Cell Coordinate splitRange doesn't support space delimeter

[mcouillard]

This is: new feature to support spaced coordinates instead of just comma delimited lists. Specific to the splitRange() method.
Issue #1457

- [ ] a bugfix
- [X] a new feature

Checklist:

• Changes are covered by unit tests
• Code style is respected
• Commit message explains why the change is made (see https://github.com/erlang/otp/wiki/Writing-good-commit-messages)
• CHANGELOG.md contains a short summary of the change
• Documentation is updated as necessary

Why this change is needed?

Excel can save protection ranges as a spaced list instead of just a comma list.

[MarkBaker]

You're right that a space can appear in a range definition; but it isn't simply an alternative for a comma.
Both space and comma are operators in a range definition:

• A comma is the Union operator (combines two references into a single reference)
• A space is the Intersection operator (returns a reference to the intersection of two ranges)
  So I need to take a much more detailed look at how well PHPSpreadsheet handles this difference when it is used.

[mcouillard]

That makes more sense! My solution didn't feel optimal and I couldn't find the right doc from Microsoft or about OpenXML to determine what these spaces here actually meant.

I appreciate your help.

[MarkBaker]

He, yes! It's pretty obscure: simple example is to fill cells A1 to C3 with the values 1 to 9, then to have a couple of formulae: =SUM(A1:B2,B2:C3) and =SUM(A1:B2 B2:C3) and look at the different results.
I'll try putting some tests together tonight to see what the effects will be.

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs.
If this is still an issue for you, please try to help by debugging it further and sharing your results.
Thank you for your contributions.

[oleibman]

Superseded by PR #4580. Removing stale label, leaving closed.