On Mon, 13 Jan 2003, Matthew Simon Cavalletto wrote: > >> What's the benefit of making this distinction between core and > >> "other" formats? > > > > Because "core" parsing would be available simply by doing: > > use DateTime; > > We can move the parsing to format modules and load them automatically.
Sure, that's possible too. The real question is whether or not parsing requires anything beyond doing "use DateTime". > > It's really a question of whether or not users must load another > > module to do parsing, that's all. > > The suggestion on the table is that even the "core" parsing be placed > in another package, but that this be transparent to end-users. But that's not my concern. I _don't_ want to discuss implementation of this. I want to talk about the API! > > Actually, I have some ideas for this. [...] the parsing modules would > > just add methods to the DateTime namespace. > > Ick -- what's the advantage of doing it this way? > > It strikes me as a lot more logical to keep those methods in their own > namespace and simply call them when needed. > > Looking at the two alternatives, does the second really seem clearer? > > use DateTime; > my $dt = DateTime->new( 'MySQL' => $mysql_dt ); > print $dt->to_string( 'MySQL' ); > > use DateTime; > use DateTime::Parse::MySQL; > my $dt = DateTime->from_mysql_datetime( $mysql_dt ); > print $dt->to_mysql_string(); Um, yeah, the second is _much_ clearer. And its less error prone as well! If I mis-type 'MySQL' as 'Mysql' then what is DateTime supposed to do? And how is DateTime->new supposed to know about all the myriad parameters that would exist with your suggestion anyway? If it finds an unknown parameter, should it call "DateTime::Parse->$param()"? What if a specific parser needs _two_ params? Your first option is not on the table. The options on the table are: use DateTime; use DateTime::Parse::MySQL; my $dt = DateTime->from_mysql_datetime( $mysql_dt ); print $dt->to_mysql_string(); or use DateTime; use DateTime::Parse::MySQL; my $dt = DateTime::Parse::MySQL->new_datetime( $mysql_dt ); print DateTime::Parse::MySQL->mysql_datetime( $dt ); Frankly, I think the first one is a lot easier to use and makes more sense. It's the decorator pattern without the dispatching overhead! -dave /*======================= House Absolute Consulting www.houseabsolute.com =======================*/
