https://github.com/satabin/gnieh-coroutines

Scala compiler plugin to support coroutines
https://github.com/satabin/gnieh-coroutines

Last synced: 11 days ago
JSON representation

Scala compiler plugin to support coroutines

• Host: GitHub
• URL: https://github.com/satabin/gnieh-coroutines
• Owner: satabin
• License: apache-2.0
• Created: 2010-10-16T22:14:16.000Z (about 14 years ago)
• Default Branch: master
• Last Pushed: 2010-12-03T16:56:20.000Z (about 14 years ago)
• Last Synced: 2023-03-11T05:22:21.965Z (almost 2 years ago)
• Language: Scala
• Homepage:
• Size: 129 KB
• Stars: 0
• Watchers: 2
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

Awesome Lists containing this project

README

        
Gnieh Coroutines

================

Introduction

------------

Gnieh Coroutines is a [Scala][1] library and a compiler plugin which makes it possible to use coroutines in Scala.

The design is based on coroutines in LUA ([Revisiting Coroutines][2], [Coroutines in LUA][3]) and natively implements asymmetric coroutines.

This project is still at an really early stage and is not finished yet. Any comments are welcome.

Usage

-----

There are two to create and use coroutines:

*   coroutines.create: create and consume the coroutine object itself

*   coroutines.wrap: create the coroutine and wrap it into a closure that takes the same parameter as the resume method

For example

    import gnieh._

    val co = coroutines.create {

      (i: Int) => {

        println("first time: " + i)

        val j: Int = coroutines.yld(i + 5)

        println("second time: " + j)

        j - 7

      }

    }

    println(co.resume(2))

    println(co.resume(5))

is equivalent to

    import gnieh._

    val co = coroutines.wrap {

      (i: Int) => {

        println("first time: " + i)

        val j: Int = coroutines.yld(i + 5)

        println("second time: " + j)

        j - 7

      }

    }

    println(co(2))

    println(co(5))

Gnieh Coroutines is based on Scala continuations, so you need to enable the Scala continuations to compile the code above:

    scalac -Xplugin:/path/to/gnieh-coroutines-plugin.jar -cp /path/to/gnieh.coroutines-library.jar -P:continuations:enable cor.scala

Limitations

-----------

There are currently different limitations:

*   coroutines.yld is only allowed in the function wrapped in the coroutine

*   recursive calls to the function wrapped in the coroutine are not supported

Implementation

--------------

*TBD*

TODOs

-----

*   Support for coroutines.yld in method not directly wrapped in the coroutine:

*      add an implicit parameter to the method passing the current coroutine

*   Support recursive calls?

[1]: http://www.scala-lang.org

[2]: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.58.4017 "Revisiting Coroutines, Ana Lúcia de Moura and Roberto Ierusalimschy"

[3]: http://www.inf.puc-rio.br/~roberto/docs/corosblp.pdf "Coroutines in LUA, Ana Lúcia de Moura, Noemi Rodriguez, Roberto Ierusalimschy"