Playing With Java Pattern's Named Capture Groups In ColdFusion

test.cfm

<cfscript>

	// The following pattern uses a VERBOSE Regular Expression flag to allow for comments
	// and whitespace to make the pattern easier to read. In this case, we're attempting
	// to extract parts of an email address using NAMED CAPTURE GROUPS.
	pattern = "(?x)^
		(?<user> [^+@]+ )
		(
			\+ (?<hash> [^@]+ )
		)?
		@
		(?<domain> .+ )
	";

	extractEmail( "jane.doe@example.com" )
	extractEmail( "jane.doe+spam@example.com" )
	extractEmail( "j.a.n.e.d.o.e@example.com" )

	// ------------------------------------------------------------------------------- //
	// ------------------------------------------------------------------------------- //

	/**
	* I match the Java Regular Expression pattern against the given input and then output
	* the NAMED CAPTURE GROUPS.
	*/
	public void function extractEmail( required string input ) {

		var matcher = createObject( "java", "java.util.regex.Pattern" )
			.compile( pattern )
			.matcher( input )
		;

		while ( matcher.find() ) {

			// NOTE: With named capture groups, the Java Pattern Matcher exposes a way for
			// us to access each group by name; but, I don't see any way to use reflection
			// to get the list of named groups - only the number of captured groups.
			dump(
				label = "Input: #input#",
				var = [
					"user": matcher.group( "user" ) ,
					"hash": matcher.group( "hash" ),
					"domain": matcher.group( "domain" )
				]
			);

		}

	}

</cfscript>