[Issue 2104] New: Escape function for regular expressions

[d-bugmail at puremagic.com]

http://d.puremagic.com/issues/show_bug.cgi?id=2104

           Summary: Escape function for regular expressions
           Product: D
           Version: 2.013
          Platform: PC
        OS/Version: All
            Status: NEW
          Severity: enhancement
          Priority: P2
         Component: Phobos
        AssignedTo: bugzilla at digitalmars.com
        ReportedBy: gaboonviper at gmx.net


I've been using regular expressions extensively and found that there was no
escape function in the std.regexp library. It's useful when using user input in
regular expressions.

Here's a simple one I built. It's probably not the most efficient one out
there, but feel free to use it.

string regEscape(string aExpression)
{
    return sub(aExpression, r"[\\\.\*\+\?\^\$\[\]\{\}\(\)\|]", "\\$&", "g");
}

Usage:

string needle1 = r"[needle]";
string needle2 = r"(needle)";

string haystack = r"[needle] (needle)";

// find needles 1 and/or 2 in the haystack
auto result = RegExp(regEscape(needle1) ~ "|" ~
regEscape(needle2)).search(haystack);

Cheers,
Boyd


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