Regular Expressions in Magik

It has been bothering me for years that Magik does not seem to support Regular Expressions. I tried to make do with the ro_charindex_mixin.matches?() method. But that method only uses wildcard characters %*, %? and %\.

So when l_santi asked a question in sw-gis about Magik support for Regular Expressions, it got me thinking: WWBD (What Would Bhimesh Do)? Bhimesh is the owner of the Magik Fun blog and many of his posts explore the interaction of Magik with various OLE objects. I began to wonder if there was an OLE object that could support regular expressions. It turns out that vbscript.regexp is exactly what I was looking for.

Here is an example of testing that a telephone number string matches the correct format for North America...

MagikSF> regexp <<  ole_client.createobject("vbscript.regexp")
$
MagikSF> regexp.pattern << "^[0-9]{3}-[0-9]{3}-[0-9]{4}$"
$
MagikSF> regexp.test("303-555")
$
False
MagikSF> regexp.test("303-555-5555")
$
True

... and another example testing if a string is in a valid e-mail format.

MagikSF> regexp.pattern << "\b[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,4}\b"
$
MagikSF> regexp.test("alfred@ifactorconsulting.com")
$
True
MagikSF> regexp.test("alfred!ifactorconsulting.com")
$
False