You can't avoid a name, but (with 5.10) you can limit it's scope:

while( my ($k, $v) = each %{ state $a = { 'a'..'z' } } ) { say "$k :> 
+$v" };;
w :> x
e :> f
a :> b
m :> n
s :> t
y :> z
u :> v
c :> d
k :> l
q :> r
g :> h
i :> j
o :> p
[download]

Not that I can see any justification for doing so.