6.2.1.1 Parsing LaTeX Documents

Predictive mode's LaTeX support parses the LaTeX file as you type (without any noticeable slow-down!), in order to identify different contexts. The main use for this information is to switch to the appropriate dictionary in different regions of a LaTeX document.

The following customization options affect this parsing:

predictive-latex-docclass-alist

Alist associating LaTeX document classes (the docclass appearing inside \documentclass{<docclass>} with dictionaries.

predictive-latex-electric-environments

When non-nil, environment names appearing inside \begin{<environment>} and \end{<environment>} are automatically synchronised.

By default, predictive mode will use the usual main dictionary in LaTeX mode, determined by predictive-main-dict (see Basic Dictionary Usage). However, by customizing predictive-latex-docclass-alist, the main dictionary can be selected automatically based on the document class.

In addition to the main dictionary, a number of LaTeX dictionaries are also used, grouped into four main categories: text-mode LaTeX commands, maths-mode LaTeX commands, preamble LaTeX commands, and LaTeX environments. The dictionaries in the different categories are used to look for completions in different contexts in the LaTeX document. The main LaTeX dictionaries in these categories are, respectively, dict-latex, dict-latex-math, dict-latex-preamble and dict-latex-env. In addition, there are dictionaries for LaTeX document classes (dict-latex-docclass), bibliography styles (dict-latex-bibstyle). Finally, a dictionary of cross-reference labels and dictionaries of locally defined LaTeX commands and environments, unique to each LaTeX file, are generated automatically (see Automatically Created Files for LaTeX).

Predictive mode will automatically complete words from the correct dictionary in different regions of your LaTeX document¹. In the main body of the document it will complete from the main dictionary, as usual, and also from the dictionaries of text-mode LaTeX commands. Inside ‘equation’ or other display-mode environments, between ‘$’'s, or between ‘\[’ and ‘\]’, it will use the dictionaries of maths commands. Inside ‘\begin{...}’ it will use the dictionaries of LaTeX environments. Inside ‘\ref{...}’ it will use the dictionary of cross-reference labels, which is created and updated automatically for each LaTeX document. Inside ‘\documentclass{...}’ and ‘\bibliographystyle{...}’, it will use the document class and bibliography style dictionaries, respectively.

When predictive-latex-electric-environments is enabled, the environment name appearing inside a LaTeX \end{<environment>} command is automatically synchronised with its matching \begin{<environment>} command. The synchronisation doesn't just occur when the \end command is first typed; it is kept synchronised at all times, even when the \begin command that it originally matched is deleted, causing it to match a different \begin somewhere else in the document. Also, when the environment name within either a \begin or an \end command is modified, the environment name within its matching partner is also modified accordingly. WARNING: this feature is known to have bugs, and should probably not be used at the moment (see Known Bugs).

Predictive LaTeX mode honours the TeX-master variable. If it is turned on in a buffer whose TeX-master variable is set to the name of another LaTeX file, the TeX-master file will be visited, predictive mode will be enabled in its buffer, and all buffers with the same TeX-master will share various predictive mode settings.

The behaviour of different character syntax classes, and the behaviour of certain individual characters, is set up appropriately for LaTeX (see Character Syntax and Key Bindings). Also, a special LaTeX completion browser menu, more appropriate for browsing LaTeX commands, is used instead of the default one.