You can point to a text authoring tool with a mode that will dim all but a selected syntactic unit of text for focused editing? I am not versed in the hundreds of text editors out there, but if one were commonly known surely a link to a screenshot would have made the candler argument much more convincing?
It sounds to me like the author doesn't like software patents regardless, and was offended by a misreading of the word "cheap": I don't think the original blog post implied that copies would be cheap-as-in-crummy but cheap-as-in-easy.
These are all linked to from other comments here. This is not new or unique. Sure, the design is different, and they are probably the first "big" name writing app to include it, but being more popular doesn't mean you invented anything.
I would distinguish the dimming aspect from the selecting syntactic units of text aspect. The former clearly isn't new[1], and adding an obvious technique to the equation doesn't make the entire method non-obvious.
So then the question should be: Is selecting syntactic units of text unique?
I don't know of any specific applications that do this, but I imagine that there are programs or libraries used in the field of machine learning that do exactly this or make doing it trivial and obvious.
[1] It's basically applying a dimming effect to an inverse selection. Off the top of my head, this is a common technique for highlighting passages from documents in video documentaries.
This is enough to make the concept of highlighting a syntactical unit a prior art (assuming the date on the said invention is not older), and the invention may now at best claim a method of solving this. The latter would barely be an invention on grounds of obviousness.
Note: IANAL, and haven't read the claims of the said invention.
But going from a *ly grep to a syntactic unit is merely a matter of using a context-free grammar instead of regular expressions. The latter extension is obvious.
It sounds to me like the author doesn't like software patents regardless, and was offended by a misreading of the word "cheap": I don't think the original blog post implied that copies would be cheap-as-in-crummy but cheap-as-in-easy.