Röda allows programming with pipelines:

primes := [2]
seq 3, 10000 | { primes += i if [ i % p != 0 ] for p in primes } for i
print p for p in primes

and supports explicitly pulling and pushing from and to the pipeline:

duplicate {
	pull value
	push value
	push value
}

The relationship becomes clearer with this formulation of duplicate:

duplicate {
	for value; do
		push value
		push value
	done
}

I love what I see. The only two hard point are the diacritics in files and the java runtime