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Download the Java source code of a lexical analyzer (Main.Java). A summary of the source code is provided below. 1. The lexical analyzer program identifies a) alphanumeric lexemes (variables) as IDENT token, b) numeric token (constant integers) as INT_LIT token, and c) all other lexemes, such as ('+', , , , , (), are identified as "UNKNOWN" category. The program uses a look-up table to retrieve the token value for these symbols. Any symbols other than these will throw an error

Download the Java source code of a lexical analyzer (Main.Java). A summary of the source code is provided below. 1. The lexical analyzer program identifies a) alphanumeric lexemes (variables) as IDENT token, b) numeric token (constant integers) as INT_LIT token, and c) all other lexemes, such as ('+', , , , , (), are identified as "UNKNOWN" category. The program uses a look-up table to retrieve the token value for these symbols. Any symbols other than these will throw an error

Database System Concepts
Database System Concepts
7th Edition
ISBN:9780078022159
Author:Abraham Silberschatz Professor, Henry F. Korth, S. Sudarshan
Publisher:Abraham Silberschatz Professor, Henry F. Korth, S. Sudarshan
Chapter1: Introduction
Section: Chapter Questions
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Download the Java source code of a lexical analyzer (Main.Java). A summary of the source code is provided below. 1. The lexical analyzer program identifies a) alphanumeric lexemes (variables) as IDENT token, b) numeric token (constant integers) as INT_LIT token, and c) all other lexemes, such as ('+','','1', (), are identified as "UNKNOWN" category. The program uses a look-up table to retrieve the token value for these symbols. Any symbols other than these will throw an error. 2. The program reads characters of a line of code from an external text file, identifies and prints the lexemes and token numbers. 3. You must type one-page report highlighting your work and any additional features you may have added (for bonus points). Upload this report on DROPBOX. NO HANDWRITTEN items will be accepted. 4. Write a line of code in a text file as follows and provide the screenshot of lexical analyzer output in your report. You need to write no more than one-page report. (15) your_last_name] = ([last two digits of your T-number]+[your first name]) - yourFavoriteCity85yourFavoriteState] Example: smith = (65+ohn) - norfolk85ny 5. Modify the code in such a way that if it gets a character that is not in the lookup table, it prints an error message "Invalid lexeme, character not found." Test this scenario placing an example character in the text file such as '$' or '%' or '#'. Provide screenshots of your modified part of the code and the output. Hint: please add a case for the '=' sign. (5) 6. For bonus points, investigate ways to add new features to your program as follows. You may obtain up to 100% additional points as bonus. Provide screenshots of the modified part of the code along with the output. a. What if someone declares a variable starting with numerals (e.g., 8varX). Throw an error message suggesting that this is an illegal variable declaration. Can you detect a semicolon as the end of line (EOF)? b. c. Can you detect reserved lexemes and their tokens such as IF, WHILE, FOR, INT?
Transcribed Image Text:Download the Java source code of a lexical analyzer (Main.Java). A summary of the source code is provided below. 1. The lexical analyzer program identifies a) alphanumeric lexemes (variables) as IDENT token, b) numeric token (constant integers) as INT_LIT token, and c) all other lexemes, such as ('+','','1', (), are identified as "UNKNOWN" category. The program uses a look-up table to retrieve the token value for these symbols. Any symbols other than these will throw an error. 2. The program reads characters of a line of code from an external text file, identifies and prints the lexemes and token numbers. 3. You must type one-page report highlighting your work and any additional features you may have added (for bonus points). Upload this report on DROPBOX. NO HANDWRITTEN items will be accepted. 4. Write a line of code in a text file as follows and provide the screenshot of lexical analyzer output in your report. You need to write no more than one-page report. (15) your_last_name] = ([last two digits of your T-number]+[your first name]) - yourFavoriteCity85yourFavoriteState] Example: smith = (65+ohn) - norfolk85ny 5. Modify the code in such a way that if it gets a character that is not in the lookup table, it prints an error message "Invalid lexeme, character not found." Test this scenario placing an example character in the text file such as '$' or '%' or '#'. Provide screenshots of your modified part of the code and the output. Hint: please add a case for the '=' sign. (5) 6. For bonus points, investigate ways to add new features to your program as follows. You may obtain up to 100% additional points as bonus. Provide screenshots of the modified part of the code along with the output. a. What if someone declares a variable starting with numerals (e.g., 8varX). Throw an error message suggesting that this is an illegal variable declaration. Can you detect a semicolon as the end of line (EOF)? b. c. Can you detect reserved lexemes and their tokens such as IF, WHILE, FOR, INT?
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