Updated alexer.py, fixed peek_next()

[nguyengiabach1201]

It should be

if self.current + 1 >= len(self.source)

than

if self.current >= len(self.source)

(At line 84!)

[vercel]

@nguyengiabach1201 is attempting to deploy a commit to the Hack Club Team on Vercel.

A member of the Team first needs to authorize it.

[jianmin-chen]

Hm, that doesn't seem right, since we're using the >= operator.