RhinoCoffeeScript

This Java library provides CoffeeScript.class precompiled with Rhino. This allows you to speed up the compiling of CoffeeScript snippets to JavaScript. For example, it usually takes several seconds to load coffee-script.js and use it to compile a simple CoffeeScript snippet. This can be reduced to several milliseconds when using the precompiled CoffeeScript.class.

Usage

Maven:

• Group: tv.cntt
• Artifact: rhinocoffeescript
• Version: 1.12.7 (= version of CoffeeScript)

If you see that a new version of CoffeeScript has been released, but there's no corresponding version of RhinoCoffeeScript, please report by creating a new issue.

Note that we have problem with CoffeeScript 2.x.

This library only includes Rhino dependency. You can use the precompiled class tv.cntt.rhinocoffeescript.CoffeeScript or the utility class tv.cntt.rhinocoffeescript.Compiler.

Scala example:

import javax.script.ScriptException
import tv.cntt.rhinocoffeescript.Compiler

object CoffeeScriptCompiler {
  def compile(coffeeScript: String): Option[String] = {
    try {
      val javaScript = Compiler.compile(coffeeScript)
      Some(javaScript)
    } catch {
      case e: ScriptException =>
        val line   = e.getLineNumber
        val column = e.getColumnNumber
        println("CoffeeScript syntax error at %d:%d".format(line, column))
        None
    }
  }
}

You can also cache the generated JavaScript snippet using local cache (you can easily implement one with LinkedHashMap) or distributed cache (like Hazelcast).

How CoffeeScript.class is created

1. Download coffee-script.js (the core compile) from http://coffeescript.org/
2. Precompile with Rhino:

org.mozilla.javascript.tools.jsc.Main.main(
  "-opt 9 -nosource -o CoffeeScript -package tv.cntt.rhinocoffeescript coffee-script.js".split(" ")
)

Please create a new issue to report if a new version of Rhino has been released or the above options can be improved.

About the options when creating CoffeeScript.class

org.mozilla.javascript.tools.jsc.Main.main(Array("-h"))

gives:

Usage: java org.mozilla.javascript.tools.jsc.Main [OPTION]... SOURCE...
Valid options are:
  -version VERSION   Use the specified language version.
                       VERSION should be one of 100|110|120|130|140|150|160|170.
  -opt LEVEL         Use optimization with the specified level.
                       LEVEL should be one of 0..9.
  -debug, -g         Include debug information.
  -nosource          Do not include source to function objects.
                       It makes f.toString() useless and violates ECMAScript
                       standard but makes generated classes smaller and
                       saves memory.
  -o CLASSNAME       Use specified name as the last component of the main
                       generated class name. When specified, only one script
                       SOURCE is allowed. If omitted, it defaults to source
                       name with stripped .js suffix.
  -package PACKAGE   Place generated classes in the specified package.
  -d DIRECTORY       Use DIRECTORY as destination directory for generated
                       classes. If omitted, it defaults to parent directory
                       of SOURCE.
  -encoding charset  Sets the character encoding of the source files.
  -extends CLASS     The main generated class will extend the specified
                       class CLASS.
  -implements INTERFACE1,INTERFACE2,... The main generated class will
                       implement the specified list of interfaces.
  -main-method-class CLASS Specify the class name used for main method
                       implementation. The class must have a method matching
                       "public static void main(Script sc, String[] args)"
  -observe-instruction-count Generate code that contains callbacks to
                       accumulate counts of executed instructions. Code
                       compiled with this flag can be monitored using
                       Context.setInstructionObserverThreshold.
  -help, --help, -h  Print this help and exit.