How can I match a regexp containing newlines?

Question

When developing a vim plugin I'll publish soon, I want to highlight a text contained in a variable g:last_completion_text.

Here below the code to

• define an highlight group named PrompterCompletion
• assign the highlight to a text in a global vim variable g:last_completion_text

:highlight PrompterCompletion  ctermbg=3  ctermfg=0
:execute 'match PrompterCompletion /' . g:last_completion_text . '/'

If g:last_completion_text is a single line the code works correctly.

echo g:last_completion_text
Hello! How can I assist you today?

But if g:last_completion_text is a multiline text (contains newline), the match command fails.

echo g:last_completion_text
21. Regione dell'enogastronomia
22. Regione della neve
23. Regione delle malghe
24. Regione delle tradizioni contadine
25. Regione delle fiabe e delle leggende
26. Regione della natura incontaminata
27. Regione delle attività all'aria aperta
28. Regione dell'architettura alpina
29. Regione delle terme e del benessere
30. Regione della storia e della cultura tirolesi.

Screenshots

echo g:last_completion_text

echom g:last_completion_text

QUESTION:

Is there a way to let the match command accept newlines in the text contained in the referenced variable?

Is there a way to correct the command:

:execute 'match PrompterCompletion /' . g:last_completion_text . '/'

Answer 1

I would try:

:execute 'match PrompterCompletion /' . substitute(g:last_completion_text, "[\n\<C-m>]", '\\n', 'g') . '/'