Dave,
I am not sure I agree with you. The AM wants to fetch all data in a specific format. The substr function extracts a substring. Perhaps you were thinking of index? While I agree that index can often be faster than a regex when detecting the precence of a string within a larger string, it requires an exact substring and is not maleable as say the \w character class in a regex. That type of flexibility seems to be required to solve this problem.

Cheers - L~R