In a comment (emphasis mine)
no, it has to change catcodes and this don't work if they are already frozen
in response to my comment on her answer Ulrike Fischer mentioned the concept of frozen catcodes. For the life of me I have no idea what frozen catcodes could be and so I thought I'd type up a question.
I scoured (searching for instances of freez
and froz
):
- TeXbook, p.326: [...] but the glue inside
\hbox{...}
is frozen at its natural width.- also p.173: [...] because these additional braces “freeze” the subformulas, [...]
- TeX Overview: no mention (just that TeX development was frozen in 1991)
- TeX for the Impatient ... nothing
- TeX by Topic ... nothing
- TikZ & PGF manual (3.1.2): several mentions of "freeze at end" but all referring to TikZ/PGF-specific features
- Babel manual (3.32): several uses of a
\frozen
command and one instance of "frozen" inline which is clearly unrelated to the topic at hand - Einführung in LuaTeX und LuaLaTeX (by Herbert Voß, in German, ISBN 978-3-86541-530-1):
font.frozen
... a boolean in the Font table, mentions ofwxLuaFreeze
- Tabellen mit LaTeX (by Herbert Voß, 3. ed., in German, ISBN 978-3-86541-936-1): "frozen" appears as text
- Einführung in LaTeX (by Herbert Voß, 3. ed., in German, ISBN 978-3-86541-798-5): several instances of "gefroren" and "erfroren" in the text
(In the German books I also looked for frier
and fror
which should catch instances of German words corresponding to freeze/frozen.)
Q: So what does this concept of "frozen" entail, what entities does it affect and how do I leverage it in my TeXnical endeavors? Clearly the concept isn't limited to catcodes either ...