or download this
The reasons are not complicated: If I use any of the perl+XML machiner
+y, it wants me either to let it read the whole thing and build a stru
+cture in memory, or go to a callback interface.
Since we're typically reading very large datasets, and typically looki
+ng at the vast majority of it, preloading it into a data structure wo
+uld be impractical not to say stupid. Thus we'd be forced to use pars
+er callbacks of one kind or another, which is sufficiently non-idioma
+tic and awkward that I'd rather just live in regexp-land.