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 consumes a list and produces the rest of the list, followed
* by the first item in the list.
*
* @author Joshua Shinavier (http://fortytwo.net)
*/
public class Unswons extends PrimitiveStackMapping {
private static final String[] IDENTIFIERS = {
StackLibrary.NS_2013_03 + "unswons",
StackLibrary.NS_2008_08 + "unswons",
StackLibrary.NS_2007_08 + "unswons",
StackLibrary.NS_2007_05 + "unswons"};
public String[] getIdentifiers() {
return IDENTIFIERS;
}
public Unswons()
throws RippleException {
super();
}
public Parameter[] getParameters() {
return new Parameter[]{
new Parameter("l", "a list", true)};
}
public String getComment() {
return "l => r f -- where f is the first member of l and r is the rest of l";
}
public void apply(final RippleList arg,
final Sink<RippleList> solutions,
final ModelConnection mc) throws RippleException {
RippleValue l;
l = arg.getFirst();
final RippleList rest = arg.getRest();
Sink<RippleList> listSink = new Sink<RippleList>() {
public void put(final RippleList list) throws RippleException {
solutions.put(
rest.push(list.getRest()).push(list.getFirst()));
}
};
mc.toList(l, listSink);
}
}