In my larger document (approx 600 pages, over 1000 references)
problematic entries like \cite[{{A, B, and C}}] did not display at all, though the document did process without claims of stack errors etc.
Curiously,
\goto{A, B, and C}[{{A, B, and C}}] 
does work as expected.

Alan

On Thu, Feb 23, 2017 at 4:12 PM, Alan Bowen <bowenalan03@gmail.com> wrote:
Thanks, Hans! That does work nicely.

On Thu, Feb 23, 2017 at 3:42 PM, Hans Hagen <pragma@wxs.nl> wrote:
On 2/22/2017 6:21 PM, Alan Bowen wrote:
Here is the file that I have been working with:

\installlanguage[packed][en]
\setuplanguage[packed][spacing=packed]
\startsetups[tightspace]
  \spaceskip 0.5\interwordspace plus .5\interwordstretch minus
\interwordshrink
\stopsetups

\def\dostartbibitem[#1]{\startBibItem[title={#1},reference={#1}]}
\def\startbibitem{\dosingleempty\dostartbibitem}
\def\stopbibitem{\stopBibItem}

\definedescription[BibItem][
width=broad,
margin=1.5pc,
indenting={no},
indentnext=no,
alternative=hanging,
hang=1,
headcommand=\gobbleoneargument,
align=right,
before={\directsetup{tightspace}\bgroup\language[packed]},
after={\egroup},
]

\definereferenceformat [cite]  [type=title,left={},right={}]
\definereferenceformat [bibpage]   [type=page]

\starttext

\startbibitem[A, B, and C]\stopbibitem % TEST by commenting these
%\startbibitem[A{,} B{,} and C]\stopbibitem% lines out

\startbibitem[ABC]\stopbibitem
\startbibitem[A]\stopbibitem
\startbibitem[B]\stopbibitem
\startbibitem[C]\stopbibitem

* \cite[A, B, and C] \qquad{\red output should  be: A{,} B{,} and C}

**\cite[ABC] \qquad{\red output should be: ABC}

***\cite[A], \cite[B], \cite[C]  \qquad{\red output should be: A, B, C}

****\cite[A]\cite[B]\cite[C] \qquad{\red output should be: ABC}

\stoptext

references can be a comma separated list, so

A, B, and C

is actually three tags:  "A" "B" "and C"

so, you run into parsing problems, so how to deal with:

[A, B, and C]

maybe:

[{A, B, and C}]

alas, in comma separated list the first level of {} is removed but we can cheat:

[{{A, B, and C}}]

works with \cite [{{A, B, and C}}]

Hans


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