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ppedemon/Bluejelly

Pure lazy functional programming on the Java Platform
Source code at GitHub null
ppedemon/Bluejelly.json
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  "createdAt": "2012-08-07T14:39:00Z",
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  "description": "Pure lazy functional programming on the Java Platform",
  "fullName": "ppedemon/Bluejelly",
  "homepage": null,
  "language": "Scala",
  "name": "Bluejelly",
  "pushedAt": "2016-05-02T00:19:10Z",
  "stargazersCount": 35,
  "topics": [],
  "updatedAt": "2019-08-13T15:07:22Z",
  "url": "https://github.com/ppedemon/Bluejelly"
}

The Bluejelly Project

Section titled “The Bluejelly Project”

Bluejelly is my attempt to execute real-world pure lazy functional programs on the Java virtual machine. If features the following toolchain:

  • The Bluejelly Runtime: a runtime system providing support for graph-reduction on the JVM. It is based on the technical report [The Lazy Virtual Machine Specification][lvm], by Daan Leijen (Utretch University, 2001). The runtime is essentialy a Java rendition of the spec.

  • The Bluejelly Assembler: a pure lazy assembly language, and its assembler. Assembly programs can be assembled to Java classes that the Bluejelly Runtime can execute on a JVM.

  • The Low Level Lazy Language (aka L4): a low level pure functional language, powerful enough to write real-world programs without too much pain. The L4 compiler compiles L4 modules to assembler, that in turn are compiled to Java classes by the Bluejelly Assembler.

Future Work

Section titled “Future Work”

The main missing piece is a full fledged Haskell-like pure functional language built on top of L4. As Bluejelly progress is dictated by my spare time, this might take a while.

Development

Section titled “Development”

Bluejelly uses [sbt][]. Pull the code and enter sbt from the main project root folder. You can then pick the runtime, assembler or L4, and run the tests with the test command. The assembler and L4 can be executed from the sbt console using the run command, but not the runtime (it does some class loading trickery that run does not like).

Yet, for all projects there is a dist task that builds a zip file holding the application jar (built with [sbt-assembly][sbtasm]) and a (Linux) launcher script. Use the dist task to build an executable runtime (or assembler, or L4 compiler).

It is possible to use [sbteclipse][] to develop from Eclipse with a [Scala IDE][scalaide] plugin installed. The .gitignore file already includes the Eclipse stuff to ignore. Remember that the runtime is a Java project, so set project flavor properly for the runtime before running eclipse:

set EclipseKeys.projectFlavor := EclipseProjectFlavor.Java

In addition, do not attempt to execute the runtime, assembler or L4 compiler (or their tests) from Eclipse, since the code requires some generated files that sbt takes care of creating as needed. Please stick to the sbt console for executing Bluejelly code.

Examples

Section titled “Examples”

Check src/test/resources/testmods.src in the assembler and L4 projects for example assembler and L4 modules, respectively.

[lvm] !: http://www.cs.uu.nl/research/techreps/repo/CS-2004/2004-052.pdf [sbt] !: http://www.scala-sbt.org/ [sbtasm] !: https://github.com/sbt/sbt-assembly [sbteclipse] !: https://github.com/typesafehub/sbteclipse [scalaide] !: http://scala-ide.org/