\setuplanguage[en]
	[leftquotation=\quotedash~,
	rightquotation=~\quotedash,
	leftsentence=\removeunwantedspaces~\endash\space,
	midsentence=\removeunwantedspaces~\endash\space,
%	leftsentence=\endash~,
%	midsentence=~\endash,
	rightsentence=~\endash]
\define\quotedash{\emdash\endash}

%\setupbackend[export=yes]

\starttext

\startsection[title=Introduction]
Any of you able to help me get my quotation dashes into line when automatically 
inserted by the semantic commands?  I'm sure a number of you look at this style 
and cringe, but \cap{A.} I'm not looking for grammatical input, and \cap{B.} 
I'm intending this for a non-English language where the quotation dash (though 
still not most common) isn't as out of place.
\stopsection

\startsection[title=Desired rendering]
\quotedash~Speech should always have a dash at the start, but none at the end 
of a paragraph.

\quotedash~Dialog asides should not duplicate dashes,~\endash\ he 
said.~\quotedash\ Also, this doesn't reflect the spacing mentioned in section 
\in[extra].  \quotedash~nor, as above, add ones at the end of paragraphs.  
\endash~he continued.
\stopsection

\startsection[title=Actual output]
\speech{Speech should always have a dash at the start, but none at the end of a 
paragraph.}

\speech{Dialog asides should not duplicate dashes, \aside{he said.}} Also, note 
the spacing isn't removed despite \type{\removeunwantedspaces}, but instead 
duplicated.  \speech{nor, as above, add ones at the end of paragraphs.  
\aside{he continued.}}
\stopsection

\startsection[title=Additional considerations and observations,reference=extra]
It would also be nice if a quote ending in a period carried the \quote{broad} 
spacing to the other side of the (ending) quote dash |=| the dash before 
\quote{Also} above would be packed on the left and broad on the right.  I know 
this might be a lot trickier to code, and only consider it a bonus.

The issue with \type{\removeunwantedspaces} only seems to affect the command 
forms.  When inserted directly |<| as here |>| the spacing acts as desired in 
the \cap{PDF} (as expected, the \cap{XML} doesn't understand the order).  Also, 
the right \type{|>|} doesn't require either of the explicit spacing 
instructions (beyond being non-breaking) while the others do; try switching the 
commented lines and re-rendering.

The quotation dash itself only \emph{looks} as I want it; when I highlight and 
copy the text or export it to the \cap{XML} backend, it's still two dashes next 
to each other.  Instead, I'd like it to be the Unicode bar U+2015.  I'm not 
sure if \TEX/\LUATEX\ allows that difference between appearance and interaction 
(I do know \cap{PDF} does), so if there's some way of adding a new glyph to the 
font |<| one that mimics the other dashes even if the font changes |>| I'd love 
to actually use the proper codepoint.  As is, that doesn't work in the standard 
font(s): [\char"2015].
\stopsection

\stoptext
