Indigo eDSL¶

Indigo eDSL is a high level language for Michelson contract development.

It is meant first and foremost to free you from the burden of manual stack management and supports common features of imperative languages.

Even with a very small example the difference in ease of use is quite visible:

exampleContract :: IndigoContract Integer Integer
exampleContract param = defContract do
  a <- new$ 1 int
  storageVar =: param + a

parameter int;
storage int;
code { # We put an empty list of operations at the beginning and remember its position,
       # it is updated when a new operation is made.
       NIL operation;
       SWAP;

       # Then we unpair the parameter and storage.
       UNPAIR;

       # We push an integer 1 and duplicate it for later use.
       PUSH int 1;
       DUP;

       # We duplicate the parameter and bring it to the top.
       DIP 2
           { DUP };
       DIG 2;

       # We add the integer 1 with the parameter value.

You can find larger examples here.

Overall idea¶

Michelson contracts are stack-based and often follow the repetitive pattern of copying the required values on top of the stack to apply an instruction to them. Indigo can associate variables to values in the stack and it's able to refer to them in order to handle this pattern automatically.

In addition to this it can override existing variables with new values, allowing the manipulation of the stack to be automatic.

Leveraging this ability, it also supports features such as: imperative statements (if, while, ...), expressions, operators (+, ||, ==, ...), scoped functions definition and errors.

Indigo is built on top of Lorentz, which in turn is built on top of Morley, a dialect that is a superset of vanilla Michelson. If you are interested more in the relationships between these projects you can head over to the repo on GitLab.

Indigo uses Morley to map values from Michelson to Haskell and to compile to Michelson code (or to any of the other projects in the chain mentioned above).

Installing Indigo CLI¶

Installing Indigo CLI via docker¶

Indigo CLI provides commands for development and interaction with Indigo project.

For new users who want faster installation just to try indigo out, we recommend installing indigo via docker.

For POSIX-compliant operating systems, simply run:

curl https://gitlab.com/morley-framework/indigo/-/raw/production/scripts/indigo.sh > ~/.local/bin/indigo
chmod +x ~/.local/bin/indigo
indigo --help

This is a wrapper over docker image that contains indigo binary and cached Haskell dependencies which provides faster insllation time for the sake of slightly slower performance and the inability to run test command.

Installing Indigo CLI from source¶

Before installing Indigo CLI by building from source, it's recommended to update the package lists of you OS repository before installing indigo via installation script. E.g. you should run sudo apt-get update if you're using Ubuntu.

For POSIX-compliant operating systems, the easiest way to install is to run:

curl -sSL https://indigo-lang.gitlab.io/install.sh | bash

or:

wget -qO- https://indigo-lang.gitlab.io/install.sh | bash

Note that installing Indigo CLI from source and using it to build a project for the very first time can take quite a bit of time. Subsequent usage will be much faster.

Also note that the https://indigo-lang.gitlab.io/install.sh script may ask for root access using sudo in order to use your platform's package manager to install dependencies and to install to /usr/local/bin.

The script also expects ~/.local/bin to be in $PATH to be able to install Indigo CLI properly.

Learning and using Indigo¶

An introduction to the syntax and the features of the Indigo language, as well as instructions on how to use it, are available in the form of a step-by-step tutorial.

This aims to be accessible to as many people as possible, but also contains more technical informations for Haskell developers that are interested in learning more.

For this reason anyone interested in learning more about the language in practice should start by taking a look at its Getting started page.

Additional documentation¶

In addition to the tutorial, this documentation contains full reference pages and, as for the other Morley projects, Indigo has Haddock documentation.

Contributing to this website¶

If you want to report a bug or request changes to this website you can do so by creating a new GitLab issue.

If you instead would like to propose changes, you can use the Edit on GitLab links at the top of every page, or open a new merge request.

The source for this website can be found here in the repository where the README contains info on how it's built.