Indeed, you are an astute observer: it is Template Toolkit code, but it runs under Perl and its errors are Perl errors.
in reply to Re: argument """ isn't numeric in numeric gt(>), error
in thread argument """ isn't numeric in numeric gt(>), error
A program should be light and agile, its subroutines connected like a string of pearls. The spirit and intent of the program should be retained throughout. There should be neither too little or too much, neither needless loops nor useless variables, neither lack of structure nor overwhelming rigidity." - The Tao of Programming, 4.1 - Geoffrey James