Editing Specification language

{{Short description|Formal language used in computer science}}
{{Refimprove|date=August 2016}}
A '''specification language''' is a [[formal language]] in [[computer science]] used during [[systems analysis]], [[requirements analysis]], and [[systems design]] to describe a system at a much higher level than a [[programming language]], which is used to produce the executable code for a system.<ref>[[Joseph Goguen]]
"One, None, A Hundred Thousand Specification Languages" Invited Paper, [[IFIP]] Congress 1986 pp 995-1004</ref>
==Overview==
Specification languages are generally not directly executed. They are meant to describe the ''what'', not the ''how''. It is considered an error if a requirement specification is cluttered with unnecessary implementation detail.

A common fundamental assumption of many specification approaches is that programs are modelled as [[algebra]]ic or [[model theory|model-theoretic]] structures that include a collection of [[set (mathematics)|sets]] of data values together with [[function (mathematics)|functions]] over those sets.  This level of abstraction coincides with the view that the correctness of the input/output behaviour of a program takes precedence over all its other properties.

In the ''property-oriented'' approach to specification (taken e.g. by [[Common Algebraic Specification Language|CASL]]), specifications of programs consist mainly of logical [[axiom]]s, usually in a [[logical system]] in which equality has a prominent role, describing the properties that the functions are required to satisfy—often just by their interrelationship.
This is in contrast to so-called [[model-based specification|model-oriented specification]] in frameworks like [[Vienna Development Method|VDM]] and [[Z notation|Z]], which consist of a simple realization of the required behaviour.

Specifications must be subject to a process of ''refinement'' (the filling-in of implementation detail) before they can actually be implemented. The result of such a refinement process is an executable algorithm, which is either formulated in a programming language, or in an executable subset of the specification language at hand. For example, [[Hartmann pipeline]]s, when properly applied, may be considered a [[dataflow]] specification which ''is'' directly executable.  Another example is the [[actor model]] which has no specific application content and must be ''specialized'' to be executable.

An important use of specification languages is enabling the creation of [[Mathematical proof|proof]]s of [[program correctness]] (''see [[Automated theorem prover|theorem prover]]'').

==Languages==
{{main article|:Category:Formal specification languages}}
{{div col|content=
*[[ANSI/ISO C Specification Language|ACSL]]
*[[Attempto Controlled English]]<ref>{{cite book |last1=Fuchs |first1=Norbert E. |first2=Uta |last2=Schwertel |first3=Rolf |last3=Schwitter |chapter=Attempto Controlled English—not just another logic specification language |chapter-url=ftp://nozdr.ru/biblio/kolxo3/Cs/CsLn/Logic%20Programming%20Synthesis%20and%20Transformation,%208%20conf.,%20LOPSTR'98(LNCS1559,%20Springer,%201990)(ISBN%203540657657)(340s).pdf#page=10 |title=International Workshop on Logic Programming Synthesis and Transformation |publisher=Springer |series=Lecture Notes in Computer Science |volume=1559 |year=1998 |isbn=978-3-540-65765-1 |pages=1–20 |doi=10.1007/3-540-48958-4_1}}</ref>
*[[Common Algebraic Specification Language|CASL]]
*[[Vienna Development Method|VDM]]
*[[Z notation]]
*[[TLA+]]
*FizzBee (Python'ish design specification language)<ref>{{cite web |url=https://fizzbee.io/ |title=Easiest-ever formal methods language for developers crafting distributed systems, microservices, and cloud applications |accessdate=May 28, 2024}}</ref>
*[[Lepus3|LePUS3]] (a visual, object-oriented design description language)
*[[Perfect Developer|Perfect]]
*[[Alloy (specification language)|Alloy]]
*[[Language Of Temporal Ordering Specification|LOTOS]]
*[[E-LOTOS]]
*[[MML (programming language)|MML]]
*Refine Language<ref>{{cite book|last=Linden|first=Theodore|author2=Lawrence Markosian|chapter=Transformational Synthesis Using Refine |editor-first=Mark |editor-last=Richer |title=AI Tools and Techniques|date=1989|publisher=Ablex|isbn=0-89391-494-0|pages=261–286|chapter-url=https://books.google.com/books?id=iMUfTzVuasUC&q=Simkit+Intellicorp&pg=PA245|access-date=6 July 2014}}</ref>
*[[SequenceL]]
*[[Symbolic Model Verification|SMV]]
*[[Specification and Design Language|SDL]]
*[[B-Method]]
}}

==See also==
*[[Formal specification]]
*[[Language-independent specification]]
*[[Pseudocode]]
*[[Specification and Description Language]]
*[[Unified Modeling Language]]

==References==
{{Reflist}}

==External links==
*{{Commonscatinline|Specification languages}}

{{Computer language}}

[[Category:Specification languages| ]]
[[Category:Computer languages]]
[[Category:Scientific modelling]]
[[Category:Formal specification]]