Hi, Danny Milosavljevic <dan...@scratchpost.org> skribis:
>>I’d prefer to add a special ‘iso-9660-uuid’ form similar to ‘uuid’ in (gnu >>system file-systems). >> That way we could detect that we get a valid UUID at macro-expansion >> time or system-instantiation time, rather than end up with an error at >> boot time. > > Hmm, I've never seen that macro before. Should it be used in config.scm ? Yes, see <https://gnu.org/software/guix/manual/html_node/File-Systems.html>. > Right now config.scm could have: > > (file-systems (cons* (file-system > (device "1234-5678-....") ^^ This is wrong, should be (uuid "1234-…"). > Which kind of UUID is it then? Should string->uuid try to be clever about > it? Or a new function string->uuid-like ? ‘uuid’ and ‘string->uuid’ are for DCE UUIDs, see (gnu build file-systems). I think it should remain this way: ‘string->uuid’ shouldn’t try to guess what kind of UUID it’s given; doing that could lead to hard-to-debug problems. > find-partition-by-uuid right now uses read-partition-uuid and then uses > bytevector=?. Right, file system UUIDs are represented as bytevectors internally in (gnu build file-systems). > So all these forms should continue to be bytevectors. Then it would work > fine without lots of changes. > > So something like this? > > - Add "string->uuid-like" and use it in canonical-title (instead of using > "string->uuid"). > - string->uuid-like would have a case analysis by some weird markers, then > parse the uuid using the right parser into a bytevector with length > typical-for-this-filesystem-but-not-unique. > - Modify uuid->string to have a case analysis by the bytevector length, then > print the uuid using the right printer into a string > typical-for-this-filesystem. This will fail to detect ISO9660 correctly > because these are the same length as real uuids (Linux uses 16 bytes of the > 17-byte iso9660-uuid) > - Leave the uuid macro as-is since it should already do the right thing then? > - Add a new macro fat32-uuid, and a new macro iso9660-uuid. I don’t like the idea of a polymorphical ‘string->uuid-like’. I would prefer to have: fat32-uuid->string (already exists) string->fat32-uuid fat32-uuid macro iso9660-uuid->string string->iso9660-uuid iso9660-uuid macro Then users should pick the right one, usually the macro, and get an error when they pass an invalid UUID. WDYT? Thanks, Ludo’.
