page range reference (how to compare references)

page range reference (how to compare references)

[MF]

Hello list,
I'm trying to reference a page range (think of a long quote spanning on
2 pages).

I need to discriminate ranges collapsing to one page from "real" ranges
(2 or more pages): "1-1" should become "1", while "1-2" should stay
like that.

Here's a not working snippet:

\starttext

Tufte quote at p.
\at[tufte:start]\doifelse{\ref[realpage][tufte:start]}{\ref[realpage][t
ufte:stop]}
{}
{-\at[tufte:stop]}

% start of quote reference
\pagereference[tufte:start]
\input{tufte}

%\page  % comment/uncomment this to toggle from range to single page

\input{tufte}
% end of quote reference
\pagereference[tufte:stop]

\stoptext

The \doifelse is always false, I think because \ref[realpage][...] is
not a string.

Thanks in advance.
BTW, best wishes for next week's meeting (hoping to join next year).
Best regards,
Massi
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___________________________________________________________________________________

Re: page range reference (how to compare references)

[MF]

I found a solution, but it's tricky (and there's no check on reference
existence in structures.references.collected).


\directlua{
  function userdata.printrange(singular, plural, label)
    local coll_ref = structures.references.collected[""]
    local pagestart = coll_ref[label .. ":start"].references.realpage
    local pagestop = coll_ref[label .. ":stop"].references.realpage
    if pagestart == pagestop then
      context(singular)
    else
      context(plural)
    end
    context("~")
    context.ref({"page"}, {label .. ":start"})
    if pagestart ~= pagestop then
      context("-")
      context.ref({"page"}, {label .. ":stop"})
    end
  end

  function userdata.printpagerange(label)
    userdata.printrange("page", "pages", label)
  end
}

\def\printpagerange#1{\ctxlua{userdata.printpagerange("#1")}}

\starttext

Tufte quote at \printpagerange{tufte}.

% start of quote reference
\pagereference[tufte:start]
\input{tufte}

%\page  % comment/uncomment this to toggle from page range to single
page

\input{tufte}
% end of quote reference
\pagereference[tufte:stop]

\stoptext
___________________________________________________________________________________
If your question is of interest to others as well, please add an entry to the Wiki!

maillist : ntg-context@ntg.nl / http://www.ntg.nl/mailman/listinfo/ntg-context
webpage  : http://www.pragma-ade.nl / http://tex.aanhet.net
archive  : http://foundry.supelec.fr/projects/contextrev/
wiki     : http://contextgarden.net
___________________________________________________________________________________