Standard library
Encyclopedia
A standard library for a programming language
is the library that is conventionally made available in every implementation of that language. In some cases, the library is described directly in the programming language specification
; in other cases, the contents of the standard library are determined by more informal social practices in the programming community.
Depending on the constructs made available by the host language, a standard library may include:
Most standard libraries include definitions for at least the following commonly used facilities:
, designer of C++
, writes:
This suggests a relatively small standard library, containing only the constructs that "every programmer" might reasonably require when building a large collection of software. This is the philosophy that is used in the C
and C++
standard libraries.
By contrast, Guido van Rossum, designer of Python
, has embraced a much more inclusive vision of the standard library; in the Python tutorial, he writes:
Van Rossum goes on to list libraries for processing XML
, XML-RPC
, email messages, and localization, facilities that the C++ standard library omits. This other philosophy is often found in Scripting language
s (as in Python
or Ruby
) or languages that use a Virtual machine
, such as Java
or the .NET Framework
languages.
Programming language
A programming language is an artificial language designed to communicate instructions to a machine, particularly a computer. Programming languages can be used to create programs that control the behavior of a machine and/or to express algorithms precisely....
is the library that is conventionally made available in every implementation of that language. In some cases, the library is described directly in the programming language specification
Programming language specification
In computing, a programming language specification is an artifact that defines a programming language so that users and implementors can agree on what programs in that language mean....
; in other cases, the contents of the standard library are determined by more informal social practices in the programming community.
Depending on the constructs made available by the host language, a standard library may include:
- SubroutineSubroutineIn computer science, a subroutine is a portion of code within a larger program that performs a specific task and is relatively independent of the remaining code....
s - Macro definitions
- Global variableGlobal variableIn computer programming, a global variable is a variable that is accessible in every scope . Interaction mechanisms with global variables are called global environment mechanisms...
s - ClassClass (computer science)In object-oriented programming, a class is a construct that is used as a blueprint to create instances of itself – referred to as class instances, class objects, instance objects or simply objects. A class defines constituent members which enable these class instances to have state and behavior...
definitions - TemplateTemplate (programming)Templates are a feature of the C++ programming language that allow functions and classes to operate with generic types. This allows a function or class to work on many different data types without being rewritten for each one....
s
Most standard libraries include definitions for at least the following commonly used facilities:
- Algorithms (such as sorting algorithms)
- Data structures (such as lists, treesTree (data structure)In computer science, a tree is a widely-used data structure that emulates a hierarchical tree structure with a set of linked nodes.Mathematically, it is an ordered directed tree, more specifically an arborescence: an acyclic connected graph where each node has zero or more children nodes and at...
and hash tableHash tableIn computer science, a hash table or hash map is a data structure that uses a hash function to map identifying values, known as keys , to their associated values . Thus, a hash table implements an associative array...
s) - Interaction with the host platform, including input/output and operating system calls
Philosophies
Philosophies of standard library design vary widely. For example, Bjarne StroustrupBjarne Stroustrup
Bjarne Stroustrup ; born December 30, 1950 in Århus, Denmark) is a Danish computer scientist, most notable for the creation and the development of the widely used C++ programming language...
, designer of C++
C++
C++ is a statically typed, free-form, multi-paradigm, compiled, general-purpose programming language. It is regarded as an intermediate-level language, as it comprises a combination of both high-level and low-level language features. It was developed by Bjarne Stroustrup starting in 1979 at Bell...
, writes:
This suggests a relatively small standard library, containing only the constructs that "every programmer" might reasonably require when building a large collection of software. This is the philosophy that is used in the C
C (programming language)
C is a general-purpose computer programming language developed between 1969 and 1973 by Dennis Ritchie at the Bell Telephone Laboratories for use with the Unix operating system....
and C++
C++
C++ is a statically typed, free-form, multi-paradigm, compiled, general-purpose programming language. It is regarded as an intermediate-level language, as it comprises a combination of both high-level and low-level language features. It was developed by Bjarne Stroustrup starting in 1979 at Bell...
standard libraries.
By contrast, Guido van Rossum, designer of Python
Python (programming language)
Python is a general-purpose, high-level programming language whose design philosophy emphasizes code readability. Python claims to "[combine] remarkable power with very clear syntax", and its standard library is large and comprehensive...
, has embraced a much more inclusive vision of the standard library; in the Python tutorial, he writes:
Van Rossum goes on to list libraries for processing XML
XML
Extensible Markup Language is a set of rules for encoding documents in machine-readable form. It is defined in the XML 1.0 Specification produced by the W3C, and several other related specifications, all gratis open standards....
, XML-RPC
XML-RPC
XML-RPC is a remote procedure call protocol which uses XML to encode its calls and HTTP as a transport mechanism. "XML-RPC" also refers generically to the use of XML for remote procedure call, independently of the specific protocol...
, email messages, and localization, facilities that the C++ standard library omits. This other philosophy is often found in Scripting language
Scripting language
A scripting language, script language, or extension language is a programming language that allows control of one or more applications. "Scripts" are distinct from the core code of the application, as they are usually written in a different language and are often created or at least modified by the...
s (as in Python
Python (programming language)
Python is a general-purpose, high-level programming language whose design philosophy emphasizes code readability. Python claims to "[combine] remarkable power with very clear syntax", and its standard library is large and comprehensive...
or Ruby
Ruby (programming language)
Ruby is a dynamic, reflective, general-purpose object-oriented programming language that combines syntax inspired by Perl with Smalltalk-like features. Ruby originated in Japan during the mid-1990s and was first developed and designed by Yukihiro "Matz" Matsumoto...
) or languages that use a Virtual machine
Virtual machine
A virtual machine is a "completely isolated guest operating system installation within a normal host operating system". Modern virtual machines are implemented with either software emulation or hardware virtualization or both together.-VM Definitions:A virtual machine is a software...
, such as Java
Java (programming language)
Java is a programming language originally developed by James Gosling at Sun Microsystems and released in 1995 as a core component of Sun Microsystems' Java platform. The language derives much of its syntax from C and C++ but has a simpler object model and fewer low-level facilities...
or the .NET Framework
.NET Framework
The .NET Framework is a software framework that runs primarily on Microsoft Windows. It includes a large library and supports several programming languages which allows language interoperability...
languages.
Examples of standard libraries
- C standard libraryC standard libraryThe C Standard Library is the standard library for the programming language C, as specified in the ANSI C standard.. It was developed at the same time as the C POSIX library, which is basically a superset of it...
, for the C programming languageC (programming language)C is a general-purpose computer programming language developed between 1969 and 1973 by Dennis Ritchie at the Bell Telephone Laboratories for use with the Unix operating system.... - C++ standard libraryC++ standard libraryIn C++, the C++ Standard Library is a collection of classes and functions, which are written in the core language and part of the C++ ISO Standard itself...
, for the C++ programming languageC++C++ is a statically typed, free-form, multi-paradigm, compiled, general-purpose programming language. It is regarded as an intermediate-level language, as it comprises a combination of both high-level and low-level language features. It was developed by Bjarne Stroustrup starting in 1979 at Bell... - Standard Template LibraryStandard Template LibraryThe Standard Template Library is a C++ software library which later evolved into the C++ Standard Library. It provides four components called algorithms, containers, functors, and iterators. More specifically, the C++ Standard Library is based on the STL published by SGI. Both include some...
(or STL), a sub-part of the C++ standard libraryC++ standard libraryIn C++, the C++ Standard Library is a collection of classes and functions, which are written in the core language and part of the C++ ISO Standard itself... - Java Class LibraryJava Class LibraryThe Java Class Library is a set of dynamically loadable libraries that Java applications can call at run time. Because the Java Platform is not dependent on any specific operating system, applications cannot rely on any of the existing libraries...
(or JCL), for the Java programming languageJava (programming language)Java is a programming language originally developed by James Gosling at Sun Microsystems and released in 1995 as a core component of Sun Microsystems' Java platform. The language derives much of its syntax from C and C++ but has a simpler object model and fewer low-level facilities...
, and Java Platform - Base Class LibraryBase Class LibraryThe Base Class Library is a standard library available to all languages using the .NET Framework. .NET includes the BCL in order to encapsulate a large number of common functions, such as file reading and writing, graphic rendering, database interaction, and XML document manipulation, which makes...
(or BCL), for the .NET Framework.NET FrameworkThe .NET Framework is a software framework that runs primarily on Microsoft Windows. It includes a large library and supports several programming languages which allows language interoperability... - Factor standard library, for the Factor programming languageFactor (programming language)Factor is a stack-oriented programming language created by Slava Pestov. Factor is dynamically typed and has automatic memory management, as well as powerful metaprogramming features. The language has a single implementation featuring a self-hosted optimizing compiler and an interactive development...