--- a/solution/cw4/lexer.sc	Thu Jan 20 08:58:38 2022 +0000
+++ b/solution/cw4/lexer.sc	Mon Jan 24 00:00:33 2022 +0000
@@ -205,13 +205,14 @@
 val SYM : Rexp = LET | RANGE(Set('.', '_', '>', '<', '=', ';', ',', ':'))
 val PARENS : Rexp = "(" | "{" | ")" | "}"
 val SEMI : Rexp = ";"
-val WHITESPACE : Rexp = PLUS(" ") | "\n" | "\t"
+val WHITESPACE : Rexp = PLUS(" ") | "\n" | "\t" | "\r"
 val DIGIT : Rexp = RANGE(('0' to '9').toSet)
 val DIGIT1 : Rexp = RANGE(('1' to '9').toSet)
 val STRING : Rexp = "\"" ~ (SYM | " " | "\\n" | DIGIT).% ~ "\""
 val ID : Rexp = LET ~ (LET | "_" | DIGIT).%
 val NUM : Rexp = "0" | (DIGIT1 ~ DIGIT.%)
-val COMMENT : Rexp = "//" ~ (SYM | " " | DIGIT).% ~ "\n" 
+val EOL : Rexp = "\n" | "\r\n"
+val COMMENT : Rexp = "//" ~ (SYM | PARENS | " " | DIGIT).% ~ EOL
 
 val WHILE_REGS = (("k" $ KEYWORD) | 
                   ("o" $ OP) |