book

Ruby by Example

Name: Ruby by Example
Author: Kevin C. Baird
ISBN: 9781593271480

by Kevin C. Baird

June 2007

Intermediate to advanced

294 pages

8h 6m

English

No Starch Press

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Ruby By Example: Concepts and Code
Acknowledgments
Introduction: What Is Ruby?
Acquiring and Configuring RubyOn a Unix or Unix-like SystemOn a Windows System
Motivations for the Book
ConventionsSummary of Chapters
1. Interactive Ruby and the Ruby Environment
Starting irb
Using irb
ExpressionsEverything Is an ObjectIntegers, Fixnums, and BignumsAddition, Concatenation, and ExceptionsCastingArraysBooleansFlow ControlMethodsVariablesConstants
Using the Ruby Interpreter and Environment
2. Amusements and Simple Utilities
#1 Is It Payday? (check_payday.rb)The CodeHow It WorksDefining ConstantsDefining VariablesThe Results
#2 Random Signature Generator (random_sig.rb and random_sig-windows.rb)
The CodeHow It WorksRunning the ScriptThe ResultsHacking the Script
#3 The 99 Bottles of Beer Song (99bottles.rb)
The CodeHow It WorksRunning the ScriptThe Results

#4 Sound File Player (shuffle_play.rb)
The CodeHow It WorksRunning the ScriptThe ResultsHacking the Script
Chapter Recap
3. Programmer Utilities
#5 What Is Truth? (boolean_golf.rb)The CodeHow It WorksHacking the ScriptRunning the ScriptThe Results
#6 Making a List (array_join.rb)
The CodeHow It WorksRunning the ScriptHacking the Script
#7 Command-Line Interface (uses_cli.rb and simple_cli.rb)
The CodeHow It WorksRunning the ScriptHacking the Script
#8 Palindromes (palindrome.rb and palindrome2.rb)
The CodeHow It WorksHacking the ScriptRunning the ScriptThe Results
Chapter Recap
4. Text Manipulation
#9 End-of-Line Conversion (dos2unix.rb)The CodeHow It WorksRunning the ScriptThe ResultsHacking the Script
#10 Showing Line Numbers (line_num.rb)
The CodeHow It WorksRunning the ScriptThe Results
#11 Wrapping Lines of Text (softwrap.rb)
The CodeRunning the ScriptThe ResultsHacking the Script
#12 Counting Words in a File (word_count.rb)
The CodeHow It WorksRunning the ScriptThe Results
#13 Word Histogram (most_common_words.rb)
The CodeHow It WorksRunning the ScriptThe ResultsHacking the Script
#14 Rotating Characters in a String (rotate.rb)
The CodeHow It WorksRecursionRunning the ScriptThe Results
Chapter Recap
5. Number Utilities
#15 Computing Powers (power_of.rb)The CodeHow It WorksRunning the ScriptThe Results
#16 Adding Commas to Numbers (commify.rb)
InheritanceModulesThe CodeHow It WorksThe format_int MethodThe format_float MethodType TestingRunning the ScriptThe Results
#17 Roman Numerals (roman_numeral.rb)
The CodeHow It WorksClass VariablesHash.mergeMore RecursionMultiples of Our BaseMultiplying Strings by IntegersRunning the ScriptThe ResultsHacking the Script
#18 Currency Conversion, Basic (currency_converter1.rb)
The CodeHow It WorksRunning the ScriptThe ResultsHacking the Script
#19 Currency Conversion, Advanced (currency_converter2.rb)
The CodeHow It WorksDownloading Rates InformationWhat If You Can’t Download New Rates?Running the ScriptThe ResultsHacking the Script
Chapter Recap
6. Functionalism with Blocks and Procs
#20 Our First lambda (make_incrementer.rb)The CodeHow It WorksThe Results
#21 Using Procs for Filtering (matching_members.rb)
The CodeHow It WorksRunning the ScriptThe Results
#22 Using Procs for Compounded Filtering (matching_compound_members.rb)
The CodeHow It WorksBlocks, Procs, and the AmpersandFiltering with Each Proc via mapFinding the Intersections with injectArray IntersectionsThe ResultsHacking the Script
#23 Returning Procs as Values (return_proc.rb)
The CodeThe ResultsHow It WorksProc.call(args) vs. Proc[args]Using Procs as BlocksThe inspect Method
#24 Nesting lambdas
The CodeHow It Works
#25 Procs for Text (willow_and_anya.rb)
The CodeThe Him ClassThe SameTimeSamePlace ClassThe willow_and_anya.rb ScriptHow It WorksThe Him Class: Creating Procs with lambdaThe SameTimeSamePlace Class: Alternatives to lambda for Creating ProcsFlexible Arity for Proc.newBlocks, Arguments, and yieldUsing Both Him and SameTimeSamePlace in willow_and_anya.rbRunning the ScriptThe ResultsHacking the Script
Chapter Recap
7. Using, Optimizing, and Testing Functional Techniques
#26 Basic Factorials and Fibonaccis (factorial1.rb through fibonacci5.rb)The CodeHow It WorksThe ResultsHacking the ScriptUsing include? (factorial2.rb and fibonacci2.rb)Passing the returns1 or returns_self Array as an Argument (factorial3.rb and fibonacci3.rb)Making RETURNS1 or RETURNS_SELF a Class Constant (factorial4.rb and fibonacci4.rb)Memoization of Results (factorial5.rb and fibonacci5.rb)
#27 Benchmarking and Profiling (tests/test_opts.rb)
BenchmarkingThe CodeHow It WorksRunning the ScriptThe ResultsProfilingHacking the Script
#28 Converting Temperatures (temperature_converter.rb)
The CodeHow It WorksThe ResultsHacking the Script
#29 Testing temperature_converter.rb (tests/test_temp_converter.rb)
The CodeThe ResultsHow It WorksHacking the Script
Chapter Recap
8. HTML and XML Tools
#30 Cleaning Up HTML (html_tidy.rb)The CodeHow It WorksRunning the ScriptThe ResultsHacking the Script
#31 Counting Tags (xml_tag_counter.rb)
The CodeHow It WorksRunning the ScriptThe ResultsHacking the Script
#32 Extracting Text from XML (xml_text_extractor.rb)
The CodeHow It WorksRunning the ScriptThe ResultsHacking the Script
#33 Validating XML (xml_well_formedness_checker.rb)
The CodeHow It WorksRunning the ScriptThe ResultsHacking the Script
Chapter Recap
9. More Complex Utilities and Tricks, Part I
#34 Finding Codes in the Bible or Moby-Dick (els_parser.rb)The CodeHow It WorksRunning the ScriptThe ResultsHacking the Script
#35 Mutating Strings into Weasels (methinks.rb)
The CodeHow It WorksRunning the ScriptThe ResultsHacking the Script
#36 Mutating the Mutation of Strings into Weasels (methinks_meta.rb)
The CodeHow It WorksRunning the ScriptThe ResultsHacking the Script
Chapter Recap
10. More Complex Utilities and Tricks, Part II
#37 Overnight DJ (radio_player1.rb)The CodeHow It WorksThe ResultsHacking the Script
#38 Better Overnight DJ (radio_player2.rb)
The CodeHow It WorksThe ResultsHacking the Script
#39 Numbers by Name (to_lang.rb)
The Coderepresentable_in_english.rbrepresentable_in_spanish.rbto_lang.rbHow It WorksThe Two MixinsThe Main CodeThe ResultsHacking the Script
#40 Elegant Maps and Injects (symbol.rb)
The CodeHow It WorksThe ResultsHacking the Script
Chapter Recap
11. CGI and the Web
Common Gateway Interface
Preparation and Installation
#41 A Simple CGI Script (simple_cgi.rb)
The CodeHow It WorksThe ResultsHacking the Script
#42 Mod Ruby (mod_ruby_demo.rhtml and mod_ruby_demo.conf)
The Codemod_ruby_demo.confmod_ruby_demo.rhtmlHow It WorksThe ResultsHacking the Script
#43 CSS Stylesheets, Part I (stylesheet.rcss)
The CodeHow It WorksThe ResultsHacking the Script
#44 CSS Stylesheets, Part II (stylesheet2.rcss)
The CodeHow It WorksThe ResultsHacking the Script
Chapter Recap
12. RubyGems and Rails Preparation
RubyGemsInstalling RubyGemsUsing RubyGemsListing Installed and Installable GemsInstalling GemsUpdating GemsLearning More About RubyGems
Rails Preparation
What Is Rails?Other Options for Installing RailsVia Operating System Package ManagerFrom SourcePre-PackagedDatabasesThe Structure of a Rails ApplicationGenerating a Rails ApplicationViewing Your Rails ApplicationBasics for Generating Applications
Chapter Recap
13. A Simple Rails Project
Creating the ApplicationInitial CreationPreparing the DatabaseAdding DataCreating the Model and ControllersCreating the Photo ModelCreating the Album and Feed Controllers
Dissecting the Application
Dissecting the Photo ModelDissecting the ControllersDissecting the Album ControllerDissecting the Application ControllerDissecting the Feed ControllerDissecting the HelpersDissecting the Album HelperDissecting the ApplicationHelperDissecting the FeedHelperDissecting the FooterHelperDissecting the Album Controller’s ViewsDissecting the index ViewDissecting the show ViewDissecting the Feed Controller’s images ViewDissecting the Album Controller’s LayoutUsing CSS
Using the Application
Learning More About Rails
Chapter Recap
A. How Does Ruby Compare to Other Languages?
C
Haskell
Java
Lisp
Perl
PHP
Python
Smalltalk
Summary of Ruby vs. Other Languages
Index
About the Author
Colophon

Content preview from Ruby by Example

#36 Mutating the Mutation of Strings into Weasels (methinks_meta.rb)

This script uses the previous one, methinks.rb, so make sure you understand how that one works before trying this one, methinks_meta.rb. This script uses techniques similar to those used in methinks.rb to find the “best” input parameters for methinks.rb.

The previous script’s performance (the number of generations it takes to match the target) can vary greatly from one run to the next. Two major factors affect that variation in our results: The first factor is the set of arbitrary starting parameters. We saw that a target of hello was much easier to reach quickly than a target of methinksitislikeaweasel. Using other values for :mutation_rate or the other parameters also has an ...

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Ruby by Example

by Kevin C. Baird

#36 Mutating the Mutation of Strings into Weasels (methinks_meta.rb)

Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
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