Finite-Automata

Finite automata (written in C) designed to recognize typical programming language tokens.

Fig.5.8(b)

Fig.5.9

Fig.5.5

Examples

• Fig.5.8(b) shows a finite automaton that recognizes identifiers.
• The identifiers can include an underscore...

Please enter the symbol: NEXT_LINE
TOKEN CORRECT

• ...But they cannot begin or end with one, or contain two consecutive ones.

Please enter the symbol: _LINE
TOKEN ERROR!

• Fig.5.9 shows a finite automaton that recognizes all the tokens listed in Fig.5.5.

Please enter the symbol: END.

VALID TOKEN!

Please enter the symbol: :=

VALID TOKEN!

Reference

Book Title: System Software - An Introduction to Systems Programming

Author: Leland Beck.