Programming Paradigm

Paradigm originally meant something like 'exemplar'/'pattern'/'template' but in the last 30 years has come to mean something more like 'zeitgeist'/'worldview'. In the former sense, ThereAreExactlyThreeParadigms, this page as about the second sense, but it will be useful to give the defining example of each way of thinking. In no particular order

A programming paradigm provides for the programmer the means and structure for the execution of a program.

Programmers can think of programs

• In ObjectOrientedProgramming
  • as a collection of interacting objects

• In FunctionalProgramming
  • as a sequence of stateless function evaluations

Many programming paradigms are as well-known for what they do not do as for what they do. This avoidance of certain techniques can make it easier to prove theorems about a program's correctness and to simply understand its behavior, without limiting it.

• PureFunctionalProgramming
  • disallows the use of side-effects

• Structured programming
  • disallows the use of goto.

Programming languages advocate different paradigms

• Languages designed
  • to support object-oriented programming
    • SmalltalkLanguage
    • JavaLanguage
  • to support functional programming
    • HaskellLanguage
    • SchemeLanguage

• Other programming languages designed
  • to support multiple paradigms
    • CommonLisp,
    • PythonLanguage
    • OzLanguage
    • RubyLanguage
  • to support SeparationOfConcerns - AspectOrientedProgramming
    • AspectJay
    • IoLanguage

• CollectionOrientedProgramming
  • programming using operations on entire collections, avoiding loops
  • languages supporting this paradigm are intrinsically suitable to both sequential and parallel/distributed execution
    • SetlLanguage
    • AplLanguage
    • JayLanguage
    • KayLanguage
    • Other query based languages

• AccessOrientedProgramming
  • using records with handlers attached to each variable/slot

• ConcatenativeProgramming
  • Based on a composition of functions to a single argument (usually a 2D stack)
    • ForthLanguage
    • MufLanguage
    • PostScript
    • JayLanguage
    • JoyLanguage

• ConceptOrientedProgramming
  • Based on a concept as the main programming construct
    • which is a pair, dual continuation methods
      • one object class
      • one reference class (see ConceptInCop).
    • It's life cycle is controlled by two pairs of dual creation/deletion methods
    • Two types of methods distinguished in any system:
      • paradigm which also includes ConceptOrientedModel.
    • More information can be found on the concept-oriented portal
      • http://conceptoriented.org

• ConstraintProgramming and ConstraintLogicProgramming
  • based on LogicProgramming with constraints
    • OzLanguage

• DataflowProgramming
  • based on FlowBasedProgramming
    • PrographLanguage
    • GeeLanguage

• DeclarativeProgramming
  • based on writing computer programs by specifying what the programs should do, and not how they should do it
  • declarative programs are ExecutableSpecifications
  • Emphasizes programming without explicit state
    • SingleAssignmentLanguages
    • FunctionalProgramming
    • LogicProgramming
    • ConstraintProgramming
    • MercuryLanguage
    • PrologLanguage

• DesignByContract* (EiffelLanguage)
• still OO.

• EventDrivenProgramming
  • Does 2iota (http://catseye.mine.nu:8080/) count?
    • TclTk

• EquationalProgramming (KjuLanguage (Q - Is kju the correct WikiWord?))
  • Extension of functional programming.

• FormalLanguages ?

• FunctionalProgramming
  • 'Functional programming is a style of programming that emphasizes the evaluation of expressions, rather than execution of commands. The expressions in these language are formed by using functions to combine basic values. A functional language is a language that supports and encourages programming in a functional style.' (from the FP FAQ)
  • see CategoryFunctionalProgramming
    • HaskellLanguage
    • MlLanguage

• GenerativeProgramming
  • Most commonly the idea that there are multiple views of a single piece of code
  • that it is best to separate these out (potentially in languages/paradigms)
  • and let the compiler worry about putting these together.
  • The separate pieces are meant to capture your intent more succinctly.
    • AspectOrientedProgramming
    • IntentionalProgramming
    • HyperSpace.

• GeneticProgramming - EvolutionaryProgramming
  • using generic optimization methods (usually GeneticAlgorithms ,
  • also SimulatedAnnealing and the like to generate programs which evolve to match a specification
  • or complete a task.
  • Akin to DeclarativeProgramming in that you try to specify the 'what' but not the 'how'.

• LogicProgramming - DeclarativeProgramming
  • using logic, specifically the PredicateCalculus.
    • PrologLanguage
    • MercuryLanguage)

• MessagePassingConcurrency - CommunicatingSequentialProcesses
  • Concurrency expressed by passing messages between processes or active objects
    • OccamLanguage
    • ErlangLanguage
    • ActorLanguages)

• FlowBasedProgramming
  • a type of MessagePassingConcurrency
  • the primary application development tool is not a language as such, but basically a list of connections defining a network of communicating components.

• TermRewriteSystems
  • powerful for modeling and theorem proving. "Variables" describe whole domains rather than individual elements. Rules are often bi-directional, allowing expansions before reductions. A program is an functional application that gets reduced to canonical form. Falls somewhere between LogicProgramming and FunctionalProgramming.
    • MaudeLanguage
    • ObjLanguage

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ModularProgramming

• ObjectBasedProgramming and ComponentBasedProgramming
  • Distinguished from OO typically by a lack of inheritance for the 'components', but still a version of OO.
    • Early versions of VisualBasic

• ObjectOrientedProgramming
  • Characterized by encapsulation, inheritance, and polymorphism, though see ObjectOrientedProgramming for a fuller discussion.
    • SmalltalkLanguage
    • CommonLispObjectSystem
    • SimulaLanguage

• ProceduralProgramming
  • Characterized by having procedures, functions, and ADTs
  • usually no inheritance, encapsulation, or polymorphism
    • PascalLanguage
    • AlgolLanguage
    • ModulaTwo)

• PrototypeBasedProgramming
  • A version of OO but characterized by cloning objects to obtain instances which can then be customized
    • SelfLanguage
    • IoLanguage
    • JavaScript

• ReflectiveProgramming
  • See http://www.tunes.org/

• RelationalLanguage
  • Programming based on the RelationalAlgebra / RelationalModel. See also TableOrientedProgramming
    • StructuredQueryLanguage
    • BusinessSystemTwelve
    • TutorialDee

• StringProgramming - ScriptingLanguage
  • EverythingIsa string: text constants are the universal media both for the program and all the data.
  • Easy handling for external programs (a feature which came from job control languages).
  • Rich string/text processing features
  • including RegularExpressions etc - Obviously this is obligatory when everything is a string
  • Eval feature, that is, the possibility to form a string and apply the language interpreter to it as a code
  • See DynamicStringsVsFunctional for examples
    • PerlLanguage
    • ToolCommandLanguage
    • AwkLanguage
    • RexxLanguage (maybe?)

• SetOrientedProgramming
  • related to ConstraintLogicProgramming and CollectionOrientedProgramming.
    • SetlLanguage

• StructuredProgramming
  • see also FunctionalDecomposition

• SymbolicProgramming
• A paradigm?
  • Well these can imitate most of the others (look at the StructureAndInterpretationOfComputerPrograms for examples of scheme doing OO, logic programming, and FunctionalProgramming)
  • perhaps these should not be listed separately from the 'pure' FunctionalLanguages
  • they are an important class of languages
  • Treat code as data and vice-versa.
    • LispLanguage
    • SchemeLanguage
    • PrologLanguage
    • SmalltalkLanguage)

• TableDrivenProgramming
  • classic example is the parsers constructed by YetAnotherCompilerCompiler.
  • most implementations of large FiniteStateMachines are built this way.
    • (no example languages)

• TableOrientedProgramming - CollectionOrientedProgramming
  • based on the RelationalModel

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• It's worth noting that a number of the styles above are
  • based more or less directly on mathematical models
    • LambdaCalculus
    • PredicateCalculus
    • RelationalCalculus
    • CommunicatingSequentialProcesses
  • While Other languages 'just happened'

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New paradigms are often not well received by those accustomed to earlier styles.

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A programming language can support multiple paradigms. CeePlusPlus is designed to support elements of procedural programming, object-based programming, object-oriented programming, functional programming, and generic programming.

Designers and programmers can decide how to build a program using any or a mix of these paradigm elements.

Thus a programmer can write a program in C++ that

• is a purely procedural program
• is a purely object-oriented program
• contains elements of both paradigms
• contains elements of functional programming
• uses methods of generic programming

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Related

• InformalHistoryOfProgrammingIdeas, GroundBreakingLanguages, MultiParadigmProgramming, MultiParadigmProgrammingLanguage, MixingParadigms, ParadigmsOfArtificialIntelligenceProgramming, WhenToUseWhatParadigm, WhatIsaParadigm

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AugustZeroSix

CategoryProgrammingLanguageComparisons CategoryRoadMap, CategoryMultiparadigm