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View build.sbt
scalaVersion := "3.3.0"
libraryDependencies += "org.openjdk.jol" % "jol-core" % "0.17"
@xuwei-k
xuwei-k / Main.scala
Created April 8, 2023 22:49
playframework Scala 3 hello world
View Main.scala
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、
View a.scala
package a {
object X
package b {
object Y
}
}
package b {
object Z
View github-actions.yml
# 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/${{github.ref_name}}/dependencies.txt
- id: get_previous_dependencies
View reverseTaskAll.sbt
commands += {
def getProjects(s: State): Seq[String] = {
val extracted = Project.extract(s)
val currentBuildUri = extracted.currentRef.build
val buildStructure = extracted.structure
val buildUnitsMap = buildStructure.units
val currentBuildUnit = buildUnitsMap(currentBuildUri)
val projectsMap = currentBuildUnit.defined
projectsMap.values.map(_.id).toVector
}
View Functor.scala
trait Functor[F[_]]
def map [A, B](fa: F[A])(f: A => B ): F[B]
trait Applicative[F[_]]
def ap [A, B](fa: F[A])(f: F[A => B]): F[B]
trait Monad[F[_]]
def bind [A, B](fa: F[A])(f: A => F[B]): F[B]
trait Contravariant[F[_]]
View play-sbt-plugin-dependency-graph.sbt
addSbtPlugin("com.typesafe.play" % "sbt-plugin" % "2.8.18" exclude ("com.typesafe.play", "twirl-api_2.12"))
resolvers += Resolver.sbtPluginRepo("releases")
import scala.sys.process.Process
Seq(Compile, Test).map { x =>
(x / TaskKey[File]("dependencySvg")) := {
val output = target.value / s"dependencies-${x.name}.svg"
Process(Seq(
@xuwei-k
xuwei-k / gist:eda3bcb11e919734069642486b91e4d0
Created October 21, 2022 08:42
Binary compatibility org.slf4j slf4j-api 1.7.36 2.0.3
View gist:eda3bcb11e919734069642486b91e4d0
* 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
View scala-Wperformance-option
$ 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 = {
View scala-2-release-default-value.txt
$ scala -version
Scala code runner version 2.13.9 -- Copyright 2002-2022, LAMP/EPFL and Lightbend, Inc.
$ java -version
openjdk version "17.0.3" 2022-04-19 LTS
OpenJDK Runtime Environment Zulu17.34+19-CA (build 17.0.3+7-LTS)
OpenJDK 64-Bit Server VM Zulu17.34+19-CA (build 17.0.3+7-LTS, mixed mode, sharing)
$ scala -release:help
Usage: -release:<release> where <release> choices are 8, 9, 10, 11, 12, 13, 14, 15, 16, 17 (default: 17).
$ jenv shell 11