A functional, immutable, gradually-typed, interprited language.
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Bike Language

What's it all about?

Bike is a programming language born out of my need to have a practical, yet purely functional programming language, with a syntax that not only matches the elegance of Python, but the terseness of Swift, and the FP bevity of Haskell.

I think that Bike does all of this. It has a fairly substantial standard library, far bigger that that of JavaScript, but still smaller that of Haskell.

OOP is carried out in a way that stays true to functional programming, and stays out of your way when your just trying to get things done. Objects and Classes are pure, and immutable, createing a good way to encapsulate code, without the normal OOP problems.


git clone https://github.com/christopherdumas/Bike.git
cd Bike/
# You might need to install ruby.
./configure # Install all the needed GEMs
./bin/bike # Get started!


Documentation currently resides in the github wiki page.


beta 10

  • Typealias
  • Better Algebraic Datatype support in the type system
  • Improved Algebraic Datatypes
  • Getting Started/Tutorials
  • Improved error handling
  • Report error line number
  • Class and function metadata


  • Better string libraries (replace, grep, etc.)
  • Improve Wheels
  • Referance and Documentation
  • Simplify syntax and streamline module syntax


  • Atom, Emacs, Vim and Sublime Text syntax highlighting
  • Observers
  • Ratios
  • Fractions

1.2 and Beyond!

  • Publicize!
  • Write a big project of some sort in Bike, to make it look more real to people
  • Macros?
  • Metaprogramming?
  • Dynamic method/variable/class names?
  • Book
  • Screencasts

Version History

beta 9: Raptor

More bugs fixed, and (almost) total Rubocop compliance. A gigantic refactor was in order. Plus, some new features:

  • Algebraic Datatypes
  • Better Debuging and error information
  • Better repl formatting Also some minor bugs were fixed:
  • Type information should be saved during currying
  • Function return type was being ignored

beta 8: Rackoon

Fixed a lot of OOP features, added optional typing and arguments, and added other little fixes.

beta 7: Pipe

This release adds a modest amount of new list functions, utility functions, fixes, and a website. Also, it adds a function application operator, that works like this: Exp |> Func, so that you could do something like: 1 |> add1 |> add1 |> add1 |> add1

beta 6: Elephant

Removed a ton of features that were unnecessary, such as:

  • Spread and rest parameters
  • Anonymous functions
  • Weird Lambda syntax (replaced by { (<arg ...>) -> <body> })
  • Mixins
  • Weird @/set array syntax (replaced by more normal array access syntax, but no setting.)
  • Mutations on classes, arrays, hashes, or packages, and mutable variable declarations
  • Added array destructuring

Now working on:

  • Argument destructuring
  • Bigger Wheels list package
  • optional typing? - I like the dynamic ruby-ishness of Bike currently, but optional typing could be useful for documentation and preventing errors

The reason for this? (1) I came back to Bike after almost a year, and realized that it had a ton of bloat. Also, most of the code was written while I had a low grade fever. Bad idea. (2) I found a sketch of a programming language in an old notebook, and decided that it was nice, and something I would want to program in, so I am working to make Bike like it.

beta 5: Hottrix (really bad name, I know)

This release basically had every single heisenbug that could possibly happen to a language designer. I fixed them all, and updated documentation and syntax as well. On the way, I added some well-needed little tricks.

beta 4: Watcher

This release adds:

  • Closures
  • Real computed Properties and getters (plus setters!)
  • private and public modifiers
  • for-of
  • elseif
  • Sets
  • Observers

beta 3: Hydra

This release adds these features to the Beta 2 release:

  • Arrow functions
  • Destructuring assignment (for Hashes and Anonymous Classes)
  • String Concatenation
  • Anonymous Classes
  • Hashes (Anonymous Classes with syntactic sugar)
  • Rest Arguments
  • Documented Source, with RDoc
  • Splat Arguments
  • Types (internal difference. No one will notice.)

beta 2: Drabbit

This release was the first actually implemented part of Bike. For the first time, I could actually run something. This release had:

  • anonymous functions (but no closures yet)
  • functions
  • variables
  • classes
  • inheritance
  • a few library functions
  • extendable Number, Object, Class, and String types
  • packages
  • imports (RequireJS style)
  • getters
  • computed properties
  • mixins

Also a color REPL with history, tab completion, a lexer mode, and a history list mode.