Dear list,
I am trying to define a command which behaves like an internal register
using the `token` library. However, there are some complications. For
example a register has to be settable using both
\register=<number>
\register<number>
Additionally, if no number is given it should raise a “cannot be used in
vmode” error or similar. Also it has to be possible to get the value
using `\the`. Below you can find a minimal example where I have already
achieved some of these things but others fail miserably.
Cheers, Henri
P.S.: I have also attached a much more complex example, so you can see
that I actually want to emulate pdfTeX's \pdfadjustinterwordglue.
---
\directlua{
local value = 0
%
function register()
local str = token.scan_string()
%
if str then
local int = string.gsub(str,"=","")
value = tonumber(int)
else
tex.sprint([[\numexpr]] .. value .. [[\relax]])
end
end
}
\protected\def\register{\directlua{register()}}
\register=1
\register=12
\register=123
\register1
\register12
\register123
\the\register
\the\register
\the\register
\bye
\ifdefined\directlua
\csname newcount\endcsname\pdfadjustinterwordglue
\begingroup
\catcode`\^^M=12
\directlua{
local subtypes = node.subtypes("glue")
local knbscode = {}
function add_knbscode(field)
local fid = token.scan_int()
local chr = token.scan_int()
local str = token.scan_string()
knbscode[fid] = knbscode[fid] or {}
knbscode[fid][chr] = knbscode[fid][chr] or {}
if str then
local int = string.gsub(str,"=","")
knbscode[fid][chr][field] = tonumber(int)
else
tex.sprint([[\numexpr]] .. (knbscode[fid][chr][field] or 0) .. [[\relax]])
end
end
local microtype_spacing = function(head, tail)
head, tail, success = node.kerning(head, tail)
if tex.count.pdfadjustinterwordglue > 0 then
for space in node.traverse_id(node.id("glue"), head) do
if subtypes[space.subtype] == "spaceskip" then
local prev = node.prev(space)
if prev.id == node.id("glyph") then
local knbs = knbscode[prev.font]
if knbs and knbs[prev.char] then
local f = font.getfont(prev.font)
local em = f.parameters.quad
local width = knbs[prev.char].width or 0
local stretch = knbs[prev.char].stretch or 0
local shrink = knbs[prev.char].shrink or 0
local glue = node.new(node.id("glue"))
glue.width = width*em/1000
glue.stretch = stretch*em/1000
glue.shrink = shrink*em/1000
head = node.insert_before(head, space, glue)
end
end
end
end
end
end
callback.register("kerning", microtype_spacing, "microtype_spacing")
}%
\endgroup
\protected\def\knbscode{\directlua{add_knbscode("width")}\fontid}
\protected\def\stbscode{\directlua{add_knbscode("stretch")}\fontid}
\protected\def\shbscode{\directlua{add_knbscode("shrink")}\fontid}
\fi
\pdfadjustinterwordglue=1
\knbscode\font`r=1100
\stbscode\font`r=10
\shbscode\font`r=10
\knbscode\font`r 1100
\stbscode\font`r 10
\shbscode\font`r 10
\the\knbscode\font`r
\the\stbscode\font`r
\the\shbscode\font`r
\input lorem
\bye
