Hi,
I find pack~/unpack~ very useful, and I wanted to see if there was a pure pd approach. Attached is a first stab at an unpack~. It gives identical results to zexy/unpack if 'length >= blocksize'. For length < blocksize a_unpack~ zeros signal vector elements >= length and drops any additional lists that fall within the current block. zexy/unpack~ does the 'right thing' and includes elements from subsequent lists in the vector.
Still a_unpack~ could be useful if you're like me and like to keep things as 'pure' as possible!
Depends on list-abs for list-drip.
Jamie