[Texmacs-dev] Explanation for patch #2590

[Nix]

In a followup on savannah, David Allouche wrote:
> You seem to be confused.
> 
> "para" is an obsure primitive, currently only used in the 
> typesetting of headers and footers. It is included in the 
> converters for completeness, but really should not currently occur >
in sane documents.
> 
> "paragraph" is the usual sectioning structure.
> 
> In the past, "para" was called "paragraph", but that caused some 
> ugliness, and now that macros and primitives are unified it would 
> be a Bad Thing (I am not even sure texmacs would behave sanely in 
> the case of such a name conflict).
> 
> The converters were not updated when the change was done (a long 
> time ago). tmtex was fixed recently. Please be more specific 
> regarding the ensuing havoc.

In 1.0.3.1 the drd-dispatcher called "tmtex-methods%" says:
...
(paragraph tmtex-paragraph)
...

Thus, when tmtex-apply encounters a key of "paragraph", it calls
tmtex-paragraph.

In 1.0.3.2 "tmtex-methods%" originally said:
...
(para tmtex-para)
...

Thus, when the "obsure (sic.) primitive, currently only used in the
typesetting of headers and footers" is encountered, tmtex-para is
executed.  But the dispatcher contains nothing about the more frequently
used and far more important "paragraph" key ! So, paragraphs are now
translated into LaTeX as

\paragraph{The entire contents of the paragraph}

instead of a mere double carriage return !  This is the ensuing havoc.

To make things worse, (tmtex-para) is no different from
(tmtex-paragraph) from 1.0.3.1 .  Thus, headers and footers would be
handled like regular paragraphs.

So, perhaps the answer is not to replace 

(paragraph tmtex-paragraph)

by

(para tmtex-para)

but instead have both

(para tmtex-para)
(paragraph tmtex-paragraph)

and copy the definition of (tmtex-paragraph) to a new function called
(tmtex-para) - at least until we decide how to handle "para" (as opposed
to "paragraph"), at which point the definition of (tmtex-para) would
start to diverge from the definition of (tmtex-paragraph).

No, I don't think we should use 

((:or paragraph para) tmtex-para)

because, as you said, the meaning of "paragraph" and "para" are vastly
different in TeXmacs (para -> header/footer related vs. paragraph ->
very common, with a very different LaTeX conversion)

This is why I said that the patch should not necessarily be applied, and
to this end I have updated the patch as described above and resubmitted
it on savannah.