How to remove a gap between two rows in longtable

Question

Good afternoon

I would like to change gap between two rows (the picture below) in longtable because it doesn't look very nice and I want to save a place. I don't know how to do it.

Thanks for help.

\documentclass[10pt,a6paper]{book}

\usepackage[utf8]{inputenc}
\usepackage[main=english,slovak]{babel}
\usepackage[cm]{fullpage}
\usepackage[a6paper, top=10mm, left=10mm, right=10mm,     bottom=10mm,foot=5mm,marginparsep=0mm,showframe]{geometry}
%showframe
\usepackage{tipa}
\usepackage{tabularx,booktabs}
\usepackage{multirow}
\usepackage{rotating}
\usepackage{graphicx}
\usepackage{array}
\usepackage{color}
\usepackage[dvipsnames]{xcolor}
\usepackage{longtable}
\usepackage{lscape}

\usepackage{enumitem}
\usepackage{tabularx,booktabs}
\usepackage{enumitem}
\usepackage{mathtools}

\begin{document}
\catcode`\-=12
\sloppy

{\small 
\begin{longtable}{llp{5cm}}
  \toprule
  {\sffamily some text}   & \textsl{some text}  &                
                            \setlist{nosep,topsep=0sp,label=--}
                            \vspace{-\baselineskip}
                            \begin{itemize}
                              \item[-] some text
                              \item[-] some text
                              \item[-] some text
                            \end{itemize}\\
{\sffamily some text}   & \textsl{some text}  &                
                            \setlist{nosep,topsep=0sp,label=--}
                            \vspace{-\baselineskip}
                            \begin{itemize}
                              \item[-] some text
                              \item[-] some text
                              \item[-] some text
                            \end{itemize}\\
  \toprule
\end{longtable}}
\end{document}

Answer 1

The command \setlist will apply to all lists if you put it in the preamble, so no need to call it each time (besides, in that case, you'd have to use the optional argument for the itemize environment). You can also assign names to this, by the way, like a style, so that only lists that have this name will inherit the list options.

In any case, you were setting the space before the list, but not afterwards. For this you can use the keys before= and after=:

\setlist{nosep,label=--,after=\vspace{-\baselineskip}, before=\vspace{-\baselineskip}}

And here's the result: