[luatex] how to assign a width to a node of type "glue"

[Mico Loretan]

> Paul Isambert <zappathustra at free.fr> wrote:
> > Mico Loretan <mico.loretan at mac.com a écrit:
> > I'm trying to create a glue node that has a specific width. Unfortunately, I seem to be missing something (probably entirely trivial to somebody who knows how it's done).
> >
> > Here's what I've tried so far:
> >
> > local glue        = node.id ( "glue" )       -- 10
> > local gluespec    = node.id ( "glue_spec" )  -- 47
> > local gluenode    = node.new ( glue )        -- create the node
> > gluenode.subtype  = 0                        -- "skip"
> > -- what next??
> >
> > I would like to make this node have a width of 0.03em (no stretchability or shrinkability needed).
> >
> > The LuaTeX reference manual (p. 178) says that I should do something with the node's field called "gluenode.spec". If I understand the manual correctly, this field should be a "pointer to an item of type 'glue_spec'." However, there's no indication on how this should be done, and the explanation of glue_spec on pp. 173f. is even terser.
> 
> 
> A glue node points to a glue_spec node that contains the real stuff; I
> *think* that that akward interface will disappear one day and glue
> nodes will contain their own information. Meanwhile:
> 
>     local gluenode = node.new(node.id("glue"))
>     local gluespec = node.new(node.id("glue_spec"))
> 
>     gluespec.width = tex.sp("0.03em")
>     gluenode.spec = gluespec
> 
> Best,
> Paul

Thanks! This is exactly what I need. Best, Mico