Agda-pkg is a simple tool to manage Agda libraries with extra features like installing libraries from different kind of sources.

This tool does not modify Agda at all, it just manages systematically the directory .agda with .agda/defaults and .agda/libraries files used by Agda to locate the available libraries. For more information about how Agda package system works, please read the official documentation here.

The most common usages of agda-pkg are the following:

• To install Agda-pkg just run the following command:

$ pip3 install agda-pkg

• To install your library, go to the root directory of your source code and run:

$ apkg install --editable .

• To install a library from agda/package-index.

$ apkg init
$ apkg install standard-library
$ apkg install [email protected]

• To install a Github repository with a specific version release:

$ apkg install --github agda/agda-stdlib --version v1.3

• To install a library from a Github repository with a specific branch with a specific library name:

$ apkg install --github plfa/plfa.github.io --branch dev --name plfa

The easiest way to install libraries is by using the package index. agda-pkg uses a local database to maintain a register of all libraries available in your system. To initialize the index and the database please run the following command:

$ apkg init
Indexing libraries from https://github.com/agda/package-index.git

Note. To use a different location for your agda files defaults and libraries, you can set up the environment variable AGDA_DIR before run apkg as follows:

$ export AGDA_DIR=$HOME/.agda

Other way is to create a directory .agda in your directory and run agda-pkg from that directory. agda-pkg will prioritize the .agda directory in the current directory.

Check all the options of a command or subcommand by using the flag --help.

$ apkg --help
$ apkg install --help

Recall updating the index every once in a while using upgrade.

$ apkg upgrade
Updating Agda-Pkg from https://github.com/agda/package-index.git

If you want to index your library go to the package index and make PR.

If there is an issue with your installation or you suspect something is going wrong. You might want to see the environmental variables used by apkg.

$ apkg environment

To see all the packages available run the following command:

$ apkg list

The list command option comes with the flag --full to display more details.

Install a library is now easy. We have multiple ways to install a package.

• from the package-index

$ apkg install standard-library

• from a local directory

$ apkg install .

or even much simpler:

$ apkg install

Installing a library creates a copy for agda in the directory assigned by agda-pkg. If you want your current directory to be taken into account for any changes use the --editable option. as shown below.

$ apkg install --editable .

• from a github repository

$ apkg install --github agda/agda-stdlib --version v1.1

• from a git repository

$ apkg install http://github.com/jonaprieto/agda-prop.git

To specify the version of a library, we use the flag --version

$ apkg install standard-library --version v1.0

Or simpler by using @ or == as it follows.

$ apkg install [email protected]
$ apkg install standard-library==v1.0

To install multiple libraries at once, we have two options:

1. Using the inline method

$ apkg install standard-library agda-base

Use @ or == if you need a specific version, see above examples.

2. Using a requirement file:

Generate a requirement file using apkg freeze:

$ apkg freeze > requirements.txt
$ cat requirements.txt
standard-library==v1.1

Now, use the flag -r to install all the listed libraries in this file:

$ apkg install -r requirements.txt

Check all the options of this command with the help information:

$ apkg install --help

Uninstalling a package will remove the library from the visible libraries for Agda.

• using the name of the library

$ apkg uninstall standard-library

• infering the library name from the current directory

$ apkg uninstall .

And if we want to remove the library completely (the sources and everything), we use the flag --remove-cache.

$ apkg uninstall standard-library --remove-cache

We can get the latest version of a package from the versions registered in the package-index.

• Update all the installed libraries:

$ apkg update

• Update a specific list of libraries. If some library is not installed, this command will installed the latest version of it.

$ apkg update standard-library agdarsec

$ apkg freeze
standard-library==v1.1

This command is useful to keep in a file the versions used for your project to install them later.

$ apkg freeze > requirements.txt

To install from this requirement file run this command.

$ apkg install < requirements.txt

We make a search (approximate) by using keywords and title of the packages from the index. To perform such a search, see the following example:

$ apkg search metis
1 result in 0.0012656739999998834seg
cubical
url: https://github.com/agda/cubical.git
installed: False

$ apkg info cubical

In this section, we describe how to build a library.

To build a project using agda-pkg, we just run the following command:

$ apkg create

Some questions are going to be prompted in order to create the necessary files for Agda and for Agda-Pkg.

The output is a folder like the following showed below.

A common Agda library has the following structure:

$ tree -L 1 mylibrary/
mylibrary/
├── LICENSE
├── README.md
├── mylibrary.agda-lib
├── mylibrary.agda-pkg
├── src
└── test

2 directories, 3 files

$ cat mylibrary.agda-lib
name: mylibrary  -- Comment
depend: LIB1 LIB2
  LIB3
  LIB4
include: PATH1
  PATH2
  PATH3

This file only works for agda-pkg. The idea of this file is to provide more information about the package, pretty similar to the cabal files in Haskell. This file has priority over its version .agda-lib.

$ cat mylibrary.agda-pkg
name:              mylibrary
version:           v0.0.1
author:
    - AuthorName1
    - AuthorName2
category:          cat1, cat2, cat3
homepage:          http://github.com/user/mylibrary
license:           MIT
license-file:      LICENSE.md
source-repository: http://github.com/user/mylibrary.git
tested-with:       2.6.0
description:       Put here a description.

include:
    - PATH1
    - PATH2
    - PATH3
depend:
    - LIB1
    - LIB2
    - LIB3
    - LIB4

A nix-shell environment that loads agda-pkg as well as agda and agda-mode for Emacs is available. To use this, apkg can put the necessary files in your project folder by running one of the following commands:

$ curl -L https://gist.github.com/jonaprieto/53e55263405ee48a831d700f27843931/download | tar -xvz --strip-components=1

or if you already have installed agda-pkg:

$ apkg nixos

Then, you will have the following files:

./hello-world.agda
./agda_requirements.txt
./shell.nix
./deps.nix
./emacs.nix

From where you can run the nix shell.

$ nix-shell

To launch Emacs with agda-mode enabled, run mymacs in the newly launched shell; mymacs will also load your ~/.emacs file if it exists. If you are using Spacemacs, you will need to edit shell.nix to use ~/.spacemacs instead.

The files provided by the commands above are also available in this repository (apkg/support/nix) and in a third-party example repository to give an idea of exactly which files need to be copied to your project.

Example:

$ cat hello-world.agda
module hello-world where
open import IO
main = run (putStrLn "Hello, World!")

Run mymacs hello-world.agda then type C-c C-x C-c in emacs to compile the loaded hello world file.

Edit any of the nix expressions as needed. In particular:

0. To add Agda dependencies via agda-pkg, edit agda_requirements.txt
1. To add more 4Haskell or other system dependencies or other target-language dependencies, edit deps.nix.
2. To add or alter the editor used, change the myEmacs references in shell.nix or add similar derivations.
3. Optionally, create .emacs_user_config in the repository root directory and add any additional config, such as (setq agda2-backend "GHC") to use GHC by default when compiling Agda files from emacs.

This is a proof of concept of an Agda Package Manager. Contributions are always welcomed.