Description
Given the description of the G++ language (G++Syntax.pdf) you are asked to implement the lexer that does the tokenization of a given G++ program in a file.
You are expected to submit the file “student_id.cl” with a function called “lexer”. This function should take a file name and perform lexical analysis of the program contained within this file. The output of the function should be the tokens in a list. Sample input and output is provided below.
| Sample Input: | Sample Output: (There may be mistake(s)) |
| (deffun sumup (x)
(if (equal x 0) 1 (+ x (sumup (- x 1))) ) ) |
((“operator” “(“) (“keyword” “deffun”)
(“identifier” “sumup”) (“operator” “(“) (“identifier” “x”) (“operator” “)”) (“operator” “(“) (“keyword” “if”) (“operator” “(“) (“keyword” “equal”) (“identifier” “x”) (“integer” “0”) (“operator” “)”) (“integer” “1”) (“operator” “(“) (“operator” “+”) (“identifier” “x”) (“operator” “(“) (“identifier” “sumup”) (“operator” “(“) (“operator” “-“) (“identifier” “x”) (“integer” “1”) (“operator” “)”) (“operator” “)”) (“operator” “)”) (“operator” “)”) (“operator” “)”) |
