Copy arbitrary collections about google-collections

[GoogleCodeExporter]

What's the use case for that kind of copying? When writing application code, I'd
rather explicitly specify the class of the copy. To maintain the iteration 
ordering
of the original, you can use a class like a LinkedHashMap.

Original comment by [email protected] on 1 Nov 2007 at 5:14

[GoogleCodeExporter]

I'm thinking in particular of utility methods that return a copy of their input 
- this includes methods like 
intersection(), transform(), and filter() for various collections types.

Original comment by limpbizkit on 1 Nov 2007 at 4:51

[GoogleCodeExporter]

Quite simply, "a wish for a clone() that worked."

I agree that this would be good to support, for the same reasons that the 
(failed)
idea of clone() was created in the first place.

This would enable things like Sets.union() to do what people expect (I think).

btw, the other thing I'm aware of that you can't do generically to a collection 
is
get an unmodifiable view of it!

  public static <C extends Collection<?>> C unmodifiableView(C collection) { ... }

This seems closely related, in that to make it work, we'd have to have tedious
itemized support for all the JDK collections plus have some interface or 
something
that other collections would be required to implement if they want to 
participate.

Big Yuck for us, but possibly useful to users?

Original comment by [email protected] on 2 Nov 2007 at 2:15

• Added labels: Type-Enhancement
• Removed labels: Type-Defect

[GoogleCodeExporter]

clone() on collections, like on the jdk collections, would be useful.

I just got the following exception from eclipselink-2.0 M7, this is the 
reference
implementation of JPA-2.0.

Target Invocation Exception: java.lang.CloneNotSupportedException:
com.google.common.collect.Lists$TwoPlusArrayList
        at
org.eclipse.persistence.internal.jpa.transaction.EntityTransactionImpl.commitInt
ernal(EntityTransactionImpl.java:102)
        at
org.eclipse.persistence.internal.jpa.transaction.EntityTransactionImpl.commit(En
tityTransactionImpl.java:63)
        at org.metawb.astro.db.PersonTest.linkPersonTag(PersonTest.java:191)

FYI, This came from Lists.asList
        em.getTransaction().begin();
        for(int i = 0; i < 3; i++) {
            ps.get(i).setTagtypeCollection(Lists.asList(
                    tts.get(0), tts.get(i+1), new Tagtype[0]));
        }
        em.getTransaction().commit();

but this works ok

            ps.get(i).setTagtypeCollection(Lists.newArrayList(
                    tts.get(0), tts.get(i+1)));

Original comment by [email protected] on 15 Sep 2009 at 6:17

[GoogleCodeExporter]

Original comment by [email protected] on 17 Sep 2009 at 6:02

• Added labels: Milestone-Post1.0

[GoogleCodeExporter]

This issue has been moved to the Guava project (keeping the same id number). 
Simply replace 'google-collections' with 'guava-libraries' in your address 
bar and it should take you there.

Original comment by [email protected] on 5 Jan 2010 at 11:09

• Changed state: Moved