seven-languages-in-seven-weeks/slides/ruby.org

Seven Languages in Seven Weeks

Introduction

Introduction

Ruby   BMCOL

Created

~1993

Author

Yukihiro Matsumoto

Interpreted, object-oriented, and dynamically typed.

Mary Poppins   BMCOL

Getting Ruby

http://www.ruby-lang.org/en/downloads/

Example

Source

  properties = ['object oriented', 'duck typed',
                'productive', 'fun']
  properties.each {|property| puts "Ruby is #{property}."}

Output

Ruby is object oriented.
Ruby is duck typed.
Ruby is productive.
Ruby is fun.

Day 1

Day 1: Finding a Nanny   B_frame

• Object-Oriented
• Simple Conditionals
• Strong / Dynamic Typing
• Duck Typing

Duck Typing

Source

  i = 0
  a = ['100', 100.0]
  while i < 2
    puts a[i].to_i
    i = i + 1
  end

Output

100
100

Exercises

EXERCISES

Day 2

Day 2: Floating Down from the Sky

• Defining Functions
• Arrays
• Hashes
• Code Blocks and Yield
• Running Ruby from a File
• Defining Classes
• Writing a Mixin
• Modules, Enumerable, and Sets

Defining Functions

  def tell_the_truth
    true
  end

Code Blocks

Source

  class Fixnum
    def my_times
      i = self
      while i > 0
        i = i - 1
        yield
      end
    end
  end

  3.my_times {puts 'mangy moose'}

Results

mangy moose
mangy moose
mangy moose

Classes

Exercises

EXERCISES

Day 3

Day 3: Serious Change

• Open Classes
• method_missing
• Modules

method_missing

Source   BMCOL

  class Roman
    def self.method_missing name, *args
      roman = name.to_s
      roman.gsub!("IV", "IIII")
      roman.gsub!("IX", "VIIII")
      roman.gsub!("XL", "XXXX")
      roman.gsub!("XC", "LXXXX")

      (roman.count("I") +  
       roman.count("V") * 5 +
       roman.count("X") * 10 + 
       roman.count("L") * 50 +
       roman.count("C") * 100)
    end
  end

  puts Roman.X
  puts Roman.XC
  puts Roman.XII
  puts Roman.X

Results   BMCOL

10
90
12
10

Exercises

EXERCISES

Wrapping Up

Wrapping Up: Core Strengths

• Scripting
• Web Development
• Time to Market

Wrapping Up: Weaknesses

• Performance
• Concurrency and OOP
• Type Safety

Final Thoughts

Syntax and flexibility vs. performance.