mjhjmtu

I'm trying to mark the end of "words" (including punctuation) with luatex callbacks. (At the end I want to inject space chars at this positions, but the example uses rules for the visualization).

With some code based on countwords from the chickenize package it works quite fine. I only have a problem with math: I would like to avoid to get marks there. Trying to do it with an attribute set in everymath doesn't work as can be seen in the code below: It also affects other places like e.g. tabulars where math mode is used internally.

Has someone an idea how to exclude only "real" math from the mark function?

documentclassarticle
usepackageluacode,amsmath

newattributemathattr

beginluacode

local MATHATTR = luatexbase.registernumber ("mathattr")
local nodetraverseid = node.traverse_id
local nodegetattribute = node.get_attribute
local GLUE = node.id("glue")
local GLYPH = node.id("glyph")

local function insertmark (head,current)
 local pdfstring = node.new("whatsit","pdf_literal")
 pdfstring.data =
 string.format("q 1 0 0 RG 1 0 0 rg 0.4 w 0 %g m 0 %g l S Q",-3,10)
 head = node.insert_after(head,current,pdfstring)
 return head
end

local markwords = function(head)
 for glyph in nodetraverseid(GLYPH,head) do
 if glyph.next and (glyph.next.id == GLUE) 
 and not nodegetattribute(glyph,MATHATTR)
 then
 insertmark(head,glyph)
 end
 end
 return head
end


luatexbase.add_to_callback("pre_linebreak_filter",markwords,"markwords")

luatexbase.add_to_callback("hpack_filter",markwords,"markwords")

endluacode
usepackagelipsum
begindocument


begintabularl
xxx xxx
endtabular

$a=b int f(x) =0quad textabc abc abc abc $

everymathsetattributemathattr1

begintabularl
xxx xxx
endtabular

$a=b int f(x) =0quad textabc abc abc abc $

bigskip

VA VA 
lipsum[1]

enddocument

The math content is enclosed by math nodes, with subtype 0 marking beginning, and subtype 1 marking closing of the math:

documentclassarticle
usepackageluacode,amsmath

newattributemathattr

beginluacode

local MATHATTR = luatexbase.registernumber ("mathattr")
local nodetraverseid = node.traverse_id
local nodetraverse = node.traverse
local nodegetattribute = node.get_attribute
local GLUE = node.id("glue")
local GLYPH = node.id("glyph")
local MATH = node.id("math")
local HLIST = node.id("hlist")
local VLIST = node.id("vlist")


local function insertmark (head,current)
 local pdfstring = node.new("whatsit","pdf_literal")
 pdfstring.data =
 string.format("q 1 0 0 RG 1 0 0 rg 0.4 w 0 %g m 0 %g l S Q",-3,10)
 head = node.insert_after(head,current,pdfstring)
 return head
end

local function markwords(head)
 local inside_math = false
 for n in nodetraverse(head) do
 local id = n.id
 if id == GLYPH then
 local glyph = n
 if glyph.next and (glyph.next.id == GLUE) 
 and not (inside_math or nodegetattribute(glyph,MATHATTR))
 then
 insertmark(head,glyph)
 end
 elseif id == MATH then
 inside_math = (n.subtype == 0)
 end
 end
 return head
end


luatexbase.add_to_callback("pre_linebreak_filter",markwords,"markwords")

luatexbase.add_to_callback("hpack_filter",markwords,"markwords")

endluacode
usepackagelipsum
begindocument


begintabularl
xxx xxx
endtabular

$a=b int f(x) =0quad textabc abc abc abc $


everymathsetattributemathattr1

begintabularl
xxx xxx
endtabular

$a=b int f(x) =0quad textabc abc abc abc $

bigskip

VA VA 
lipsum[1]

enddocument

Contrary to your screenshot, the code in your question doesn't put bar behind last word in textabc abc abc abc and at the end of a paragraph: