Parse tree design

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

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

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.

Issues Discussed

Around this design we constructed a variety of patterns and discussed them.

Patterns in Use

• DTSTTCPW Design

Standard Composite Solution

Wal's Solution

Wal's Solution Refactored

See Also

• Avoid no-ops
• Beware type switches
• Decorator
• Refactoring