Incorrect warning about "a" versus "an" when using digits as adjective

[neil-lindquist]

Textidote gives a warning that "an" should be used instead of "a" when preceding math mode.

With the following latex file,

\documentclass{article}
\begin{document}
This gives a \(30\times\) improvement.
\end{document}

I get

$ java -jar textidote.jar-0.9.jar --check en --no-color textidote-mwe.tex                                                                                                                                         
TeXtidote v0.9 - A linter for LaTeX documents and others                                                                                                                                                          
(C) 2018-2021 Sylvain Hall▒ - All rights reserved                                                                                                                                                                 
                                                                                                                                                                                                                  
Found 1 warning(s)                                                                                                                                                                                                
Total analysis time: 3 second(s)                                                                                                                                                                                  
                                                                                                                                                                                                                  
* L3C12-L3C12 Use 'an' instead of 'a' if the following                                                                                                                                                            
  word starts with a vowel sound, e.g. 'an article', 'an hour'.. Suggestions:                                                                                                                                     
  [an] (11) [lt:en:EN_A_VS_AN]                                                                                                                                                                                    
  This gives a \(30\times\) improvement.                                                                                                                                                                          
             ^                                                                                                                                                                                                    

Using $30\times$ instead of \(30\times\) gives the same warning, but 30\times (without math mode) doesn't result in any warnings. So, it looks like this is an issue with how math mode is detexified.

I've reproduced this with both the 0.9 draft and the 0.8.2 release.

[sylvainhalle]

Inline math is converted to the single character "X" for the purpose of grammar checking. This choice is unfortunate as the grammar checker then expects you to write "an X" and not "a X".

I suppose that if we replace "X" by something like "P", it should not trigger this warning.

[neil-lindquist]

"P" would probably reduce the frequency of the issue, but there's still 1, 8, etc. Maybe there's a reasonable way to pull initial digits out of inline math? I.e., $30\times$ would become something like 30X.

But, this rabbit hole might not be worth going down, given that proper grammar for inline math is complicated and Latex doesn't have much semantic information to work with.