Parse tree design

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(Class-Design)
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[[Image:ParseTree.jpeg]]
 
[[Image:ParseTree.jpeg]]
  
That's the first Design that came up in class:
+
That's the first Design that came up in class. It is a [[Composite]] Pattern.
 
*the addKid()-function in the Terminal class throws an exception
 
*the addKid()-function in the Terminal class throws an exception
 
*symbol is of type enum, which has a representation for every symbol of the grammar.
 
*symbol is of type enum, which has a representation for every symbol of the grammar.

Revision as of 05:43, 9 September 2008

A context free grammar defines a language, e.g.

Grammar.gif

A parse tree shows how a sentence in the language is structured according to the grammar.

Parsetree.gif

Terminology

In parsing lingo a symbol is a name in a grammar. Each symbol is either a terminal or a non-terminal. Non-terminals appear on the left hand side of a grammar production; terminals don't.

Class-Design

ParseTree.jpeg

That's the first Design that came up in class. It is a Composite Pattern.

  • the addKid()-function in the Terminal class throws an exception
  • symbol is of type enum, which has a representation for every symbol of the grammar.
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