Editing Finite-state machine (section)

=== Finite-state machines and compilers ===
Finite automata are often used in the [[Compilers#Front end|frontend]] of programming language compilers. Such a frontend may comprise several finite-state machines that implement a [[lexical analysis|lexical analyzer]] and a parser.
Starting from a sequence of characters, the lexical analyzer builds a sequence of language tokens (such as reserved words, literals, and identifiers) from which the parser builds a syntax tree. The lexical analyzer and the parser handle the regular and [[context-free grammar|context-free]] parts of the programming language's grammar.<ref>{{cite book |author-link1=Alfred V. Aho |last1=Aho |first1=Alfred V. |author-link2 = Ravi Sethi |last2=Sethi |first2=Ravi |author-link3=Jeffrey D. Ullman |last3=Ullman |first3=Jeffrey D. |title=Compilers: Principles, Techniques, and Tools |isbn=978-0-201-10088-4 |publisher=[[Addison-Wesley]] |year=1986 |edition=1st|title-link=Compilers: Principles, Techniques, and Tools }}</ref>