Misleading wording in the documentation on Matlab package (+) folders.

16 views (last 30 days)
In the page Packages Create Namespaces there are two sections on how to reference package members:
  • From inside the package
  • From outside
When considering the 'within' case, there is an explicit statement:
Functions, classes, and other packages contained in a package are scoped to that package
Further considering how namespaces work in other languages I would have thought that within a package, it would not be necessary to use the package prefix to call other members of a package. Unfortunately however, this seems not to be the case.
+mypack\functionOne.m +mypack\functionTwo.m
If I want to call functionOne from functionTwo, I still have to use mypack.functionOne()
Why is this?? Am I missing something because this just seems very unpractical and makes me wonder about the meaning of the statement:
Functions, classes, and other packages contained in a package are scoped to that package
  1 Comment
Kris Janssen
Kris Janssen on 21 Apr 2016
Edited: Kris Janssen on 21 Apr 2016
Thinking about it, the 'scope' statements probably refers to precedence of function names when there are similarly named functions on the path. Then again, it would have been convenient to not have to go and rename tons of lines of codes when files get moved from one package to the next.

Sign in to comment.

Accepted Answer

Guillaume on 21 Apr 2016
It does say in the documentation that you've linked under Referencing Package Members Within Packages that "All references to packages, functions, and classes in the package must use the package name prefix, unless you import the package".
In my opinion, it's a very stupid decision by Mathworks that completely kills the usefulness of packages. Rename the package and you've got to edit every single file within the package that references other files in the package.
It also stop the user of your code to simply wrap it into a package name of his choice (that he knows is not going to conflict with another package name) since the user is then force to edit your code to add references to the package name. So, this just moved the problem of you having to choose a name for your function that is not going to conflict with somebody's else functions to you having to choose a name for a package that is going to conflict with somebody's else package.

Sign in to comment.

More Answers (4)

Miron Voin
Miron Voin on 22 Mar 2020
This behavior seems to be unacceptable - looks just like a bug. Any workaround from Mathworks?
  1 Comment
Nathan Zimmerberg
Nathan Zimmerberg on 31 Mar 2020
This is a workaround I came up with, it works on my Mac os 2019b MATLAB.
[filepath,~,~] = fileparts(mfilename('fullpath'));
packages= split(string(filepath),filesep+"+")';
for i= 2:length(packages)
I add this to the begining of all of my functions, and it just imports all the parent packages. I have no idea what effect this might have on performance, and there is a warning that importing using variables will no longer be supported in a future version of MATLAB, but hopefully mathworks will create a better workaround by then.

Sign in to comment.

jg on 22 Apr 2020
Edited: jg on 22 Apr 2020
Ouch, I knew I wasn't only one that thinks this is a mess. The main benefit of packages is that members of the package don't have to refer to other members of the same package by using the package name.
That's like addressing everyone in your immediate family using Firstname Middlename Lastname every time you talk to them.

Jim Svensson
Jim Svensson on 18 Jan 2019
I just concur that this is one of the top stupidest design desisions of the Matlab language.

Dariusz Borkowski
Dariusz Borkowski on 6 Dec 2019
I can confirm. The current package design is a no-go.


Find more on Software Development Tools in Help Center and File Exchange

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by