On 1/5/2023 4:21 AM, Rik Kabel via ntg-context wrote:

    [ snipped by rik]

Here is a more lmtx-ish variant:

\starttexdefinition tolerant protected BD #=#*#=
   \removeunwantedspaces
   \space % insert a space
   (
   \ifparameter#2\or
       #1|–|#2
   \orelse\ifparameter#1\or
       #1–
   \else
       {\red I NEED A DATE OR DATES!}
   \fi
   )
   \autoinsertedspace
\stoptexdefinition

Hans

Thank you for that. This works for me with \optionalspace, but fails in some cases with \autoinsertedspace.

I have now re-read lowlevel-macros.pdf and have a better understanding of what I read when first I approached it; I still have a way to go.

Tolerant removes the need for dodoubleempty and friends and the two-step macro and doMacro dance. There was a small advantage to the two-step, however. I had two separate macros, BD and BDNP (no parens), as shown.

The old code in full was:

%-------------------- Birth and death dates -----------------------%
% Ferdinand de Saussure\BD{1857}{1913}
% Noam Chomsky \BD{1928}
%
% Perhaps this could be tied to an acronym-like database so that the
%   dates are printed only once per person.
% \removeunwantedspaces allows this to directly follow, or follow
%   after whitespace, the associated name: Name\BD{1}{2} or
%   Name \BD{1}{2}.
% Using the compound indication (|–|) allows hyphenation after the
%   endash. Omitting it and using a bare endash inhibits hyphenation
%   ‘twixt the endash and the paren.
% By default, add parens around the dates. If none are needed due to
%   the context, use \BDNP.
%
\newif\ifBDParen
\starttexdefinition unexpanded BD
  \BDParentrue
  \dodoublegroupempty
  \doBD
\stoptexdefinition
\starttexdefinition unexpanded BDNP
  \BDParenfalse
  \dodoublegroupempty
  \doBD
\stoptexdefinition
\starttexdefinition doBD #1#2
   \removeunwantedspaces\
   \ifBDParen(\fi
   \ifsecondargument
       #1|–|#2
   \else\iffirstargument
       #1–
   \else
       {\red I NEED A DATE OR DATES!}
   \fi\fi
   \ifBDParen)\fi
   \autoinsertedspace
\stoptexdefinition

Both call the same doBD, but they set a flag (newif) to control insertion or not of the parens. While there is no performance benefit compared to having two fully separate macros, there is a maintenance benefit in having only one place, doBD, to make changes should they be required.

Can you suggest a way to do this under the new one-step scheme, or am I over-thinking this?

Finally, is there any reason to go back to previously written and properly functioning macros and convert them to the LMTX-only syntax? It does imply committing to LMTX-only (or

--
Rik