Camel – Types

Chapter 2 : Types

Welcome onboard captain, I’m the ship’s mechanic. The first thing to do before departing is to define your ship’s parameters. Go ahead!

LIGO is a strongly and statically typed language. This means that the compiler checks how your contract processes data. If it passes the test, your contract will not fail at run-time due to inconsistent assumptions on your data. This is called type checking.

Built-in types

LIGO comes with all basic types built-in like string, int or tez for account balance or monetary transactions. You can find all built-in types on the LIGO gitlab.

Type aliases

Type aliasing consists in renaming a given type, when the context calls for a more precise name. This increases readability and maintainability of your smart contracts. For example we can choose to alias a string type as an animal breed – this will allow us to comunicate our intent with added clarity.

Simple types

The type account_balances denotes a map from addresses to tez

ℹ️We will look more deeply into the map construct in the following chapters.

Structured types

Often contracts require complex data structures, which in turn require well-typed storage or functions to work with. LIGO offers a simple way to compose simple types into structured types. The first of those structured types is the record, which aggregates types as fields and index them with a field name. In the example below we define an account type whick keeps the balance and number of previous transactions for a given account.

ℹ️We will look more deeply into the record construct in the following chapters.

Your mission

1- There is an online editor in the top right corner of this page. In the editor, define ship_code as a string type.

2- Then define the constant my_ship as a ship_code of value “020433”.

3- Then go ahead and validate your mission for a comparative view with the solution.

1 // Type your solution below 2