Regent

Perl compatible regular expressions

Several text editors such as UltraEdit, NoteTab Light and EditPad Pro support Perl compatible regular expressions syntax for search and replace. Editors screenshots and some small search and replace inconsistencies are listed below.

	UltraEdit doesn't support more than 9 tagged expressions - it interprets $10 in replace expression as $1 and 0. For example, with search expression (1)(2)(3)(4)(5)(6)(7)(8)(9)(0) and replace expression $10 after replacement text 1234567890 becomes 10 instead of 0. It also incorrectly handles escaped back slash and dollar followed by a digit in replace expression. For example, with search expression (abc) and replace expression \\1 or \$1 after replacement text abc remains the same instead of becoming \1 or $1.
	NoteTab Light doesn't find non-English letters with [[:lower:]], [[:upper:]], [[:alpha:]], [[:alnum:]] and [[:word:]] character classes.
	EditPad Pro doesn't match tab with [[:space:]] character class. Use \s as a workaround. Make sure Case Sensitive checkbox is on. Without it EditPad Pro matches both upper and lower letters with [[:lower:]] and [[:upper:]] character classes. For example, with search expression [[:lower:]]+ and text abcABC it matches whole word abcABC instead of only abc part.