Editing Interpreter pattern (section)

== Structure ==
=== UML class and object diagram ===
[[File:w3sDesign Interpreter Design Pattern UML.jpg|frame|none|A sample UML class and object diagram for the Interpreter design pattern.<ref>{{cite web|title=The Interpreter design pattern - Structure and Collaboration|url=http://w3sdesign.com/?gr=b03&ugr=struct|website=w3sDesign.com|access-date=2017-08-12}}</ref>]]

In the above [[Unified Modeling Language|UML]] [[class diagram]], the <code>Client</code> class refers to the common <code>AbstractExpression</code> interface for interpreting an expression
<code>interpret(context)</code>.
<br>
The <code>TerminalExpression</code> class has no children and interprets an expression directly.
<br>
The <code>NonTerminalExpression</code> class maintains a container of child expressions
(<code>expressions</code>) and forwards interpret requests
to these <code>expressions</code>.
<br>

The object collaboration diagram 
shows the run-time interactions: The <code>Client</code> object sends an interpret request to the abstract syntax tree.
The request is forwarded to (performed on) all objects downwards the tree structure.
<br>The <code>NonTerminalExpression</code> objects (<code>ntExpr1,ntExpr2</code>) forward the request to their child expressions.
<br>The <code>TerminalExpression</code> objects (<code>tExpr1,tExpr2,&hellip;</code>) perform the interpretation directly.

=== UML class diagram ===
[[Image:Interpreter_UML_class_diagram.svg]]