REBOL 3 Functions: import

import module /version ver /check sum /isolate /only

Imports a module; locate, load, make, and setup its bindings.

Arguments:

module [word! file! url! module! block!]

Refinements:

/version

ver [tuple!] - Module must be this version or greater

/check

sum [binary!] - Module checksum as (checksum/secure of mold/flat)

/isolate - Force module to create and use its own non-shared global namespace

/only - Load and return module, but don't export to system

Description

The import function is used to import modules into your runtime environment. For a full description see the modules: loading modules section of this documentation.

For example, you can write:

import 'mysql

and the system will search for the mysql module.

You can also use a filename or URL for the module identifier:

import %mysql.r

import http://www.rebol.com/mods/mysql.r

Return value

When successful, the import function returns a module! datatype as its result.

This allows you to write:

mysql: import 'mysql

Now, the mysql variable can be used to refer to values within the mysql module.

For example the module value is used here to reference a function:

mysql/open-db %my-database.sql

See below for more.

Useful refinements

Like the header needs field, the import function also lets you specify a version and a checksum.

These are all supported:

import/version mysql 1.2.3

import/check mysql #{A94A8FE5CCB19BA61C4C0873D391E987982FBBD3}

import/version/check mysql 1.2.3 #{A94A8FE5CCB19BA61C4C0873D391E987982FBBD3}

When to use IMPORT

The benefit of using the import function compared to the needs header field is that the arguments can be variables.

A basic example is:

mod: 'mysql
import mod

Or, something like:

mod-list: [
    mysql 1.2.3
    db-gui 2.4.5
    http-server 1.0.1
]

foreach [id ver] mod-list [
    import/version id ver
]

REBOL 3 Functions: import

Contents

Description

Return value

Useful refinements

When to use IMPORT