I wonder if anything should be considered for multi-instance support as well (externals compiled w/ PDINSTANCE) -seb Date: Tue, 29 Mar 2022 11:28:57 +0200 From: IOhannes m zmoelnig zmoelnig@iem.at To: Pd-dev@lists.iem.at Subject: [PD-dev] call for discussion double-precision file extension hi,

TL;DR i'd like to suggest to use deken-specifiers as (optional) part of external filenames, in order to allow co-installability of externals of different OSs, architectures and floatsizes (and more to come).

i would really love to push the double precision saga towards a (happy) end. we have been able to compile Pd for 64bit double precision numbers. there's even a double-precision variant available in the Debian "experimental" repositories (but who knows that?)

*very* few people have started to provide externals (i counted: 4).

afaict the biggest hurdle is that you can't really co-install single and double variants of the same external. since there are so few double-precision externals available, people who rely on externals will be forced to use single-precision Pd for some time. but since installing a double-precision external might overwrite an existing single-precision external (required in your other project), i understand why people are not exactly eager to do that.?

one solution to this problem is to use different installation paths (e.g. ~/Documents/Pd/extra/ vs ~/Documents/Pd/extra64/). this doesn't play well with how deken currently works (as it stores the installation path globally (for all versions/variants of Pd).

Lucas suggested to use different file extensions (a year ago...time flies), by inserting `.float64` (and possibly `.float32`) right before our known extension (so we get `foo.float64.m_amd64`) I didn't especially like this back then, but in the meantime i've come to the conclusion that it's probably the best way forward.

however, i think that we might do better than just inserting a single `.float64`, and just unify the entire naming scheme to hold all the information we need.

i'd therefore suggest to use the deken-specifier together with the native extension (for dynamic-link libraries), as a new extension.

the "native extension for dynamic-link libraries" is typically defined on an OS level, and is something like ".dll" on Windows, ".dylib" on macOS and ".so" in the un*x world.

the "deken-specifier" is what we use in deken packages to know that they contain binaries for your specific combination of CPU, OS and precision, and looks like "<OS>-<CPU>-<precision>", e.g. "Darwin-arm64-32" (which denotes a macOS binary ("Darwin") that runs on the M1 processor ("arm64") and uses single-precision numbers ("32" bits).

this would give us filenames like "zexy.windows-amd64-32.dll" to keep things simple (and reduce the noise with -verbose), i would suggest to only allow lower case specifiers, and no arch variants (e.g. i386 for all x86_32 variants, and amd64 for all x86_64 variants)

pros

- using the system extension does not require us to invent our own extension for each new platform - system tools often use the file-extension to recognize the file type - deken-specifiers fully cover what we need to know (the problem space is the same for deken package files and externals: allow coexistence of files with multiple OS/arch/precision specs) - people can relate the files within a deken-package with the deken-package-filename - if we ever need to add a new parameter, the deken specifier and the externals are likely to be affected in a similar way, so we need to solve the problem only once. - it gets rid of the super-cryptic .<first-letter-of-the-os>_<cpu-arch> specifier (.o_ia64 anybody?)

cons

it shares the same (final) extensions as any support libraries. eg. "zexy.linux-amd64-32.so" + "libzexy.linux-amd64-32.so" (or even libzexy.linux-amd64-32.so.so, but I guess we don't want this)

probably some more...

instead of using the system extension for dynamic libraries, we might pick a general unified (final) extension, instead of the system ones, e.g. .pdx (but that is already taken) or .pd_external. but i think the less we invent ourselves, the better.

Lucas had started a feature-request/discussion on this very topic a year ago, but it was dormant until now.

https://github.com/pure-data/pure-data/issues/902

i would like to hear your opinion on this (here or at the issue tracker; or both), and eventually get this done.

once this is solved, i will start to push Pd64 packages to the Debian repositories, so people can start to use it (without having to compile themselves).

gfmsdr IOhannes

? just for the record: the biggest hurdle is of course that there is no double-precision download available right now... but that's a bit of an egg-hen problem.