", null, true)};
}
public String getComment() {
return "x y z a => z y x a";
}
public void apply(final RippleList arg,
final Sink<RippleList> solutions,
final ModelConnection mc) throws RippleException {
RippleList stack = arg;
RippleValue w, z, y, x;
w = stack.getFirst();
stack = stack.getRest();
z = stack.getFirst();
stack = stack.getRest();
y = stack.getFirst();
stack = stack.getRest();
x = stack.getFirst();
stack = stack.getRest();
solutions.put(
stack.push(z).push(y).push(x).push(w));
}
}