Ruby - Revision history

Guillaume at 16:02, 28 October 2010

2010-10-28T16:02:08Z

Guillaume at 16:00, 28 October 2010

2010-10-28T16:00:40Z

Guillaume at 22:37, 12 December 2008

2008-12-12T22:37:44Z

Guillaume: 1 revision

2008-12-03T10:39:04Z

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192.168.20.177: /* Irb */

2008-11-19T11:46:25Z

‎Irb

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Ruby is (said to be) a great language. People say that programming is fun again. Everything in Ruby is an object. Strings, floats, integers, regexps, arrays are all objects, and all have their methods and fields.

==Starters==
# [http://www.ruby-lang.org/en/documentation/quickstart/ Ruby in 20 minute]

Install ruby
> sudo apt-get install ruby irb rdoc

==Features==
Here we list the interesting features that make ruby so interesting, besides its interesting programming features. These are the extra tools that make working with [[ruby]] appealing and easy.
# interactive shell (irb),
# extension packages manager (gems),
# documentation generator from in-line comments (rdoc),
# unit-testing framework (utest),
# web-apps development framework (rails),

[[Python]] also possesses all of these features built-in (ipython, install, pydoc, unit-tests and django).

===Irb===
The most interesting thing in shell scripting ([[bash]], [[batch|dos]]) is that you can play right from the shell command line. This is what makes interpreted languages so interesting in the first place. Thus, like [[matlab]] or [[python]] (however, I'm not aware of one for [[perl]]), ruby has an interactive shell called [[#irb|irb]].
Interactive ruby allows to experiment and debug interactively in ruby. Similar (but not so powerful) to [[python|ipython]].
> irb
irb(main):001:0> puts "Hello world!"
Hello world!
=> nil
The most interesting method to call in irb is ''public_methods'' which lists all the object's available methods:
irb(main):001:0> puts 11.public_methods.sort.join(" | ")
% | & | * | ** | + | +@ | - | -@ | / | < | << | <= | <=>
| == | === | =~ | > | >= | >> | [] | ^ | __id__ | __send__
| abs | between? | ceil | chr | class | clone | coerce
| denominator | display | div | divmod | downto | dup | eql?
| equal? | extend | floor | freeze | frozen? | gcd | gcdlcm
| gem | hash | id | id2name | inspect | instance_eval | instance_of?
| instance_variable_defined? | instance_variable_get | instance_variable_set
| instance_variables | integer? | is_a? | kind_of? | lcm | method | methods
| modulo | next | nil? | nonzero? | numerator | object_id | power! | prec
| prec_f | prec_i | pretty_inspect | pretty_print | pretty_print_cycle
| pretty_print_inspect | pretty_print_instance_variables | private_methods
| protected_methods | public_methods | quo | rdiv | remainder | require
| require_gem | respond_to? | round | rpower | send | singleton_method_added
| singleton_methods | size | step | succ | taguri | taguri= | taint | tainted?
| times | to_a | to_bn | to_f | to_i | to_int | to_r | to_s | to_sym | to_yaml
| to_yaml_properties | to_yaml_style | truncate | type | untaint | upto | zero? | | | ~
=> nil

===[[Gems]]===
Requires [http://rubygems.org/ rubygems] to be installed. [[gems|Rubygems]] is the extension manager for ruby. Much like cpan is the extension manager for [[Perl]]. [[Gems]] is more than a packaging manager: it's a library versioning manager too!
[http://blade.nagaokaut.ac.jp/cgi-bin/scat.rb/ruby/ruby-talk/132899 That is also it's achille's heel].

===Rdoc===
Rdoc is the automatic html documentation generator for ruby scripts. Much like javadoc is for java. It requires [[#Starters|rdoc]] to be installed.
> rdoc --main mywork/mywork.rb

===Unit testing===
Unit tests are XP's method of choice to build safe long-lasting software. Still looking to see how these work...

===Rails===
Hopefully we'll get there soon enough...

===Ruby2exe===
[http://www.erikveen.dds.nl/rubyscript2exe/index.html#6.0.0 rubyscript2exe] allows to transform ruby scripts into full-bloated executable programs.

> gem install rubyscript2exe

==Sample code==

===loop===
<code lang=ruby >
object = Array.new(["one", "two", "three", "four"])
object.each do |a|
puts a + "\n"
end
</code>

===array===
<code lang=ruby >
object = ["one", "two", "three", "four"]
target = []
object.each { |a|
target.push(a)
}
puts target
</code>

===i/o===
<code lang=ruby >
if File.exist? "sample.txt"
File.open("sample.txt", "r") { |fs|
while line = fs.gets
puts "Line read was '#{line.chomp}'.\n"
end
fs.close
}
end
</code>
<code lang=ruby >
File.open("sample.txt", "w") { |fw|
fw.puts "Hi, this a new line.\n"
fw.close
}
</code>

===regexp===
<code lang=ruby >
pattern = Regexp.new("[a-z]+", "i")
#or
pattern = /[a-z]+/i
if File.exist? "sample.txt"
File.open("sample.txt", "r") { |fs|
while line = fs.gets
if line.match(pattern)
puts "Line read was '#{line.chomp}'.\n"
end
end
fs.close
}
end
</code>

===method===
<code lang=ruby >
def whatisit?(arg1, arg2="optional")
#Ducktyping: Does it walk like a duck? Does quacks like a duck?
if arg1.responds_to? :capitalize
puts "Then '#{arg1.capitalize}' must be a string.\n"
else
if arg1.responds_to? :modulo && arg1.responds_to? :numerator
puts "Then '#{arg1.to_s}' must be an integer.\n"
else
if arg1.responds_to? :modulo && arg1.responds_to? :truncate
puts "Then '#{arg1.to_s}' must be a float.\n"
end
end
end
puts "Input '#{arg2}' was completely optional.\n"
end
</code>

===class===
<code lang=ruby >
#File checktype.rb
class Checktype

#Constructor
def initialize(arg)
#class Checktype field
@variable = arg
end

#class Checktype method
def isWhat?(arg=@variable)
#Ducktyping: Does it walk like a duck? Does it quack like a duck?
if arg.responds_to? :capitalize
puts "Then '#{arg.capitalize}' must be a string.\n"
else
if arg.responds_to? :modulo && arg.responds_to? :numerator
puts "Then '#{arg.to_s}' must be an integer.\n"
else
if arg.responds_to? :modulo && arg.responds_to? :truncate
puts "Then '#{arg.to_s}' must be a float.\n"
end
end
end
end

end
</code>

<code lang=ruby >
require 'checktype'
somevar = Checktype(23)
somevar.isWhat?
#=> '23' must be an integer
Checktype.isWhat? "Hi"
#=> 'Hi' must be a string
</code>

===Complex examples===
*[[Ruby examples|RootTransform classes]]

==External References==
*[http://www.ruby-lang.org/en/ ruby-lang],
*[http://www.ruby-doc.org/docs/ProgrammingRuby/ Programming Ruby]

[[Category:programming]]
[[Category:linux]]
[[Category:ruby]]

@@ Line 66: / Line 66: @@
 ===loop===
-<code lang=ruby >
+<htm>
 object = Array.new(["one", "two", "three", "four"])
 object.each do |a|
    puts a + "\n"
 end
-</code>
+</pre>
 ===array===
-<code lang=ruby >
+<htm>
 object = ["one", "two", "three", "four"]
 target = []
@@ Line 81: / Line 84: @@
+}
 puts target
-</code>
+</pre>
 ===i/o===
-<code lang=ruby >
+<htm>
 if File.exist? "sample.txt"
    File.open("sample.txt", "r") { |fs|
@@ Line 93: / Line 98: @@
+   }
 end
-</code>
+</pre>
-<code lang=ruby >
+</htm>
 File.open("sample.txt", "w") { |fw|
    fw.puts "Hi, this a new line.\n"
    fw.close
+}
-</code>
+</pre>
 ===regexp===
-<code lang=ruby >
+<htm>
 pattern = Regexp.new("[a-z]+", "i")
 #or
@@ Line 116: / Line 125: @@
+   }
 end
-</code>
+</pre>
 ===method===

@@ Line 140: / Line 140: @@
 ===class===
-<code lang=ruby >
+<htm>
 #File checktype.rb
 class Checktype
@@ Line 167: / Line 168: @@
 end
-</code>
+</pre>
-<code lang=ruby >
+<htm>
 require 'checktype'
 somevar = Checktype(23)
@@ Line 176: / Line 179: @@
 Checktype.isWhat? "Hi"
 #=> 'Hi' must be a string
-</code>
+</pre>
 ===Complex examples===

@@ Line 119: / Line 119: @@
 ===method===
-<code lang=ruby >
+<htm>
 def whatisit?(arg1, arg2="optional")
    #Ducktyping: Does it walk like a duck? Does quacks like a duck?
@@ Line 135: / Line 136: @@
    puts "Input '#{arg2}' was completely optional.\n"
 end
-</code>
+</pre>
 ===class===

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