Editing Interpreter pattern (section)

{{Short description|Approach in computer programming}}
{{Refimprove|date=November 2008}}

In [[computer programming]], the '''interpreter pattern''' is a [[design pattern (computer science)|design pattern]] that specifies how to evaluate sentences in a language.
The basic idea is to have a [[Class (computer science)|class]] for each symbol ([[Terminal symbol|terminal]] or [[Nonterminal symbol|nonterminal]]) in a [[Domain specific languages|specialized computer language]]. The [[abstract syntax tree|syntax tree]] of a sentence in the language is an instance of the [[composite pattern]] and is used to evaluate (interpret) the sentence for a client.<ref name=GoF>{{cite book |author1=Gamma, Erich |author2-link=Richard Helm |author2=Helm, Richard |author3=Johnson, Ralph |author4=Vlissides, John |
 title=Design Patterns: Elements of Reusable Object-Oriented Software |
 publisher=Addison-Wesley |
 year=1994 |
 isbn=0-201-63361-2
 |author1-link=Erich Gamma |title-link=Design Patterns }}</ref>{{rp|243}} See also [[Composite pattern]].