Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

Request to Add CoflatMap Instance for Vector #818

Merged
merged 5 commits into from
Jan 19, 2016
Merged

Request to Add CoflatMap Instance for Vector #818

Show file tree
Hide file tree
Changes from 4 commits
Commits
Show all changes
5 commits
Select commit Hold shift + click to select a range
0864952
cats#813 - Adds CoflatMap type class to the Vector Instance
juanpedromoreno Jan 18, 2016
5d87506
cats#813 - Provides CoflatMap tests for VectorTests
juanpedromoreno Jan 18, 2016
4da172f
cats#813 - Removes non-necessary import
juanpedromoreno Jan 19, 2016
c20f6ed
cats#813 - Changes the coflatMap implementation in order to use ListB…
juanpedromoreno Jan 19, 2016
7ee5f2f
cats#813 - Addresses a code review comment, changing the coflatMap im…
juanpedromoreno Jan 19, 2016
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
17 changes: 15 additions & 2 deletions core/src/main/scala/cats/std/vector.scala
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -4,9 +4,13 @@ package std
import cats.data.Streaming
import cats.syntax.show._

import scala.annotation.tailrec
import scala.collection.+:
import scala.collection.mutable.ListBuffer

trait VectorInstances {
implicit val vectorInstance: Traverse[Vector] with MonadCombine[Vector] =
new Traverse[Vector] with MonadCombine[Vector] {
implicit val vectorInstance: Traverse[Vector] with MonadCombine[Vector] with CoflatMap[Vector] =
new Traverse[Vector] with MonadCombine[Vector] with CoflatMap[Vector] {

def empty[A]: Vector[A] = Vector.empty[A]

Expand All @@ -23,6 +27,15 @@ trait VectorInstances {
override def map2[A, B, Z](fa: Vector[A], fb: Vector[B])(f: (A, B) => Z): Vector[Z] =
fa.flatMap(a => fb.map(b => f(a, b)))

def coflatMap[A, B](fa: Vector[A])(f: Vector[A] => B): Vector[B] = {
@tailrec def loop(buf: ListBuffer[B], as: Vector[A]): Vector[B] =
Copy link
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Would it make sense to use VectorBuilder instead of ListBuffer here?

Copy link
Contributor Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

@fthomas Yes, definitely. Done!

as match {
case _ +: rest => loop(buf += f(as), rest)
case _ => buf.to[Vector]
}
loop(ListBuffer.empty[B], fa)
}

def foldLeft[A, B](fa: Vector[A], b: B)(f: (B, A) => B): B =
fa.foldLeft(b)(f)

Expand Down
6 changes: 5 additions & 1 deletion tests/src/test/scala/cats/tests/VectorTests.scala
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -1,13 +1,17 @@
package cats
package tests

import cats.laws.discipline.{MonadCombineTests, SerializableTests, TraverseTests, MonoidalTests}
import cats.laws.discipline.{MonadCombineTests, CoflatMapTests, SerializableTests, TraverseTests, MonoidalTests}
import cats.laws.discipline.eq.tuple3Eq

class VectorTests extends CatsSuite {

checkAll("Vector[Int]", MonoidalTests[Vector].monoidal[Int, Int, Int])
checkAll("Monoidal[Vector]", SerializableTests.serializable(Monoidal[Vector]))

checkAll("Vector[Int]", CoflatMapTests[Vector].coflatMap[Int, Int, Int])
checkAll("CoflatMap[Vector]", SerializableTests.serializable(CoflatMap[Vector]))

checkAll("Vector[Int]", MonadCombineTests[Vector].monadCombine[Int, Int, Int])
checkAll("MonadCombine[Vector]", SerializableTests.serializable(MonadCombine[Vector]))

Expand Down