@imagejan I had a look at the KNIME CSV reader options just now as you suggested. I like column delimiter and row delimiter more than separator and eol, I would rename them.

Sorry for not getting back to this earlier.

@frauzufall as far as I can see, scijava-optional has now stabilized and is at 1.0.0.
Do you want me to test and review, or do you still want to change anything (rename options etc.)?

@imagejan I made it use the stable scijava-optional version and renamed the options, it'd be great if you could review this!

Beautiful, thanks @frauzufall!

• the export command needs to be tested and polished to include more / all options

We can do that later, after making some progress on scijava/scijava-plugins-io-table#6.

I agree. Thanks for reviewing!!

@frauzufall not important, but for improved toString() of the Values classes you could add forEach implementations.
E.g., in TableIOOptions.Values:

@Override
public void forEach( final BiConsumer< String, Object > action )
{
	action.accept( readColHeadersKey, readColumnHeaders() );
	action.accept( writeColHeadersKey, writeColumnHeaders() );
	action.accept( writeRowHeadersKey, writeRowHeaders() );
	action.accept( columnDelimiterKey, columnDelimiter() );
	// etc...
}

Then, if you print option.values (e.g., inspecting it in the debugger), the default values will show up.
I.e., for a vanilla new TableIOOptions().values, no default option has been overridden. so printing it will give you
options.values = {}
while with the overridden forEach it will give something like
options.values = {readColHeaders = true [default], writeColHeaders = true [default], ...}