[6.0] New collection methods #1010
Conversation
aslesarenko
left a comment
aslesarenko
left a comment
There was a problem hiding this comment.
Approved, but please address the comments.
| * @return the element at the given index | ||
| * @throws ArrayIndexOutOfBoundsException if `i < 0` or `length <= i` | ||
| */ | ||
| def get(i: Int): Option[A] = { |
There was a problem hiding this comment.
ScalaDoc doesn't correspond to the method.
|
|
||
| /** For this collection (x0, ..., xN) and other collection (y0, ..., yM) | ||
| * produces a collection ((x0, y0), ..., (xK, yK)) where K = min(N, M) */ | ||
| def startsWith(ys: Coll[A]): Boolean |
|
|
||
| /** For this collection (x0, ..., xN) and other collection (y0, ..., yM) | ||
| * produces a collection ((x0, y0), ..., (xK, yK)) where K = min(N, M) */ | ||
| def endsWith(ys: Coll[A]): Boolean |
|
|
||
| def startsWith(ys: Coll[(L, R)]): Boolean = toArray.startsWith(ys.toArray) | ||
|
|
||
| def endsWith(ys: Coll[(L, R)]): Boolean = toArray.endsWith(ys.toArray) |
There was a problem hiding this comment.
This is simple, but inefficient ((ys.length + 1)*2 allocations) fallback implementation.
In the case when ys has type PairOfCols, it is possible to recursively call into ls and rs, and avoid allocations.
| // ======== 6.0 methods below =========== | ||
|
|
||
| val ReverseMethod = SMethod(this, "reverse", | ||
| SFunc(Array(ThisType), ThisType, paramIVSeq), 30, Zip_CostKind) // todo: costing |
There was a problem hiding this comment.
Suggest to declare the descriptor by just cloning from Append (Zip is too small).
| } | ||
|
|
||
| val DistinctMethod = SMethod(this, "distinct", | ||
| SFunc(Array(ThisType), ThisType, paramIVSeq), 31, Zip_CostKind) // todo: costing |
There was a problem hiding this comment.
The cost of distinct is larger then zip or Append, probably by a factor of 2.
| Seq( | ||
| Coll(1, 2) -> Expected(ExpectedResult(Success(Coll(1, 2)), None)), | ||
| Coll(1, 1, 2) -> Expected(ExpectedResult(Success(Coll(1, 2)), None)), | ||
| Coll(1, 2, 2) -> Expected(ExpectedResult(Success(Coll(1, 2)), None)), |
There was a problem hiding this comment.
Suggest to add a case with unordered collections and many different duplicates.
| (Coll(1, 2, 3), Coll(1, 2)) -> Expected(ExpectedResult(Success(true), None)), | ||
| (Coll(1, 2, 3), Coll(1, 2, 3)) -> Expected(ExpectedResult(Success(true), None)), | ||
| (Coll(1, 2, 3), Coll(1, 2, 3, 4)) -> Expected(ExpectedResult(Success(false), None)), | ||
| (Coll[Int](), Coll[Int]()) -> Expected(ExpectedResult(Success(true), None)) |
There was a problem hiding this comment.
Not covered cases:
- Coll(1, 2, 3), Coll(1, 2, 4)
- Coll[Int](1, 2), CollInt
In this PR, new collection methods got introduced:
close #1004