Shortcode empty attribute

There could be a couple ways to do this. Unfortunately, I don’t think any will result in exactly what you’re going for. ( [paragraph last] )

1. You could just create separate shortcodes for [paragraph_first] [paragraph_last] [paragraph_foobar] that handle $content without needing any attributes

2. You could set the default value for last to false instead of '', then require users to do [paragraph last=""]content[/paragraph]

3. You could add a more meaningful attribute such as position which could then be used like [paragraph position="first"] or [paragraph position="last"]

Because of the fact that WordPress discards any atts not given defaults, and the fact that an att without an ="value" is given the default value same as if it’s not listed at all, I don’t see any way to achieve [paragraph last]

Hopefully one of my 3 workaround will prove useful. Good luck!