tut powered blog

Author: larsrh

.gitignore

@@ -6,3 +6,4 @@ Gemfile.lock
 /vendor/bundle
 css/main.css
 .sass-cache
+target

_config.yml

@@ -14,7 +14,7 @@ kramdown:
   hard_wrap: false
 highlighter: rouge
 exclude:
-  ["node_modules", "gulpfile.js", "package.json", "README.md", "CNAME", "vendor"]
+  ["node_modules", "gulpfile.js", "package.json", "README.md", "CNAME", "vendor", "src", "project", "build.sbt", "_tut"]
 permalink: /blog/:year/:month/:day/:title.html
 paginate: 10
 paginate_path: "/blog/:num/"

build.sbt

@@ -0,0 +1,31 @@
+scalaVersion := "2.11.8"
+
+name := "typelevel-blog-tut"
+
+scalacOptions ++= Seq(
+  "-deprecation",
+  "-feature"
+)
+
+libraryDependencies ++= Seq(
+  "io.get-coursier" %% "coursier" % "1.0.0-M14",
+  "io.get-coursier" %% "coursier-cache" % "1.0.0-M14",
+  "com.chuusai" %% "shapeless" % "2.3.0",
+  "org.yaml" % "snakeyaml" % "1.17"
+)
+
+lazy val tutInput = SettingKey[File]("tutInput")
+lazy val tutOutput = SettingKey[File]("tutOutput")
+lazy val tutVersion = SettingKey[String]("tutVersion")
+
+tutInput := (baseDirectory in ThisBuild).value / "_tut"
+tutOutput := (baseDirectory in ThisBuild).value / "_posts"
+tutVersion := "0.4.4"
+
+watchSources ++= (tutInput.value ** "*.md").get
+
+enablePlugins(BuildInfoPlugin)
+
+buildInfoKeys := Seq[BuildInfoKey](tutInput, tutOutput, tutVersion)
+
+buildInfoPackage := "org.typelevel.blog"

project/build.properties

@@ -0,0 +1 @@
+sbt.version=0.13.12

project/plugins.sbt

@@ -0,0 +1 @@
+addSbtPlugin("com.eed3si9n" % "sbt-buildinfo" % "0.6.1")

src/main/scala/FrontMatter.scala

@@ -0,0 +1,39 @@
+package org.typelevel.blog
+
+import coursier._
+import coursier.util.Parse
+import java.io.File
+import java.net.URLClassLoader
+
+case class Tut(scala: String, binaryScala: String, dependencies: List[String]) {
+
+  val tutResolution: Resolution = Resolution(Set(
+    Dependency(Module("org.tpolecat", s"tut-core_$binaryScala"), BuildInfo.tutVersion)
+  ))
+
+  val libResolution: Resolution = Resolution(dependencies.map { dep =>
+    val (mod, v) = Parse.moduleVersion(dep, binaryScala).right.get
+    Dependency(mod, v)
+  }.toSet)
+
+  def invoke(file: File): Unit = {
+    val tutClasspath = resolve(tutResolution).get
+    val libClasspath = resolve(libResolution).get
+
+    val classLoader = new URLClassLoader(tutClasspath.map(_.toURI.toURL).toArray, null)
+    val tutClass = classLoader.loadClass("tut.TutMain")
+    val tutMain = tutClass.getDeclaredMethod("main", classOf[Array[String]])
+
+    val commandLine = Array(
+      file.toString,
+      BuildInfo.tutOutput.toString,
+      ".*",
+      "-classpath",
+      libClasspath.mkString(File.pathSeparator)
+    )
+
+    tutMain.invoke(null, commandLine)
+  }
+}
+
+case class FrontMatter(tut: Tut)

src/main/scala/Main.scala

@@ -0,0 +1,13 @@
+package org.typelevel.blog
+
+import org.yaml.snakeyaml.Yaml
+
+object Main extends App {
+
+  val posts = BuildInfo.tutInput.listFiles().toList.filter { file =>
+    file.isFile() && file.getName.endsWith(".md")
+  }.map(Post(_))
+
+  posts.foreach(_.process())
+
+}

src/main/scala/Post.scala

@@ -0,0 +1,41 @@
+package org.typelevel.blog
+
+import coursier._
+import java.io.{File, FileInputStream}
+import java.nio.file.Files
+import org.yaml.snakeyaml.Yaml
+import scala.util.Try
+
+case class Post(file: File) {
+
+  lazy val frontMatter: Option[FrontMatter] = Try {
+    val yaml = new Yaml()
+    val stream = new FileInputStream(file)
+    val any = yaml.loadAll(stream).iterator.next()
+    stream.close()
+    any
+  }.flatMap(YAML.decodeTo[FrontMatter]).toOption
+
+  lazy val out: File =
+    new File(BuildInfo.tutOutput.toString + File.separator + file.getName)
+
+  def outdated(): Boolean =
+    !(out.exists() && out.isFile() && file.lastModified() <= out.lastModified())
+
+  def process(): Unit =
+    if (outdated()) {
+      println(s"Processing ${file.getName} ...")
+
+      frontMatter match {
+        case Some(FrontMatter(tut)) => 
+          tut.invoke(file)
+        case None =>
+          println("No tut header, copying.")
+          Files.copy(file.toPath, out.toPath)
+      }
+    }
+    else {
+      println(s"Skipping ${file.getName} (up to date).")
+    }
+
+}

src/main/scala/YAML.scala

@@ -0,0 +1,66 @@
+package org.typelevel.blog
+
+import org.yaml.snakeyaml.Yaml
+import scala.collection.JavaConverters._
+import scala.util.Try
+import shapeless._
+import shapeless.labelled.FieldType
+
+trait YAML[T] {
+  def rawDecode(any: Any): T
+
+  final def decode(any: Any): Try[T] =
+    Try(rawDecode(any))
+}
+
+trait LowPriorityYAML {
+
+  implicit def deriveInstance[F, G](implicit gen: LabelledGeneric.Aux[F, G], yg: Lazy[YAML[G]]): YAML[F] =
+    new YAML[F] {
+      def rawDecode(any: Any) = gen.from(yg.value.rawDecode(any))
+    }
+
+}
+
+object YAML extends LowPriorityYAML {
+
+  def apply[T](implicit T: YAML[T]): YAML[T] = T
+
+  def decodeTo[T : YAML](any: Any): Try[T] =
+    YAML[T].decode(any)
+
+  implicit def listYAML[T : YAML]: YAML[List[T]] =
+    new YAML[List[T]] {
+      def rawDecode(any: Any) =
+        any.asInstanceOf[java.util.List[_]].asScala.toList.map(YAML[T].rawDecode)
+    }
+
+  implicit def stringYAML: YAML[String] =
+    new YAML[String] {
+      def rawDecode(any: Any) =
+        any.asInstanceOf[String]
+    }
+
+  implicit def deriveHNil: YAML[HNil] =
+    new YAML[HNil] {
+      def rawDecode(any: Any) = HNil
+    }
+
+  implicit def deriveHCons[K <: Symbol, V, T <: HList]
+    (implicit
+      key: Witness.Aux[K],
+      yv: Lazy[YAML[V]],
+      yt: Lazy[YAML[T]]
+    ): YAML[FieldType[K, V] :: T] = new YAML[FieldType[K, V] :: T] {
+    def rawDecode(any: Any) = {
+      val k = key.value.name
+      val map = any.asInstanceOf[java.util.Map[String, _]]
+      if (!map.containsKey(k))
+        throw new IllegalArgumentException(s"key $k not defined")
+      val head: FieldType[K, V] = labelled.field(yv.value.rawDecode(map.get(k)))
+      val tail = yt.value.rawDecode(map)
+      head :: tail
+    }
+  }
+
+}

src/main/scala/package.scala

@@ -0,0 +1,55 @@
+package org.typelevel.blog
+
+import coursier._
+import java.io.File
+import scala.language.implicitConversions
+import scala.util.{Failure, Success, Try}
+import scalaz.\/
+import scalaz.concurrent.Task
+import scalaz.std.list._
+import scalaz.syntax.traverse._
+
+object `package` {
+
+  val repositories = Seq(
+    Cache.ivy2Local,
+    MavenRepository("https://repo1.maven.org/maven2"),
+    MavenRepository("https://dl.bintray.com/tpolecat/maven/")
+  )
+
+  implicit def eitherToTry[T](e: Throwable \/ T): Try[T] =
+    e.fold(Failure(_), Success(_))
+
+  def resolve(start: Resolution): Try[List[File]] = {
+    val logger = new Cache.Logger {
+      override def downloadingArtifact(url: String, file: File) =
+        println(s"Downloading artifact from $url ...")
+      override def downloadedArtifact(url: String, success: Boolean) = {
+        val file = url.split('/').last
+        if (success)
+          println(s"Successfully downloaded $file")
+        else
+          println(s"Failed to download $file")
+      }
+    }
+
+    val fetch = Fetch.from(repositories, Cache.fetch(logger = Some(logger)))
+
+    start.process.run(fetch).unsafePerformSyncAttempt.flatMap { resolution =>
+      if (!resolution.isDone)
+        \/.left(new RuntimeException("resolution did not converge"))
+      else if (!resolution.conflicts.isEmpty)
+        \/.left(new RuntimeException(s"resolution has conflicts: ${resolution.conflicts.mkString(", ")}"))
+      else if (!resolution.errors.isEmpty)
+        \/.left(new RuntimeException(s"resolution has errors: ${resolution.errors.mkString(", ")}"))
+      else {
+        Task.gatherUnordered(
+          resolution.artifacts.map(artifact =>
+            Cache.file(artifact, logger = Some(logger)).run
+          )
+        ).unsafePerformSyncAttempt.map(_.sequenceU).flatMap(_.leftMap(err => new RuntimeException(err.describe)))
+      }
+    }
+  }
+
+}