Hiding Helpers

Hiding Named Helper Visitor inside of ToString1

Comments

package listFW.visitor;
import listFW.*;
public class ToString1WithHiddenHelper implements IListAlgo { 
public static final
ToString1WithHiddenHelper Singleton = new ToString1WithHiddenHelper();
private ToString1WithHiddenHelper() {
}
 

Singleton Pattern

private static class HiddenHelper implements IListAlgo {
public static final HiddenHelper Singleton = new HiddenHelper();
private HiddenHelper() {
}
public Object emptyCase(IMTList host, Object... acc) {
return acc[0] + ")";
}
public Object nonEmptyCase(INEList host, Object... acc) {
return host.getRest().execute(this, acc[0] + ", " + host.getFirst());
}
}
 

The helper visitor has a name, HiddenHelper, and is defined privately and globally (static) inside of the main visitor ToString1WithHiddenHelper.

public Object emptyCase(IMTList host, Object... nu) {
return "()";
}
public Object nonEmptyCase(INEList host, Object... nu) {
return host.getRest().execute(HiddenHelper.Singleton, "(" + host.getFirst());
}
}
 

The main visitor calls on its hidden helper singleton to help complete the job.

Hiding Named Helper Visitor inside of ToString2

Comments

package listFW.visitor;
import listFW.*;
public class ToString2WithHiddenHelper implements IListAlgo { 
public static final 
ToString2WithHiddenHelper Singleton = new ToString2WithHiddenHelper();
private ToString2WithHiddenHelper() {
}
 

private static class HiddenHelper implements IListAlgo {
public static final HiddenHelper Singleton = new HiddenHelper();
private HiddenHelper() {
}
public Object emptyCase(IMTList host, Object... acc) {
return "(" + acc[0] + ")";
}
public Object nonEmptyCase(INEList host, Object... acc) {
return host.getRest().execute(this, acc[0] + ", " + host.getFirst());
}
}
 

public Object emptyCase(IMTList host, Object... nu) {
return "()";
}
 
public Object nonEmptyCase(INEList host, Object... nu) {
return host.getRest().execute(HiddenHelper.Singleton, host.getFirst().toString());
}
}
 

Hiding Named Helper Visitor inside of ToString3

Comments

package listFW.visitor;
import listFW.*;
public class ToString3WithHiddenHelper implements IListAlgo {
public static final 
ToString3WithHiddenHelper Singleton = new ToString3WithHiddenHelper();
private ToString3WithHiddenHelper() {
}
 

package listFW.visitor;
import listFW.*;
public class ToString3WithHiddenHelper implements IListAlgo {
public static final 
ToString3WithHiddenHelper Singleton = new ToString3WithHiddenHelper();
private ToString3WithHiddenHelper() {
}
 

public Object emptyCase(IMTList host, Object... nu) {
return "()";
}
public Object nonEmptyCase(INEList host, Object...bu) {
return "(" + host.getFirst() + host.getRest().execute(HiddenHelper.Singleton);
}
}