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Commits on May 1, 2012
  1. @axel22

    Widen types in signatures of Future companion methods, refactor OnceC…

    axel22 authored
    Removed the implicit modifier on the OnceCanBuildFrom, as we don't
    support implicit classes with zero arguments.
    Added an implicit OnceCanBuildFrom method.
    The idea behind OnceCanBuildFrom is for it to be used by methods which
    construct collections, but are defined outside of collection classes.
    OnceCanBuildFrom so far worked only for objects of type TraversableOnce:
        shuffle(List(1, 2, 3).iterator: TraversableOnce[Int])
    but this used to result in an implicit resolution error:
        shuffle(List(1, 2, 3).iterator)
    because after the type parameter M for `shuffle` was inferred to Iterator, no implicit
    of type CanBuildFrom[Iterator[_], A, Iterator[A]] could be found.
    Introduced another CanBuildFrom to the Iterator companion object.
    Modified Future tests appropriately.
Commits on Apr 19, 2011
  1. @axel22

    Removed GenTravOnceLike and TravOnceLike, put t...

    axel22 authored
    Removed GenTravOnceLike and TravOnceLike, put their functionality to
    GenTravOnce and TravOnce. Remove immutable Gen* traits. Removing mutable
    Gen* traits.
    No review.
Commits on Apr 13, 2011
  1. @axel22

    Refactoring the collections api to support diff...

    axel22 authored
    Refactoring the collections api to support differentiation between
    referring to a sequential collection and a parallel collection, and to
    support referring to both types of collections.
    New set of traits Gen* are now superclasses of both their * and Par* subclasses. For example, GenIterable is a superclass of both Iterable and ParIterable. Iterable and ParIterable are not in a subclassing relation. The new class hierarchy is illustrated below (simplified, not all relations and classes are shown):
    TraversableOnce --> GenTraversableOnce
      ^                    ^
      |                    |
    Traversable     --> GenTraversable
      ^                    ^
      |                    |
    Iterable        --> GenIterable        <-- ParIterable
      ^                    ^                      ^
      |                    |                      |
    Seq             --> GenSeq             <-- ParSeq
    (the *Like, *View and *ViewLike traits have a similar hierarchy)
    General views extract common view functionality from parallel and
    sequential collections.
    This design also allows for more flexible extensions to the collections
    framework. It also allows slowly factoring out common functionality up
    into Gen* traits.
    From now on, it is possible to write this:
    import collection._
    val p = parallel.ParSeq(1, 2, 3)
    val g: GenSeq[Int] = p // meaning a General Sequence
    val s = g.seq // type of s is Seq[Int]
    for (elem <- g) {
      // do something without guarantees on sequentiality of foreach
      // this foreach may be executed in parallel
    for (elem <- s) {
      // do something with a guarantee that foreach is executed in order, sequentially
    for (elem <- p) {
      // do something concurrently, in parallel
    This also means that some signatures had to be changed. For example,
    method `flatMap` now takes `A => GenTraversableOnce[B]`, and `zip` takes
    a `GenIterable[B]`.
    Also, there are mutable & immutable Gen* trait variants. They have
    generic companion functionality.
Commits on Mar 22, 2011
  1. @axel22

    Implementing foreach to work in parallel in Par...

    axel22 authored
    Implementing foreach to work in parallel in ParIterableLike.
    Doing a bunch of refactoring around in the collection framework to
    ensure a parallel foreach is never called with a side-effecting method.
    This still leaves other parts of the standard library and the compiler
    No review.
  2. @axel22
Commits on Mar 18, 2011
  1. @axel22

    Removing toPar* methods, since we've agreed the...

    axel22 authored
    Removing toPar* methods, since we've agreed they're difficult to: -
    underestand - maintain
    Also, changed the docs and some tests appropriately.
    1) Every collection is now parallelizable - switch to the parallel version of the collection is done via `par`.
    - Traversable collections and iterators have `par` return a parallel
    - collection of type `ParIterable[A]` with the implementation being the
    - representative of `ParIterable`s (currently, `ParArray`). Iterable
    - collections do the same thing. Sequences refine `par`'s returns type
    - to `ParSeq[A]`. Maps and sets do a similar thing.
    The above means that the contract for `par` changed - it is no longer guaranteed to be O(1), nor reflect the same underlying data, as was the case for mutable collections before. Method `par` is now at worst linear.
    Furthermore, specific collection implementations override `par` to a more efficient alternative - instead of copying the dataset, the dataset is shared between the old and the new version. Implementation complexity may be sublinear or constant in these cases, and the underlying data structure may be shared. Currently, these data structures include parallel arrays, maps and sets, vectors, hash trie maps and sets, and ranges.
    Finally, parallel collections implement `par` trivially.
    2) Methods `toMap`, `toSet`, `toSeq` and `toIterable` have been refined
    for parallel collections to switch between collection types, however,
    they never switch an implementation from parallel to sequential. They
    may or may not copy the elements, as is the case with sequential
    variants of these methods.
    3) The preferred way to switch between different collection types,
    whether maps, sets and seqs, or parallel and sequential, is now via use
    of methods `toIterable`, `toSeq`, `toSet` and `toMap` in combination
    with `par` and `seq`.
    Review by odersky.
Commits on Jan 26, 2011
  1. @axel22

    Merge branch 'work'

    axel22 authored
Commits on Dec 21, 2010
  1. @axel22

    Finer conversions for immutable parallel collec...

    axel22 authored
    Finer conversions for immutable parallel collections.
    Added some missing traits.
    No review.
Commits on Nov 25, 2010
  1. @axel22

    Added toParIterable, toParSeq, toParSet and toP...

    axel22 authored
    Added toParIterable, toParSeq, toParSet and toParMap conversions.
    No review.
Commits on Nov 19, 2010
  1. @axel22

    Rewording for #3958, and a few doc changes.

    axel22 authored
    No review.
Commits on Nov 17, 2010
  1. @axel22

    Closes #3958. No review.

    axel22 authored
Commits on Jun 16, 2010
  1. @axel22

    Fixes #3563. Review by extempore.

    axel22 authored
Commits on Apr 8, 2010
  1. @axel22
  2. @axel22
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