A big source of trying to do too much is environments that offer easy regex-based transformations defined as a pair of regex and a single replacement string (t

A big source of trying to do too much is environments that offer easy regex-based transformations defined as a pair of regex and a single replacement string (that may contain references to matching groups) and make other transformations hard ("while find + rest"). When you have the option to provide a "process match" closure instead of the replacement string the lure of putting too much into a single regex almost collapses.