Modules

Table of contents

1. Modules
   1. Importing
      1. Standard library
      2. User created scripts
      3. __file__

Modules

Modularity is important in any project, and a project in Dictu is obviously no exception to this rule. Dictu solves this problem by breaking files up into “modules”. Every file is it’s own module, and each module has it’s own namespace, this means a variable defined in file.du will not overwrite a variable in file1.du if imported.

Importing

Standard library

When you wish to import a module from the standard library you use the import keyword. Importing from the standard library is slightly different to importing a user created script (see below).

import Math;

Math.PI; // 3.14... 

If however you wish to import something specific from the module into the current scope you can use a from import, this accepts a single identifier or multiple separated by a comma.

from Math import pi;

pi; // 3.14...

// Import multiple things
from JSON import parse, stringify;

User created scripts

When you wish to import another Dictu script, you use the import keyword. This takes an optional identifier which will be the identifier of the module being imported. This is different to importing from the standard library as a string path is passed rather than an identifier. The path to the module is relative to the importing scripts location, not where the process is executed.

// Module not imported into current namespace, however the code in "some/file.du" is still ran.
import "some/file.du";

// This will import the module into the current namespace under the SomeModule identifier.
import "some/file.du" as SomeModule;

When importing a module with an identifier, you can access the top level module variables using the . operator, much like you would for a class.

some/file.du

var x = 10;

def test() {
    return "test";
}

main.du

import "some/file.du" as SomeModule;

print(SomeModule.x); // 10
print(SomeModule.test()); // "test"

Once an module has been imported, it is stored within the VM, and is not executed again even if it is imported elsewhere. What happens is the module is “loaded” again, which means if it was to change in the time from import, it will not be changed within your program even if re-importing the module.

Same as importing specific items from a builtin module, from imports also work on user created files.

from "some/file.du" import x, test;

print(x); // 10
print(test()); // "test"

__file__

Similar to the built-in variable, __file__ is also available on built-in modules.

import HTTP;
print(HTTP.__file__); // 'HTTP'