package org.jf.util;
import com.google.common.collect.ImmutableList;
import com.google.common.collect.ImmutableSet;
import com.google.common.collect.ImmutableSortedSet;
import javax.annotation.Nonnull;
import javax.annotation.Nullable;
import java.util.Comparator;
import java.util.Iterator;
import java.util.SortedSet;
public abstract class ImmutableConverter<ImmutableItem, Item> {
protected abstract boolean isImmutable(@Nonnull Item item);
@Nonnull protected abstract ImmutableItem makeImmutable(@Nonnull Item item);
@Nonnull
public ImmutableList<ImmutableItem> toList(@Nullable final Iterable<? extends Item> iterable) {
if (iterable == null) {
return ImmutableList.of();
}
boolean needsCopy = false;
if (iterable instanceof ImmutableList) {
for (Item element: iterable) {
if (!isImmutable(element)) {
needsCopy = true;
break;
}
}
} else {
needsCopy = true;
}
if (!needsCopy) {
return (ImmutableList<ImmutableItem>)iterable;
}
final Iterator<? extends Item> iter = iterable.iterator();
return ImmutableList.copyOf(new Iterator<ImmutableItem>() {
@Override public boolean hasNext() { return iter.hasNext(); }
@Override public ImmutableItem next() { return makeImmutable(iter.next()); }
@Override public void remove() { iter.remove(); }
});
}
@Nonnull
public ImmutableSet<ImmutableItem> toSet(@Nullable final Iterable<? extends Item> iterable) {
if (iterable == null) {
return ImmutableSet.of();
}
boolean needsCopy = false;
if (iterable instanceof ImmutableSet) {
for (Item element: iterable) {
if (!isImmutable(element)) {
needsCopy = true;
break;
}
}
} else {
needsCopy = true;
}
if (!needsCopy) {
return (ImmutableSet<ImmutableItem>)iterable;
}
final Iterator<? extends Item> iter = iterable.iterator();
return ImmutableSet.copyOf(new Iterator<ImmutableItem>() {
@Override public boolean hasNext() { return iter.hasNext(); }
@Override public ImmutableItem next() { return makeImmutable(iter.next()); }
@Override public void remove() { iter.remove(); }
});
}
@Nonnull
public ImmutableSortedSet<ImmutableItem> toSortedSet(@Nonnull Comparator<? super ImmutableItem> comparator,
@Nullable final Iterable<? extends Item> iterable) {
if (iterable == null) {
return ImmutableSortedSet.of();
}
boolean needsCopy = false;
if (iterable instanceof ImmutableSortedSet &&
((ImmutableSortedSet)iterable).comparator().equals(comparator)) {
for (Item element: iterable) {
if (!isImmutable(element)) {
needsCopy = true;
break;
}
}
} else {
needsCopy = true;
}
if (!needsCopy) {
return (ImmutableSortedSet<ImmutableItem>)iterable;
}
final Iterator<? extends Item> iter = iterable.iterator();
return ImmutableSortedSet.copyOf(comparator, new Iterator<ImmutableItem>() {
@Override public boolean hasNext() { return iter.hasNext(); }
@Override public ImmutableItem next() { return makeImmutable(iter.next()); }
@Override public void remove() { iter.remove(); }
});
}
@Nonnull
public SortedSet<ImmutableItem> toSortedSet(@Nonnull Comparator<? super ImmutableItem> comparator,
@Nullable final SortedSet<? extends Item> sortedSet) {
if (sortedSet == null || sortedSet.size() == 0) {
return ImmutableSortedSet.of();
}
@SuppressWarnings("unchecked")
ImmutableItem[] newItems = (ImmutableItem[])new Object[sortedSet.size()];
int index = 0;
for (Item item: sortedSet) {
newItems[index++] = makeImmutable(item);
}
return ArraySortedSet.of(comparator, newItems);
}
}