## LaTeX forum ⇒ General ⇒ More wishes - error messages

LaTeX specific issues not fitting into one of the other forums of this category.
pireddag
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### More wishes - error messages

Johannes_B wrote:The different things to press when an error happens, `h` or `q`, or `s`, or `x` are all documented. In the TeXbook. When you are interacting, you are interacting with TeX.

I looked at an electronic copy which I found on ctex (I do not have a printed copy), and the reference I found is in chapter 6, pages 31 and 32. It says (pag. 32)

"Type ‘X’. This stands for “exit.” It causes TEX to stop working on your job, after putting the finishing touches on your log file and on any pages that have already been output to your dvi file. The current (incomplete) page will not be output."

It does not say that typing ‘X’ can corrupt the .aux file, one has to figure it out on their own - I did not do it. The only place where I ever read it is in the chat message of David Carlisle. So: IMHO it should be documented.

Johannes_B wrote:
As Ulrike and David said, it is possible to make adjustments ... which will probably cause havoc in thousands of documents ... automated error parsing/detection by some guis worthless.

Maybe LaTeX3 can do something about it in the future, but no need to wait impatientely. It will take a while.

Ok. By the way I have seen that the warnings of LaTeX are marked by "LaTeX Warning", I had never noticed it before. As well as the warning messages issued by every package.
And the LaTeX errors as well are marked as "LaTeX error".

It might be that the amsmath package is an exception; I have tested the \align command with a blank line, and it does not say that the error comes from amsmath, it just says

! Paragraph ended before \align was complete.

So I do not know whether there the message is issued by TeX or by amsmath. I suspect that it is issued by the latter (TeX does not know environments).

Johannes_B
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The smart way: Calm down and take a deep breath, read posts and provided links attentively, try to understand and ask if necessary.

pireddag
Posts: 28
Joined: Tue Nov 21, 2017 3:06 am
Johannes_B wrote:https://chat.stackexchange.com/transcript/message/47582068#47582068

It is a bit complicated chatting through two websites. At any rate what he implies is not what I meant. Equation is a LaTeX environment (or amsmath if it re-defined by that). Since it will be first parsed by LaTeX and LaTeX can know that TeX will issue an error message, LaTeX (or amsmth) could pre-empt (this word is perhaps the one we need here) TeX and issue its own error message.

This in any case has been already commented on by Enrico Gregorio, who told that this is possible only if the
"contents of (align) equation (would be read) as a macro argument"
https://chat.stackexchange.com/transcri ... 2#47557472

Which means that we have to wait for LaTeX3.