This article's lead section may be too technical for most readers to understand.(June 2022) |
Paradigm | Multi-paradigm: functional, imperative, object-oriented, reflective |
---|---|
Designed by | Yukihiro Matsumoto |
Developer | Yukihiro Matsumoto, et al. |
First appeared | 1995 |
Stable release | |
Typing discipline | Duck, dynamic, strong |
Scope | Lexical, sometimes dynamic |
Implementation language | C |
OS | Cross-platform |
License | Ruby License |
Filename extensions | .rb, .ru |
Website | ruby-lang.org |
Major implementations | |
Ruby MRI, TruffleRuby, YARV, Rubinius, JRuby, RubyMotion, mruby | |
Influenced by | |
Ada, [2] Basic, [3] C++, [2] CLU, [4] Dylan, [4] Eiffel, [2] Lisp, [4] Lua, Perl, [4] Python, [4] Smalltalk [4] | |
Influenced | |
Clojure, CoffeeScript, Crystal, D, Elixir, Groovy, Julia, [5] Mirah, Nu, [6] Ring, [7] Rust, [8] Swift [9] | |
|
Ruby is an interpreted, high-level, general-purpose programming language. It was designed with an emphasis on programming productivity and simplicity. In Ruby, everything is an object, including primitive data types. It was developed in the mid-1990s by Yukihiro "Matz" Matsumoto in Japan.
Ruby is dynamically typed and uses garbage collection and just-in-time compilation. It supports multiple programming paradigms, including procedural, object-oriented, and functional programming. According to the creator, Ruby was influenced by Perl, Smalltalk, Eiffel, Ada, BASIC, Java, and Lisp. [10] [3]
Matsumoto has said that Ruby was conceived in 1993. In a 1999 post to the ruby-talk mailing list, he describes some of his early ideas about the language:
I was talking with my colleague about the possibility of an object-oriented scripting language. I knew Perl (Perl4, not Perl5), but I didn't like it really, because it had the smell of a toy language (it still has). The object-oriented language seemed very promising. I knew Python then. But I didn't like it, because I didn't think it was a true object-oriented language – OO features appeared to be add-on to the language. As a language maniac and OO fan for 15 years, 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. [11]
The name "Ruby" originated during an online chat session between Matsumoto and Keiju Ishitsuka on February 24, 1993, before any code had been written for the language. [12] Initially two names were proposed: "Coral" and "Ruby". Matsumoto chose the latter in a later e-mail to Ishitsuka. [13] Matsumoto later noted a factor in choosing the name "Ruby"–it was the birthstone of one of his colleagues. [14] [15]
The first public release of Ruby 0.95 was announced on Japanese domestic newsgroups on December 21, 1995. [16] [17] Subsequently, three more versions of Ruby were released in two days. [12] The release coincided with the launch of the Japanese-language ruby-list mailing list, which was the first mailing list for the new language.
Already present at this stage of development were many of the features familiar in later releases of Ruby, including object-oriented design, classes with inheritance, mixins, iterators, closures, exception handling and garbage collection. [18]
After the release of Ruby 0.95 in 1995, several stable versions of Ruby were released in these years:
In 1997, the first article about Ruby was published on the Web. In the same year, Matsumoto was hired by netlab.jp to work on Ruby as a full-time developer. [12]
In 1998, the Ruby Application Archive was launched by Matsumoto, along with a simple English-language homepage for Ruby. [12]
In 1999, the first English language mailing list ruby-talk began, which signaled a growing interest in the language outside Japan. [19] In this same year, Matsumoto and Keiju Ishitsuka wrote the first book on Ruby, The Object-oriented Scripting Language Ruby (オブジェクト指向スクリプト言語 Ruby), which was published in Japan in October 1999. It would be followed in the early 2000s by around 20 books on Ruby published in Japanese. [12]
By 2000, Ruby was more popular than Python in Japan. [20] In September 2000, the first English language book Programming Ruby was printed, which was later freely released to the public, further widening the adoption of Ruby amongst English speakers. In early 2002, the English-language ruby-talk mailing list was receiving more messages than the Japanese-language ruby-list, demonstrating Ruby's increasing popularity in the non-Japanese speaking world.
Ruby 1.8 was initially released August 2003, was stable for a long time, and was retired June 2013. [21] Although deprecated, there is still code based on it. Ruby 1.8 is only partially compatible with Ruby 1.9.
Ruby 1.8 has been the subject of several industry standards. 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 3017) in 2011 [22] and an international standard (ISO/IEC 30170) in 2012. [23] [24]
Around 2005, interest in the Ruby language surged in tandem with Ruby on Rails, a web framework written in Ruby. Rails is frequently credited with increasing awareness of Ruby. [25]
Effective with Ruby 1.9.3, released October 31, 2011, [26] Ruby switched from being dual-licensed under the Ruby License and the GPL to being dual-licensed under the Ruby License and the two-clause BSD license. [27] Adoption of 1.9 was slowed by changes from 1.8 that required many popular third party gems to be rewritten. Ruby 1.9 introduces many significant changes over the 1.8 series. Examples include: [28]
f=->(a,b){putsa+b}
{symbol_key:"value"}=={:symbol_key=>"value"}
require_relative
import securityRuby 2.0 was intended to be fully backward compatible with Ruby 1.9.3. As of the official 2.0.0 release on February 24, 2013, there were only five known (minor) incompatibilities. [29] Ruby 2.0 added several new features, including:
Module#prepend
, to extend a classStarting with 2.1.0, Ruby's versioning policy changed to be more similar to semantic versioning. [31]
Ruby 2.2.0 includes speed-ups, bugfixes, and library updates and removes some deprecated APIs. Most notably, Ruby 2.2.0 introduces changes to memory handling –an incremental garbage collector, support for garbage collection of symbols and the option to compile directly against jemalloc. It also contains experimental support for using vfork(2) with system() and spawn(), and added support for the Unicode 7.0 specification. Since version 2.2.1, [32] Ruby MRI performance on PowerPC64 was improved. [33] [34] [35] Features that were made obsolete or removed include callcc, the DL library, Digest::HMAC, lib/rational.rb, lib/complex.rb, GServer, Logger::Application as well as various C API functions. [36]
Ruby 2.3.0 includes many performance improvements, updates, and bugfixes including changes to Proc#call, Socket and IO use of exception keywords, Thread#name handling, default passive Net::FTP connections, and Rake being removed from stdlib. [37] Other notable changes include:
&.
that can ease nil handling (e.g. instead of ifobj&&obj.foo&&obj.foo.bar
, we can use if obj&.foo&.bar
).profile={social:{wikipedia:{name:'Foo Baz'}}}
, the value Foo Baz can now be retrieved by profile.dig(:social, :wikipedia, :name)
)..grep_v(regexp)
which will match all negative examples of a given regular expression in addition to other new features.Ruby 2.4.0 includes performance improvements to hash table, Array#max, Array#min, and instance variable access. [39] Other notable changes include:
A few notable changes in Ruby 2.5.0 include rescue and ensure statements automatically use a surrounding do-end block (less need for extra begin-end blocks), method-chaining with yield_self, support for branch coverage and method coverage measurement, and easier Hash transformations with Hash#slice and Hash#transform_keys On top of that come a lot of performance improvements like faster block passing (3 times faster), faster Mutexes, faster ERB templates and improvements on some concatenation methods.
A few notable changes in Ruby 2.6.0 include an experimental just-in-time compiler (JIT), and RubyVM::AbstractSyntaxTree (experimental).
A few notable changes in Ruby 2.7.0 include pattern Matching (experimental), REPL improvements, a compaction GC, and separation of positional and keyword arguments.
Ruby 3.0.0 was released on Christmas Day in 2020. [40] It is known as Ruby 3x3 which means that programs would run three times faster in Ruby 3.0 comparing to Ruby 2.0. [41] and some had already implemented in intermediate releases on the road from 2 to 3. To achieve 3x3, Ruby 3 comes with MJIT, and later YJIT, Just-In-Time Compilers, to make programs faster, although they are described as experimental and remain disabled by default (enabled by flags at runtime).
Another goal of Ruby 3.0 is to improve concurrency and two more utilities Fibre Scheduler, and experimental Ractor facilitate the goal. [40] Ractor is light-weight and thread-safe as it is achieved by exchanging messages rather than shared objects.
Ruby 3.0 introduces RBS language to describe the types of Ruby programs for static analysis. [40] It is separated from general Ruby programs.
There are some syntax enhancements and library changes in Ruby 3.0 as well. [40]
Ruby 3.1 was released on December 25, 2021. [42] It includes YJIT, a new, experimental, Just-In-Time Compiler developed by Shopify, to enhance the performance of real world business applications. A new debugger is also included. There are some syntax enhancements and other improvements in this release. Network libraries for FTP, SMTP, IMAP, and POP are moved from default gems to bundled gems. [43]
Ruby 3.2 was released on December 25, 2022. [44] It brings support for being run inside of a WebAssembly environment via a WASI interface. Regular expressions also receives some improvements, including a faster, memoized matching algorithm to protect against certain ReDoS attacks, and configurable timeouts for regular expression matching. Additional debugging and syntax features are also included in this release, which include syntax suggestion, as well as error highlighting. The MJIT compiler has been re-implemented as a standard library module, while the YJIT, a Rust-based JIT compiler now supports more architectures on Linux.
Ruby 3.3 was released on December 25, 2023. [1] Ruby 3.3 introduces significant enhancements and performance improvements to the language. Key features include the introduction of the Prism parser for portable and maintainable parsing, the addition of the pure-Ruby JIT compiler RJIT, and major performance boosts in the YJIT compiler. Additionally, improvements in memory usage, the introduction of an M:N thread scheduler, and updates to the standard library contribute to a more efficient and developer-friendly Ruby ecosystem.
Matsumoto has said that Ruby is designed for programmer productivity and fun, following the principles of good user interface design. [45] At a Google Tech Talk in 2008 he said, "I hope to see Ruby help every programmer in the world to be productive, and to enjoy programming, and to be happy. That is the primary purpose of Ruby language." [46] He stresses that systems design needs to emphasize human, rather than computer, needs: [47]
Often people, especially computer engineers, focus on the machines. They think, "By doing this, the machine will run fast. By doing this, the machine will run more effectively. By doing this, the machine will something something something." They are focusing on machines. But in fact we need to focus on humans, on how humans care about doing programming or operating the application of the machines. We are the masters. They are the slaves.
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 (POLA) to the design of Ruby; [47] in a May 2005 discussion on the newsgroup comp.lang.ruby, 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. [48]
Matsumoto defined it this way in an interview: [47]
Everyone has an individual background. 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. 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.
Ruby is object-oriented: every value is an object, including classes and instances of types that many other languages designate as primitives (such as integers, Booleans, and "null"). Because everything in Ruby is an object, everything in Ruby has certain built-in abilities called methods. Every function is a method and methods are always called on an object. Methods defined at the top level scope become methods 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 "global" procedures. 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, reflective programming, metaprogramming, and interpreter-based threads. Ruby features dynamic typing, and supports parametric polymorphism.
According to the Ruby FAQ, the syntax is similar to Perl's and the semantics are similar to Smalltalk's, but the design philosophy differs greatly from Python's. [49]
false
and nil
)method_missing
and const_missing
)The syntax of Ruby is broadly similar to that of Perl and Python. Class and method definitions are signaled by keywords, whereas code blocks can be defined by either 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. [57] [58] Line breaks are significant and taken as the end of a statement; a semicolon may be equivalently used. Unlike Python, indentation is not significant.
One of the differences from 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_writer
, attr_reader
, etc.). Unlike the "getter" and "setter" methods of other languages like C++ or Java, accessor methods in Ruby can be created with a single line of code via metaprogramming; however, accessor methods can also be created in the traditional fashion of C++ and Java. 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 calling 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 trade-off 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. Ruby's design forces all instance variables to be private, but also provides a simple way to declare set
and get
methods. 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.
The original Ruby interpreter is often referred to as Matz's Ruby Interpreter or MRI. This implementation is written in C and uses its own Ruby-specific virtual machine.
The standardized and retired Ruby 1.8 implementation was written in C, as a single-pass interpreted language. [21]
Starting with Ruby 1.9, and continuing with Ruby 2.x and above, the official Ruby interpreter has been YARV ("Yet Another Ruby VM"), and this implementation has superseded the slower virtual machine used in previous releases of MRI.
As of 2018 [update] , there are a number of alternative implementations of Ruby, including JRuby, Rubinius, and mruby. Each takes a different approach, with JRuby and Rubinius providing just-in-time compilation and mruby also providing ahead-of-time compilation.
Ruby has three major alternative implementations:
Other Ruby implementations include:
Other now defunct Ruby implementations were:
The maturity of Ruby implementations tends to be measured by their ability to run the Ruby on Rails (Rails) framework, because it is complex to implement and uses many Ruby-specific features. The point when a particular implementation achieves this goal is called "the Rails singularity". The reference implementation, JRuby, and Rubinius [60] are all able to run Rails unmodified in a production environment.
Matsumoto originally developed Ruby on the 4.3BSD-based Sony NEWS-OS 3.x, but later migrated his work to SunOS 4.x, and finally to Linux. [61] [62] By 1999, Ruby was known to work across many different operating systems. Modern Ruby versions and implementations are available on all major desktop, mobile and server-based operating systems. Ruby is also supported across a number of cloud hosting platforms like Jelastic, Heroku, Google Cloud Platform and others.
Tools such as RVM and RBEnv, facilitate installation and partitioning of multiple ruby versions, and multiple 'gemsets' on one machine.
RubyGems is Ruby's package manager. A Ruby package is called a "gem" and can be installed via the command line. Most gems are libraries, though a few exist that are applications, such as IDEs. [63] There are over 100,000 Ruby gems hosted on RubyGems.org. [64]
Many new and existing Ruby libraries are hosted on GitHub, a service that offers version control repository hosting for Git.
The Ruby Application Archive, which hosted applications, documentation, and libraries for Ruby programming, was maintained until 2013, when its function was transferred to RubyGems. [65]
Multiple inheritance is a feature of some object-oriented computer programming languages in which an object or class can inherit features from more than one parent object or parent class. It is distinct from single inheritance, where an object or class may only inherit from one particular object or class.
Python is a high-level, general-purpose programming language. Its design philosophy emphasizes code readability with the use of significant indentation.
Perl is a high-level, general-purpose, interpreted, dynamic programming language. Though Perl is not officially an acronym, there are various backronyms in use, including "Practical Extraction and Reporting Language".
In computing, serialization is the process of translating a data structure or object state into a format that can be stored or transmitted and reconstructed later. When the resulting series of bits is reread according to the serialization format, it can be used to create a semantically identical clone of the original object. For many complex objects, such as those that make extensive use of references, this process is not straightforward. Serialization of objects does not include any of their associated methods with which they were previously linked.
In object-oriented (OO) and functional programming, an immutable object is an object whose state cannot be modified after it is created. This is in contrast to a mutable object, which can be modified after it is created. In some cases, an object is considered immutable even if some internally used attributes change, but the object's state appears unchanging from an external point of view. For example, an object that uses memoization to cache the results of expensive computations could still be considered an immutable object.
A dynamic programming language is a type of programming language that allows various operations to be determined and executed at runtime. This is different from the compilation phase. Key decisions about variables, method calls, or data types are made when the program is running, unlike in static languages, where the structure and types are fixed during compilation. Dynamic languages provide flexibility. This allows developers to write more adaptable and concise code.
The Microsoft Windows Script Host (WSH) is an automation technology for Microsoft Windows operating systems that provides scripting abilities comparable to batch files, but with a wider range of supported features. This tool was first provided on Windows 95 after Build 950a on the installation discs as an optional installation configurable and installable by means of the Control Panel, and then a standard component of Windows 98 and subsequent and Windows NT 4.0 Build 1381 and by means of Service Pack 4. The WSH is also a means of automation for Internet Explorer via the installed WSH engines from IE Version 3.0 onwards; at this time VBScript became means of automation for Microsoft Outlook 97. The WSH is also an optional install provided with a VBScript and JScript engine for Windows CE 3.0 and following and some third-party engines including Rexx and other forms of Basic are also available.
In the Perl programming language, autovivification is the automatic creation of new arrays and hashes as required every time an undefined value is dereferenced. Perl autovivification allows a programmer to refer to a structured variable, and arbitrary sub-elements of that structured variable, without expressly declaring the existence of the variable and its complete structure beforehand.
In computer programming, a sigil is a symbol affixed to a variable name, showing the variable's datatype or scope, usually a prefix, as in $foo
, where $
is the sigil.
In computer programming, thread-local storage (TLS) is a memory management method that uses static or global memory local to a thread. The concept allows storage of data that appears to be global in a system with separate threads.
JRuby is an implementation of the Ruby programming language atop the Java Virtual Machine, written largely in Java. It is free software released under a three-way EPL/GPL/LGPL license. JRuby is tightly integrated with Java to allow the embedding of the interpreter into any Java application with full two-way access between the Java and the Ruby code.
In computer science, future, promise, delay, and deferred refer to constructs used for synchronizing program execution in some concurrent programming languages. They describe an object that acts as a proxy for a result that is initially unknown, usually because the computation of its value is not yet complete.
The syntax of the Python programming language is the set of rules that defines how a Python program will be written and interpreted. The Python language has many similarities to Perl, C, and Java. However, there are some definite differences between the languages. It supports multiple programming paradigms, including structured, object-oriented programming, and functional programming, and boasts a dynamic type system and automatic memory management.
Aptana, Inc. is a company that makes web application development tools for use with a variety of programming languages. Aptana's main products include Aptana Studio, Aptana Cloud and Aptana Jaxer.
The fat comma is a syntactic construction that appears in a position in a function call where a comma would usually appear. The original usage refers to the ")
letters:(
" construction in ALGOL 60. Newer usage refers to the "=>
" operator present in some programming languages. It is primarily associated with PHP, Ruby and Perl programming languages, which use it to declare hashes. Using a fat comma to bind key-value pairs in a hash, instead of using a comma, is considered an example of good idiomatic Perl. In CoffeeScript and TypeScript, the fat comma is used to declare a function that is bound to this
.
This comparison of programming languages compares how object-oriented programming languages such as C++, Java, Smalltalk, Object Pascal, Perl, Python, and others manipulate data structures.
CoffeeScript is a programming language that compiles to JavaScript. It adds syntactic sugar inspired by Ruby, Python, and Haskell in an effort to enhance JavaScript's brevity and readability. Specific additional features include list comprehension and destructuring assignment.
The structure of the Perl programming language encompasses both the syntactical rules of the language and the general ways in which programs are organized. Perl's design philosophy is expressed in the commonly cited motto "there's more than one way to do it". As a multi-paradigm, dynamically typed language, Perl allows a great degree of flexibility in program design. Perl also encourages modularization; this has been attributed to the component-based design structure of its Unix roots, and is responsible for the size of the CPAN archive, a community-maintained repository of more than 100,000 modules.
The history of the Ruby programming language began when Yukihiro Matsumoto first conceived of the language in 1993, then released it in 1995. Annual releases of the language often take place on Christmas Day. Interest in the language surged around 2005 because of the Ruby on Rails framework.
To a lesser extent, Python, LISP, Eiffel, Ada, and C++ have also influenced Ruby.
It draws primarily on features from Perl, Smalltalk, Python, Lisp, Dylan, and CLU.
The Swift language is the product of tireless effort from a team of language experts, documentation gurus, compiler optimization ninjas, and an incredibly important internal dogfooding group who provided feedback to help refine and battle-test ideas. Of course, it also greatly benefited from the experiences hard-won by many other languages in the field, drawing ideas from Objective-C, Rust, Haskell, Ruby, Python, C#, CLU, and far too many others to list.
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: CS1 maint: bot: original URL status unknown (link)In Ruby's syntax, statement is just a special case of an expression that cannot appear as an argument (e.g. multiple assignment).
statement [...] can not be part of expression unless grouped within parentheses.