bishabosha’s gists

bishabosha / ordinalOf.scala

Created January 28, 2022 09:51

Statically get the ordinal of any child of a sum-type in Scala

	import scala.compiletime.ops.int.S
	import scala.compiletime.constValue
	import scala.deriving.Mirror

	object Tuples {
	type IndexOf[Q, T <: Tuple, I <: Int] <: Int = T match {
	case EmptyTuple => -1
	case Q *: ts => I
	case _ *: ts => IndexOf[Q, ts, S[I]]
	}

bishabosha / example.scala

Last active February 18, 2022 12:45

ISO Continents and Countries, with lookup

	@main def addContinents(path: String): Unit =
	val lines = scala.io.Source.fromFile(path).getLines
	for case s"$country, $visitors" <- lines.drop(1) do
	continentFromCountry(country) match
	case Some(continent) =>
	println(s"${continent.name}, $country, $visitors")
	case None =>
	Console.err.println(
	"[error] no continent found for country: " + country
	)

bishabosha / derived-plugins.scala

Created May 9, 2022 20:41

Showing how the type class derivation mechanism can be used to add methods to the companion object with low boilerplate from the client side

	trait Plugin:

	type Companion

	val exports: Companion

	object Plugin:
	transparent inline def exports[P <: Plugin](using plugin: P): plugin.exports.type = plugin.exports

	trait Hashable[-T] extends Plugin:

bishabosha / BashScriptTests.out

Created May 19, 2022 18:03

output from on macOS dotty.tools.scripting.BashScriptTests

	sbt:scala3> dist/pack
	... truncated
	sbt:scala3> scala3-bootstrapped/testOnly dotty.tools.scripting.BashScriptsTests
	[info] Passed: Total 0, Failed 0, Errors 0, Passed 0
	[info] No tests to run for scala3-interfaces / Test / testOnly
	[info] Passed: Total 0, Failed 0, Errors 0, Passed 0
	[info] No tests to run for scala3-sbt-bridge / Test / testOnly
	[info] Passed: Total 0, Failed 0, Errors 0, Passed 0
	[info] No tests to run for scala3-library-bootstrapped / Test / testOnly
	[info] Passed: Total 0, Failed 0, Errors 0, Passed 0

bishabosha / FlagMirror.scala

Created June 1, 2022 09:28

A Bitfield implementation intended for use with type class derivation on Scala enums

	package tastyquery.util

	import compiletime.constValue
	import compiletime.error
	import compiletime.summonAll

	sealed abstract class FlagMirror[A <: reflect.Enum]():
	outer =>

	opaque type FlagSet = Long

bishabosha / aoc-day-6-optimal.scala

Created December 6, 2022 16:30

AOC 2022 day 6 optimal

	def part1(input: String): Int =
	findIndexOptimal(input, n = 4)

	def part2(input: String): Int =
	findIndexOptimal(input, n = 14)

	class MultiSet:
	private val counts = new Array[Int](128)
	private var total = 0
	def size = total

bishabosha / loops.scala

Last active December 14, 2024 22:55

Scala break/continue zero-cost loop abstraction

	//> using scala "3.3.0"

	import scala.util.boundary, boundary.break

	object Loops:

	type ExitToken = Unit { type Exit }
	type ContinueToken = Unit { type Continue }

	type Exit = boundary.Label[ExitToken]

bishabosha / MH.scala

Created July 19, 2023 09:48

MethodHandles with static fields in scala 3

	package foo

	import scala.annotation.static

	import java.lang.invoke.{MethodHandle, MethodHandles, MethodType}

	class MH

	object MH:
	@static private val lookup = MethodHandles.lookup()

bishabosha / LazyClasspathSuite.test.scala

Last active November 1, 2023 10:42

tasty-query classpath from dotty classpath

	//> using toolkit 0.2.1
	//> using scala 3.3.1
	//> using dep ch.epfl.scala::tasty-query:0.11.0
	//> using dep org.scala-lang::scala3-compiler:3.3.1
	//> using dep io.get-coursier:coursier_2.13:2.1.7

	package tastyquery.jdk.classpaths

	import tastyquery.Classpaths.Classpath
	import tastyquery.Classpaths.ClasspathEntry

bishabosha / day17-aoc-2021.scala

Last active November 30, 2023 11:17

Advent of Code Day 17 2021 using named tuples

	//> using scala "3.4.0-RC1-namedtuples-bin-SNAPSHOT"
	// original solution taken from https://scalacenter.github.io/scala-advent-of-code/puzzles/day17#final-code (by @bishabosha)

	import scala.language.experimental.namedTuples

	type Target = (xs: Range, ys: Range)
	type Point = (x: Int, y: Int)
	type Probe = (position: Point, velocity: Point)

	val initial = (x = 0, y = 0)

Jamie Thompson bishabosha