I'm changing the item group for this report to be "Feature Request" instead of "Matlab Compatibility".  There are compatibility concerns, but supporting functions with local scope in script files is a new feature.

I just hit this (compatibility) issue as well. Are there any news or plans to implement this change?

(I only ask this, because to me there seemed to be a consensus in the discussion of this thread already: to add a special tag for a script file that is intended to contain global functions).

RE: comment #13:  Ah, right, like an include file that includes a set of variables and function definitions.  OK.

I think the real problem with globally visible functions in a script file is that reloading the script if it changes in order to get updated function definitions is problematic.  The script could do more than just define functions.  Executing the script again at a random time is probably not good.  And I think we currently do that (don't try to reload function definitions if they come from a script file).  So maybe all that is needed is some other way to indicate "this is a script file that may contain functions that should be globally visible" instead of the old "1;" thing.

>  Maybe we could repurpose the `global` keyword

I think something backwards compatible would be nice, how about a special comment tag that marks the m-file as an import script?

The following would work in old versions of Octave and in the latest Octave if this support is added

## OCTAVE-SPECIAL-IMPORT-MARKER
1;

function myfunc1
...

I suppose it is possible, but I don't see why they would be considered nested unless they were actually defined inside another function (not just the script).

If we discourage the expectation that a script will define globally visible functions, then any future transition will be easier.

Many uses of script files that contain functions could be handled perfectly well with Matlab-style local functions that are not globally visible.  Converting Octave scripts to work that way would be fairly easy.

If people really want to be able to define globally visible functions in a script file, then maybe we could provide some way to mark them as such (an export function or command?).

Since Matlab requires local function definitions to all be at the end of the script, and Octave requires all functions defined in scripts to be available before they are used, I don't see a conflict except for Octave scripts that are used as include files to define multiple global functions.  Although I thought that was a nifty feature back in the day, I would be OK with discouraging it now.

On the maintainers list I asked for someone to run a couple of scripts to test.

I don't see that detecting Matlab-style local functions based on what the file contains is much different from detecting subfunctions vs. nested functions based on the presence of "end" tokens.

I also don't see that we have much of a choice about whether to support Matlab-style local functions in scripts.

I think we can detect the Matlab-style local functions by noting that all the functions definitions occur at the end of the script and that once a function definition is parsed, the only thing that we see in the file are more function definitions and no other code.  Otherwise, we could proceed as we do now and make functions in the script globally visible.  That still leaves a change in behavior for scripts that begin with some trivial code like "1;" and then simply define functions.  We could recognize that as a special case (it's been the recommended way to do this forever) though I'm not sure that's a good thing to do.

Ah, you're right. I didn't realize they stayed available after the script run. But some simple testing confirms that.

Hmm. I don't see a way to add local function support in a way that doesn't break command-line function support. Maybe this is a WONTFIX.

Both Matlab and Octave now support the use of local functions inside scripts. But they do it differently: Octave requires that the local functions be defined before their use, whereas Matlab requires that all local functions be defined at the end of the script. So any script that uses local functions will only work on one of the two, depending on how it's written.

It would be nice to add support for defining local functions at the end of scripts, for Matlab compatibility, and more flexibility in how users write their source code.

References:
- https://stackoverflow.com/questions/50404236/error-when-running-simple-script-containing-local-function-in-octave
- https://stackoverflow.com/questions/55770635/how-to-write-a-single-octave-script-with-function-definitions-compatible-with-ma