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{{Short description|Design pattern in software development}}
{{for|the use in distributed object communication|Distributed object communication#Skeleton}}
{{redirect|Dummy code|dummy coding|Categorical variable}}
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Skeleton programming facilitates a [[Top-down and bottom-up design|top-down]] design approach, where a partially functional system with complete high-level structures is designed and coded, and this system is then progressively expanded to fulfill the requirements of the project. Program skeletons are also sometimes used for high-level descriptions of [[algorithm]]s. A program skeleton may also be utilized as a template that reflects syntax and structures commonly used in a wide class of problems.
Skeleton programs are utilized in the [[template method design pattern]] used in [[object-oriented programming]]. In [[object-oriented programming]], dummy code corresponds to an [[abstract method]], a [[method stub]] or a [[mock object]]. In the [[Java remote method invocation]] (Java RMI) nomenclature, a [[Stub (computer science)|stub]] communicates on the client-side with a skeleton on the [[server-side]].<ref>{{cite
| last1 = Freeman
| first1 = Eric
| last2 = Freeman
| first2 = Elisabeth
| last3 = Kathy
| first3 = Sierra
| last4 = Bert
| first4 = Bates
| editor1-last = Hendrickson
| editor1-first = Mike
| editor2-last = Loukides
| editor2-first = Mike
| year = 2004
| title = Head First Design Patterns
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| format = paperback
| isbn = 978-0-596-00712-6
|
| url = http://shop.oreilly.com/product/9780596007126.do
}}</ref>
A '''class skeleton''' is an outline of a [[class (computer science)|class]] that is used in [[software engineering]]. It contains a description of the class's roles, and describes the purposes of the [[Variable (programming)|variables]] and [[method (computer science)|method]]s, but does not implement them. The class is later [[implementation|implemented]] from the skeleton. The skeleton can also be known as either an [[Interface (computing)|interface]] or an [[abstract class]], with languages that follow a polymorphic paradigm.
== Background ==
Modern [[
Skeleton code is most commonly found in [[Parallel computing|parallel programming]], but is also applied in other situations, like [[documentation]] in [[Programming language|programming languages]]. This helps to simplify the core functionality of a potentially confusing method. It can also be used to allow for a small function within a larger program to operate without full functionality temporarily.▼
▲Skeleton code is most commonly found in [[Parallel computing|parallel programming]], but is also applied in other situations, like [[documentation]] in [[
This method of programming is easier than writing a complete function, as these skeleton functions do not have to include main functionalities and can instead be hardcoded to use during development. They usually involve syntactically correct code to introduce the method, as well as comments to indicate the operation of the program. This is not always necessary to call a piece of text skeleton code.
== Relation to
[[File:PXL 20201120 092248538.jpg|thumb|A generic example of pseudocode]]
[[Pseudocode]] is most commonly found when [[Plan|developing]] the structure of a new piece of [[software]]. It is a plain English portrayal of a particular function within a larger system, or can even be a representation of a whole program. Pseudocode is similar to skeleton programming, however deviates in the fact that pseudocode is primarily an informal method of programming.<ref name=":0">{{Cite journal|last=Bellamy|first=Rachel K. E.|date=1994-06-01|title=What Does Pseudo-Code Do? A Psychological Analysis of the use of Pseudo-Code by Experienced Programmers|url=https://www.tandfonline.com/doi/abs/10.1207/s15327051hci0902_3|journal=Human–Computer Interaction|volume=9|issue=2|pages=225–246|doi=10.1207/s15327051hci0902_3|issn=0737-0024|url-access=subscription}}</ref> Dummy code is also very similar to this, where code is used simply as a placeholder, or to signify the intended existence of a method in a class or interface.
[[Programmer|Computer programmers]] are extremely dependent on pseudocode, so much so that it has a measurable impact on their [[Psyche (psychology)|psyche]].<ref name=":0" /> A typical programmer is so conditioned with the idea of writing simplified code in some manner, be it by writing pseudocode or skeleton code, or even just by drawing a diagram, that this has a measurable impact on how well they can write their final implementation. This has been found over a number of applications, with different programmers working in different languages and varied [[
This method of program design is also most often done on pen and paper, further moving the text from what is actually to be implemented. Skeleton programming mimics this, but differs in the way that it is commonly written in an [[integrated development environment]], or [[
== Implementation ==
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=== Programming language documentation ===
[[Java (programming language)|Java]], an [[Object-oriented programming|object oriented language]], focuses heavily on a structured documentation page with completely separated methods for each object part of
Each method is defined in the same format, with the name of the method as well as the syntax to be used in
[[Python (programming language)|Python]] has a similar approach to document
=== Class definition ===
[[Class (computer programming)|Classes]] written by third-party developers, primarily as a part of libraries, also showcase their programming in the form of skeleton code. This helps to inform any that are new to the library as to how the functions and methods operate. [[P5.js|P5.Js]] uses this format on their documentation page to explain the intended use of certain included functions.<ref>{{Cite web|title=reference {{!}} p5.js|url=https://p5js.org/reference/#/p5/alpha|access-date=2020-11-15|website=p5js.org}}</ref>
[[Natural-language user interface|Natural Language Interfaces]] (NLIs) are most typically found in situations where programmers attempt to take an [[Input/output|input]], usually [[Colloquialism|colloquially]] termed (without the use of programming language specific [[jargon]]) and use this to create a program or a method. An implementation of this uses a small set of skeleton code to imply the function running in the background.<ref>{{Cite web|last=Granger|first=Chris|date=2020-11-18|title=A first peek at something new we're working on.|url=https://twitter.com/ibdknox/status/1328797793138266113
Other forms of NLIs use different forms of input, ranging from other users speaking different languages, to gesture based input to produce a very similar result. With programming languages being developed and written primarily in
===
[[Polymorphism (computer science)|Polymorphism]] is an ideology that follows with the [[
Very similar to class implementation, skeleton code can be used to define the methods that are part of an [[Interface (computing)|interface]]. An interface is essentially a [[blueprint]] of a class, which allows for strict object oriented languages (such as [[Java (programming language)|Java]]) to use classes from different [[Java package|packages]] without the need to fully understand the internal functions. Interfaces simply define the methods that have to be present within the class, allowing anyone else to use the methods or implement the class for their personal needs
<syntaxhighlight lang="java">
public skeletonExample();
</syntaxhighlight>
An [[abstract class]] is almost the same as a class implementation, however depending on the language, at least one method is defined as abstract. This implies that any children of this class (any classes that extend or implement) need to have a method defined for this. Abstract classes have a very similar definition style to interfaces, however a keyword ‘abstract’ is typically used to identify the fact that it needs to be implemented in child classes.
<syntaxhighlight lang="java">
public abstract skeletonExample();
</syntaxhighlight>
These examples use the [[Java syntax]].
== Parallel programming ==
[[Parallel computing|Parallel programming]] is the operation of multiple functions simultaneously most commonly used to increase efficiency. These are typically the hardest types of programs to develop, due to their complexity and interconnectedness with the [[Computer hardware|hardware]] in question as well. Many developers have attempted to write programs with this core functionality,<ref name=":1">{{Cite journal|
[[Algorithmic skeleton]] frameworks are used in parallel programming to abstractly describe the methods in question for later development. The frameworks are not limited to a single type, and each of these types have different purposes to increase the efficiency of the
=== Data-
These skeleton algorithms are used to develop programs that work on large data based software, usually identifying the connections between data for later use. Data parallel algorithms include ‘maps’, ‘forks’ and ‘reduces’ or ‘scans’.
* ‘Maps’ are the most commonly used data parallel algorithms, and typically involve a single operation completed on a large set of data. To increase efficiency, a number of data sets have this operation applied to them simultaneously, before the data is structured together again at the end.
* ‘Forks’ are similar to ‘maps’ but they use a different operation for certain data types. This is known as [[Data parallelism|multiple data parallelism]].<ref name=":1" />
* ‘Reduces’ or ‘scans’ are used to apply prefixes to a set of data, before then applying an operation upon the data. These are different to ‘maps’ as they have a set of partial results during the runtime of the method itself.
▲* ‘Reduces’ or ‘scans’ are used to apply prefixes to a set of data, before then applying an operation upon the data. These are different to ‘maps’ as they have a set of partial results during the runtime of the method itself.
These operations, as their name suggests, work on tasks. Each type of algorithm under this is different due to a change in the behaviour between tasks. Task parallel algorithms include ‘sequentials’, ‘farms’, ‘pipes’, ‘if’, ‘for’ and ‘while’.
▲=== '''Task-Parallel''' ===
▲These operations, as their name suggests, work on tasks. Each type of algorithm under this is different due to a change in the behaviour between tasks. Task parallel algorithms include ‘sequentials’, ‘farms’, ‘pipes’, ‘if’, ‘for’ and ‘while’.
* ‘Sequential’ closes and terminates a nested set of skeleton algorithms. The methods and programs that are part of the skeletons are included as terminating aspects of the program, before closing.
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* ‘If’ gives the program a conditional split of tasks, where a set of skeleton code is split into two main sections. A conditional statement is given to the program, therefore giving it a specified algorithm to follow.
* ‘For’ operates a task a number of times, both specified by the programmer, allowing for a more efficient set of code. The number of times that the code runs is a preset value, indicating that at [[Run-time type information|runtime]], this cannot be changed. It must complete the task the number of times given.
* ‘While’ is an algorithm very similar to the operation of a ‘for’ algorithm, where a task is completed a number of times. However, in ‘while’ algorithms, the program computes the task a number of times before a conditional statement is met. This means that the ‘while’ algorithm can perform its task a different number of times for each time it is run.
===
These skeletons are very different to the typical skeletons found above. ‘Resolution’ algorithms use a combination of methods to solve a specified problem. The
* ‘Divide and conquer’ uses a map skeleton as
*
{{Portal|Computer programming}}
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[[Category:Programming language topics]]
[[Category:Software]]
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