latexdiff should add more braces to usual commands

[EB2000]

Hi!

latexdiff makes some effort to add some braces where needed to be able to process inputs such as \frac ab instead of \frac{a}{b}. unfortunately, it is not enough to cover all usual cases.

• Using modern engines (such as lualatex) and package unicode-math, it is possible to type commands such as \frac αβ, which latexdiff will fail to brace properly.
• Using again engines such as lualatex, it is possible to define commands with unicode letters, such as \résumé or \Δ. latexdiff will fail to add braces to \frac \Δ 2.
• Many commands beyond \frac are often used without braces. latexdiff could do the same kind of preprocessing as for frac to these commands. For instance, right now, latexdiff will output incorrect latex if asked to highlight the differences between x \in \mathbb R and x \in \mathbf R in an equation environment. latexdiff could maintain a list of commands with one arguments (such as \mathbb), with two arguments (such as \frac), etc. and add braces when needed to the arguments.

For information, this is not theoretical: I am using these constructs in my documents. (For instance, \Δ is \symup{Δ} to have an upright Δ, while Δ alone is slanted.)