Homework Description
In this homework, you need to complete lexer.py that we’ve worked on during the class. In our interpreter, a lexer needs to handle seven tokens as shown below.
COMP 340 – HW 5 Due date: 04/20/2020 11:59 pm Total Points: 20 pts
Token Type
NUMBER
PLUS
MINUS MULTIPLICATION DIVISION LPAREN
RPAREN
Token Value
0,1,2,3,….,9 +
–
*
/ ( )
Currently, our lexer produces NUMBER token and PLUS token. Complete lexer.py so that our lexer also produces other tokens (MINUS, MULTIPLICATION, DIVISION, LPAREN, RPAREN).
Assume that we run main.py with srcCode=“((12+3*5)+5/4)” with the completed lexer.py like the below.
|
import lexer |
|
srcCode = “((12+3*5)+5/4)” tokSeq = lexer.tokenize(srcCode) for i in tokSeq: print(i.type, i.value) |
main.py
Page 1 of 3
Then, it should print a sequence of tokens:
LPAREN ( LPAREN ( NUMBER 12 PLUS + NUMBER 3 MULTIPLICATION * NUMBER 5
RPAREN ) PLUS + NUMBER 5 DIVISION / NUMBER 4 RPAREN )
