The primary key of the sort is the number of literal characters in the full URI matching pattern.
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The secondary key of the sort is the number of template expressions embedded within the pattern—that is, {id} or {id : .+}. This sort is in descending order.
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The tertiary key of the sort is the number of nondefault template expressions. A default template expression is one that does not define a regular expression—that is, {id}.
S. Rapps, und E. Weyuker. ICSE '82: Proceedings of the 6th international conference on Software engineering, Seite 272--278. Los Alamitos, CA, USA, IEEE Computer Society Press, (1982)
T. Sederberg, P. Gao, G. Wang, und H. Mu. Proceedings of the 20th annual conference on Computer graphics and interactive techniques, Seite 15--18. New York, NY, USA, ACM, (1993)