Modula 3 intro

[MarcusE1W]

20/04: Updated from comment below

Hi.
I have written this as an introduction into Modula-3 for the Pinebook Pro forum.
As I am new to Module 3 I was wondering if people here could have one look and let me know any suggestions.

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Modula-3 on the Pinebook

Installation

Modula-3 is a programming language based on Pascal and Modula 2 from Niklaus Wirth. Modula-3 has been developed in ~1992 by DEC with the blessing of Mr. Wirth.

Modula-3 is strongly typed, has a powerful module system and has generics, OO additions as well as build in support for concurrent programming. The additions to the language add some comport to programming. Here is an overview of the main differences between Modula-3 and Modula 2.

It also seems to be an historic oversight that the multi platform GUI library Trestle has not become more well known and popular.

The Trestle multi-platform GUI library from beginning of the 90th allows you to write Modula-3 programmes for X11 and Windows (Win32) with the same code and it all still works. In 1994 that was almost unique. Well worth to explore a bit.

There is an up-to-date Modula-3 compiler that installs and runs well on the Pinebook with Manjaro: CM3

A good install guide is in the Wiki

The steps to install on Manjaro are:

sudo pacman -S base-devel cmake
sudo pacman -S glu mesa xorg-server-devel
git clone https://github.com/modula3/cm3 cm3-git
mkdir build
cd build
../cm3-git/scripts/concierge.py install --prefix $HOME/cm3 all --target ARM64_LINUX

Notes for the install process:

• The final install folder is called cm3, that's why the git folder is called cm3-git to keep things separate
• You probably don't have to install all prerequisites. Some are installed already
• the build folder is created on the same level as the cm3-git folder

The compile process takes some time on the Pinebook Pro. This is probably a good opportunity to have a look at some of the highlights of the documentation:

• Modula-3 web site
• A good overview of the language can be found here. More a reference with examples than a tutorial.
• Overview of the Standard Library. Modula-3 is very module oriented, so this is a good start.
• The highlight for me is the GUI library Trestle. (Some makefiles in this document are in an older version and need small updates like "" added for names.)

The highlight for me is definitely the GUI library Trestle. Works perfect on Manjaro with X11. I have not tested it on Windows, but apparently that works as well. For an 30 years old library that is truly remarkable.

Have I mentioned the WYSIWYG GUI design app FormsVBT already ?

So, now the install should be completed. The compiler has been installed in ~/cm3
Add this bin folder to the PATH export PATH="$HOME/cm3/bin:$PATH"

Starting with Modula-3

Example 1: Hello World

Before the example here is the first m3makefile. Some help for the m3mankefile is here. For a small example it is not strictly necessary but this is how Modula-3 ticks so let's just use it:

Create a folder example
Create a subfolder example/src
Create the makefile example/src/m3makefile
Create the Modula-3 example example/src/Hello.m3

m3makefile

% HelloTrestle

import ( "ui")

implementation ("Hello")
program ("Hello")

Hello.m3

MODULE Hello EXPORTS Main;

IMPORT TextVBT, Trestle;

VAR v := TextVBT.New("Hello Trestle on Pinebook");

BEGIN
  Trestle.Install(v);
  Trestle.AwaitDelete(v)
END Hello.

In folder example use the command cm3 and the programme will be compiled.
The result is in ARM64_LINUX/. Start the example with ./ARM64_LINUX/Hello.

You get a nice little Window with a Hello message.

If you compare the m3makefile to some documentation you will also notice how to update some of the older m3makefiles mentioned there. Often additional "" are needed.

Example 2: Module concept

Modula-3 has it's name from the module concept. Her is how it works:
Every module has an interface definition in a file with .i3 ending. The implementation is in a file with .m3 ending.

Create another folder example2
Create example2/src

Place all files into the src/ folder:

The Interface description looks like this: A.i3

    INTERFACE A; 
    
    PROCEDURE DoIt();
      
    END A.

Here is the implementation of the interface: A.m3:

    MODULE A;
    IMPORT IO;

    PROCEDURE DoIt() = 
      BEGIN 
          IO.Put("Hello World\n"); 
      END DoIt; 
      
    BEGIN
    END A.

And the main programe: Example2.m3:

    MODULE Example2 EXPORTS Main; 
    IMPORT A; 
    
    BEGIN 
      A.DoIt(); 
    END Example2.

All brought together with the m3makefile

import ("libm3")
implementation ("Example2")
module ("A")
program ("test2")

Although some of the source material and documentation is old it still works nicely and Modula-3 is even by today's standards a very useful, flexible and pleasant language.

Key characteristics:

• compiles to native
• safe (almost always), with the option to be unsafe and manage memory
• garbage collected (optional)
• very portable
• has generics

The kink with the capitalised KEYWORDS is sorted in the editor, e.g. Emacs or VSCode. You don't need to actually types like that but it makes the structure of the source code very clear and readable.

[RodneyBates]

This looks very good.  No substantive suggestions, but two very minor bikeshedding, spelling things.  Niklaus Wirth and Trestle.                        ^              ^ Glad to hear of some uses of Trestle, FormsVBT, etc. Keep up the good work.

…

On 4/1/22 05:02, MarcusE1W wrote: Hi. I have written this as an introduction into Modula 3 for the Pinebook Pro forum <https://forum.pine64.org/forumdisplay.php?fid=111>. As I am new to Module 3 I was wondering if people here could have one look and let me know any suggestions. ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ Modula 3 on the Pinebook Installation Modula 3 is a programming language based on Pascal and Modula 2 from Niklas Wirth. Modula 3 has been developed in ~1992 by DEC with the blessing of Mr. Wirth. Modula 3 is strongly typed, has a powerful module system and has generics, OO additions as well as build in support for concurrent programming. The additions to the language add some comport to programming. Here <XXX> is an overview of the main differences between Modula 3 and Modula 2. It also seems to be an historic oversight that the multi platform GUI library Tristle has not become more well known and popular. The Tristle multi-platform GUI library from beginning of the 90th allows you to write Modula 3 programmes for X11 and Windows (Win32) with the same code and it all still works. In 1994 that was almost unique. Well worth to explore a bit. There is an up-to-date Modula 3 compiler that installs and runs well on the Pinebook with Manjaro: CM3 <https://github.com/modula3/cm3> A good install guide is in the Wiki <https://github.com/modula3/cm3/wiki/Getting-Started:-Linux> The steps to install on Manjaro are: |sudo pacman -S base-devel cmake sudo pacman -S glu mesa xorg-server-devel git clone https://github.com/modula3/cm3 cm3-git mkdir build cd build ../cm3-git/scripts/concierge.py install --prefix $HOME/cm3 all --target ARM64_LINUX | Notes for the install process: * The final install folder is called |cm3|, that's why the git folder is called |cm3-git| to keep things separate * You probably don't have to install all prerequisites. Some are installed already * the |build| folder is created on the same level as the |cm3-git| folder The compile process takes some time on the Pinebook Pro. This is probably a good opportunity to have a look at some of the highlights of the documentation: * Modula 3 web site <http://modula3.github.io/cm3/> * A good overview of the language can be found here <http://modula3.github.io/cm3/tutorial/m3/m3_toc.html>. More a reference with examples than a tutorial. * Overview of the Standard Library <http://modula3.github.io/cm3/help/interfaces.html>. Modula 3 is very module oriented, so this is a good start. * The highlight for me is the GUI library Tristle <http://modula3.github.io/cm3/src_reports/src-069.pdf>. (Some makefiles in this document are in an older version and need small updates like "" added for names.) The highlight for me is definitely the GUI library Tristle. Works perfect on Manjaro with X11. I have not tested it on Windows, but apparently that works as well. For an 30 years old library that is truly remarkable. Have I mentioned the WYSIWYG GUI design app FormsVBT <http://modula3.github.io/cm3/src_reports/formsvbt.pdf> already ? formsedit <https://camo.githubusercontent.com/92c9661661376bb865c85ccf613fee8c225b8fcf4854aff425cfc55c6b303667/68747470733a2f2f692e706f7374696d672e63632f5a306b77745358582f466f726d735642542e706e67> So, now the install should be completed. The compiler has been installed in |~/cm3| Add this bin folder to the PATH |export PATH="$HOME/cm3/bin:$PATH"| Starting with Modula 3 Example 1: Hello World Before the example here is the first m3makefile. Some help for the m3mankefile is here <http://modula3.github.io/cm3/tutorial/m3/m3_3.html#SEC3>. For a small example it is not strictly necessary but this is how Modula 3 ticks so let's just use it: Create a folder |example| Create a subfolder |example/src| Create the makefile |example/src/m3makefile| Create the Modula 3 example |example/src/Hello.m3| m3makefile |% HelloTrestle import ( "ui") implementation ("Hello") program ("Hello") | Hello.m3 |MODULE Hello EXPORTS Main; IMPORT TextVBT, Trestle; VAR v := TextVBT.New("Hello Trestle on Pinebook"); BEGIN Trestle.Install(v); Trestle.AwaitDelete(v) END Hello. | In folder |example| use the command |cm3| and the programme will be compiled. The result is in |ARM64_LINUX/|. Start the example with |./ARM64_LINUX/Hello|. You get a nice little Window with a Hello message. Hello window <https://camo.githubusercontent.com/79bf70fa026821dbda1d1e85c75f4051be563a56abccdde8c8f54f14918d3e3d/68747470733a2f2f692e706f7374696d672e63632f58716363424372372f48656c6c6f2e706e67> If you compare the m3makefile to some documentation you will also notice how to update some of the older m3makefiles mentioned there. Often additional "" are needed. Example 2: Module concept Modula 3 has it's name from the module concept. Her is how it works: Every module has an interface definition in a file with |.i3| ending. The implementation is in a file with |.m3| ending. Create another folder |example2| Create |example2/src| Place all files into the |src/| folder: The Interface description looks like this: |A.i3| |INTERFACE A; PROCEDURE DoIt(); END A. | Here is the implementation of the interface: |A.m3|: |MODULE A; IMPORT IO; PROCEDURE DoIt() = BEGIN IO.Put("Hello World\n"); END DoIt; BEGIN END A. | And the main programe: |Example2.m3|: |MODULE Example2 EXPORTS Main; IMPORT A; BEGIN A.DoIt(); END Example2. | All brought together with the |m3makefile| |import ("libm3") implementation ("Example2") module ("A") program ("test2") | Although some of the source material and documentation is old it still works nicely and Modula 3 is even by today's standards a very useful, flexible and pleasant language. The kink with the capitalised KEYWORDS is sorted in the editor, e.g. Emacs <https://github.com/modula3/cm3/tree/master/m3-tools/gnuemacs/src> or VSCode. You don't need to actually types like that but it makes the structure of the source code very clear and readable. — Reply to this email directly, view it on GitHub <#1021>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ABSVZNHGQSRWXH5O4PPZDXDVC3CSHANCNFSM5SIF3XZA>. You are receiving this because you are subscribed to this thread.Message ID: ***@***.***>

[jaykrell]

"Modula 3" can you remove the space or maybe put in a dash?
Optionally safe. Optionally garbage collected. Always compiles to native. Never JITed. Has generics. Has a decent builtin build system. And very portable by virtue of targeting C++ and Posix or Windows. And written in itself. :)

[mikanystrom]

Ah, Jay... I agree it is "Modula-3". But... I'd write, "Optionally unsafe", "optionally self-managed memory"... the clear design intent of the language is to be "almost always" safe & garbage collected! I think your views are a bit skewed since you work a lot in the twilight-zone interface world between M3, the OS, and C bindings. My experience is that if you actually write a lot of application code in M3, you almost never resort to using the keyword "UNSAFE". Yeah you can sometimes get some more performance by using it, but even without it, I think you tend to do a lot better than Java in most cases. Mika

…

On Tue, Apr 19, 2022 at 3:55 AM Jay Krell ***@***.***> wrote: "Modula 3" can you remove the space or maybe put in a dash? Optionally safe. Optionally garbage collected. Always compiles to native. Never JITed. Has generics. Has a decent builtin build system. And very portable by virtue of targeting C++ and Posix or Windows. And written in itself. :) — Reply to this email directly, view it on GitHub <#1021 (reply in thread)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ABKYNJIW7KOXIQ5ADZNBUOLVF2GJVANCNFSM5SIF3XZA> . You are receiving this because you are subscribed to this thread.Message ID: ***@***.***>

[jaykrell]

I have grown to be wary of garbage collectors, sorry.

[jaykrell]

But optionally safe is much better than safe. Always safe languages cannot be written in themselves.
Optionally safe is historically rare. Compiled to native is historically rare. They are less rare these days: .Net.Native, Rust, and Go, share these characteristics. Java, Ruby, Python, Perl, C++, do not.

[mikanystrom]

I'm not disagreeing with you! Just proposing a change in emphasis. "Optionally unsafe" rather than "Optionally safe". Why are you wary of garbage collectors?

…

On Wed, Apr 20, 2022 at 12:15 AM Jay Krell ***@***.***> wrote: But optionally safe is much better than safe. Always safe languages cannot be written in themselves. Optionally safe is historically rare. Compiled to native is historically rare. They are less rare these days: .Net.Native, Rust, and Go, share these characteristics. Java, Ruby, Python, Perl, C++, do not. — Reply to this email directly, view it on GitHub <#1021 (reply in thread)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ABKYNJOOEY6WAYP2JD7LXM3VF6VIVANCNFSM5SIF3XZA> . You are receiving this because you commented.Message ID: ***@***.***>