cmark-scala provides Scala Native bindings for cmark. cmark allows to parse, manipulate and render CommonMark documents.

The bindings were directly derived from cmark.h. Comments were retained and adapted if necessary. The naming of functions and their encapsulation follows Scala's conventions. Note that *_new functions were renamed to create as to prevent name collisions with the eponymous Scala keyword.

Example

import cmark._
import scalanative.unsafe._
import scalanative.unsigned._

var level = -1
def onNode(eventType: EventType, node: Ptr[Node]): Unit = {
  eventType match {
    case EventType.Enter => level += 1
    case EventType.Exit  => level -= 1
  }

  val levelStr = "  " * level
  val startLine = Node.getStartLine(node)
  val endLine   = Node.getEndLine(node)

  Node.getType(node) match {
    case NodeType.Text =>
      val text = fromCString(Node.getLiteral(node))
      println(s"${levelStr}text node @ line $startLine-$endLine: $text")

    case _ =>
      val nodeTypeStr = fromCString(Node.getTypeString(node))
      println(s"$levelStr$nodeTypeStr node @ $startLine-$endLine")
  }
}

val test =
  """# Chapter
    |## Section
    |### Sub-section
    |
    |Hello World from *cmark-scala*!
  """.stripMargin

println("cmark version: " + fromCString(cmark.versionString()))
println()

val docNode = Parser.parseDocument(
  toCString(test), test.length.toULong, Options.SourcePosition)
val iter = Iter.create(docNode)
var evType = Iter.next(iter)
while (evType != EventType.Done) {
  onNode(evType, Iter.getNode(iter))
  evType = Iter.next(iter)
}
Iter.free(iter)

val html = fromCString(Render.html(docNode, Options.Default))
println()
println(html)

Node.free(docNode)

Output:

cmark version: 0.27.1

document node @ 1-6
  heading node @ 1-1
    text node @ line 0-0: Chapter
  heading node @ 1-1
    heading node @ 2-2
      text node @ line 0-0: Section
    heading node @ 2-2
      heading node @ 3-3
        text node @ line 0-0: Sub-section
      heading node @ 3-3
        paragraph node @ 5-5
          text node @ line 0-0: Hello World from 
            emph node @ 0-0
              text node @ line 0-0: cmark-scala
            emph node @ 0-0
              text node @ line 0-0: !
            paragraph node @ 5-5
          document node @ 1-6

<h1>Chapter</h1>
<h2>Section</h2>
<h3>Sub-section</h3>
<p>Hello World from <em>cmark-scala</em>!</p>

Dependency

libraryDependencies += "tech.sparse" %%  "cmark-scala" % "0.2.0-SNAPSHOT"

Install Native Library

In order to use this library you need to install cmark which installs libcmark.

• macOS users can use the following command.

$ brew install cmark

• Linux/Ubuntu users can use the following commands.

$ sudo apt update
$ sudo apt install cmark

License

cmark-scala is licensed under the terms of the Apache v2.0 license. Its function interfaces and comments were derived from cmark.h, which is licensed under BSD-2-Clause.

Authors

• Tim Nieradzik