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//> using scala "3.2.1" | |
//> using lib "com.monovore::decline-effect::2.4.1" | |
//> using lib "co.fs2::fs2-io::3.4.0" | |
//> using packaging.output "mkString" | |
//> using platform "scala-native" | |
//> using nativeMode "release-fast" | |
//> using nativeGc "none" | |
import cats.effect.* | |
import cats.effect.std.* | |
import cats.syntax.all.* | |
import com.monovore.decline.* | |
import com.monovore.decline.effect.* | |
import fs2.* | |
import fs2.io.* | |
import cats.data.NonEmptyList | |
val prefix: Opts[String] = Opts.option("prefix", "The prefix").withDefault("") | |
val delimiter: Opts[String] = Opts | |
.option[String]("delimiter", "Delimiter to place between the elements", "d") | |
.withDefault(",") | |
val suffix: Opts[String] = Opts.option("suffix", "The suffix").withDefault("") | |
val argument: Opts[String] = Opts.argument[String]("input").withDefault("--") | |
val chunkSize: Opts[Option[Int]] = | |
Opts.option[Int]("chunkSize", "Grouping size").orNone | |
def inputStream[F[_]: Sync](input: String): Stream[F, String] = | |
if input =!= "--" then Stream.emits(input.split("\n")) | |
else stdinUtf8[F](1024 * 1024 * 10) | |
.repartition(s => Chunk.array(s.split("\n", -1))) | |
.filterNot(_.isEmpty) | |
def composeString[F[_]: Sync](pre: String, delim: String, post: String)( | |
s: Stream[F, String] | |
): Stream[F, String] = | |
Stream.emit(pre) ++ s.intersperse(delim) ++ Stream.emit(post) | |
def streamArg[F[_]: Sync]: Opts[Stream[F, String]] = | |
(prefix, delimiter, suffix, argument, chunkSize).mapN { | |
(pre, delim, post, input, chunk) => | |
val stringStream: Stream[F, String] = inputStream(input) | |
val pipe: Pipe[F, String, String] = composeString(pre, delim, post) | |
val unchunkedStream: Stream[F, String] = stringStream.through(pipe) | |
val chunkedStream: Int => Stream[F, String] = n => stringStream.chunkN(n) | |
.flatMap(c => Stream.chunk(c).through(pipe).append(Stream.emit("\n"))).append(Stream.emit("\n")) | |
chunk.fold(unchunkedStream)(chunkedStream) | |
} | |
def printStream[F[_]: Console: Sync](stream: Stream[F, String]): F[ExitCode] = | |
stream.foreach(Console[F].print).compile.drain.as(ExitCode.Success) | |
abstract class CommandStreamApp extends CommandIOApp( | |
name = "mkString", | |
header = """|Builds a string from a list of strings. | |
|Reads from stdin if no argument or -- is used""".stripMargin | |
) | |
object Main extends CommandStreamApp { | |
def main = streamArg[IO].map(printStream[IO]) | |
} |
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