Honestly, I'd really prefer to unpack that statement into 20 lines of clear code. Not because I'm not familiar with and not used to this syntax: my preference equally applies to similar terse Numpy statements which I can understand (but which are error prone and require mental effort).
Tacit expressions like that are interesting and very rewarding to write, but I'd agree that it's way too terse. The Iversonian array languages tend to be like that, since they're derived from mathematical notation. (Though I have heard that tacit expressions are pretty much absent from production APL code.)
The aspect I find most interesting is the way primitives can be combined to build up functionality. It's closer to a declarative syntax, where the focus is on the end result instead of the steps to get there.
Honestly, I'd really prefer to unpack that statement into 20 lines of clear code. Not because I'm not familiar with and not used to this syntax: my preference equally applies to similar terse Numpy statements which I can understand (but which are error prone and require mental effort).