Introduction - If you have any usage issues, please Google them yourself
Analysis of the preparation of an integer identifier, a separator, the main operator and the main keyword lexical analysis procedures. Specific requirements: the design of a lexical analysis program, each call to a document from the source sequence of symbols to identify a word, and words return to the type of binary information symbols (all the internal code word and the word itself symbolic value). Encountered an error when the error message to return and continue to skip the error part of analysis.