Submodules that have a freeform type set behave as if that was the type
of the option itself (for values that don't have an option). Since the
submodules options are shown as separate entries in the manual, it makes
sense to show the freeform type as the submodule type.
For programs that have a lot of (Nix-representable) configuration options,
a simple way to represent this in a NixOS module is to declare an
option of a type like `attrsOf str`, representing a key-value mapping
which then gets generated into a config file. However with such a type,
there's no way to add type checking for only some key values.
On the other end of the spectrum, one can declare a single separate
option for every key value that the program supports, ending up with a module
with potentially 100s of options. This has the benefit that every value
gets type checked, catching mistakes at evaluation time already. However
the disadvantage is that the module becomes big, becomes coupled to the
program version and takes a lot of effort to write and maintain.
Previously there was a middle ground between these two
extremes: Declare an option of a type like `attrsOf str`, but declare
additional separate options for the values you wish to have type
checked, and assign their values to the `attrsOf str` option. While this
works decently, it has the problem of duplicated options, since now both
the additional options and the `attrsOf str` option can be used to set a
key value. This leads to confusion about what should happen if both are
set, which defaults should apply, and more.
Now with this change, a middle ground becomes available that solves above
problems: The module system now supports setting a freeform type, which
gets used for all definitions that don't have an associated option. This
means that you can now declare all options you wish to have type
checked, while for the rest a freeform type like `attrsOf str` can be
used.
This fundamentally changes how the module evaluation internally
handles definitions without an associated option.
Previously the values of these definitions were discarded and only
the names were propagated. This was fine because that's all that's
needed for optionally checking whether all definitions have an
associated option with _module.check.
However with the upcoming change of supporting freeform modules,
we *do* need the values of these.
With this change, the module evaluation cleanly separates definitions
that match an option, and ones that do not.
`toHex` converts the given positive integer to a string of the hexadecimal
representation of that integer. For example:
```
toHex 0 => "0"
toHex 16 => "10"
toHex 250 => "FA"
```
`toBase base i` converts the positive integer `i` to a list of it
digits in the given `base`. For example:
```
toBase 10 123 => [ 1 2 3 ]
toBase 2 6 => [ 1 1 0 ]
toBase 16 250 => [ 15 10 ]
```
The previous hash was too short and caused evaluation-time errors like:
invalid SRI hash 'sha256-AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA='
Additionally, since the fact that this is broken implies that nobody
could have been using it, "SRI" is a bit of a vague and obscure term,
`fakeSriHash` would be somewhat of a mouthful, and the relevant fetcher
parameters are just called `hash`, rename it to `fakeHash`.
This is used in in the manual generation for option identifiers that can
be linked. This, unike what the example describes, doesn't preserve
quotes which is needed for these identifiers to be valid.
This reverts commit 124cccbe3b63122733e02e41e45a383ec48752fd.
124cccbe3b
broke the build of NixOS manual.
It does not make sense to be as strict as with attributes since we
are not limited by the CLI's inability to handle numbers.
Placeholders should not be quoted either as they are not part of Nix
syntax but a meta-level construct.
