Ruby (programming language) - Wikipedia, the free encyclopedia. Ruby. Paradigm. Multi- paradigm: Object- oriented, imperative, functional, reflective. Designed by. Yukihiro Matsumoto. ![]() Developer. Yukihiro Matsumoto, et al. First appeared. 19. Stable release. 2. April 2. 6, 2. 01. It was designed and developed in the mid- 1. Yukihiro . It also has a dynamic type system and automatic memory management. History. In a 1. 99. Ruby author Yukihiro Matsumoto describes some of his early ideas about the language. I knew Perl (Perl. Perl. 5), but I didn't like it really, because it had the smell of a toy language (it still has).
![]() Learn to Program (2nd edition), by: Chris Pine. Chris Pine’s book will teach you how to program. You’ll learn to use your. The object- oriented language seemed very promising. But I didn't like it, because I didn't think it was a true object- oriented language . ![]() As a language maniac and OO fan for 1. I really wanted a genuine object- oriented, easy- to- use scripting language. I looked for but couldn't find one. So I decided to make it. Matsumoto describes the design of Ruby as being like a simple Lisp language at its core, with an object system like that of Smalltalk, blocks inspired by higher- order functions, and practical utility like that of Perl. Matsumoto chose the latter in a later e- mail to Ishitsuka. In the same year, Matsumoto was hired by netlab. Ruby as a full- time developer. ![]() It would be followed in the early 2. Ruby published in Japanese. In early 2. 00. 2, the English- language ruby- talk mailing list was receiving more messages than the Japanese- language ruby- list, demonstrating Ruby's increasing popularity in the English- speaking world. Ruby 1. 8. Ruby 1. Ruby 1. 9. Ruby 1. The language specifications for Ruby were developed by the Open Standards Promotion Center of the Information- Technology Promotion Agency (a Japanese government agency) for submission to the Japanese Industrial Standards Committee (JISC) and then to the International Organization for Standardization (ISO). It was accepted as a Japanese Industrial Standard (JIS X 3. Rails is frequently credited with increasing awareness of Ruby. Effective with Ruby 1. October 3. 1, 2. 01. Users are advised to upgrade to a more recent version. Ruby 2. 0. As of the official 2. February 2. 4, 2. Users are advised to upgrade to a more recent version. Ruby 2. 1. Reserved for special events. MAJOR: Increased when you make incompatible API changes. MINOR: increased every Christmas, may be API incompatible. MINOR: increased when you add functionality in a backwards- compatible manner. TEENY: security or bug fix which maintains API compatibility. May be increased more than 1. Most notably, Ruby 2. Ruby is a dynamic, reflective. And it means the principle of least surprise after you learn Ruby very well. Yielding the flow of program control to a block that was provided at calling time. Ruby Learn to program in Ruby, a 10 Great Resources to Learn Ruby for Free 2. Is Ruby a Good First Language to Learn? 5 Must Know Features of the Ruby Language 5. What would it be like if two cartoon foxes taught you how to program in. Ruby Study Notes: TOC Core Ruby Programming. Introduction; Installation. Downloading Ruby and an Editor; Ruby Programming Environment; First Ruby Program; Features; Numbers in Ruby. Operators and Precedence. It also contains experimental support for using vfork(2) with system() and spawn(), and added support for the Unicode 7. Features that were made obsolete or removed include callcc, the DL library, Digest: :HMAC, lib/rational. GServer, Logger: :Application as well as various C API functions. A few notable changes include: The ability to mark all strings literals as frozen by default with consequently large performance increase in string operations. That is the primary purpose of Ruby language. ![]() By doing this, the machine will run more effectively. By doing this, the machine will something something something. But in fact we need to focus on humans, on how humans care about doing programming or operating the application of the machines. They are the slaves. Ruby is said to follow the principle of least astonishment (POLA), meaning that the language should behave in such a way as to minimize confusion for experienced users. Matsumoto has said his primary design goal was to make a language that he himself enjoyed using, by minimizing programmer work and possible confusion. He has said that he had not applied the principle of least astonishment to the design of Ruby. The phrase has itself been a source of surprise, as novice users may take it to mean that Ruby's behaviors try to closely match behaviors familiar from other languages. In a May 2. 00. 5 discussion on the newsgroup comp. Matsumoto attempted to distance Ruby from POLA, explaining that because any design choice will be surprising to someone, he uses a personal standard in evaluating surprise. If that personal standard remains consistent, there would be few surprises for those familiar with the standard. Someone may come from Python, someone else may come from Perl, and they may be surprised by different aspects of the language. Then they come up to me and say, 'I was surprised by this feature of the language, so Ruby violates the principle of least surprise.' Wait. The principle of least surprise is not for you only. The principle of least surprise means principle of least my surprise. And it means the principle of least surprise after you learn Ruby very well. For example, I was a C++ programmer before I started designing Ruby. I programmed in C++ exclusively for two or three years. And after two years of C++ programming, it still surprises me. Features. Variables always hold references to objects. Every function is a method and methods are always called on an object. Methods defined at the top level scope become members of the Object class. Since this class is an ancestor of every other class, such methods can be called on any object. They are also visible in all scopes, effectively serving as . Ruby supports inheritance with dynamic dispatch, mixins and singleton methods (belonging to, and defined for, a single instance rather than being defined on the class). Though Ruby does not support multiple inheritance, classes can import modules as mixins. Ruby has been described as a multi- paradigm programming language: it allows procedural programming (defining functions/variables outside classes makes them part of the root, 'self' Object), with object orientation (everything is an object) or functional programming (it has anonymous functions, closures, and continuations; statements all have values, and functions return the last evaluation). It has support for introspection, reflection and metaprogramming, as well as support for interpreter- based. Ruby features dynamic typing, and supports parametric polymorphism. According to the Ruby FAQ, the syntax is similar to Perl and the semantics are similar to Smalltalk but it differs greatly from Python. Class and method definitions are signaled by keywords, whereas code blocks can be both defined by keywords or braces. In contrast to Perl, variables are not obligatorily prefixed with a sigil. When used, the sigil changes the semantics of scope of the variable. For practical purposes there is no distinction between expressions and statements. Unlike Python, indentation is not significant. One of the differences of Ruby compared to Python and Perl is that Ruby keeps all of its instance variables completely private to the class and only exposes them through accessor methods (attr. As invocation of these methods does not require the use of parentheses, it is trivial to change an instance variable into a full function, without modifying a single line of code or having to do any refactoring achieving similar functionality to C# and VB. NET property members. Python's property descriptors are similar, but come with a tradeoff in the development process. If one begins in Python by using a publicly exposed instance variable, and later changes the implementation to use a private instance variable exposed through a property descriptor, code internal to the class may need to be adjusted to use the private variable rather than the public property. This is in keeping with the idea that in Ruby, one never directly accesses the internal members of a class from outside the class; rather, one passes a message to the class and receives a response. See the Examples section below for samples of code demonstrating Ruby syntax. Differences from other languages. Class and module names are constants and refer to objects derived from Class and Module. The sigils$ and @ do not indicate variable data type as in Perl, but rather function as scope resolution operators. Floating point literals must have digits on both sides of the decimal point: neither . The reason for requiring a digit before the decimal point is less clear; it might relate either to method invocation again, or perhaps to the . Smalltalk and Java), but their mapping to boolean values differs markedly from some other languages: 0 and . This may cause surprises when slicing strings: . This is because statement until expression is actually syntactic sugar over until expression; statement; end, the equivalent of which in C/C++ is while (!(expression)) . However, the notation begin statement end until expression in Ruby will in fact run the statement once even if the expression is already true, acting similar to the do- while of other languages. For example, Greeting< <. This is similar to final variables in Java or a const pointer to a non- const object in C++. Ruby provides the functionality to freeze an object. The usual conjunctive and disjunctive operators for conditional expressions have the same precedence, so and does not bind tighter than or in Ruby, a behaviour similar to languages such as APL, Ada, VHDL, Mathematica, zkl and others. However, Ruby also has C- like operators . A similar list in the 1st edition pertained to an older version of Ruby (version 1. For example, retry now works with while, until, and for, as well as with iterators. Interaction. The following code fragment represents a sample session using irb: $ irbirb(main): 0. Hello, World'Hello, World => nilirb(main): 0. Examples. Many built- in methods have such arguments: File. The inject method iterates over each member of a list, performing some function on it while retaining an aggregate. This is analogous to the foldl function in functional programming languages. This returns 1. 1, which then becomes sum on the next pass. It is added to 3 to get 1. Using an enumeration and a block to square the numbers 1 to 1.
0 Comments
Leave a Reply. |
Details
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |