text stringlengths 1 1k | source stringlengths 31 152 |
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as in forming tuple literal; as a whole, the results are then put on the left-hand side of the equal sign in an assignment statement. This statement expects an iterable object on the right-hand side of the equal sign to produce the same number of values as the writable expressions on the left-hand side; while iteratin... | https://en.wikipedia.org/wiki/Python_(programming_language) |
e.g., "spam" + "eggs" returns "spameggs". If strings contain numbers, they are concatenated as strings rather than as integers, e.g. "2" + "2" returns "22".
Python supports string literals in several ways:
Delimited by single or double quotation marks; single and double quotation marks have equivalent functionality (un... | https://en.wikipedia.org/wiki/Python_(programming_language) |
C#.)
Python has array index and array slicing expressions in lists, which are written as a[key], a[start:stop] or a[start:stop:step]. Indexes are zero-based, and negative indexes are relative to the end. Slices take elements from the start index up to, but not including, the stop index. The (optional) third slice param... | https://en.wikipedia.org/wiki/Python_(programming_language) |
ements
A statement cannot be part of an expression; because of this restriction, expressions such as list and dict comprehensions (and lambda expressions) cannot contain statements. As a particular case, an assignment statement such as a = 1 cannot be part of the conditional expression of a conditional statement.
===... | https://en.wikipedia.org/wiki/Python_(programming_language) |
cluding length, comparison, arithmetic, and type conversion.
=== Typing ===
Python uses duck typing, and it has typed objects but untyped variable names. Type constraints are not checked at definition time; rather, operations on an object may fail at usage time, indicating that the object is not of an appropriate ty... | https://en.wikipedia.org/wiki/Python_(programming_language) |
yle and new-style. Current Python versions support the semantics of only the new style.
Python supports optional type annotations. These annotations are not enforced by the language, but may be used by external tools such as mypy to catch errors. Mypy also supports a Python compiler called mypyc, which leverages type a... | https://en.wikipedia.org/wiki/Python_(programming_language) |
produces floating-point results. The behavior of division has changed significantly over time:
The current version of Python (i.e., since 3.0) changed the / operator to always represent floating-point division, e.g., 5/2 == 2.5.
The floor division // operator was introduced. Thus 7//3 == 2, -7//3 == -3, 7.5//3 == 2.0,... | https://en.wikipedia.org/wiki/Python_(programming_language) |
b*(a//b) + a%b == a is valid for both positive and negative values of a. As expected, the result of a%b lies in the half-open interval [0, b), where b is a positive integer; however, maintaining the validity of the equation requires that the result must lie in the interval (b, 0] when b is negative.
Python provides a r... | https://en.wikipedia.org/wiki/Python_(programming_language) |
ould then be compared with c.
Python uses arbitrary-precision arithmetic for all integer operations. The Decimal type/class in the decimal module provides decimal floating-point numbers to a pre-defined arbitrary precision with several rounding modes. The Fraction class in the fractions module provides arbitrary precis... | https://en.wikipedia.org/wiki/Python_(programming_language) |
nside the function header.
== Code examples ==
"Hello, World!" program:
Program to calculate the factorial of a positive integer:
== Libraries ==
Python's large standard library is commonly cited as one of its greatest strengths. For Internet-facing applications, many standard formats and protocols such as MIME an... | https://en.wikipedia.org/wiki/Python_(programming_language) |
variant implementations.
As of 13 March 2025, the Python Package Index (PyPI), the official repository for third-party Python software, contains over 614,339 packages. These have a wide range of functionality, including the following:
== Development environments ==
Most Python implementations (including CPython) inc... | https://en.wikipedia.org/wiki/Python_(programming_language) |
eloping science- and math-related programs;
Jupyter Notebooks, an open-source interactive computing platform;
PythonAnywhere, a browser-based IDE and hosting environment; and
Canopy IDE, a commercial IDE that emphasizes scientific computing.
== Implementations ==
=== Reference implementation ===
CPython is the refe... | https://en.wikipedia.org/wiki/Python_(programming_language) |
1 Macs, since Python 3.9.1, using an experimental installer). Starting with Python 3.9, the Python installer intentionally fails to install on Windows 7 and 8; Windows XP was supported until Python 3.5, with unofficial support for VMS. Platform portability was one of Python's earliest priorities. During development of ... | https://en.wikipedia.org/wiki/Python_(programming_language) |
ernative implementations include the following:
PyPy is a fast, compliant interpreter of Python 2.7 and 3.10. PyPy's just-in-time compiler often improves speed significantly relative to CPython, but PyPy does not support some libraries written in C. PyPy offers support for the RISC-V instruction-set architecture, for... | https://en.wikipedia.org/wiki/Python_(programming_language) |
on 3 variants that are optimized for microcontrollers, including the Lego Mindstorms EV3.
Pyston is a variant of the Python runtime that uses just-in-time compilation to speed up execution of Python programs.
Cinder is a performance-oriented fork of CPython 3.8 that features a number of optimizations, including bytecod... | https://en.wikipedia.org/wiki/Python_(programming_language) |
ingle precision (resembling JavaScript numbers, though smaller).
=== Unsupported implementations ===
Stackless Python is a significant fork of CPython that implements microthreads. This implementation uses the call stack differently, thus allowing massively concurrent programs. PyPy also offers a stackless version.
J... | https://en.wikipedia.org/wiki/Python_(programming_language) |
later.
PyS60 was a Python 2 interpreter for Series 60 mobile phones, which was released by Nokia in 2005. The interpreter implemented many modules from Python's standard library, as well as additional modules for integration with the Symbian operating system. The Nokia N900 also supports Python through the GTK widget ... | https://en.wikipedia.org/wiki/Python_(programming_language) |
Julia source code". Despite the developers' performance claims, this is not possible for arbitrary Python code; that is, compiling to a faster language or machine code is known to be impossible in the general case. The semantics of Python might potentially be changed, but in many cases speedup is possible with few or ... | https://en.wikipedia.org/wiki/Python_(programming_language) |
at is used from Python; the compiler translates a subset of Python and NumPy code into fast machine code. This tool is enabled by adding a decorator to the relevant Python code.
Pythran compiles a subset of Python 3 to C++ (C++11).
RPython can be compiled to C, and it is used to build the PyPy interpreter for Python.
T... | https://en.wikipedia.org/wiki/Python_(programming_language) |
."
Jython compiles Python 2.7 to Java bytecode, allowing the use of Java libraries from a Python program.
Pyrex (last released in 2010) and Shed Skin (last released in 2013) compile to C and C++ respectively.
=== Performance ===
A perforance comparison among various Python implementations, using a non-numerical (comb... | https://en.wikipedia.org/wiki/Python_(programming_language) |
s Cython, which compiles Python into C.
Concurrency and parallelism: Multiple tasks can be run simultaneously. Python contains modules such as `multiprocessing` to support this form of parallelism. Moreover, this approach helps to overcome limitations of the Global Interpreter Lock (GIL) in CPU tasks.
Efficient data st... | https://en.wikipedia.org/wiki/Python_(programming_language) |
n reference implementation. The mailing list python-dev is the primary forum for the language's development. Specific issues were originally discussed in the Roundup bug tracker hosted by the foundation. In 2022, all issues and discussions were migrated to GitHub. Development originally took place on a self-hosted sour... | https://en.wikipedia.org/wiki/Python_(programming_language) |
mber is incremented. Starting with Python 3.9, these releases are expected to occur annually. Each major version is supported by bug fixes for several years after its release.
Bug fix releases, which introduce no new features, occur approximately every three months; these releases are made when a sufficient number of b... | https://en.wikipedia.org/wiki/Python_(programming_language) |
cumentation generators ==
Tools that can generate documentation for Python API include pydoc (available as part of the standard library); Sphinx; and Pdoc and its forks, Doxygen and Graphviz.
== Naming ==
Python's name is inspired by the British comedy group Monty Python, whom Python creator Guido van Rossum enjoyed ... | https://en.wikipedia.org/wiki/Python_(programming_language) |
n respectively;
PyPy, a Python implementation originally written in Python;
NumPy, a Python library for numerical processing.
== Popularity ==
Since 2003, Python has consistently ranked in the top ten of the most popular programming languages in the TIOBE Programming Community Index; as of December 2022, Python was t... | https://en.wikipedia.org/wiki/Python_(programming_language) |
rary, and application in data science and machine learning fields.
Large organizations that use Python include Wikipedia, Google, Yahoo!, CERN, NASA, Facebook, Amazon, Instagram, Spotify, and some smaller entities such as Industrial Light & Magic and ITA. The social news networking site Reddit was developed mostly in ... | https://en.wikipedia.org/wiki/Python_(programming_language) |
Django, Pylons, Pyramid, TurboGears, web2py, Tornado, Flask, Bottle, and Zope support developers in the design and maintenance of complex applications. Pyjs and IronPython can be used to develop the client-side of Ajax-based applications. SQLAlchemy can be used as a data mapper to a relational database. Twisted is a fr... | https://en.wikipedia.org/wiki/Python_(programming_language) |
cessing.
Python is commonly used in artificial-intelligence and machine-learning projects, with support from libraries such as TensorFlow, Keras, Pytorch, scikit-learn and ProbLog (a logic language). As a scripting language with a modular architecture, simple syntax, and rich text processing tools, Python is often used... | https://en.wikipedia.org/wiki/Python_(programming_language) |
to-text generators such as GPT3, and text-to-image generators such as DALL-E or Stable Diffusion.
Python can be used for graphical user interfaces (GUIs), by using libraries such as Tkinter. Similarly, for the One Laptop per Child XO computer, most of the Sugar desktop environment is written in Python (as of 2008).
Pyt... | https://en.wikipedia.org/wiki/Python_(programming_language) |
s Python as the best choice for writing scripts in ArcGIS. Python has also been used in several video games, and it has been adopted as first of the three programming languages available in Google App Engine (the other two being Java and Go). LibreOffice includes Python, and its developers plan to replace Java with Pyt... | https://en.wikipedia.org/wiki/Python_(programming_language) |
installer. Gentoo Linux uses Python in its package management system, Portage.
Python is used extensively in the information security industry, including in exploit development.
== Languages influenced by Python ==
Python's design and philosophy have influenced many other programming languages:
Boo uses indentatio... | https://en.wikipedia.org/wiki/Python_(programming_language) |
Java.
Julia was designed to be "as usable for general programming as Python".
Mojo is a non-strict superset of Python (e.g., omitting classes, and adding struct).
Nim uses indentation and a similar syntax.
Ruby's creator, Yukihiro Matsumoto, said that "I wanted a scripting language that was more powerful than Perl, and... | https://en.wikipedia.org/wiki/Python_(programming_language) |
mantics
pip (package manager)
List of programming languages
History of programming languages
Comparison of programming languages
== Notes ==
== References ==
=== Sources ===
"Python for Artificial Intelligence". Python Wiki. 19 July 2012. Archived from the original on 1 November 2012. Retrieved 3 December 2012.
P... | https://en.wikipedia.org/wiki/Python_(programming_language) |
Summerfield, Mark (2009). Programming in Python 3 (2nd ed.). Addison-Wesley Professional. ISBN 978-0-321-68056-3.
Ramalho, Luciano (May 2022). Fluent Python. O'Reilly Media. ISBN 978-1-4920-5632-4.
== External links ==
Official website
The Python Tutorial | https://en.wikipedia.org/wiki/Python_(programming_language) |
In computer science, array programming refers to solutions that allow the application of operations to an entire set of values at once. Such solutions are commonly used in scientific and engineering settings.
Modern programming languages that support array programming (also known as vector or multidimensional language... | https://en.wikipedia.org/wiki/Array_programming |
not uncommon to find array programming language one-liners that require several pages of object-oriented code.
== Concepts of array ==
The fundamental idea behind array programming is that operations apply at once to an entire set of values. This makes it a high-level programming model as it allows the programmer to ... | https://en.wikipedia.org/wiki/Array_programming |
notation. it is important to distinguish the difficulty of describing and of learning a piece of notation from the difficulty of mastering its implications. For example, learning the rules for computing a matrix product is easy, but a mastery of its implications (such as its associativity, its distributivity over addit... | https://en.wikipedia.org/wiki/Array_programming |
t algorithm.
The basis behind array programming and thinking is to find and exploit the properties of data where individual elements are similar or adjacent. Unlike object orientation which implicitly breaks down data to its constituent parts (or scalar quantities), array orientation looks to group data and apply a uni... | https://en.wikipedia.org/wiki/Array_programming |
ity of an input data array by one or more dimensions. For example, summing over elements collapses the input array by 1 dimension.
== Uses ==
Array programming is very well suited to implicit parallelization; a topic of much research nowadays. Further, Intel and compatible CPUs developed and produced after 1997 conta... | https://en.wikipedia.org/wiki/Array_programming |
common as of 2023.
== Languages ==
The canonical examples of array programming languages are Fortran, APL, and J. Others include: A+, Analytica, Chapel, IDL, Julia, K, Klong, Q, MATLAB, GNU Octave, Scilab, FreeMat, Perl Data Language (PDL), R, Raku, S-Lang, SAC, Nial, ZPL, Futhark, and TI-BASIC.
=== Scalar languag... | https://en.wikipedia.org/wiki/Array_programming |
ing techniques of vectorization (i.e., utilizing a CPU's vector-based instructions if it has them or by using multiple CPU cores). Some C compilers like GCC at some optimization levels detect and vectorize sections of code that its heuristics determine would benefit from it. Another approach is given by the OpenMP API,... | https://en.wikipedia.org/wiki/Array_programming |
quently encountered during the same execution, causing unnecessary repeated lookups.) Even the most sophisticated optimizing compiler would have an extremely hard time amalgamating two or more apparently disparate functions which might appear in different program sections or sub-routines, even though a programmer could... | https://en.wikipedia.org/wiki/Array_programming |
nipulation in its third edition (1966).
==== Mata ====
Stata's matrix programming language Mata supports array programming. Below, we illustrate addition, multiplication, addition of a matrix and a scalar, element by element multiplication, subscripting, and one of Mata's many inverse matrix functions.
==== MATLAB ... | https://en.wikipedia.org/wiki/Array_programming |
n vector of size [n 1].
a * b;
By contrast, the entrywise product is implemented as:
a .* b;
The inner product between two matrices having the same number of elements can be implemented with the auxiliary operator (:), which reshapes a given matrix into a column vector, and the transpose operator ':
A(:)' * B(:);
... | https://en.wikipedia.org/wiki/Array_programming |
ng and language notation ==
The matrix left-division operator concisely expresses some semantic properties of matrices. As in the scalar equivalent, if the (determinant of the) coefficient (matrix) A is not null then it is possible to solve the (vectorial) equation A * x = b by left-multiplying both sides by the invers... | https://en.wikipedia.org/wiki/Array_programming |
nverse A−1, as follows:
pinv(A) *(A * x)==pinv(A) * (b)
(pinv(A) * A)* x ==pinv(A) * b (matrix-multiplication associativity)
x = pinv(A) * b
However, these solutions are neither the most concise ones (e.g. still remains the need to notationally differentiate overdetermined systems) nor the most computationally ... | https://en.wikipedia.org/wiki/Array_programming |
with the scalar case, therefore simplifying the mathematical reasoning and preserving the conciseness:
A \ (A * x)==A \ b
(A \ A)* x ==A \ b (associativity also holds for matrices, commutativity is no more required)
x = A \ b
This is not only an example of terse array programming from the coding point of view bu... | https://en.wikipedia.org/wiki/Array_programming |
tions and geometric operations) is a different and much more difficult matter.
Indeed, the very suggestiveness of a notation may make it seem harder to learn because of the many properties it suggests for explorations.
== Third-party libraries ==
The use of specialized and efficient libraries to provide more terse ab... | https://en.wikipedia.org/wiki/Array_programming |
Defensive programming is a form of defensive design intended to develop programs that are capable of detecting potential security abnormalities and make predetermined responses. It ensures the continuing function of a piece of software under unforeseen circumstances. Defensive programming practices are often used where... | https://en.wikipedia.org/wiki/Defensive_programming |
e subset of defensive programming concerned with computer security. Security is the concern, not necessarily safety or availability (the software may be allowed to fail in certain ways). As with all kinds of defensive programming, avoiding bugs is a primary objective; however, the motivation is not as much to reduce th... | https://en.wikipedia.org/wiki/Defensive_programming |
y of defensive programming, with the added emphasis that certain errors should not be handled defensively. In this practice, only errors from outside the program's control are to be handled (such as user input); the software itself, as well as data from within the program's line of defense, are to be trusted in this me... | https://en.wikipedia.org/wiki/Defensive_programming |
ith it all the security and vulnerabilities of the reused code.
When considering using existing source code, a quick review of the modules(sub-sections such as classes or functions) will help eliminate or make the developer aware of any potential vulnerabilities and ensure it is suitable to use in the project.
==== ... | https://en.wikipedia.org/wiki/Defensive_programming |
wly designed source code.
Legacy code may have been written and tested under conditions which no longer apply. The old quality assurance tests may have no validity any more.
Example 1: legacy code may have been designed for ASCII input but now the input is UTF-8.
Example 2: legacy code may have been compiled and tested... | https://en.wikipedia.org/wiki/Defensive_programming |
rewrite", "Security was a key consideration in design", naming security, robustness, scalability and new protocols as key concerns for rewriting old legacy code.
Microsoft Windows suffered from "the" Windows Metafile vulnerability and other exploits related to the WMF format. Microsoft Security Response Center describe... | https://en.wikipedia.org/wiki/Defensive_programming |
ations (largely a legacy from old versions) are not aligned with their own security recommendations, such as Oracle Database Security Checklist, which is hard to amend as many applications require the less secure legacy settings to function correctly.
=== Canonicalization ===
Malicious users are likely to invent new ... | https://en.wikipedia.org/wiki/Defensive_programming |
=== Other ways of securing code ===
One of the most common problems is unchecked use of constant-size or pre-allocated structures for dynamic-size data such as inputs to the program (the buffer overflow problem). This is especially common for string data in C. C library functions like gets should never be used since t... | https://en.wikipedia.org/wiki/Defensive_programming |
insecure until proven otherwise.
You cannot prove the security of any code in userland, or, more commonly known as: "never trust the client".
These three rules about data security describe how to handle any data, internally or externally sourced:
All data is important until proven otherwise - means that all data must b... | https://en.wikipedia.org/wiki/Defensive_programming |
o called assertive programming)
Prefer exceptions to return codes
Generally speaking, it is preferable to throw exception messages that enforce part of your API contract and guide the developer instead of returning error code values that do not point to where the exception occurred or what the program stack looked like... | https://en.wikipedia.org/wiki/Defensive_programming |
Generic programming is a style of computer programming in which algorithms are written in terms of data types to-be-specified-later that are then instantiated when needed for specific types provided as parameters. This approach, pioneered in the programming language ML in 1973, permits writing common functions or data ... | https://en.wikipedia.org/wiki/Generic_programming |
cs in Ada, C#, Delphi, Eiffel, F#, Java, Nim, Python, Go, Rust, Swift, TypeScript, and Visual Basic (.NET). They are known as parametric polymorphism in ML, Scala, Julia, and Haskell. (Haskell terminology also uses the term generic for a related but somewhat different concept.)
The term generic programming was original... | https://en.wikipedia.org/wiki/Generic_programming |
algorithms to obtain generic algorithms that can be combined with different data representations to produce a wide variety of useful software.
The "generic programming" paradigm is an approach to software decomposition whereby fundamental requirements on types are abstracted from across concrete examples of algorithms ... | https://en.wikipedia.org/wiki/Generic_programming |
giving N × M combinations to implement. However, in the generic programming approach, each data structure returns a model of an iterator concept (a simple value type that can be dereferenced to retrieve the current value, or changed to point to another value in the sequence) and each algorithm is instead written gener... | https://en.wikipedia.org/wiki/Generic_programming |
structure will return a model of the most general concept that can be implemented efficiently—computational complexity requirements are explicitly part of the concept definition. This limits the data structures a given algorithm can be applied to and such complexity requirements are a major determinant of data structur... | https://en.wikipedia.org/wiki/Generic_programming |
ieve that iterator theories are as central to Computer Science as theories of rings or Banach spaces are central to Mathematics.
Bjarne Stroustrup noted,
Following Stepanov, we can define generic programming without mentioning language features: Lift algorithms and data structures from concrete examples to their most ... | https://en.wikipedia.org/wiki/Generic_programming |
age support for genericity ==
Genericity facilities have existed in high-level languages since at least the 1970s in languages such as ML, CLU and Ada, and were subsequently adopted by many object-based and object-oriented languages, including BETA, C++, D, Eiffel, Java, and DEC's now defunct Trellis-Owl.
Genericity is... | https://en.wikipedia.org/wiki/Generic_programming |
value assignment are type-indifferent and such behavior is often used for abstraction or code terseness, however this is not typically labeled genericity as it's a direct consequence of the dynamic typing system employed by the language. The term has been used in functional programming, specifically in Haskell-like la... | https://en.wikipedia.org/wiki/Generic_programming |
le programming languages try to unify built-in and user defined generic types.
A broad survey of genericity mechanisms in programming languages follows. For a specific survey comparing suitability of mechanisms for generic programming, see.
=== In object-oriented languages ===
When creating container classes in stati... | https://en.wikipedia.org/wiki/Generic_programming |
c usage of exchangeable sub-classes: for instance, a list of objects of type Moving_Object containing objects of type Animal and Car. Templates can also be used for type-independent functions as in the Swap example below:
The C++ template construct used above is widely cited as the genericity construct that popularize... | https://en.wikipedia.org/wiki/Generic_programming |
1980. The standard library uses generics to provide many services. Ada 2005 adds a comprehensive generic container library to the standard library, which was inspired by C++'s Standard Template Library.
A generic unit is a package or a subprogram that takes one or more generic formal parameters.
A generic formal parame... | https://en.wikipedia.org/wiki/Generic_programming |
g an instance of a generic package:
===== Advantages and limits =====
The language syntax allows precise specification of constraints on generic formal parameters. For example, it is possible to specify that a generic formal type will only accept a modular type as the actual. It is also possible to express constraint... | https://en.wikipedia.org/wiki/Generic_programming |
sequences:
the compiler can implement shared generics: the object code for a generic unit can be shared between all instances (unless the programmer requests inlining of subprograms, of course). As further consequences:
there is no possibility of code bloat (code bloat is common in C++ and requires special care, as ex... | https://en.wikipedia.org/wiki/Generic_programming |
a does not permit arbitrary computation at compile time, because operations on generic arguments are performed at runtime.
==== Templates in C++ ====
C++ uses templates to enable generic programming techniques. The C++ Standard Library includes the Standard Template Library or STL that provides a framework of templa... | https://en.wikipedia.org/wiki/Generic_programming |
ions that return either x or y, whichever is larger. max() could be defined like this:
Specializations of this function template, instantiations with specific types, can be called just like an ordinary function:
The compiler examines the arguments used to call max and determines that this is a call to max(int, int).... | https://en.wikipedia.org/wiki/Generic_programming |
a minor benefit in this isolated example, in the context of a comprehensive library like the STL it allows the programmer to get extensive functionality for a new data type, just by defining a few operators for it. Merely defining < allows a type to be used with the standard sort(), stable_sort(), and binary_search() a... | https://en.wikipedia.org/wiki/Generic_programming |
nerate somewhat esoteric, long, and unhelpful error messages for this sort of error. Ensuring that a certain object adheres to a method protocol can alleviate this issue. Languages which use compare instead of < can also use complex values as keys.
Another kind of template, a class template, extends the same concept to... | https://en.wikipedia.org/wiki/Generic_programming |
ecialization has two purposes: to allow certain forms of optimization, and to reduce code bloat.
For example, consider a sort() template function. One of the primary activities that such a function does is to swap or exchange the values in two of the container's positions. If the values are large (in terms of the numbe... | https://en.wikipedia.org/wiki/Generic_programming |
function templates, class templates can be partially specialized. That means that an alternate version of the class template code can be provided when some of the template parameters are known, while leaving other template parameters generic. This can be used, for example, to create a default implementation (the primar... | https://en.wikipedia.org/wiki/Generic_programming |
formerly filled by function-like preprocessor macros (a legacy of the C language). For example, here is a possible implementation of such macro:
Macros are expanded (copy pasted) by the preprocessor, before program compiling; templates are actual real functions. Macros are always expanded inline; templates can also b... | https://en.wikipedia.org/wiki/Generic_programming |
de bloat:
Templates in C++ lack many features, which makes implementing them and using them in a straightforward way often impossible. Instead programmers have to rely on complex tricks which leads to bloated, hard to understand and hard to maintain code. Current developments in the C++ standards exacerbate this probl... | https://en.wikipedia.org/wiki/Generic_programming |
the compiler to generate a separate instance of the templated class or function for every type parameters used with it. (This is necessary because types in C++ are not all the same size, and the sizes of data fields are important to how classes work.) So the indiscriminate use of templates can lead to code bloat, resul... | https://en.wikipedia.org/wiki/Generic_programming |
require rewriting of an entire class for a specific template parameters used by it.
The extra instantiations generated by templates can also cause some debuggers to have difficulty working gracefully with templates. For example, setting a debug breakpoint within a template from a source file may either miss setting the... | https://en.wikipedia.org/wiki/Generic_programming |
ct its use in closed-source projects.
==== Templates in D ====
The D language supports templates based in design on C++. Most C++ template idioms work in D without alteration, but D adds some functionality:
Template parameters in D are not restricted to just types and primitive values (as it was in C++ before C++20)... | https://en.wikipedia.org/wiki/Generic_programming |
nt syntax than in C++: whereas in C++ template parameters are wrapped in angular brackets (Template<param1, param2>),
D uses an exclamation sign and parentheses: Template!(param1, param2).
This avoids the C++ parsing difficulties due to ambiguity with comparison operators.
If there is only one parameter, the parenthese... | https://en.wikipedia.org/wiki/Generic_programming |
me reflection allows enumerating and inspecting declarations and their members during compiling.
User-defined attributes allow users to attach arbitrary identifiers to declarations, which can then be enumerated using compile-time reflection.
Compile-time function execution (CTFE) allows a subset of D (restricted to saf... | https://en.wikipedia.org/wiki/Generic_programming |
iven a function that takes a string containing an HTML template and returns equivalent D source code, it is possible to use it in the following way:
==== Genericity in Eiffel ====
Generic classes have been a part of Eiffel since the original method and language design. The foundation publications of Eiffel, use the t... | https://en.wikipedia.org/wiki/Generic_programming |
for G in actual use.
Within the Eiffel type system, although class LIST [G] is considered a class, it is not considered a type. However, a generic derivation of LIST [G] such as LIST [ACCOUNT] is considered a type.
===== Constrained genericity =====
For the list class shown above, an actual generic parameter substi... | https://en.wikipedia.org/wiki/Generic_programming |
le time for type correctness. The generic type information is then removed via a process called type erasure, to maintain compatibility with old JVM implementations, making it unavailable at runtime. For example, a List<String> is converted to the raw type List. The compiler inserts type casts to convert the elements t... | https://en.wikipedia.org/wiki/Generic_programming |
of the limits of erasure (such as being unable to create generic arrays). This also means that there is no performance hit from runtime casts and normally expensive boxing conversions. When primitive and value types are used as generic arguments, they get specialized implementations, allowing for efficient generic coll... | https://en.wikipedia.org/wiki/Generic_programming |
ts the generic IComparable<T> interface. This ensures a compile time error, if the method is called if the type does not support comparison. The interface provides the generic method CompareTo(T).
The above method could also be written without generic types, simply using the non-generic Array type. However, since array... | https://en.wikipedia.org/wiki/Generic_programming |
==== Genericity in Pascal ====
For Pascal, generics were first implemented in 2006, in the implementation Free Pascal.
===== In Delphi =====
The Object Pascal dialect Delphi acquired generics in the 2007 Delphi 11 release by CodeGear, initially only with the .NET compiler (since discontinued) before being added to t... | https://en.wikipedia.org/wiki/Generic_programming |
s constructor. Multiple constraints act as an additive union.
===== In Free Pascal =====
Free Pascal implemented generics in 2006 in version 2.2.0, before Delphi and with different syntax and semantics. However, since FPC version 2.6.0, the Delphi-style syntax is available when using the language mode {$mode Delphi}.... | https://en.wikipedia.org/wiki/Generic_programming |
thods as is usually necessary when declaring class instances. All the necessary methods will be "derived" – that is, constructed automatically – based on the structure of the type. For example, the following declaration of a type of binary trees states that it is to be an instance of the classes Eq and Show:
This resu... | https://en.wikipedia.org/wiki/Generic_programming |
fect can be achieved for user-defined type classes by certain programming techniques. Other researchers have proposed approaches to this and other kinds of genericity in the context of Haskell and extensions to Haskell (discussed below).
===== PolyP =====
PolyP was the first generic programming language extension to ... | https://en.wikipedia.org/wiki/Generic_programming |
as an example:
===== Generic Haskell =====
Generic Haskell is another extension to Haskell, developed at Utrecht University in the Netherlands. The extensions it provides are:
Type-indexed values are defined as a value indexed over the various Haskell type constructors (unit, primitive types, sums, products, and use... | https://en.wikipedia.org/wiki/Generic_programming |
is applied.
Generic abstraction enables generic definitions be defined by abstracting a type parameter (of a given kind).
Type-indexed types are types that are indexed over the type constructors. These can be used to give types to more involved generic values. The resulting type-indexed types can be specialized to any... | https://en.wikipedia.org/wiki/Generic_programming |
dule may take one or more parameters, to which their actual values are assigned upon the instantiation of the module. One example is a generic register array where the array width is given via a parameter. Such an array, combined with a generic wire vector, can make a generic buffer or memory module with an arbitrary b... | https://en.wikipedia.org/wiki/Generic_programming |
cture Notes in Computer Science. Vol. 4719. Heidelberg: Springer. pp. 1–71. CiteSeerX 10.1.1.159.1228.
Meyer, Bertrand (1986). "Genericity versus inheritance". Conference proceedings on Object-oriented programming systems, languages and applications - OOPSLA '86. pp. 391–405. doi:10.1145/28697.28738. ISBN 0897912047. S... | https://en.wikipedia.org/wiki/Generic_programming |
wers Guide," October 2008, Embarcadero Developer Network, Embarcadero.
Craig Stuntz, "Delphi 2009 Generics and Type Constraints," October 2008
Dr. Bob, "Delphi 2009 Generics"
Free Pascal: Free Pascal Reference guide Chapter 8: Generics, Michaël Van Canneyt, 2007
Delphi for Win32: Generics with Delphi 2009 Win32, Sébast... | https://en.wikipedia.org/wiki/Generic_programming |
ical Design Pattern for Generic Programming," In Proceedings of the ACM SIGPLAN International Workshop on Types in Language Design and Implementation (TLDI'03), 2003. (Also see the website devoted to this research)
Andres Löh, Exploring Generic Haskell, PhD thesis, 2004 Utrecht University. ISBN 90-393-3765-9
Generic Ha... | https://en.wikipedia.org/wiki/Generic_programming |
Procedural programming is a programming paradigm, classified as imperative programming, that involves implementing the behavior of a computer program as procedures (a.k.a. functions, subroutines) that call each other. The resulting program is a series of steps that forms a hierarchy of calls to its constituent procedur... | https://en.wikipedia.org/wiki/Procedural_programming |
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