Modules

A module is a collection of source code, such as types and methods, in its own namespace. Each Inko source file is automatically a module. There is no way to define a module manually.

Module names

The name of a module is derived from the path (relative to a source directory) of the Inko source file the module belongs to. Imagine your project structure is as follows:

src/
└── foo/
    └── bar.inko

Here src/ is added to the list of directories the compiler will search for Inko source files. The foo/ directory defines a namespace (foo), and contains a single module: bar. In Inko, the namespace separator is ::, meaning the full name of this module is foo::bar.

The methods and types in a module are always public, and there is no way to declare these as private. If your module relies on certain types or methods that you don't want to expose as part of the public API, moving these types and/or methods to a separate module is the best solution. For example, the module std::fs::file relies on various methods provided by the module std::fs::bits.

Info

We are considering adding support for private methods and constants, though this is not a priority for the time being. For more information, take a look at the issue "Private constants and methods".

Referring to the current module

Inside a module, self refers to the module itself:

def foo {}

self.foo # Same as just `foo`

You can also use the global ThisModule, which is automatically defined for every module and refers to the module itself:

def foo {}

ThisModule.foo # Same as `self.foo`, which is the same as `foo` in this case

This is useful if we want to send a message to the module, but the lack of an explicit receiver would cause a conflict:

def example -> Integer {
  10
}

class Example {
  def example -> Integer {
    # This ensures we return `10`, instead of recursing back into the current
    # method.
    ThisModule.example
  }
}

Importing modules

Modules can import other modules, as well as their types; optionally binding them using a different name. You can import a module using the import keyword.

Imports can only occur at the top-level of a module. So this is fine:

import foo

But this is not:

def example {
  import foo
}

Importing a module itself is done as follows:

import std::fs::file

The file module can then be accessed using the file global.

Importing a single constant from a module (instead of importing the module as a whole) is done as follows:

import std::fs::file::ReadOnlyFile

If you want to import multiple constants, you can do so as follows:

import std::fs::file::(ReadOnlyFile, WriteOnlyFile)

If you want to bind a constant to a different name, you can do so as follows:

import std::fs::file::(ReadOnlyFile as File)

File         # => OK
ReadOnlyFile # => undefined

If you want to import both a module and some of its constants, you can do so as follows:

import std::fs::file::(self, ReadOnlyFile)

You can also import a module as a whole and bind it to a different name:

import std::fs::file::(self as foo)

Info

Importing of methods isn't supported. For more information, refer to the issue "Allow importing of just methods from a module".

Import order

Imports are always processed before executing any code in a module, in the same order as the import statements. This means that this:

import std::stdio::stdout

stdout.print('hello')

import std::fs::file

Is executed as if it were written like this:

import std::stdio::stdout
import std::fs::file

stdout.print('hello')