CS 3040, Assignment 4

CS 3040, Assignment 4: Complex Antlers

Reimplement Assignment 3 using ANTLR. Notes:

You can work with others on this assignment, but each student must turn in their own solution.
Place your grammar and the associated actions in the file ~~complex.g4~~ plan.g4.
If it helps, you may restructure the grammar from what is shown in assignment 3. For instance, you will probably want to rewrite the productions using * to into ones that use recursively defined nonterminals; for example,
```
        a -> b (c)*
```
can be rewritten as
```
        a -> b multiple_cs
        multiple_cs -> ε
        multiple_cs -> c multiple_cs
```
You must use inline actions (such as shown in my ANTLR examples) to implement computing the area information printed in assignment 3.
Do indent the ANTLR code as shown in the examples. Note that you can have multiple actions associated with a particular production:
```
        something : TOKEN1 somethingElse TOKEN2
                {x = a}
                {y = b}
                ;
```
Another way to fix complex actions that cannot fit on one line is to write a function and call that instead. Those actions would go in a @header section as illustrated in the eval example.
Ensure your solution catches ~~errors in way that is similar to~~ the same errors as for assignment 3. Because ANTLR catches and reports errors in a very different way, expect the error messages to differ. In particular, it will often be difficult to report a line number and/or column number.

Submitting

Submit the following

A PDF giving evidence that your solution works. You can add other cases, but start by running the examples from assignment 3. ~~Show it on the case that is in the assignment 3 writeup, at least one or two additional legal cases, and a few error cases.~~
In addition to the output, document who you worked with (if anyone) and the version of ANTLR you used to test your solution. Typing
```
        antlr4
```
(with no arguments) will print the version number on the first line of output. You could simply include that line or just record the version number.
Your source files; that is, plan.g4 and any supporting Python files you wrote.

Do not submit the files generated by ANTLR.

You can receive substantial partial credit for a solution that just identifies inputs as legal or not. In such cases, be sure to show it runs on multiple legal inputs and that it does catch errors on multiple incorrect solutions.