[Vim-latex-devel] folding in latex-suite

[Srinath A. <sr...@fa...>]

Hello...

As you might know, Zhang Linbo has added quite a bit of new
functionality to the folding scheme in latex-suite. Now we can customize
various things to fold etc. Unfortunately, we also uncovered what seemed
to be a few "unfixable" problems. (or at least very hard to fix using the
current methods). The problem arises from the fact that we use
a simplified syntax folding algorithm implemented in SyntaxFolds.vim to
generate the folds. Although the algorithm can handle a fair amount of
complexities like folds being nested etc, it fails in some common cases.

One problem arises when we try to fold commands. The problem case is to
fold something like:

\footnote{This is a footnote with
\textbf{\texttt{arbitrarily nested}} commands
within it}

The problem with this set of lines is that there are commands which are
arbitrarily nested and the way the inner commands terminate is the same
as the way the outer footnote terminates (all commands terminate with
a '}'). Other problems arise when we attempt to fold \item's which might
have figures in them. In the present scheme we will not be able to fold
\begin{figures} environments nested inside \items... (wonder why no one
reported this...)

In the long term (quite long), we might therefore need to move to using
vim's native syntax folding capabilities which are able to handle all
these issues. Ofcourse, the present way seems to be more than adequate
for most if not all users (no?)

I spent some time today learning about vim's syntax scheme... (quite
complex too...)

Here's a little demo of what can be done without syntaxfolds.vim.

Open the attached .tex file and then source the attached .vim file. This
should create some of the necessary syntax folds... Its still a /huge/
hack and doesn't fold any sections like latex-suite does, but it does
show how relatively simply we can get around the afore-mentioned
problems...

Ofcourse, even if we do use vim's syntax folding instead of
syntaxFolds.vim, folding.vim will not change. (LB, your patches will not
be in vain :-)). What will need to change is the interface between
folding.vim and syntaxFolds.vim. Basically SyntaxFolds.vim will
essentially contain a simple wrapper function which will call vim's :syn
command with various parameters.

The reason for this e-mail is to hopefully spark some interest in
someone to take a further look at things in this direction...

Srinath

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