On 11/28/2012 07:44 PM, Paul Isambert wrote:
Actually it IS set (try "print(n.prev)"), and I'm surprised myself, because I thought ``natural'' nodelists (created by TeX) didn't set the prev field of their nodes, but actually they're all set. (I thought that because node.slide() is said to set those prev fields, so I concluded that by default they aren't.)
prev nodes are normally set automatically by the internal functions, but sometimes while building a list 'by hand' it is a bit impractical to set them right away. That is why node.slide() exists. (and it also made a useful debugging tool for the internals when prev fields were still new). Best wishes, Taco
