Hi Enzo, Here is what the regex means:

^ is a exclusion operator.

!-~ is a range which matches all characters between ! and ~. The range is set between ! and ~ because these are the first and last characters in the ASCII table (Alt+033 for ! and Alt+126 for ~ in Windows). As this range does not include whitespace, \s is separately included. \t simply represents a tab character. \s is similar to \t but the metacharacter \s is a shorthand for a whole character class that matches any whitespace character. This includes space, tab, newline and carriage return.

The meaning of the complete statement is "If anything which is not between the ASCII range of ! and ~ and if not a whitespace, test is true."

Sriram