Boo is a new, object oriented, statically typed, programming language for the Common Language Infrastructure with a Python-inspired syntax and a special focus on language and compiler extensibility. Some features of note include type inference, generators, multimethods, optional duck typing, macros, true closures, currying, and first class functions.

Boo is open source–licensed under an MIT/BSD style license.

Code samples

Hello world program:

print "Hello, world!"

Fibonacci series generator function:

def fib():
    a as long, b as long = 0, 1
    while true:
        yield b
        a, b = b, a + b

Basic Windows Form example demonstrating classes, closures, and events:

import System.Windows.Forms
import System.Drawing

class MyForm(Form):
    def constructor():
        b = Button(Text: "Click Me")
        b.Location = Point(100, 50)
        b.Click += do():
            MessageBox.Show("you clicked the button!")
            
        self.Controls.Add(b)

f = MyForm()
Application.Run(f)

Asynchronous design pattern with a closure:

import System

def run():
    print("executing")

print "started" 
result = run.BeginInvoke({ print("called back") })
System.Threading.Thread.Sleep(50ms)
run.EndInvoke(result)

print "done"

Currying:

plusX = { a as int | return { b as int | return a + b }}

print plusX(3)(4)

External links

• Boo Homepage
• Boo Language Guide
• Boo Google discussion group
• "Gotchas" for Python users
• Boo Recipes, including:
  • Serializing objects
  • Regular expressions
  • Invoking native methods with DllImport
  • 3D OpenGL Samples
  • Multimethods in boo
  • Dynamic Inheritance - fun with IQuackFu