SOMns - A Simple Newspeak Implementation

Introduction

Newspeak is a dynamic, class-based, purely object-oriented language in the tradition of Smalltalk and Self. SOMns is an implementation of the Newspeak Specification Version 0.0.95 derived from the SOM(Simple Object Machine) class libraries, and based on the TruffleSOM. Thus, SOMns is implemented using the Truffle framework and runs on the JVM platform.

A simple Hello World program looks like:

class Hello usingPlatform: platform = (
  public main: platform args: args = (
    'Hello World!' println.
    ^ 0
  )
)

Implementation and Deviations from the Specification

SOMns is implemented as self-optimizing AST interpreter using the Truffle framework. Thus, it can utilize the Truffle support for just-in-time compilation to optimize the execution performance at runtime. It is completely file-based and does not have support for images. The parser is written in Java and creates a custom AST that is geared towards representing the executable semantics.

The overall goal is to be compliant with the specification, but include only absolutely necessary features. The current list of intended deviations from the specifications are as follows:

• the mixin support of slots is not yet complete, see deactivate tests in core-lib/TestSuite/MixinTests.som

• simultaneous slots clauses are not supported (spec. 6.3.2)

• the file syntax is adapted to be more practical. This includes that category names are optional instead of being mandatory.

• setter send syntax is still based on the classic Smalltalk :=

• local variables in methods do not yet support the full slotDeclartion style

• as in SOM method chains are not supported

• as in SOM, blocks can only have 3 arguments (counting self)

Obtaining and Running SOMns

This is a brief guide, a more comprehensive overview is available here: Getting Started Guide.

To checkout the code:

git clone https://github.com/smarr/SOMns.git

Then, SOMns can be build with Ant:

ant compile

Afterwards, the simple Hello World program is executed with:

./som core-lib/Hello.som

Information on previous authors are included in the AUTHORS file. This code is distributed under the MIT License. Please see the LICENSE file for details.

Setup Development Environment with Eclipse and VS Code

1. Install JDK 1.8 and Eclipse Mars (or later)

2. Download the project from Github git clone https://github.com/smarr/SOMns

3. Run ant compile on the command line, or via Eclipse, to make sure that all libraries are loaded and available.

4. Create Truffle Eclipse projects with ant ideinit.

5. Import SOMns project and the Truffle projects into Eclipse

6. For debugging the interpreter, create a run configuration with the Mandelbrot benchmark. In option Run Configurations go to Java Application/SOMns and select tab arguments, enter:

   In Program arguments: core-lib/Benchmarks/Harness.som Mandelbrot 2 0 500

   In VM arguments: -ea -esa

For testing on the command line, the full command is ./som -G core-lib/Benchmarks/Harness.som Mandelbrot 2 0 500

Additionally, there are JUnit tests and ant test for executing the test suite.

To use VS Code as IDE and debugger for SOMns programs, it needs to be installed manually from: https://code.visualstudio.com/Download

The SOMns support can then be installed via the Marketplace.

Instructions for Ubuntu

sudo add-apt-repository ppa:webupd8team/java
curl -sL https://deb.nodesource.com/setup_7.x | sudo -E bash -
sudo apt install oracle-java8-installer git ant npm nodejs

git clone --recursive https://github.com/smarr/GraalBasic.git
cd GraalBasic
yes "n" | ./build.sh
cd ..

git clone https://github.com/smarr/SOMns.git
cd SOMns
ant       ## build SOMns
ant tests ## run all tests

ant ideinit ## Generate all Truffle Eclipse projects

Build Status

The current build status is:

Academic Work

SOMns is designed as platform for research on concurrent programming models, and their interactions. Here, we collect related papers:

• Kómpos: A Platform for Debugging Complex Concurrent Applications, S. Marr, C. Torres Lopez, D. Aumayr, E. Gonzalez Boix, H. Mössenböck; Demonstration at the <Programming>'17 conference.

• Toward Virtual Machine Adaption Rather than Reimplementation: Adapting SOMns for Grace, R. Roberts, S. Marr, M. Homer, J. Noble; Presentation at the MoreVMs'17 workshop at the <Programming>'17 conference.

• Optimizing Communicating Event-Loop Languages with Truffle, S. Marr, H. Mössenböck; Presentation at the AGERE!’15 Workshop, co-located with SPLASH’15.

• Cross-Language Compiler Benchmarking: Are We Fast Yet? S. Marr, B. Daloze, H. Mössenböck at the 12th Symposium on Dynamic Languages co-located with SPLASH'16.