Specification language
Template:Short description Template:Refimprove 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.[1]
Overview
Specification languages are generally not directly executed. They are meant to describe the what, not the how.[2] 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 algebraic or model-theoretic structures that include a collection of sets of data values together with 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 CASL), specifications of programs consist mainly of logical axioms, 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-oriented specification in frameworks like VDM and the Z notation, 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 pipelines, 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.Script error: No such module "Unsubst".
An important use of specification languages is enabling the creation of proofs of program correctness (see theorem prover).Script error: No such module "Unsubst".
Languages
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- ACSL
- Attempto Controlled English[3]
- CASL
- VDM
- Z notation
- TLA+
- FizzBee (Python'ish design specification language)[4]
- LePUS3 (a visual, object-oriented design description language)Script error: No such module "Unsubst".
- Perfect
- Alloy
- LOTOS
- E-LOTOS
- MML
- Refine Language[5]
- Rosetta-lang
- SequenceL
- SMV
- SDL
- B-Method
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See also
- Formal specification
- Language-independent specification
- Pseudocode
- Specification and Description Language
- Unified Modeling Language
References
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- ↑ Joseph Goguen, "One, None, A Hundred Thousand Specification Languages" Invited Paper, IFIP Congress 1986, pp. 995–1004.
- ↑ Script error: No such module "Citation/CS1".
- ↑ Script error: No such module "citation/CS1".
- ↑ Script error: No such module "citation/CS1".
- ↑ Script error: No such module "citation/CS1".
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External links
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