xuwei-k

package example

trait Functor[F[_]] {
  def map[A, B](fa: F[A])(f: A => B): F[B]
}

object Functor {
  def fromPolyFunction[F[_]](x: [A, B] => (fa: F[A]) => (f: A => B) => F[B]): Functor[F] =
    new Functor[F] {
      def map[A, B](fa: F[A])(f: A => B): F[B] = x(fa)(f)

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scalaVersion := "3.3.0"

libraryDependencies += "org.openjdk.jol" % "jol-core" % "0.17"

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import play.api.BuiltInComponents
import play.api.Mode
import play.api.mvc._
import play.api.routing._
import play.api.routing.sird._
import play.core.server.NettyServer
import play.core.server.ServerConfig

object Main {
  // 1つのScalaファイルで済むので、

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package a {
  object X

  package b {
    object Y
  }
}

package b {
  object Z

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    # checkoutその他は省略
    - run: sbt compileなどの他のタスク色々 writeExternalDependencies
    - name: upload dependencies.txt
      if: github.event_name == 'push'
      run: |
        # いい感じにuploadとdownloadできれば、
        # github actionsのartifactでもなんでも良い。
        # 最近某所ではS3の方が便利というか楽なので、それ使ったりもしているので、その場合の例
        aws s3 cp target/dependencies.txt s3://適当なURI/${{github.ref_name}}/dependencies.txt
    - id: get_previous_dependencies

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commands += {
  def getProjects(s: State): Seq[String] = {
    val extracted = Project.extract(s)
    val currentBuildUri = extracted.currentRef.build
    val buildStructure = extracted.structure
    val buildUnitsMap = buildStructure.units
    val currentBuildUnit = buildUnitsMap(currentBuildUri)
    val projectsMap = currentBuildUnit.defined
    projectsMap.values.map(_.id).toVector
  }

xuwei-k

trait Functor[F[_]]
  def map      [A, B](fa: F[A])(f:   A  =>   B ): F[B]

trait Applicative[F[_]]
  def ap       [A, B](fa: F[A])(f: F[A  =>   B]): F[B]

trait Monad[F[_]]
  def bind     [A, B](fa: F[A])(f:   A  => F[B]): F[B]

trait Contravariant[F[_]]

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addSbtPlugin("com.typesafe.play" % "sbt-plugin" % "2.8.18" exclude ("com.typesafe.play", "twirl-api_2.12"))

resolvers += Resolver.sbtPluginRepo("releases")

import scala.sys.process.Process

Seq(Compile, Test).map { x =>
  (x / TaskKey[File]("dependencySvg")) := {
    val output = target.value / s"dependencies-${x.name}.svg"
    Process(Seq(

xuwei-k

 * class org.slf4j.event.EventRecodingLogger does not have a correspondent in current version
   filter with: ProblemFilters.exclude[MissingClassProblem]("org.slf4j.event.EventRecodingLogger")
 * abstract method getMarker()org.slf4j.Marker in interface org.slf4j.event.LoggingEvent does not have a correspondent in current version
   filter with: ProblemFilters.exclude[DirectMissingMethodProblem]("org.slf4j.event.LoggingEvent.getMarker")
 * abstract method getArguments()java.util.List in interface org.slf4j.event.LoggingEvent is present only in current version
   filter with: ProblemFilters.exclude[ReversedMissingMethodProblem]("org.slf4j.event.LoggingEvent.getArguments")
 * abstract method getMarkers()java.util.List in interface org.slf4j.event.LoggingEvent is present only in current version
   filter with: ProblemFilters.exclude[ReversedMissingMethodProblem]("org.slf4j.event.LoggingEvent.getMarkers")
 * abstract method getKeyValuePairs()java.util.List in interface org.slf4j.event.LoggingEvent is present only 

xuwei-k

$ scala --version
Scala code runner version 2.13.10 -- Copyright 2002-2022, LAMP/EPFL and Lightbend, Inc.
$ scala -Wperformance -Xprint:jvm -e "def foo: Int = { var a = 10; @annotation.tailrec def loop(): Int = if (a == 0) 3 else { a -= 1 ; loop() } ; loop() }"
/var/folders/nz/vb2z3s8j7719gg71zgz9gj_40000gn/T/scalacmd2181293633408592115.scala:1: warning: Modification of variable a within a closure causes it to be boxed.
def foo: Int = { var a = 10; @annotation.tailrec def loop(): Int = if (a == 0) 3 else { a -= 1 ; loop() } ; loop() }
                     ^
[[syntax trees at end of                       jvm]] // scalacmd2181293633408592115.scala
package <empty> {
  object Main extends Object {
    def main(args: Array[String]): Unit = {