It creates interoperability issues that can not be reconciled by
`lib` or maintainers of projects that use the Nixpkgs library.
Occasionally, end users may be able to solve the problems they run
into, but most are not prepared to deal with this set of problems,
nor should they be.
Typical conflict:
- User wants to propagate their own lib, because it has some function
they like to use throughout their projects
- Project maintainer requires the project's lib to be used
No sane language uses a single namespace for combining all the things.
(Arguably not even C with its extensive use of prefixing)
Meanwhile, in Nix, all symbols are first class variables. We don't even
have the concept of a global top-level namespace to pour everything into.
With `lib` you can try to approximate that, I get the appeal of its
apparent simplicity, but since `lib` can't be global, we just don't even
get that apparent simplicity.
I apologize for not offering concrete solutions to this in the text.
The manuals are limited to reference documentation.
Alternatives - of which we have multiple - are best provided in
task-oriented documentation, e.g. nix.dev.
- Expose `lib.licensesSpdx`
- Create bindings for the needed internal functions
- Mention that some SPDX licenses might be missing (in the future I hope
we can autogenerate the Nixpkgs license list from some SPDX endpoint
`strings.trim` returns a copy of the string with all leading and trailing
whitespace removed.
`strings.trimWith` does the same thing, but calling code can decide
whether to trim the start and/or end of the string.
All builtins should be in mirrored in lib, for consistency, as well
as control to let the Nixpkgs pin effect *subtle* improvements in
behavior (such as the foldl' accumulator strictness).
Add lib.meta.getLicenseFromSpdxIdOr as a variant of
lib.meta.getLicenseFromSpdxId that explicitly state the default
(fallback) value if there's no license matching the given SPDX ID.
Add a library function to parse and validate an IPv6 address from a
string. It can parse the first two versions of an IPv6 address according
to https://datatracker.ietf.org/doc/html/rfc4291#section-2.2. The third
form "x❌x❌x:x.d.d.d.d" is not yet implemented. Optionally parser can accept prefix length (128 is default).
Add shell script network.sh to test IPv6 parser functionality.
