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GSoC 2014 Ideas

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Dominik Picheta edited this page Feb 13, 2014 · 105 revisions

Introduction

Below is a list of project ideas for GSoC 2014. All these projects require familiarity with the Nimrod programming language, or at minimum, experience with similar programming languages such as C, C#, Java, Python, etc. It is absolutely essential that you become familiar with Nimrod ahead of time.

Nimrod is a statically typed programming language which compiles primarily to C. Areas of the project you may wish to work on include the Nimrod compiler which is itself written in Nimrod, Nimrod's standard library and/or the tools and infrastructure of Nimrod which includes the Nimrod build farm (Nimbuild) and the Nimrod package manager (babel).

We encourage you to join the #nimrod IRC channel on Freenode to discuss these projects with the community and our mentors. The Nimrod Forum is also available. Because communication is a big part of open source development you are expected to get in touch with us before making your application, failure to do so will put your application at a great disadvantage.

The following list of projects are just some ideas that the community and the developers have come up with. You will be contributing to a programming language so there is a lot of flexibility when it comes to the projects that you can work on, this list is certainly not comprehensive so we are happy to hear any suggestions that you may have.

Projects

Nimrod Compiler

Add support for full coroutines

Desirable skills: Knowledge of coroutines, C and Assembly language.

Description:

Implement proper coroutines that provide light-weight collaborative multi-tasking. The coroutines must be cooperative - this means a coroutine is suspended only when it explicitly yields. The coroutines must never be migrated across threads - this means that of all the coroutines started from a thread, exactly one is running at any point in time while the others are suspended. Other semantic details are to be nailed down as part of the project.

Nimrod already supports "closure iterators" which are comparable to Python's generators. However closure iterators are much less powerful than proper coroutines because they don't allow capturing the full call stack. This means, for instance, that closure iterators cannot be recursive.

Here is a sketch of a possible implementation, but there are lots of other possibilities to implement full coroutines for Nimrod:

  • Implement the necessary stack switching via inline assembler.
  • The GC needs to support conservative marking of multiple stacks.
  • In particular the write barrier in the GC which does the 'isOnStack' check needs to be changed.
  • Using a bloom filter for quick testing whether an address belongs to some stack is likely to pay off.
  • Creating a coroutine needs to register a new stack to the GC.
  • Deleting a coroutine needs to unregister the stack to the GC.
  • Builtin 'yld' must save the current stack pointer so that the GC knows which part of the stack is really in use.

Expected Result: A working coroutine implementation in Nimrod that plays well with the GC.

Difficulty: Hard

Mentor: Araq (@Araq)

Add a code generator for OpenCL

Desirable skills: Good OpenCL knowledge, knowledge of the compiler internals, basics of type theory.

Description:

Nimrod currently supports C, C++, Objective C and JavaScript code generation. However to run efficiently on GPUs an OpenCL backend is required. The easy way to do this is to copy OpenCL's low level mode of operation with its different private, local, global storage and simply provide a nimrodic syntax for OpenCL. So apart from syntactic sugar users get all of Nimrod's meta programming advantages plus good integration into Nimrod's infrastructure.

The vision is a gpu pragma that means a proc and all of its dependencies are translated into OpenCL instead of C but can be invoked from ordinary Nimrod code that is translated to C. The gpu code generator is allowed to only translate a subset of Nimrod, in particular things like function pointers that are not supported by OpenCL do not have to be supported. The compiler should produce a clean error message for unsupported features.

Expected Result: The GPU code generator works on a selected set of examples/test cases.

Tasks:

Bonus points: Support version 1.2 of the OpenCL specification: https://www.khronos.org/registry/cl/sdk/1.2/docs/man/xhtml/. This should be significantly harder as version 1.2 doesn't support a shared address space with the host environment.

Difficulty: Hard

Mentor: Araq (@Araq)

Make Nimrod a viable research platform for Garbage Collection algorithms

Desirable skills: Familiarity with the various GC approaches and algorithms, knowledge of the compiler codegen modules.

Description:

Most of the popular garbage collected languages of today require a separately distributed run-time environment, providing only a predetermined set of garbage collection algorithms. This leaves little room for experimentation with various approaches and condemns GC researchers to develop and test their algorithms on specialized platforms such as the Jikes RVM that have limited practical significance.

In contrast, in Nimrod, the garbage collection algorithm is chosen at compile-time and embedded in the resulting stand-alone native executable. This enables the users to pick a GC algorithm that's most suitable to their project and allows for a proliferation of GC algorithms, developed by independent groups and individuals, without requiring any modifications to be made to the standard Nimrod distribution.

The Nimrod code generator and type system can provide various GC roots marking strategies, various kinds of write/read barriers and all necessary static type information (e.g. static cycle analysis) and a GC implementation will consist only of a single Nimrod module (supplied as a command-line parameter) that provides configuration for the code generator and implements the logic of the garbage collection algorithm. This module will be compiled as C code with the rest of the program and it could be easily debugged using standard C/C++ debugging and profiling tools.

Tasks:

  • Add support for precise stack marking
  • Add support for read barriers and polish the support for Levanoni/Petrank style of write barriers
  • Implement the infrastructure for picking a user-supplied GC module

Bonus points: Implement simple forms of variety of GC algorithms as a proof-of-concept

Difficulty: Medium to Hard

Mentor: zahary (@zah)

Fix/Expand Nimrod's "Compiler as a Service" and idetools features

Desirable skills: Command line argument parsing, good knowledge of compiler internals and theory.

Description:

Nimrod's Compiler as a Service feature allows IDEs to query the compiler for things like code suggestions, definition lookups and more. The current implementation works but has some issues.

Tasks:

  • Review and resolve related issues.
  • Provide commands to execute macros. Allow IDEs to quickly get the code macros generate with different inputs.
  • Provide a mechanism to track a dirty file without saving it to disk.
  • Provide better diagnostic messages for invalid commands.
  • Add commands to retrieve information about project layout and compilation settings.

Related issues: #804, #274, #325, #452, #484, #474, #477, #450, #449, #415, #471, #344

Bonus points: Implement "Compiler as a Service" support to major IDEs/text editors such as Light Table, Sublime Text, or Visual Studio.

Difficulty: Medium to Hard

Mentor: zahary (@zah)

Standard Library

Implement a YAML parser library

Desirable skills: Ability to write efficient parsers.

Description:

The Nimrod standard library currently lacks a YAML parsing module. YAML is a popular "human-readable data serialization format", its popularity is especially evident in the Ruby community. As such it would be a great addition to Nimrod's standard library. This task requires you to read the YAML specification and to create a module which will be able to parse YAML data into an AST. Subsequently the parser can be used to create a high-level API to access the data similar to the current design of the json module which provides a low-level parser and a higher-level interface which builds on top of the parser.

Tasks:

  • Write an efficient parser which will turn YAML data into an AST.
  • Design and implement an API on top of the AST to query the data contained in the AST easily.

Expected Result: A working YAML module with the ability to read all YAML compliant data.

Bonus points: Thorough testing of the YAML module to ensure that the parser works as expected.

Difficulty: Medium

Mentor: Araq (@Araq), dom96 (@dom96)

Enhance the filesystem monitoring module fsmonitor

Desirable skills: Knowledge of the Microsoft Windows API.

Description: Nimrod's standard library currently has a fsmonitor (source code) module which allows the programmer to monitor the filesystem for directory and file changes. The problem is that this module currently only supports Linux.

Tasks:

  • Allow the fsmonitor module to work on Microsoft Windows by using native APIs to gather information about changes in monitored files and directories.
  • Revise the fsmonitor module API to decouple Unix/Linux file handle paradigms from the API, allowing easier implementations of multiple native backends.
  • Integrate the fsmonitor module's polling mechanism into the new asynchronous IO modules.

Difficulty: Easy

Mentor: dom96 (@dom96)

Enhance and expand standard library documentation

Desirable skills: Basic writing and documentation skills, web design and infrastructure setup.

Description: The Nimrod documentation is generally good but it lacks helpful code examples. It is also using a rather old design which is not on par with some of the documentation of other software projects out there. Read the docs is a good example of documentation done well. Our documentation is currently not very attractive and lacks some useful functionality too. This project aims to change that.

Tasks:

  • Ensure that documentation exists for all public methods and modules.
  • Create and design new CSS and HTML layouts for the documentation, the design should put readability above eyecandy. That said, the new design should be attractive to developers.
  • Add search capabilities to the online documentation.
  • Add code examples to all modules and to all procedures (where appropriate).

Difficulty: Medium

Mentor: zahary (@zah)

Add documentation to the Nimrod compiler internals

Desirable skills: Basic writing and documentation skills.

Description:

  • Add comments to the compiler internals, documenting the various mechanisms and mechanics the compiler uses to analyze and transform nimrod code to the code of the specified backend.

Difficulty: Medium

Mentor: Araq (@Araq), zahary (@zah)

Improve times module

Desirable skills: Knowledge of date time representations, native time api's.

Description:

  • Fix limitations to do with time intervals, specifically subtracting a TTimeInterval from a TTimeInfo.
  • Provide a $ for TTimeInterval. Goal is to be able to get timing info like "5 minutes ago".

Difficulty: Easy

Mentor: dom96 (@dom96)

Add an implementation of the ISAAC psuedorandom number generator

Desirable skills: Pseudo-Random number generation theory, C programming.

Description:

Difficulty: Medium

Mentor: Araq (@Araq)

Wrap and test the Qt framework

Desirable skills: Knowledge of C++. Experience with the Qt framework is desirable.

Description:

  • Wrap the Qt framework with the help of the c2nim tool, or otherwise.
  • Write tests which use the wrapper.

Bonus points: Write high-level bindings which provide an idiomatic Nimrod API on top of the wrapper.

Difficulty: Medium

Mentor: Araq (@Araq), zahary (@zah)

Wrap and test GTK3

Desirable skills: Knowledge of C. Experience with the GTK+ is desirable.

Description:

  • Wrap GTK3 with the help of the c2nim tool, or otherwise.
  • Write tests which use the wrapper.

Bonus Points: Write high-level bindings which provide an idiomatic Nimrod API on top of the wrapper.

Difficulty: Medium

Mentor: dom96 (@dom96), Araq (@Araq)

Tools & Infrastructure

Nimbuild

Desirable skills: JSON parsing, modular program construction, inter-process communication.

Description:

  • Reduce the number of assumptions the Nimrod builder makes about its host system, in order to reduce configuration restrictions. Assumptions include location and usage of external tools, such as git.
  • Implement benchmark tests in the builder and generate graphs showing the time taken to perform those benchmarks on the Nimbuild site. This can include bootstrap times, and test times too.
  • Generate images showing the status of the build to be shown in Nimrod's Github repo and/or Nimrod's website.
  • Improve the download tables on Nimbuild's homepage and generate embeddable download tables for the Nimrod website.

Difficulty: Medium

Mentor: dom96 (@dom96)

Babel

Desirable skills: Knowledge of Git and other version control systems.

Description:

Babel is the Nimrod package manager. It is currently very basic and some important features are still missing. Babel packages are stored in user-controlled repositories with support for Git and Mercurial currently present.

Possible tasks:

  • Add support for other VCS' alongside Git and Mercurial.
  • Create a website which tracks packages similar to hackage, npm, the DUB registry etc.
  • Add support for the removal of packages.
  • Automate the package submission process.
  • Expand the babel tester to test more dependency scenarios.

Difficulty: Medium

Mentor: dom96 (@dom96)

Implement re2nim, a lexer generator for nimrod

Description:

  • Model it after re2c or the Ragel state machine generator
  • Alternatively model it after Flex.

Desirable skills: Knowledge of lexer generators. How to translate regexes into DFAs and how to optimize the resulting automatons.

Difficulty: Medium to Hard

Mentor: zahary (@zah)

Implement a Nimrod backend for the Ragel state machine generator

Description:

Desirable skills: Knowledge of Ragel's internals.

Difficulty: Medium

Mentor: zahary (@zah)

Template

The following is a rough template that each proposal shall use.

Short description

Desirable skills: list of desirable skills

Description:

Description of the tasks involved.

Difficulty: Easy/Medium/Hard

Mentor: Potential mentor(s)

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