解释<-（chan字符串）（无）

I found this <-(chan string)(nil) strange construct in the Gobetween sources.

• Is it just a fancy way to block forever or it has some kind of advantage over select{}?
• How to parse this statement?

The statement casts nil as type chan string, then reads from it.

According to Dave Cheney's Channel Axioms:

A receive from a nil channel blocks forever