I find the modules implementation in Julia the most annoying “feature” of the language. For large projects it makes sense that developers would want to organise their code in separate modules (not packages), each one in a separate directory with a number of files. But, in Julia the executed code should be formed so that it includes each module once and one after the other in the proper order of usage. This is like manually joining together all the files forming the code in the right order and therefore the concept of modules loses its meaning. Are there any plans for the future to build a proper module system like that present in other languages e.g. Python or Java?

The order of modules don’t matter if they are independent. If they are very interdependent, then why are they modules? If they are interdependent, don’t you need to specify the direction of the dependencies?

They can have dependencies. E.g. I may have a Mesh module which does some geometry work and then a Flow module which uses the mesh for solving the flow equations using various methods stored in separate modules which may need e.g, a Thermodynamics module and a Flow Properties module which needs to compute gradients and therefore it also needs the Mesh module etc. In a large code there are all kinds of possible dependencies that cannot be done in a way that somehow the modules are loaded one after the other in some particular sequence that includes them once and yet the result actually works correctly.

I think this is the same issue discussed here [image] [ANN] PatModules.jl: a better module system for Julia Package Announcements Okay, quite a lot to unpack here. Some quotes-with-answers deliberately out of chronological order for better presentation. I’ll start off by apologising if I’ve come across the wrong way. I certainly don’t mean to offend anyone. Clearly I have a controversial opinion – I am trying to express disagreement without derogation. I’ll restate that for emphasis: I absolutely don’t mean to cause offense. Thanks for the welcome! Okay, let’s get into the meat of this. I’m constructing a module/pac…

I am not surprised to see that other people are also frustrated by the modules in Julia. I guess that if the primary purpose of Julia was to be used for Jupyter notebooks and relatively small pieces of code which make heavy use of external packages then the module system is not important. But for a large scale scientific/engineering project things become very difficult with this implementation of modular programming.

I wouldn’t say that many people are frustrated with modules. One thread doesn’t prove it. I have used multiple modules in many (most of) my packages, and never with any ill effects or frustration.

Let’s say then that “some” people find it hard to cope with modules!

Rereading that thread I don’t quite understand the situation. Can you lay out a simple concrete scenario to discuss?

What I understand regarding the way Julia works is that it needs to have a single file with all the code inside and in the proper sequence (so that some piece of code does not e.g. uses types not defined yet but only later on) and then it executes it line after line until the end. So, if you use multiple files you need to include them to some main file and run this file. If you have modules again you need to include their source code manually so that they are only included once and in the right order. As a result, modules are not giving you any value like in other programming languages because you need to manually take care of their code so that at the end you create this large file with all the code for Julia to execute. And let’s not get into the whole dot notation for Julia to locate the modules with the “using” statements!

It seems that the issues you raise were addressed in this thread [image] Julia Modules Internals & Design The current situation with Julia modules is a nightmare with various keywords (include, using, import) and a lack of a simple and standard system for the compiler to find modules without playing around with source files. The same goes for exports. Rust has a nice and clean system of addressing these issues. Are there any plans for version 1.0 or beyond to provide a solution for this problem? that you opened some years ago. There doesn’t seem to be any new complaints in this iteration. Was the advice in that thread not helpful?

Apparently not! I’ve been waiting to see some improvements to the language ever since but modules remain the same.

Implicitly loaded modules in the future?

Internals & Design

jzr June 9, 2021, 9:10pm 4

I think this is the same issue discussed here

Topic		Replies	Views
[ANN] PatModules.jl: a better module system for Julia Package Announcements code-organization	70	10768	January 4, 2021
Organization of multiple modules in same package General Usage packages , modules , code-organization	18	5841	May 4, 2021
Proper way of organizing code into subpackages New to Julia packages , code-organization	48	9046	August 24, 2022
How to structure project in julia New to Julia	48	6967	June 5, 2023
How does the module system actually work? New to Julia question , package , first-steps	20	3457	January 21, 2021

Implicitly loaded modules in the future?

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