Parser
*This homework is a programming assignment.
*You need to include your name as a comment in Python files.
*While working on the assignment, read this document THOROUGHLY.
Homework
In this homework, you need to complete parserr.py (and modify other files if necessary) so that our parser builds a tree from the below three cases.
1. Grouped Expression (ex. 1 * (2 + 5))
2. Single Number Expression (ex. 25)
3. Expression with Negative Sign (ex. -25 * 3)
Test Cases
This section provides several test cases to check whether you wrote a parser correctly. In the main.py, you will change srcCode with the below test cases and see whether your output results are matched with the ones given in the table.
import lexer import parserr
srcCode = "1 * (2 + 5)" tokSeq = lexer.tokenize(srcCode) rootNode = parserr.parse(tokSeq) parserr.printTree(rootNode) print()
main.py
Test Case (srcCode)
Output Result
1 * ( 2 + 5 )
(1 * ( 2 + 5 ))
(1 + 2) * 5 + 4
(((1 + 2) * 5) + 4)
23 * ((1 + 5) * 33)
(23 * ((1 + 5) * 33))
24
24
125
125
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-5
((0 - 1) * 5)
- -5
(((0-1)*(0-1))*5)
- (-5)
((0-1)*((0-1)*5))
