I've done various tests with GNU Texinfo 6.8 (texinfo 2021-04-25.21)
and GNU Texinfo 7.0 (texinfo 2022-11-07.17). They give the same
results; see comments in the testcase below.
------------------------------------------------------------------
\input texinfo @c -*-texinfo-*-
@tex
\gdef\texMM{\mathop{\tt MM}}
@end tex
@iftex
@macro MM
\\mathop{\\tt MM}
@end macro
@macro MMa {T}
\\mathop{\\tt MM}
@end macro
@macro MMb {T}
{\\mathop{\\tt MM}}
@end macro
@end iftex
Spacing test with mathop.
@math{\mathop{\tt MM}(x)}
@math{\texMM(x)}
@math{@MM{}(x)} @c Space before and after "MM"
@math{@MMa{}(x)} @c Space before "MM"
@math{@MMb{}(x)} @c Correct
@math{k\mathop{\tt MM}(x)}
@math{k\texMM(x)}
@math{k@MMa{}(x)} @c Correct
@math{k@MMb{}(x)} @c Missing space before "MM"
@math{1 + \mathop{\tt MM}(x)}
@math{1 + \texMM(x)}
@math{1 + @MMa{}(x)} @c Space before "MM"
@math{1 + @MMb{}(x)} @c Correct
@bye
------------------------------------------------------------------
It seems that Texinfo adds something like {} at the beginning of
the Texinfo macro expansion, because in the test of the TeX macro,
if I change
\gdef\texMM{\mathop{\tt MM}}
to
\gdef\texMM{{}\mathop{\tt MM}}
then I get exactly the same behavior as with the Texinfo macro
@macro MMa {T}
\\mathop{\\tt MM}
@end macro
While there is a workaround for the space after the operator name
(i.e. adding a dummy argument in the macro definition), there does
not seem any for the space before the operator name (as soon as
Texinfo has added something like {}, information on what is present
before is lost), except case-by-case hacks (which is precisely what
should be avoided). But ideally, both issues should be fixed.
--
Vincent Lefèvre <vinc...@vinc17.net> - Web: <https://www.vinc17.net/>
100% accessible validated (X)HTML - Blog: <https://www.vinc17.net/blog/>
Work: CR INRIA - computer arithmetic / AriC project (LIP, ENS-Lyon)
