Support for (gnu?) dc's ! commands?

[abathur]

dc has an instance of sub-exec via its ! command that isn't as straightforward to support as some others.

I managed to find a way to raise an error when this form is encountered:

I don't know how to handle dc `!` commands yet--sorry :(

Next step: - See the feedback issue for a workaround

https://github.com/abathur/resholve/issues/40

That said, I get the impression this feature is very rarely used, so I currently plan to leave it here for now until/unless users show up documenting real use/test-cases in this issue.