🙂 ah that one ....the use of IF _N_ = 1 then do; or W/O it doesn't makes any difference( thank god i remember this 🙂 ) coz for constant regular expression the compilation happens only once and the value to the left side variable would be same for next successive observations as was for 1st observation. So successive calls to PRXPARSE will not cause a recompile, but will return the same value to the left side variable for the regular expression that was already compiled.
Again, as you said - "many ways to skin a cat" 🙂 ..w/ or w/o doesn't makes any difference in case of constant regular expression like the one above.
Thanks Chris, for pointing that out 🙂