[Dev-luatex] unique node id?

Hans Hagen pragma at wxs.nl
Sun Aug 29 13:32:20 CEST 2010

On 29-8-2010 1:22, Patrick Gundlach wrote:
> Am 29.08.2010 um 13:15 schrieb Hans Hagen:
>> On 29-8-2010 9:03, Taco Hoekwater wrote:
>>> On 08/29/2010 08:48 AM, Patrick Gundlach wrote:
>>>>> Is the following 172 something like I need? How would I access that
>>>>> (besides string.gsub())?
>>>>> <node nil<  172>  nil : hlist 2>
>>>> I am currently using this number in the middle via tostring() and
>>>> gsub(). But I'd still like to know if this can be used as an id.
>>> This number uniquely identifies a node for as long as it stays
>>> allocated, yes. If it is freed, a new node may have the same
>>> number.
>> but for storing the node's id one can as well use the nodes user object itself as it's equally unique during the livespan of a node and one can compare pointers so the 'id' snippet in the string is not giving more uniqueness than the node user object itself
> I need to generate some unique text for that node (I am creating a visual representation of a nodelist using graphviz), so I see two choices: a) get some id string or b) create a look table with the nodes as an index and some random string as the value for each node. But somehow b) didn't work. Is there a way to get the "value of a pointer" as a text string in Lua? Such as when you do tostring({}).

isn't tostring(n) unique enough then? as long is the node is not freed

                                           Hans Hagen | PRAGMA ADE
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