Download Lec03-RubyRegExpr - Computer Science & Engineering

CSCE 740 Software Engineering
Ruby and the tools
740Tools03RubyRegExpr
Topics

January 22, 2014
Ruby Reg Expressions
Ruby
 http://www.ruby-doc.org/
 Starting-up
 http://ruby.about.com/od/tutorialsontheweb/tp/10waysfr
ee.htm
Rails and Beyond
 http://ruby.railstutorial.org/ruby-on-rails-tutorial-book
–2–
CSCE 740 Spring 2014
Ruby.new
 Really Object Oriented – everything is an object


For Java you might use
pos = Math.abs(num)
In Ruby
num = -123
pos = num.abs
 Variables inside literal strings #{ … } notation

puts “the absolute value of #{num} is #{pos}\n”
 Variable Name Punctuation




– 3 –
name - local variable
$name, $NAME, - globals (never use anyway!)
@name – instance variables
Prog Ruby 1.9 Dave Thomas
@@name – class variables
Name – class names and constants
CSCE 740 Spring 2014
Puts_examples
song = 1
sam = ""
def sam.play(a)
"duh dum, da dum de dum ..."
end
puts "gin joint".length
puts "Rick".index("c")
puts 42.even?
puts sam.play(song)
print “string with no newline”
–4–
Programming Ruby 1.9 Dave Thomas
CSCE 740 Spring 2014
Method definition
def say_goodnight(name)
result = "Good night, " + name
return result
end
# Time for bed...
puts say_goodnight("John-Boy")
puts say_goodnight("Mary-Ellen")
–5–
Programming Ruby 1.9 Dave Thomas
CSCE 740 Spring 2014
CSE Linux Labs
• 1D39 – Combination on secure site
•
•
CSE home page – login with CEC credentials
Computer resources/Computer labs
• List of Linux workstations
•
IP addresses – machine names
• Ifconfig // interface config IPv4 addr and
Hardware=ethernet addr
• “man keyword” online unix documentation
–6–
CSCE 740 Spring 2014
List of Ruby 3 Examples
1. Getting Started – “hello, Ruby Programmer”
2. Intro –
a.
b.
c.
d.
e.
f.
Hello1 – def say_goodnight
Puts examples
Cmd_line – command line args passed into ruby program
“arrays” – non-homogeneous
hash_with_symbol_keys_19.rb –
Weekdays – control structures – if-elseif-else example
3. Tutclasses-
–7–
CSCE 740 Spring 2014
google(ruby 1.9 tutorial)
• Ruby Programming Language - ruby-lang.org/
• http://www.ruby-doc.org/ (again)
• http://pragprog.com/titles/ruby3/source_code (again)
• http://pragprog.com/book/ruby3/programming-ruby1-9 “Buy the book” page
•
•
•
Regular Expressions (download pdf)
Namespaces, Source Files, and Distribution (download pdf)
Ruby Library Reference
• Built-in Classes and Modules (download pdf of the entry for
class Array)
• Standard Library
• http://www.ruby-doc.org/stdlib-1.9.3/
–8–
CSCE 740 Spring 2014
"gin joint".length
»
9
"Rick".index("c")
»
2
-1942.abs
»
1942
sam.play(aSong)
»
"duh dum, da dum de dum
..."
–9–
Programming Ruby 1.9 Dave Thomas
CSCE 740 Spring 2014
def sayGoodnight(name)
result = "Goodnight, " + name
return result
end
# Time for bed...
puts sayGoodnight("John-Boy")
puts sayGoodnight("Mary-Ellen")
– 10 –
Programming Ruby 1.9 Dave Thomas
CSCE 740 Spring 2014
Simplifying
def sayGoodnight(name)
result = "Goodnight, #{name}“
return result
end
#Simplifying further eliminating the return statement
def sayGoodnight(name)
result = "Goodnight, #{name}“
end
– 11 –
Programming Ruby 1.9 Dave Thomas
CSCE 740 Spring 2014
instSection['bassoon']
Arrays and Hashes
a = [ 1, 'cat', 3.14 ] # array with three elements
a[0]
>>
1
>>
[1, "cat", nil]
a[2] = nil
#dump array
puts a
empty1 = []
empty2 = Array.new
a = %w{ ant bee cat dog elk }
– 12 –
Programming Ruby 1.9 Dave Thomas
CSCE 740 Spring 2014
Hashes
instSection = {
'cello'
=> 'string',
'clarinet' => 'woodwind',
'drum'
'oboe'
In the online text “>>”
means evaluates to
instSection['oboe'] >>
=> 'percussion',
=> 'woodwind',
instSection['cello'] >>
'trumpet' => 'brass',
'violin'
=> 'string’
instSection['bassoon'] >>
}
– 13 –
Programming Ruby 1.9 Dave Thomas
CSCE 740 Spring 2014
histogram = Hash.new(0)
histogram['key1'] = histogram['key1'] + 1
– 14 –
Programming Ruby 1.9 Dave Thomas
CSCE 740 Spring 2014
Control Structures IF
if count > 10
puts "Try again"
elsif tries == 3
puts "You lose"
else
puts "Enter a number"
end
– 15 –
// body
http://ruby-doc.org/docs/ProgrammingRuby/
CSCE 740 Spring 2014
Control Structures While
while weight < 100 and numPallets <= 30
pallet = nextPallet()
weight += pallet.weight
numPallets += 1
end
– 16 –
http://ruby-doc.org/docs/ProgrammingRuby/
CSCE 740 Spring 2014
More control
puts "Danger, Will Robinson" if radiation > 3000
while square < 1000
square = square*square
end
More concisely, but readability??
square = square*square while square < 1000
– 17 –
http://ruby-doc.org/docs/ProgrammingRuby/
CSCE 740 Spring 2014
Regular Expressions
Regular expressions are expressions that specify
collections of strings (formally languages)
Main operators: Assume r and s are regular expressions
then so are:
r|s
alternation denotes L(r) U L(s)
rs
concatenation which denotes L(r) L(s)
r*
Kleene closure zero or more occurrences of
strings from L(r) concatenated
Base regular expressions
• strings are regexpr that match themselves,L(“ab”) = {“ab”}
• the empty string ε is a regular expr L(ε) = {“”}
– 18 –
CSCE 740 Spring 2014
Ruby Regular Expressions
[abc]
A single character of: a, b or c
[^abc]
Any single character except: a, b, or c
[a-z]
Any single character in the range a-z
[a-zA-Z]
Any single character in the range a-z
or A-Z
^
Start of line
$
End of line
\A
Start of string
\z
End of string
– 19 –
http://rubular.com/
CSCE 740 Spring 2014
Ruby Regular Expressions
(...)
Capture everything enclosed
(a|b)
a or b
a?
Zero or one of a
a*
Zero or more of a
a+
One or more of a
a{3}
Exactly 3 of a
a{3,}
3 or more of a
a{3,6}
Between 3 and 6 of a
– 20 –
http://rubular.com/
CSCE 740 Spring 2014
Quoting
First, always remember that you need to escape any of
these characters with a backslash if you want them
to be treated as regular characters to match:
show_regexp('yes | no', /\|/)
# => yes ->|<- no
show_regexp('yes (no)', /\(no\)/)
# => yes ->(no)<show_regexp('are you sure?', /e\?/)
# => are you sur->e?<– 21 –
http://ruby-doc.org/docs/ProgrammingRuby/
CSCE 740 Spring 2014
Matching Strings with Patterns
Ruby operator =~ matches a string against a pattern. It
returns the character offset into the string at which
the match occurred:
/cat/ =~ "dog and cat"
# => 8
/cat/ =~ "catch"
# => 0
/cat/ =~ "Cat"
# => nil
You can put the string first if you prefer:2
"dog and cat" =~ /cat/
# => 8
"catch" =~ /cat/
# => 0
"Cat" =~ /cat/
# => nil
– 22 –
http://ruby-doc.org/docs/ProgrammingRuby/
CSCE 740 Spring 2014
Regular Expressions Examples
– 23 –
http://ruby-doc.org/docs/ProgrammingRuby/
CSCE 740 Spring 2014
Using Match results in Control Flow
str = "cat and dog"
if str =~ /cat/
puts "There's a cat here somewhere"
end
• testing when a pattern does not match a string using !~:
File.foreach("testfile").with_index do |line, index|
puts "#{index}: #{line}" if line !~ /on/
end
produces:
1: This is line two
2: This is line three
– 24 –
http://ruby-doc.org/docs/ProgrammingRuby/
CSCE 740 Spring 2014
Changing Strings with Patterns
str = "Dog and Cat"
new_str1 = str.sub(/a/, "*")
new_str2 = str.gsub(/a/, "*")
puts "Using sub: #{new_str1}"
puts "Using gsub: #{new_str2}“
produces:
Using sub: Dog *nd Cat
Using gsub: Dog *nd C*t
– 25 –
http://ruby-doc.org/docs/ProgrammingRuby/
CSCE 740 Spring 2014
Grouping
You can use parentheses to group terms within a
regular expression. Everything within the group is
treated as a single regular expression.
# This matches an 'a' followed by one or more 'n's
show_regexp('banana', /an+/) # => b->an<-ana
# This matches the sequence 'an' one or more times
show_regexp('banana', /(an)+/) # => b->anan<-a
– 26 –
CSCE 740 Spring 2014
Grouping to save portions that match
/(\d\d):(\d\d)(..)/ =~ "12:50am"
# => 0
"Hour is #$1, minute #$2" # => "Hour is 12, minute 50"
/((\d\d):(\d\d))(..)/ =~ "12:50am" # => 0
"Time is #$1" # => "Time is 12:50"
"Hour is #$2, minute #$3" # => "Hour is 12, minute 50"
"AM/PM is #$4" # => "AM/PM is am"
– 27 –
CSCE 740 Spring 2014
show_regexp
def show_regexp(string, pattern)
match = pattern.match(string)
if match
"#{match.pre_match}->#{match[0]}<-#{match.post_match}"
else
"no match"
end
end
– 28 –
http://ruby-doc.org/docs/ProgrammingRuby/
CSCE 740 Spring 2014
show_regexp Examples
show_regexp('very interesting', /t/)
# => very in->t<-eresting
show_regexp('Fats Waller', /a/)
# => F->a<-ts Waller
show_regexp('Fats Waller', /lle/)
# => Fats Wa->lle<-r
show_regexp('Fats Waller', /z/)
# => no match
– 29 –
http://ruby-doc.org/docs/ProgrammingRuby/
CSCE 740 Spring 2014
Anchors
Pattern
^
$
\A
\z and \Z
\Z
description
match the beginning of a line
match the end of a line
matches the beginning of a string
Match the end of a string
matches the end of a string unless the string ends
with \n; it matches just before
match word boundaries and nonword boundaries
\b and \B
– 30 –
http://ruby-doc.org/docs/ProgrammingRuby/
CSCE 740 Spring 2014
Anchor Regular Expressions Examples
str = "this is\nthe time"
show_regexp(str, /^the/)
# => this is\n->the<- time
show_regexp(str, /is$/)
# => this ->is<-\nthe time
show_regexp(str, /\Athis/)
# => ->this<- is\nthe time
show_regexp(str, /\Athe/)
# => no match
show_regexp("this is\nthe time", /\bis/)
# => this ->is<-\nthe time
show_regexp("this is\nthe time", /\Bis/)
# => th->is<- is\nthe time
– 31 –
http://ruby-doc.org/docs/ProgrammingRuby/
CSCE 740 Spring 2014
Character classes
 character class - [characters] matches any single
character between the brackets
 For example


[aeiou]
[cat] = [tac]
 negated class - [^xyz] matches any single character not
x, y or z
show_regexp('Price $12.', /[aeiou]/)
show_regexp('Price $12.', /[\s]/)
show_regexp('Price $12.', /[$.]/)
– 32 –
# => Pr->i<-ce $12.
# => Price-> <-$12.
# => Price ->$<-12.
http://ruby-doc.org/docs/ProgrammingRuby/
CSCE 740 Spring 2014
Character class Examples
a = 'see [The PickAxe-page 123]'
show_regexp(a, /[A-F]/)
# => see [The Pick->A<-xe-page 123]
show_regexp(a, /[A-Fa-f]/)
# => s->e<-e [The PickAxe-page 123]
show_regexp(a, /[0-9]/)
# => see [The PickAxe-page ->1<-23]
show_regexp(a, /[0-9][0-9]/)
# => see [The PickAxe-page ->12<-3]
– 33 –
http://ruby-doc.org/docs/ProgrammingRuby/
CSCE 740 Spring 2014
Character class abbreviations
Sequence
As [ ... ]
\d
[0-9]
ASCII decimal digit character
\D
[^0-9]
Any character except a digit
\h
[0-9a-fA-F]
Hexadecimal digit character
\H
[^0-9a-fA-F]
Any character except a hex digit
\s
[ \t\r\n\f]
ASCII whitespace character
\S
[^ \t\r\n\f]
Any character except whitespace
\w
[A-Za-z0-9\_]
ASCII word character
\W
[^A-Za-z0-9\_]
Any character except a word character
– 34 –
Meaning
http://ruby-doc.org/docs/ProgrammingRuby/
CSCE 740 Spring 2014
Ruby Regular Expr Changing text
if line =~ /Perl|Python/
puts "Scripting language mentioned: #{line}”
end
line.sub(/Perl/, 'Ruby')
# replace first 'Perl' with 'Ruby‘
line.gsub(/Python/, 'Ruby') # replace every 'Python' with
'Ruby'
– 35 –
http://ruby-doc.org/docs/ProgrammingRuby/
CSCE 740 Spring 2014
Regexp Constructor
Regexps are created using the
 /.../ and
 %r{...} literals, “r” for raw don’t cook the ‘/’ and by the
 Regexp::new constructor.
– 36 –
CSCE 740 Spring 2014
the %r{...} syntax
The %r syntax is particularly useful when creating
patterns that contain forward slashes:
%r{} is equivalent to the /.../ notation, but allows you to
have '/' in your regexp without having to escape
them:
%r{/home/user}
is equivalent to
/\\/home\\/user/
/mm\/dd/ # => /mm\/dd/
Regexp.new("mm/dd") # => /mm\/dd/
%r{mm/dd} # => /mm\/dd/
– 37 –
CSCE 740 Spring 2014
Regular Expressions Examples
date = "12/25/2010"
date =~ %r{(\d+)(/|:)(\d+)(/|:)(\d+)}
[$1,$2,$3,$4,$5] # => ["12", "/", "25", "/", "2010"]
date =~ %r{(\d+)(?:/|:)(\d+)(?:/|:)(\d+)}
[$1,$2,$3] # => ["12", "25", "2010"]
– 38 –
http://ruby-doc.org/docs/ProgrammingRuby/
CSCE 740 Spring 2014
Backslash Sequences in Substitutions
puts "fred:smith".sub(/(\w+):(\w+)/, '\2, \1')
puts "nercpyitno".gsub(/(.)(.)/, '\2\1')
produces:
smith, fred
encryption
More use of backslashes
 \& (last match),
 \+ (last matched group),
 \‘ (string prior to match),
 \’ (string after match), and
 \\ (a literal backslash).
– 39 –
CSCE 740 Spring 2014
str = 'a\b\c' # => "a\b\c"
str.gsub(/\\/, '\\\\\\\\') # => "a\\b\\c“
However, using the fact that \& is replaced by the
matched string, you could also write this:
str = 'a\b\c' # => "a\b\c"
str.gsub(/\\/, '\&\&') # => "a\\b\\c"
If you use the block form of gsub, the string for
substitution is analyzed only once :
str = 'a\b\c' # => "a\b\c"
str.gsub(/\\/) { '\\\\' } # => "a\\b\\c"
– 40 –
CSCE 740 Spring 2014
Backslashes in Patterns
same = "12:15-12:45"
differ = "12:45-13:15“
# use numbered backreference
same =~ /(\d\d):\d\d-\1:\d\d/
# => 0
differ =~ /(\d\d):\d\d-\1:\d\d/
# => nil
– 41 –
CSCE 740 Spring 2014
Cases
/pat/i
# i for ignore case
/\.(gif|jpg|jpeg|png)$/i
def mixed_case(name)
name.downcase.gsub(/\b\w/) {|first| first.upcase }
end
mixed_case("DAVE THOMAS") # => "Dave Thomas"
mixed_case("dave thomas") # => "Dave Thomas"
mixed_case("dAvE tHoMas") # => "Dave Thomas"
– 42 –
CSCE 740 Spring 2014
Lookahead and Lookbehind
– 43 –
CSCE 740 Spring 2014
Rubular
Rubular: a Ruby regular expression editor and tester
[abc]
A single character of: a, b or c
[^abc]
Any single character except: a, b, or c
[a-z]
Any single character in the range a-z
[a-zA-Z]
Any single character in the range a-z
or A-Z
^
Start of line
$
End of line
\A
Start of string
\z
End of string
– 44 –
http://rubular.com/
CSCE 740 Spring 2014
(?<month>\d{1,2})\/(?<day>\d{1,2})\/(?<year>\d{4})
Today's date is: 1/21/2014.
– 45 –
CSCE 740 Spring 2014
Regular Expression Options
i Case insensitive. The pattern match will ignore the
case of letters in the pattern and string.
o Substitute once. Any #{...} substitutions in a particular
regular expression literal will be performed just once,
the first time it is evaluated. Otherwise, the
substitutions will be performed every time the literal
generates a Regexp object.
m Multiline mode. Normally, “.” matches any character
except a newline.With the /m option, “.” matches any
character.
x Extended mode. Complex regular expressions can be
difficult to read. The x option allows you to insert
spaces and newlines in the pattern to make it more
readable. You can also use # to introduce comments.
– 46 –
CSCE 740 Spring 2014
BLOCKS
– 47 –
CSCE 740 Spring 2014
Blocks
a = %w( ant bee cat dog elk )
# create an array
a.each { |animal| puts animal } # iterate over the contents
Yield – will be discussed next time
[ 'cat', 'dog', 'horse' ].each do |animal|
print animal, " -- "
– 48 –
http://ruby-doc.org/docs/ProgrammingRuby/
CSCE 740 Spring 2014
{ puts "Hello" }
do
# this is a block
#
club.enroll(person) # and so is this
person.socialize
end
– 49 –
http://ruby-doc.org/docs/ProgrammingRuby/
CSCE 740 Spring 2014
Blocks
5.times { print "*" }
3.upto(6) {|i| print i }
('a'..'e').each {|char| print char }
*****3456abcde
– 50 –
http://ruby-doc.org/docs/ProgrammingRuby/
CSCE 740 Spring 2014
def callBlock
yield
yield
end
callBlock { puts "In the block" }
Produces
In the block
In the block
– 51 –
http://ruby-doc.org/docs/ProgrammingRuby/
CSCE 740 Spring 2014
Ruby I/O
• Already seen
•
•
•
puts
print
P
• On reading
•
•
Gets reads line from stdin  variable $_
Iterate over lines of file
line = gets
print line
– 52 –
http://ruby-doc.org/docs/ProgrammingRuby/
CSCE 740 Spring 2014
Processing stdin
while gets
if /Ruby/
print
end
end
= ARGF
# assigns line to $_
# matches against $_
# prints $_
Now the “ruby way”
ARGF.each { |line| print line if line =~ /Ruby/ }
– 53 –
http://ruby-doc.org/docs/ProgrammingRuby/
CSCE 740 Spring 2014
Classes, Objects, and Variables
class Song
def initialize(name, artist, duration)
@name
= name
@artist = artist
@duration = duration
end
end
aSong = Song.new("Bicylops", "Fleck", 260)
– 54 –
http://ruby-doc.org/docs/ProgrammingRuby/
CSCE 740 Spring 2014
aSong = Song.new("Bicylops", "Fleck", 260)
aSong.inspect >>
#<Song:0x401b4924 @duration=260, @artist=\"Fl
eck\", @name=\"Bicylops\">
aSong.to_s
– 55 –
>> "#<Song:0x401b499c>”
http://ruby-doc.org/docs/ProgrammingRuby/
CSCE 740 Spring 2014
New improved to_s
class Song
def to_s
“Song: #{@name} -- #{ @artist } ( #{ @duration } )”
end
end
aSong = Song.new("Bicylops", "Fleck", 260)
aSong.to_s
– 56 –
>> “Song: Bicylops--Fleck (260)”
http://ruby-doc.org/docs/ProgrammingRuby/
CSCE 740 Spring 2014
Inheritance
class KaraokeSong < Song
def initialize(name, artist, duration, lyrics)
super(name, artist, duration)
@lyrics = lyrics
end
End
aSong = KaraokeSong.new("My Way", "Sinatra", 225, "
And now, the...")
aSong.to_s …
– 57 –
http://ruby-doc.org/docs/ProgrammingRuby/
CSCE 740 Spring 2014
overriding to_s
class KarokeSong
def to_s
“KS: #{@name} -- #{ @artist } ( #{ @duration } )
[#{@lyrics}]”
end
end
class KaraokeSong < Song
def to_s
super + " [#{@lyrics}]“
end
end
– 58 –
http://ruby-doc.org/docs/ProgrammingRuby/
CSCE 740 Spring 2014
Accessing instance variables
Class Song
attr_reader :name, :artist, :duration
attr_writer :duration
…
end
– 59 –
http://ruby-doc.org/docs/ProgrammingRuby/
CSCE 740 Spring 2014
class JavaSong {
// Java code
private Duration myDuration;
public void setDuration(Duration newDuration) {
myDuration = newDuration;
}
}
class Song
attr_writer :duration
end
aSong = Song.new("Bicylops", "Fleck", 260)
aSong.duration = 257
– 60 –
http://ruby-doc.org/docs/ProgrammingRuby/
CSCE 740 Spring 2014
class Song
@@plays = 0
def initialize(name, artist, duration)
@name = name
@artist = artist
@duration = duration
@plays = 0
end
def play
@plays += 1
@@plays += 1
"song: #@plays plays. Total #@@plays plays."
end
– 61 –
http://ruby-doc.org/docs/ProgrammingRuby/
CSCE 740 Spring 2014
Implementing a SongList Container
append( aSong ) » list
Append the given song to the list.
deleteFirst() » aSong
Remove the first song from the list, returning that
song.
deleteLast() » aSong
Remove the last song from the list, returning that
song.
[ anIndex } » aSong
Return the song identified by anIndex, which may be
an integer index or a song title.
– 62 –
http://ruby-doc.org/docs/ProgrammingRuby/
CSCE 740 Spring 2014
SongList: Initializer & append
# Initializer
class SongList
def initialize
@songs = Array.new
end
end
#append method
class SongList
def append(aSong)
@songs.push(aSong)
self
end
– 63 –
http://ruby-doc.org/docs/ProgrammingRuby/
end
CSCE 740 Spring 2014
SongList:
class SongList
def deleteFirst
@songs.shift
end
def deleteLast
@songs.pop
end
end
– 64 –
http://ruby-doc.org/docs/ProgrammingRuby/
CSCE 740 Spring 2014
SongList: [ ] method 1rst version
class SongList
def [ ](key)
if key.kind_of?(Integer)
@songs[key]
else
# ...
end
end
end
– 65 –
CSCE 740 Spring 2014
Class Variables
class Song @@plays = 0
def initialize(name, artist, duration)
@name = name
@artist = artist
@duration = duration
@plays = 0
end
def play
@plays += 1
@@plays += 1
"This song: #@plays plays. Total #@@plays plays.
end
end
– 66 –
CSCE 740 Spring 2014
Class Methods
class Example
def instMeth
# instance method
…
end
def Example.classMeth
# class method
…
end
end
– 67 –
http://ruby-doc.org/docs/ProgrammingRuby/
CSCE 740 Spring 2014
Singletons
class Logger
private_class_method
:new
@@logger = nil
def Logger.create
@@logger = new unless @@logger
@@logger
end
end
Logger.create.id
Logger.create.id
– 68 –
»
»
537766930
537766930
http://ruby-doc.org/docs/ProgrammingRuby/
CSCE 740 Spring 2014
Access Control
“Public methods can be called by anyone---there is no
access control. Methods are public by default
(except for initialize, which is always private).
Protected methods can be invoked only by objects of
the defining class and its subclasses. Access is kept
within the family.
Private methods cannot be called with an explicit
receiver. Because you cannot specify an object when
using them, private methods can be called only in
the defining class and by direct descendents within
that same object.”
– 69 –
http://ruby-doc.org/docs/ProgrammingRuby/
CSCE 740 Spring 2014
Specifying Access
class MyClass
def method1
# default is 'public'
#...
end
protected
# subsequent methods will be 'protected'
def method2
# will be 'protected'
#...
end
private
# subsequent methods will be 'private'
def method3
# will be 'private'
#...
end
public
# subsequent methods will be 'public'
def method4
# and this will be 'public'
#...
end
end
http://ruby-doc.org/docs/ProgrammingRuby/
– 70 –
CSCE 740 Spring 2014
Ruby 1.9 “Buy the book page”
http://pragprog.com/book/ruby3/programming-ruby-1-9
• Regular Expressions (download pdf)
• Namespaces, Source Files, and Distribution
(download pdf)
• Built-in Classes and Modules (download pdf of the
entry for class Array)
• Free Content …
More on reg expr
• http://www.ruby-doc.org/core-2.1.0/Regexp.html
– 71 –
http://ruby-doc.org/docs/ProgrammingRuby/
CSCE 740 Spring 2014