nixpkgs/doc/languages-frameworks/idris.section.md
V 7616206b77
doc: add function argument order convention (#110060)
* doc: add function argument order convention

Ordering by usage is the de facto ordering given to arguments. It's
logical, and makes finding argument usage easier. Putting lib first is
common in NixOS modules, so it's reasonable to mirror this in nixpkgs
proper. Additionally, it's not a package as such, has zero dependencies,
and can be found used anywhere in a derivation.

* doc: clean up usage of lib
2021-01-20 19:07:16 -05:00

144 lines
3.4 KiB
Markdown

# Idris {#idris}
## Installing Idris
The easiest way to get a working idris version is to install the `idris` attribute:
```
$ # On NixOS
$ nix-env -i nixos.idris
$ # On non-NixOS
$ nix-env -i nixpkgs.idris
```
This however only provides the `prelude` and `base` libraries. To install idris with additional libraries, you can use the `idrisPackages.with-packages` function, e.g. in an overlay in `~/.config/nixpkgs/overlays/my-idris.nix`:
```nix
self: super: {
myIdris = with self.idrisPackages; with-packages [ contrib pruviloj ];
}
```
And then:
```
$ # On NixOS
$ nix-env -iA nixos.myIdris
$ # On non-NixOS
$ nix-env -iA nixpkgs.myIdris
```
To see all available Idris packages:
```
$ # On NixOS
$ nix-env -qaPA nixos.idrisPackages
$ # On non-NixOS
$ nix-env -qaPA nixpkgs.idrisPackages
```
Similarly, entering a `nix-shell`:
```
$ nix-shell -p 'idrisPackages.with-packages (with idrisPackages; [ contrib pruviloj ])'
```
## Starting Idris with library support
To have access to these libraries in idris, call it with an argument `-p <library name>` for each library:
```
$ nix-shell -p 'idrisPackages.with-packages (with idrisPackages; [ contrib pruviloj ])'
[nix-shell:~]$ idris -p contrib -p pruviloj
```
A listing of all available packages the Idris binary has access to is available via `--listlibs`:
```
$ idris --listlibs
00prelude-idx.ibc
pruviloj
base
contrib
prelude
00pruviloj-idx.ibc
00base-idx.ibc
00contrib-idx.ibc
```
## Building an Idris project with Nix
As an example of how a Nix expression for an Idris package can be created, here is the one for `idrisPackages.yaml`:
```nix
{ lib
, build-idris-package
, fetchFromGitHub
, contrib
, lightyear
}:
build-idris-package {
name = "yaml";
version = "2018-01-25";
# This is the .ipkg file that should be built, defaults to the package name
# In this case it should build `Yaml.ipkg` instead of `yaml.ipkg`
# This is only necessary because the yaml packages ipkg file is
# different from its package name here.
ipkgName = "Yaml";
# Idris dependencies to provide for the build
idrisDeps = [ contrib lightyear ];
src = fetchFromGitHub {
owner = "Heather";
repo = "Idris.Yaml";
rev = "5afa51ffc839844862b8316faba3bafa15656db4";
sha256 = "1g4pi0swmg214kndj85hj50ccmckni7piprsxfdzdfhg87s0avw7";
};
meta = with lib; {
description = "Idris YAML lib";
homepage = "https://github.com/Heather/Idris.Yaml";
license = licenses.mit;
maintainers = [ maintainers.brainrape ];
};
}
```
Assuming this file is saved as `yaml.nix`, it's buildable using
```
$ nix-build -E '(import <nixpkgs> {}).idrisPackages.callPackage ./yaml.nix {}'
```
Or it's possible to use
```nix
with import <nixpkgs> {};
{
yaml = idrisPackages.callPackage ./yaml.nix {};
}
```
in another file (say `default.nix`) to be able to build it with
```
$ nix-build -A yaml
```
## Passing options to `idris` commands
The `build-idris-package` function provides also optional input values to set additional options for the used `idris` commands.
Specifically, you can set `idrisBuildOptions`, `idrisTestOptions`, `idrisInstallOptions` and `idrisDocOptions` to provide additional options to the `idris` command respectively when building, testing, installing and generating docs for your package.
For example you could set
```
build-idris-package {
idrisBuildOptions = [ "--log" "1" "--verbose" ]
...
}
```
to require verbose output during `idris` build phase.