MATLAB: Does the custom function signatures specified in the ‘functionSignatures.json’ file do not show up in the MATLAB Editor or the Command Window

I tried to implement the "Create Function Signature File" example present in the following link, without any modifications:

https://www.mathworks.com/help/releases/R2018b/matlab/matlab_prog/customize-code-suggestions-and-completions.html#mw_386ccd79-c5ee-4923-be23-ce9be17d83fa

I even kept the 'functionSignatures.json' file unchanged.

When I try to pull up the code suggestion for 'myFunc' (by pressing the keys 'CTRL+F1' on Windows), I don't get the correct signatures (as defined in the 'functionSignatures.json' file and shown in the tutorial).

I get the following code suggestion:

While I should be getting something like:

It seems that the 'functionSignatures.json' file is not being used at all. Why does this happen?

Best Answer

The code suggestions derived from the 'functionSignatures.json' file only apply to Live Scripts (i.e., '.mlx' files) in MATLAB.

To quote from the official MATLAB documentation page for code suggestions at:

https://www.mathworks.com/help/releases/R2018b/matlab/matlab_prog/customize-code-suggestions-and-completions.html

"To experiment with code suggestions, start to call the function from a live script and observe the suggestions...."

Moreover, if you look closely, the screenshots in the documentation page are from a live script and not from the MATLAB Command Line or the MATLAB Editor.

If you will try <TAB> completion in a live script, as per the tutorial published at:

You will be able to get the code suggestions, as defined in the JSON file.