I leafed through Quirk et al's Comprehensive Grammar, and it seems that this might be an example of what they call subjectless supplementive clause.
They provide the following ambiguous example:
I saw Pam going home.
If we read it as "I saw [Pam going home]", then going home supplements Pam. "Pam" is the "overt subject" of "going home".
If we read it as "Going home, I saw Pam", then going home is a "subjectless supplementive clause" with the pronoun I as its "implied subject".
I don't know how other grammars treat such constructions, and "supplementive clause" is a rarely-used term.
Reference:
Quirk et al., "A Comprehensive Grammar of the English Language", 15.62, 'Supplementive Clauses in Final Position'.
Their definition of a supplemental clause:
Supplemental clauses: adverbial participle and verbless clauses without a subordinator.
P.S. In CGEL, such constructions are discussed in Chapter 14, Part 9: "Non-finite clauses as modifiers and supplements"
I think it replaces a passive: You did too a good of a job writing this thing = which was written. – Alejandro – 2015-12-28T15:50:18.473
It must be one of those leading roles. Something pretty important, I would imagine. Too bad I don't know any grammar terms. I sort of know what a "subject" is. I also remember "predicate," although I'm not altogether certain what it means, whether it's a bunch of words or just one word or whatever. – Ricky – 2015-12-28T16:12:38.237
@Subjunctive I think it is completely impossible.Reducing a relative clause which contain a passive voice is done in that formula : being +v3. In our example it should have like this "a job being written" if you are seeking a passive voice.Plus "write" verb takes an object "this thing". – Cihangir Çam – 2015-12-28T16:56:39.720