(function(Reddit) {
	"use strict";
	var anchor = '<a href="http://reddit.com$1" target="_blank">$1</a>';

	Reddit.parse = function(postContent, callback) {
		var	regex = /(\/r\/\w+)/g;

		if (postContent.match(regex)) {
			postContent = postContent.replace(regex, anchor);
		}

		callback(null, postContent);
	};
}(module.exports));

(function(Reddit) {
	"use strict";
	var anchor = '<a href="http://reddit.com$1" target="_blank">$1</a>';

	Reddit.parse = function(postContent, callback) {
		var	regex = /(?:^|\s)(\/r\/\w+)/g;

		if (postContent.match(regex)) {
			postContent = postContent.replace(regex, anchor);
		}

		callback(null, postContent);
	};
}(module.exports));

Update regex Only match if /r/* is the beginning of the string or if it is prefixed by a whitespace
Update regex
Only match if /r/* is the beginning of the string or if it is prefixed by a whitespace
