define class <vehicle> (<object>)
  slot owner :: <string>,
    init-keyword: owner:,
    init-value: "Northern Motors";
end class <vehicle>;

define class <car> (<vehicle>)
end class <car>;

define class <truck> (<vehicle>)
  slot capacity,
    required-init-keyword: tons:;
end class <truck>;

define generic tax
    (v :: <vehicle>) => (tax-in-dollars :: <float>);

define method tax
    (v :: <vehicle>) => (tax-in-dollars :: <float>)
  100.00
end;

define method tax
    (c :: <car>) => (tax-in-dollars :: <float>)
  50.0;
end method;

define method tax
    (t :: <truck>) => (tax-in-dollars :: <float>)
  // standard vehicle tax plus $10/ton
  next-method() + t.capacity * 10.0;
end method;

define function make-fibonacci()
  let n = 0;
  let m = 1;
  method ()
    let result = n + m;
    n := m;
    m := result  // return value
  end
end;

define constant fib = make-fibonacci();

for (i from 1 to 15)
  format-out("%d ", fib())
end;

‹ ›

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New release: 2019.1 - 2019-03-31

Open Dylan 2019.1 released.

New release: 2014.1 - 2015-01-01

We just released Open Dylan 2014.1.

Nix Packages Available - 2014-05-28

Open Dylan is now available in the Nix package manager.

Call for Help! - 2014-01-28

We’re looking for help with various projects!

New release: 2013.2 - 2013-12-23

We just released Open Dylan 2013.2.

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Dylan is a multi-paradigm functional and object-oriented programming language. It is dynamic while providing a programming model designed to support efficient machine code generation, including fine-grained control over dynamic and static behaviors.

Get Started

Downloading Dylan is easy. Once downloaded, we recommend reading through Introduction to Dylan and exploring some examples.

Learn about Dylan

Dylan has a large amount of documentation available:

• Introduction to Dylan:

  A tutorial written for those with solid programming experience in C++ or another object-oriented, static language. It provides a gentler introduction to Dylan than does the Dylan Reference Manual (DRM).

• Dylan Programming Guide:

  A book length Dylan tutorial.

• Dylan Reference Manual:

  The official definition of the Dylan language and standard library.

• Open Dylan Documentation:

  All of the Open Dylan documentation.