andeks (1) [Avatar] Offline
#1
The part:

result = list.inject(0){ clinks, guests ->
clinks += guests
}

should instead read:

result = list.inject(0){ clinks, guests ->
clinks + guests
}

(redundant assignment in closure)
Mittie (397) [Avatar] Offline
#2
Re: Errata suggestion, listing 4.9 (p.108)
true.

Thanks for the suggestion!
(It is not an erratum, though smilie)

Dierk