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What is MPM?

MPM or MetaReal Package Manager is a set of tools for organizing, downloading, and uploading MetaReal projects and packages.
It directly interacts with the MetaReal main repository and can download packages to improve your project quality.
Packages are MetaReal projects created by programmers globally to simplify specific tasks and help programmers focus more on their program logic rather than its implementation.
To start, let's get the installed MPM version.

$ mpm --version
MPM (MetaReal Package Manager) version 1.0.0
MPM is running on MetaReal version 1.0.0

Or you can use the command down below.

$ metareal --mpm --version
MPM (MetaReal Package Manager) version 1.0.0
MPM is running on MetaReal version 1.0.0

MPM's reason for existence is:

  1. To download available packages from the MetaReal online repository.
  2. To upload packages that you created to the MetaReal online repository.
  3. To organize, update, and link your installed packages.

Install Packages​

Let's install a sample MetaReal project to see the MPM in action.

tip

To install the package properly, check your network connection.
If the MPM fails to download the project due to network issues, MPM will schedule your installation request until it finds a stable network connection.

We will install mr_sample. It is a sample package that includes various functions and data structures.
Use the following command to install the mr_sample package.

$ mpm --install mr_sample
...
downloading process
...
MPM: "mr_sample" package installed successfully

To check if the package installation is complete, type down the following command that displays the package information.

$ mpm --info mr_sample
Library:      mr_sample
Version:      1.0.0
Last Update:  29/12/2023 9:27:30
Author:       MetaReal
Description:
mr_sample is a sample library that features all of MetaReal's capabilities.

Write The Code​

We will write a simple program that uses the mr_sample library.

mpm.mr
import mr_sample

mr_sample.say("Hello World")

The import is a MetaReal keyword that imports definitions of a library into your program.
You can access a particular definition with the following syntax: <library name>.<definition>. If you compile it, you get a Hello World message, just like the print function.

$ metareal mpm.mr
$ ./mpm
Hello World

A summary of what you learned:

  • MPM and its use cases
  • mpm --version, mpm --install, and mpm --info commands
  • mr_sample library
  • The import keyword
  • Accessing definitions of a library

This section was a quick but useful guide about the powerful MetaReal Package Manager.
We will return to the MPM for more complicated installations and when we want to create our project and upload it into the MetaReal repository.
But as for now, let's start learning the MetaReal, for real.