On 08/31/2010 03:29 PM, Patrick Gundlach wrote:

Hi,

this gives me an error:

---------------------------------------- \directlua{ local second=node.new("rule")

local v=node.vpack(second)

local first=node.new("rule")

node.insert_before(v,second,first) }

\bye ----------------------------------------

Attempt to node.insert_before() a non-existing node

I assumed that node.insert_before would put the first node before the second node and "corrects" the list pointer of v.

Q: why do I get the error?

Because 'second' is not part of the chain that starts at _v_, it is part of the chain that starts at _v.list_. Best wishes, Taco