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2021.12 mixtape

2021-12-01 / mixtape

sudori part 3

2021-11-12 / sbt

I’m hacking on a small project called sudori, an experimental sbt. The initial goal is to port the macro to Scala 3. It’s an exercise to take the macro apart and see if we can build it from the ground up. This an advanced area of Scala 2 and 3, and I’m finding my way around by trial and error. This is part 3.

It’s been a while since I wrote part 2, but in between I’ve written intro to Scala 3 macros, which is sort of a sudori prequel.

Starlark 4.2.1

2021-09-26 / scala / bazel

Starlark is a dialect of Python, originally designed as a configuration language for the Bazel build tool. Currently there are implementations in Go, Java, and Rust. As far as I know, the main Java implementation of Starlark has only been available as Bazel’s source repo on GitHub.

Since it would be convenient to have a binary distribution, I’ve forked the repo, and published it as "com.eed3si9n.starlark" % "starlark" % "4.2.1" (com.eed3si9n.starlark:starlark:4.2.1) on Maven Central. The code is the same as Bazel 4.2.1.

JDK 17 on GitHub Actions

2021-09-17 / scala

Here’s a quick tutorial of how to test your project on JDK 17 using Ólaf’s olafurpg/setup-scala. As the starting point we’ll use the following setup, which is documented in Setting up GitHub Actions with sbt:

name: CI
on:
  pull_request:
  push:
jobs:
  test:
    strategy:
      fail-fast: false
      matrix:
        include:
          - os: ubuntu-latest
            java: 11
            jobtype: 1
          - os: ubuntu-latest
            java: 11
            jobtype: 2
          - os: ubuntu-latest
            java: 11
            jobtype: 3
    runs-on: ${{ matrix.os }}
    steps:
    - name: Checkout
      uses: actions/checkout@v1
    - name: Setup
      uses: olafurpg/setup-scala@v13
      with:
        java-version: "adopt@1.${{ matrix.java }}"
    - name: Build and test
      run: |
        case ${{ matrix.jobtype }} in
          1)
            sbt -v "mimaReportBinaryIssues; scalafmtCheckAll; +test;"
            ;;
          2)
            sbt -v "scripted actions/*"
            ;;
          3)
            sbt -v "dependency-management/*"
            ;;
          *)
            echo unknown jobtype
            exit 1
        esac
      shell: bash

Let’s say for jobtype 3 we’d like to use JDK 8, and for jobtype 1 and 2 we’d like to test on JDK 17. sbt-ci-release uses jabba to grab the JDKs, and at the moment the openjdk 17.0 distros are not available on jabba yet. However, Eclipse Adoptium fka AdoptOpenJDK does have the binary available, so we can use the custom JDK mode to use it as follows:

intro to Scala 3 macros

2021-09-06 / scala

Introduction

Macro is a fun and powerful tool, but overuse of the macro could cause harm as well. Please enjoy macros responsibly.

What is macro? A common explanation given is that a macro is a program that is able to take code as an input and output code. While it’s true, it might not immediately make sense since Scala programmers are often familiar with higher-order functions like (map {...}) and by-name parameter, which on the surface it might seem like it is passing a block of code around.

2021.09 mixtape

2021-09-05 / mixtape

Jar Jar Abrams 1.8.0 and sbt-assembly 1.1.0

2021-09-01 / sbt

Jar Jar Abrams 1.8.0 and sbt-assembly 1.1.0 are released.

Jar Jar Abrams is an experimental extension to Jar Jar Links, intended to shade Scala libraries. Thus far we have been using Pants team’s fork of Jar Jar Links, but now that it’s been abandaned, Eric Peters has in-sourced it to jarjar-abrams repo so we can patch it.

Our jarjar fork is released under com.eed3si9n.jarjar organization name and package name.

bug fixes

Eric has fixed a bug around ShadeRules.keep.

enhancement

ASM was updated to 9.2.

sbt-assembly 1.1.0 upgrades the Jar Jar Abrams dependency to 1.8.0.

sudori part 2

2021-08-01 / sbt

I’m hacking on a small project called sudori, an experimental sbt. The initial goal is to port the macro to Scala 3. It’s an exercise to take the macro apart and see if we can build it from the ground up. This an advanced area of Scala 2 and 3, and I’m finding my way around by trial and error. This is part 2.

Reference:

Instance

When we think of the build.sbt macro, the first thing that comes to our mind is the Applicative do macro that it implements using .value even though some may not use those terms exactly. The main driver for this imperative-to-functional is in the companion object for an oddly named Instance class:

sudori part 1

2021-07-18 / sbt

I’m hacking on a small project called sudori, an experimental sbt. The initial goal is to port the macro to Scala 3. It’s an exercise to take the macro apart and see if we can build it from the ground up. This an advanced area of Scala 2 and 3, and I’m finding my way around by trial and error.

Reference:

Scala 3 Reference: Metaprogramming

Convert

I think I’ve identified a basic part called Convert, which doesn’t really depend on anything.

sbt 1.5.5

2021-07-12 / sbt

I’m happy to announce sbt 1.5.5 patch release is available. Full release note is here - https://github.com/sbt/sbt/releases/tag/v1.5.5

Highlights

Various Zinc fixes and enhancements by @ephemerist and @retronym
Adds buildTarget/resources support for BSP #6552 by @samuelClarencTeads
Adds build.sbt support for BSP import #6553 by @retronym
Fixes BSP task error handling #6565 by @adpi2
Fixes remote caching not managing resource files #6554 by @Nirvikalpa108
Fixes launcher causing NoClassDefFoundError when launching sbt 1.4.0 - 1.4.2 launcher#98 by @eed3si9n
Fixes cross-Scala suffix conflict warning involving _3 lm#383 by @eed3si9n

sbt 1.5.4

2021-06-14 / sbt

I’m happy to announce sbt 1.5.4 patch release is available. Full release note is here - https://github.com/sbt/sbt/releases/tag/v1.5.4

How to upgrade

Download the official sbt runner + launcher from SDKMAN or download from https://github.com/sbt/sbt/releases/.

In addition, the sbt version used for your build is upgraded by putting the following in project/build.properties:

sbt.version=1.5.4

This mechanism allows that sbt 1.5.4 is used only for the builds that you want.

Highlights

Fixes compiler ClassLoader list to use compilerJars.toList (For Scala 3, this drops support for 3.0.0-M2) #6538 by @adpi2
Fixes undercompilation of package object causing “Symbol ’type X’ is missing from the classpath” zinc#983 by @retronym
Fixes overcompilation with scalac -release flag zinc#982 by @retronym
Fixes BSP on ARM Macs by keeping JNI server socket to keep using JNI ipcsocket#14 by @quelgar

For more details please see https://github.com/sbt/sbt/releases/tag/v1.5.4

sbt-assembly 1.0.0

2021-06-07 / sbt

In June of 2011, I started working on sbt-assembly for sbt 0.10, based on Coda Hale’s assembly-sbt from sbt 0.7, which in turn was probably inspired by maven-assembly-plugin. After ten years, I’m going to call this one 1.0.0. sbt-assembly 1.0.0 is published to Maven Central.

sbt 1.5.3

2021-06-01 / sbt

I’m happy to announce sbt 1.5.3 patch release is available. Full release note is here - https://github.com/sbt/sbt/releases/tag/v1.5.3

How to upgrade

Download the official sbt runner + launcher from SDKMAN or download from https://github.com/sbt/sbt/releases/.

In addition, the sbt version used for your build is upgraded by putting the following in project/build.properties:

sbt.version=1.5.3

This mechanism allows that sbt 1.5.3 is used only for the builds that you want.

Highlights

Fixes scalacOptions not getting forwarded to ScalaDoc in Scala 3 #6499 by @pikinier20
Fixes undercompilation of sealed traits that extends other seal traits zinc#979 by @dwijnand
Fixes version parsing not recognizing dots in a prerelease tag lm#377 by @Nirvikalpa108
Fixes inputFile resolving to incorrect files when file specific globs are used io#319 by @eatkins
Updates to Scala 2.12.14 #6522 by @mkurz

For more details please see https://github.com/sbt/sbt/releases/tag/v1.5.3

music inspired by yasuke (2021.06 mixtape)

2021-05-31 / mixtape

Scala, Python quick reference

2021-05-30

syntax	Scala	Python
immutable variable	`val x = 1`	Starlark: `REV = "1.1.0"`
lazy variable	`lazy val x = 1`	n/a
mutable variable	`var x = 1`	in function: `x = 1`
if expression	`if (x > 1) "a" else "b"`	`"a" if x > 1 else "b"`
———————-	—————————-	—————————-
function	`def add3(x: Int): Int =` `x + 3`	`def add3(x):` `return x + 3`
anonymous function	`_ * 2`	not in Starlark: `lambda x: x * 2`
———————-	—————————-	—————————-
List	`val xs = List(1, 2, 3, 4)`	`xs = [1, 2, 3, 4]`
size	`xs.size`	`len(xs)`
empty test	`xs.isEmpty`	`not xs`
head	`xs.head`	`xs[0]`
tail	`// List(2, 3, 4)` `xs.tail`	`# [2, 3, 4]` `xs[1:]`
take	`// List(1, 2)` `xs.take(2)`	`# [1, 2]` `xs[:2]`
drop	`// List(3, 4)` `xs.drop(2)`	`# [3, 4]` `xs[2:]`
drop right	`// List(1, 2, 3)` `xs.dropRight(1)`	`# [1, 2, 3]` `xs[:-1]`
nth element	`xs(2)`	`xs[2]`
map	`xs.map(_ * 2)` `for {` `x <- xs` `} yield x * 2`	`map(lambda x: x * 2, xs)` `[x * 2 for x in xs]`
filter	`xs.filter(_ % 2 == 0)` `for {` `x <- xs if x % 2 == 0` `} yield x`	`filter(lambda x: not x % 2, xs)` `[x for x in xs if not x % 2 ]`
fold from left	`// "a1234"` `xs.foldLeft("a") { _ + _ }`	`from functools import reduce` `# "a1234"` `reduce(lambda a,x: a + str(x), xs, "a")`
membership	`xs.contains(3)`	`3 in xs`
———————-	—————————-	—————————-
String	`val s = "hello"`	`s = "hello"`
variable interpolation	`val count = 3` `s"$count items"`	not in Starlark: `count = 3` `f"{count} items"`
split	`// Array(1.2.3, M1)` `"1.2.3-M1".split("-")`	`# ['1.2.3', 'M1']` `"1.2.3-M1".split("-")`
substring test	`s.contains("el")`	`"el" in s`
———————-	—————————-	—————————-
Map	`val d = Map("a" -> 1,` `“b” -> 2)`	`d = { "a": 1, "b": 2 }`

Skylark one-page overview
Many of the examples were borrowed from Hyperpolyglot: Rust, Swift, Scala

notes

I’m picking up Python and its Bazel dialect Skylark lately. On the other hand, I’m familiar with Scala and its sbt dialect. Often I know exactly what I want to express, and I am fairly certain Python has the equivalent concept as Scala, but just don’t remember the exact incantation. For people starting Scala, maybe they could use this table in reverse.

POM consistency for sbt plugins

2021-05-23 / sbt

There’s a long-standing bug that sbt maintainers have known for a while, which is that when sbt plugin is published to a Maven repository, the POM file sbt generates is not valid. From a mailing list thread titled [0.12] plan for instance, Mark McBride reported it in 2012:

On the maven note, the poms generated for plugins aren’t actually valid. Trying to upload them to artifactory without disabling pom consistency checks fails :/

Read More…

sbt 1.5.2

2021-05-10 / sbt

I’m happy to announce sbt 1.5.2 patch release is available. Full release note is here - https://github.com/sbt/sbt/releases/tag/v1.5.2

How to upgrade

Download the official sbt runner + launcher from SDKMAN or download from https://github.com/sbt/sbt/releases/.

In addition, the sbt version used for your build is upgraded by putting the following in project/build.properties:

sbt.version=1.5.2

This mechanism allows that sbt 1.5.2 is used only for the builds that you want.

Highlights

Fixes sbt new leaving behind target directory #6488 by @eed3si9n
Fixes ConcurrentModificationException while compiling Scala 2.13.4 and Java sources zinc#974 by @lefou
Improved developer guide for new contributors #6469 by @Nirvikalpa108
Fixes -client by making it the same as --client #6500 by @Nirvikalpa108
Uses -Duser.home instead of $HOME to download launcher JAR #6483 by @rdesgroppes

For more details please see https://github.com/sbt/sbt/releases/tag/v1.5.2

Bintray to JFrog Artifactory migration status and sbt 1.5.1

2021-04-26

I’m happy to announce sbt 1.5.1 patch release is available. Full release note is here - https://github.com/sbt/sbt/releases/tag/v1.5.1. This post will also report the Bintray to JFrog Artifactory migration.

Bintray to JFrog Artifactory migration status

First and foremost, I would like to thank JFrog for their continued support of sbt project and the Scala ecosystem.

As sbt was taking off in the number of contributors and plugins, we had a Bintray-shaped problem. We wanted individuals to create Ivy-layout repository, publish sbt plugins, but somehow aggregate the resolution to them. Having Github sbt organization allowed fluid ownership of plugin sources, but distributing the binary files were challenge as sbt version was churning. We adopted Bintray in 2014 and it provided the distribution mechanism during our growth years. In addition, we used Bintray to host Debian and RPM installers for sbt, paid for by Lightbend.

herding cats: day 19

2021-04-19 / scala

Wrote herding cats: day 19 featuring FunctionK, or Rúnar’s encoding of rank-2 polymorphic function, and Resource datatype, which he envisioned rank-N polymorphism would unlock back in 2010.

sbt 1.5.0

2021-04-04 / sbt

Hi everyone. On behalf of the sbt project, I am happy to announce sbt 1.5.0. This is the fifth feature release of sbt 1.x, a binary compatible release focusing on new features. sbt 1.x is released under Semantic Versioning, and the plugins are expected to work throughout the 1.x series.

The headline features of sbt 1.5.0 are:

Scala 3 support
Eviction error
Deprecation of sbt 0.13 syntax
Coursier-based launcher

How to upgrade

Download the official sbt launcher from SDKMAN or download from https://github.com/sbt/sbt/releases/tag/v1.5.0. This installer includes the new Coursier-based launcher.

sbt 1.5.0-RC2

2021-03-22 / sbt

Hi everyone. On behalf of the sbt project, I am happy to announce sbt 1.5.0-RC2. This is the fifth feature release of sbt 1.x, a binary compatible release focusing on new features. sbt 1.x is released under Semantic Versioning, and the plugins are expected to work throughout the 1.x series.

If no serious issues are found by Saturday, April 3rd 2021, 1.5.0-RC2 will become 1.5.0 final.
~~If no serious issues are found by Saturday, March 27th 2021, 1.5.0-RC1 will become 1.5.0 final.~~

The headline features of sbt 1.5.0 are:

sbt 1.4.9

2021-03-10 / sbt

I’m happy to announce sbt 1.4.9 patch release is available. Full release note is here - https://github.com/sbt/sbt/releases/tag/v1.4.9

How to upgrade

Download the official sbt launcher from SDKMAN or download from https://github.com/sbt/sbt/releases/.

In addition, the sbt version used for your build is upgraded by putting the following in project/build.properties:

sbt.version=1.4.9

This mechanism allows that sbt 1.4.9 is used only for the builds that you want.

Highlights

sbt 1.4.9 fixes JLine 2 fork + JAnsi version to match that of JLine 3.19.0 to fix line reading, which among other things affected IntelliJ import.
sbt 1.4.9 is a maintenance patch. The most notable thing is that this was that it was released without using Bintray, and a few things were dropped. See below for details.

Changes with compatibility implications

sbt 1.4.9 is published to Sonatype OSS without going through Bintray.

sbt 1.4.8

2021-03-08 / sbt

I’m happy to announce sbt 1.4.8 patch release is available. Full release note is here - https://github.com/sbt/sbt/releases/tag/v1.4.8

How to upgrade

Download the official sbt launcher from SDKMAN or download from https://github.com/sbt/sbt/releases/.

In addition, the sbt version used for your build is upgraded by putting the following in project/build.properties:

sbt.version=1.4.8

This mechanism allows that sbt 1.4.8 is used only for the builds that you want.

Highlights

sbt 1.4.8 is a maintenance patch. The most notable thing is that this was the first release that was released without using Bintray, and a few things were dropped. See below for details.

Changes with compatibility implications

sbt 1.4.8 is published to Sonatype OSS without going through Bintray.

2021.03 mixtape

2021-03-01 / mixtape

syntactic Scalafix rule for unified slash syntax

2021-02-16 / sbt

In sbt 1.1.0 I implemented unified slash syntax for sbt. Today I sent a pull request to deprecate the old sbt 0.13 shell syntax #6309.

Naturally, the topic of deprecating old syntax for build.sbt also came up.

will you also deprecate `scalacOptions in (Compile, console)` in *.sbt and *.scala files? I hope so
— Seth Tisue (@SethTisue) February 16, 2021

This is because “unified” slash syntax is called so because it unifies the shell syntax and the build syntax together. Thus, it makes sense to deprecate the old build.sbt syntax that uses in like skip in publish or scalacOptions in (Compile, console), if we’re deprecating the old shell syntax.

git bisecting scala/scala

2021-02-06 / scala / git git bisecting is a useful technique to locate the source of a bug. For scala/scala in particular, bisect.sh can save a lot of time by using the pre-build compiler artifacts on the Scala CI Artifactory.

sbt 1.4.7

2021-01-31 / sbt

I’m happy to announce sbt 1.4.7 patch release is available. Full release note is here - https://github.com/sbt/sbt/releases/tag/v1.4.7

How to upgrade

Download the official sbt launcher from SDKMAN or download from https://github.com/sbt/sbt/releases/.

In addition, the sbt version used for your build is upgraded by putting the following in project/build.properties:

sbt.version=1.4.7

This mechanism allows that sbt 1.4.7 is used only for the builds that you want.

Highlights

Updates to Coursier 2.0.9, fixing authentication with Sonatype Nexus #6278 / [coursier#1948] by @cchepelov
Fixes Ctrl-C printing out stack trace #6213 by @eatkins
GNU Emacs support for sbtn and sbt --client #6276 by @fommil

Participation

sbt 1.4.7 was brought to you by 5 contributors. Sam Halliday, Eugene Yokota (eed3si9n), Adrien Piquerez, Cyrille Chepelov, Ethan Atkins. Thank you!

sbt 1.4.6

2020-12-24 / sbt

I’m happy to announce sbt 1.4.6 patch release is available. Full release note is here - https://github.com/sbt/sbt/releases/tag/v1.4.6

How to upgrade

Download the official sbt launcher from SDKMAN or download from https://github.com/sbt/sbt/releases/.

In addition, the sbt version used for your build is upgraded by putting the following in project/build.properties:

sbt.version=1.4.6

This mechanism allows that sbt 1.4.6 is used only for the builds that you want.

Highlights

Updates to Coursier 2.0.8, which fixes the cache directory setting on Windows (Fix contributed by Frank Thomas)
Fixes performance regression in shell tab completion #6214 by @eed3si9n
Fixes match error when using withDottyCompat lm#352 by @eed3si9n
Fixes thread-safety in AnalysisCallback handler zinc#957 by @dotta

Participation

sbt 1.4.6 was brought to you by 3 contributors. Eugene Yokota (eed3si9n), Mirco Dotta, and Frank Thomas. Thank you!

enforcing Semantic Versioning with sbt-strict-update

2020-12-14 / scala

I want to tell sbt “this specific version breaks binary compatibility, so don’t resolve it via eviction, fail the build instead.” How do I do this? Complete answers only, I’m done trying to figure it out by following clues.

I wrote a small sbt plugin sbt-strict-update to do this.

Add this to project/plugins.sbt:

addSbtPlugin("com.eed3si9n" % "sbt-strict-update" % "0.1.0")

and then add this to build.sbt:

ThisBuild / libraryDependencySchemes += "org.typelevel" %% "cats-effect" % "early-semver"

That’s it.

ThisBuild / scalaVersion := "2.13.3"
ThisBuild / libraryDependencySchemes += "org.typelevel" %% "cats-effect" % "early-semver"

lazy val root = (project in file("."))
  .settings(
    name := "demo",
    libraryDependencies ++= List(
      "org.http4s" %% "http4s-blaze-server" % "0.21.11",
      "org.typelevel" %% "cats-effect" % "3.0-8096649",
    ),
  )

Now if Rob tries to compile this build, he should get:

sbt 1.4.5

2020-12-14 / sbt

I’m happy to announce sbt 1.4.5 patch release is available. Full release note is here - https://github.com/sbt/sbt/releases/tag/v1.4.5

How to upgrade

Download the official sbt launcher from SDKMAN or download from https://github.com/sbt/sbt/releases/.

In addition, the sbt version used for your build is upgraded by putting the following in project/build.properties:

sbt.version=1.4.5

This mechanism allows that sbt 1.4.5 is used only for the builds that you want.

Highlights

sbt 1.4.5 adds support for Apple silicon (AArch64 also called ARM64) #6162/#6169 by @eatkins
Updates to Coursier 2.0.7 #6120 by @jtjeferreira
Fixes watch shell option #6166 by @eatkins
Fixes onLoad to run with the correct FileTreeRepository and CacheStoreFactory #6190 by @mkurz

Participation

sbt 1.4.5 was brought to you by 4 contributors. Ethan Atkins, Matthias Kurz, Eugene Yokota (eed3si9n), João Ferreira. Thank you!

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