In
computer science,
lexical analysis is the process of converting a sequence of characters (such as in a computer program or web page) into a sequence of tokens (strings with an identified "meaning"). A program that performs lexical analysis may be called a
lexer,
tokenizer, or
scanner (though "scanner" is also used to refer to the first stage of a lexer). Such a lexer is generally combined with a
parser, which together analyze the
syntax of
programming languages, web pages, and so forth.