jcornaz / collekt Goto Github PK

Pros

• Smoother integration with any other library/codebase
• No need to maintain (document and test) helpers like first, forEach, any in this project. (less code = less bugs)

Cons

• explicit import of com.github.jcornaz.collekt.* may be necessary for ractive operator like filter, map, etc.

Overall the advantages seems bigger, especially, if we consider the explicit import is not necessary for + and -, and forgetting it for reactive operator like filter, map etc. would not affect correctness (only performances).

Here is the minimum operator list that should be available for immutable collections:

• filter
• filterIsInstance
• filterNotNull
• map
• mapNotNull
• flatMap

Dexx is obviously discontinued and should be removed from this project.

Alternatives:

Paguro provide efficient implementations for Java 8+. This project show some activity, and was very quick to fix the only issue reported.

As PCollection don't support null elements, and vavri.io is not compatible with java version prior to 8, the best is probably to drop Java 6/7 support for now.

It would mean only 3 methods on the immutable collection interface. And there is no need to support iterable for which the size is not known. Persistent collection are always finite.

• contains belongs to sets only. Other collection type should use any, none or all extension functions
• iterator() could be extracted to a Traversable interface (name may be improved).
• size and isEmpty could be extracted to a Sized interface
• There could be a difference between Immutable and Persistent to not force immutable implementations to implement plus/minus

Dexx set implementation had to be removed in #37 because it doesn't support null elements.

So it is necessary to provide an alternative for Java 6.

A user should be able to write immutableListOf() or toImmutableList()

Currently the only way to perform an equivalent of clear is to use an emptyPersistent*() function. But this completely ignore the persistent data structure used. So an empty method present in the persistent interface would make possible to get an empty version of the same implementation.

Evaluate at least:

• Paguro
• vavr.io
• pcollections
• dexx
• clojure collections?

And ensure the best one is uses as a default implementation.

If null elements are supported, it should be tested.
If null elements are not supported, non-null element types should be enforced by the compiler.

https://github.com/rschmitt/collider

The following functions should be tested:

• persistentListOf
• emptyPersistentList
• toPersistentList