Editing Metalinguistic abstraction

{{Short description|Principle in computer science of domain-specific languages for problem solving}}
In [[computer science]], '''metalinguistic abstraction''' is the process of solving complex problems by creating a new [[Programming language|language]] or vocabulary to better understand the problem space. More generally, it also encompasses the ability or skill of a programmer to think outside of the pre-conceived notions of a specific language in order to exploratorily investigate a problem space in search of the kind of solutions which are most natural or cognitively ergonomic to it. It is a recurring theme in the seminal [[MIT Press|MIT]] textbook ''[[Structure and Interpretation of Computer Programs]]'', which uses [[Scheme (programming language)|Scheme]], a dialect of [[Lisp (programming language)|Lisp]], as a framework for constructing new languages.

==Explanation==
For example, consider modelling an airport inside a computer. The airport has elements like passengers, bookings, employees, budgets, planes, luggage, arrivals and departures, and transit services.

A [[procedural language|procedural]] (e.g. [[C (programming language)|C]]) programmer might create data structures to represent these elements of an airport and procedures or routines to operate on those data structures and update them, modelling the airport as a series of processes undergone by its various elements. E.g., bookings is a database used to keep passengers and planes synchronised via updates logged as arrivals and departures, budgets are similar but for money: airports  are a lot of things that need to get done in the right order to see that passengers get where they're going.

An [[object-oriented]] (e.g. [[Java (programming language)|Java]]) programmer might create [[object (computer science)|object]]s to represent the elements of the airport with [[Method (computer science)|method]]s which represent their behaviors, modelling the airport as a collection of possibly related things which characteristically interact with each other. E.g., passengers, employees, and planes possess location attributes which can be modified via applicable transit methods: transit services have methods to bring employees and passengers to and from airports, planes have methods to bring passengers along with themselves between different airports: airports are a grouping of things working together as intended.

A [[functional programming|functional]] (e.g. [[Scheme (programming language)|Scheme]]) programmer might create [[higher-order function]]s representing both the elements and behaviors or processes of the airport, modelling the airport as a map of relations between elements in its various domains and those in their assorted codomains. E.g., airports map budgets to bookings schedules, each of which is itself a map of elements to elements: balances of income and expenditure, and balances of arrivals and departures, each of which is, recursively, its own mapping of elements and their own mappings in kind, collectively comprising a set of morphisms: airports are, transitively, the evaluative transformation of a certain spacetime economy.

Finally, a metalinguistic programmer might abstract the problem by creating new [[domain-specific language]]s for modelling airports, with peculiar [[primitive (computer science)|primitives]] and [[type (computer science)|types]] for doing so. The new language could encompass any or all of the above approaches where most suitable,<ref name="SICP text">''Structure and Interpretation of Computer Programs, Part 4 — Metalinguistic Abstraction''</ref> potentially enabling the programmer to retain both the abstract generality of the functional model, the intuitive sensibility of the object model, and the detail-driven pragmatism of the procedural model.

Because the creation of [[functional programming|functional]] metalinguistic abstractions in [[imperative programming|non-functional]] languages can be cumbersome while the reverse is usually trivial (e.g. it is generally much easier to take a [[Side effect (programming)|side-effect-free]] programming abstraction and simply add effects to it than it is to take a stateful abstraction and work around or encapsulate its propagation of state), and because of the syntactic flexibility and [[referential transparency|referential safety]] of [[hygienic macro|functional macro]]s, metalinguistic programming is mostly idiomatic of functional programming languages.

==See also==
* {{annotated link|Domain-specific language}}
* {{annotated link|Domain-specific multimodeling}}
* {{annotated link|Language-oriented programming}}
* {{annotated link|Metacompiler}}
* {{annotated link|Metalanguage}}
* {{annotated link|Metalinguistic awareness}}

==References==
<references />

{{DEFAULTSORT:Metalinguistic Abstraction}}
[[Category:Programming paradigms]]