Along the lines of `assertOneOf`, but expects a list of values to be
compared. This gives a good error message and is useful for lists of
values, like `supportedGhcVersions` in the arguments of
`haskell-language-server`.
If all the docs are auto-generated, it should be easier to convert
them to Commonmark.
Co-Authored-By: Valentin Gagarin <valentin.gagarin@tweag.io>
Co-Authored-By: Silvan Mosberger <contact@infinisil.com>
`assert` has the annoying property that it dumps a lot of code at the
user without the built in capability to display a nicer message. We have
worked around this using `assertMsg` which would *additionally* display
a nice message. We can do even better: By using `throw` we can make
evaluation fail before assert draws its conclusions and prevent it from
displaying the code making up the assert condition, so we get the nicer
message of `throw` and the syntactical convenience of `assert`.
Before:
nix-repl> python.override { reproducibleBuild = true; stripBytecode = false; }
trace: Deterministic builds require stripping bytecode.
error: assertion (((lib).assertMsg (reproducibleBuild -> stripBytecode)) "Deterministic builds require stripping bytecode.") failed at /home/lukas/src/nix/nixpkgs/pkgs/development/interpreters/python/cpython/2.7/default.nix:45:1
After:
nix-repl> python.override { reproducibleBuild = true; stripBytecode = false; }
error: Deterministic builds require stripping bytecode.
Johannes Kirschbauer