Lexical characteristics of keywords in COBOL, FORTRAN, Pascal, and PL/I

Lexical techniques for the study of texts invvarious forms are based upon the symbols used. Common lexical measures are word counts, word frequency distributions, word length distributions, and character frequency distributions. Lexical analysis involves no direct consideration of the grammatical structure or meaning of the text. Thus, it is less powerful than syntactic or semantic analysis. But, when ~t is applicable, it is usually much easier than the more powerful techniques and thus more likely to lead to practical tools.