`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 semantic difference between `encode` and `to` is not apparent.
Users are likely to confuse both functions (which leads to unexpected
error messages about the wrong types). Like in `generators.nix`, all
functions should be prefixed by `to`.
Furthermore, converting to a string depends on the target context. In
this case, it’s a POSIX shell, so we should name it that (compare
`escapeShellArg` in `strings.nix`).
We can later add versions that escape for embedding in e.g. python
scripts or similar.
Fix the broken test in https://github.com/NixOS/nixpkgs/pull/77416
Apparently hydra uses `nix-build lib/tests/release.nix` to run all
tests, where IFD isn't allowed. Fortunately we can get around this with
builtins.toFile, which doesn't require IFD, but still can test the
properties we want.
This adds a new utility to intelligently convert Nix records to
command line options to reduce boilerplate for simple use cases and to
also reduce the likelihood of malformed command lines
`pipe` is a useful operator for creating pipelines of functions.
It works around the usual problem of e.g. string operations becoming
deeply nested functions.
In principle, there are four different ways this function could be
written:
pipe val [ f1 .. fn ]
pipe val [ fn .. f1 ]
compose [ f1 .. fn ] val
compose [ fn .. f1 ] val
The third and fourth form mirror composition of functions, they would
be the same as e.g. `(f1 << f2 << f3 .. << fn) val`.
However, it is not clear which direction the list should have (as one
can see in the second form, which is the most absurd.
In order not to confuse users, we decide for the most “intuitive”
form, which mirrors the way unix pipes work (thus the name `pipe`).
The flow of data goes from left to right.
Co-Authored-By: Silvan Mosberger <infinisil@icloud.com>
This reverts commit ce2f74df2c.
Doubles are treated as -darwin here, to provide some consistency.
There is some ambiguity between “x86_64-darwin” and “i686-darwin”
which could refer to binaries linked between iOS simulator or real
macOS binaries. useiOSPrebuilt can be used to determine which to use,
however.
