Scala Single-File Scripts

def fetchLinks(title: String): Seq[String] = {
  val resp = requests.get.stream(
    "https://en.wikipedia.org/w/api.php",
    params = Seq(
      "action" -> "query",
      "titles" -> title,
      "prop" -> "links",
      "format" -> "json"
    )
  )
  for {
    page <- ujson.read(resp)("query")("pages").obj.values.toSeq
    links <- page.obj.get("links").toSeq
    link <- links.arr
  } yield link("title").str
}

@main
def main(startArticle: String, depth: Int) = {
  var seen = Set(startArticle)
  var current = Set(startArticle)
  for (i <- Range(0, depth)) {
    current = current.flatMap(fetchLinks(_)).filter(!seen.contains(_))
    seen = seen ++ current
  }

  pprint.log(seen)
  os.write(os.pwd / "fetched.json", upickle.stream(seen, indent = 4))
}

> ./mill JsonApiClient.scala --start-article singapore --depth 2
...
  "Calling code",
  "+65",
  "British Empire",
  "1st Parliament of Singapore",
...
)

> cat fetched.json
[
    "Calling code",
    "+65",
    "British Empire",
    "1st Parliament of Singapore",
    ...
]

//| mvnDeps: [org.jsoup:jsoup:1.7.2]
import org.jsoup._
import scala.collection.JavaConverters._

def fetchLinks(title: String): Seq[String] = {
  Jsoup.connect(s"https://en.wikipedia.org/wiki/$title")
    .header("User-Agent", "Mozilla/5.0 (compatible; JsoupBot/1.0; +https://example.com/bot)")
    .get().select("main p a").asScala.toSeq.map(_.attr("href"))
    .collect { case s"/wiki/$rest" => rest }
}

@main
def main(startArticle: String, depth: Int) = {
  var seen = Set(startArticle)
  var current = Set(startArticle)
  for (i <- Range(0, depth)) {
    current = current.flatMap(fetchLinks(_)).filter(!seen.contains(_))
    seen = seen ++ current
  }

  pprint.log(seen)
}

> ./mill HtmlScraper.scala --start-article singapore --depth 1
...
  "Hokkien",
  "Conscription_in_Singapore",
  "Malaysia_Agreement",
  "Government_of_Singapore",
...

//| mvnDeps: [com.lihaoyi::cask:0.9.1]

object WebServer extends cask.MainRoutes {
  @cask.post("/reverse-string")
  def doThing(request: cask.Request) = {
    request.text().reverse
  }

  initialize()
}

> ./mill WebServer.scala:runBackground

> curl -d 'helloworld' localhost:8080/reverse-string
dlrowolleh

//| mvnDeps:
//| - com.lihaoyi::scalasql:0.2.3
//| - com.lihaoyi::scalasql-namedtuples:0.2.3
//| - org.xerial:sqlite-jdbc:3.43.0.0

import scalasql.simple._, SqliteDialect._
import java.time.LocalDate

case class Buyer(id: Int, name: String, dateOfBirth: LocalDate)
object Buyer extends SimpleTable[Buyer]

case class ShippingInfo(id: Int, buyerId: Int, shippingDate: LocalDate)
object ShippingInfo extends SimpleTable[ShippingInfo]

def main(args: Array[String]): Unit = {
  // Initialize database
  val dataSource = new org.sqlite.SQLiteDataSource()
  dataSource.setUrl(s"jdbc:sqlite:./file.db")
  val sqliteClient = new scalasql.DbClient.DataSource(dataSource, config = new scalasql.Config {})

  sqliteClient.transaction { db =>
    db.updateRaw(os.read(os.pwd / "sqlite-customers.sql")) // Populate database from SQL file

    val names = db.run( // Find names of buyers whose shipping date is today or later
      Buyer.select.join(ShippingInfo)(_.id === _.buyerId)
        .filter { case (b, s) => s.shippingDate >= LocalDate.parse(args(0)) }
        .map { case (b, s) => b.name })

    for (name <- names) println(name)
  }
}

> ./mill Database.scala 2011-01-01
James Bond
John Doe

//| mvnDeps:
//| - com.lihaoyi::scalatags:0.13.1
//| - com.atlassian.commonmark:commonmark:0.13.1
import scalatags.Text.all._

@main def main() = {
  val postInfo = os
    .list(os.pwd / "post")
    .map { p =>
      val s"$prefix - $suffix.md" = p.last
      (prefix, suffix, p)
    }
    .sortBy(_._1.toInt)

  os.remove.all(os.pwd / "site-out")
  os.makeDir.all(os.pwd / "site-out/post")

  for ((_, suffix, path) <- postInfo) {
    val parser = org.commonmark.parser.Parser.builder().build()
    val document = parser.parse(os.read(path))
    val renderer = org.commonmark.renderer.html.HtmlRenderer.builder().build()
    val output = renderer.render(document)
    os.write(
      os.pwd / "site-out/post" / (suffix.replace(" ", "-").toLowerCase + ".html"),
      doctype("html")(
        html(
          body(
            h1(a("Blog"), " / ", suffix),
            raw(output)
          )
        )
      )
    )
  }
}

> ./mill -i StaticSite.scala

> cat site-out/post/my-first-post.html
<!DOCTYPE html><html><body><h1><a>Blog</a> / My First Post</h1><p>Sometimes you want numbered lists:</p>
<ol>
<li>One</li>
<li>Two</li>
<li>Three</li>
</ol>
</body></html>