Algorithm2e - 禁用特定行的行号

Question

Algorithm2e 包有特定的选项，可以禁用/隐藏整个文档或算法的行号，然后为特定行启用/显示行号。我想做相反的事情。我的意思是，为整个文档启用行号，然后为特定行禁用行号。（A类似主题的问题已经被问过了，但是针对的是不同的目标。

为了进一步说明，我需要手动换行和适当的缩进。因此，我找到了@Werner 的回答非常好这里。但问题是，手动创建的行会被编号，这对我来说是不可取的。下面是直接从 Werner 的回答中摘录的示例，启用了行号：

\documentclass{article}
\usepackage[linesnumbered]{algorithm2e}% http://ctan.org/pkg/algorithm2e
\makeatletter
\newcommand{\nosemic}{\renewcommand{\@endalgocfline}{\relax}}% Drop semi-colon ;
\newcommand{\dosemic}{\renewcommand{\@endalgocfline}{\algocf@endline}}% Reinstate semi-colon ;
\newcommand{\pushline}{\Indp}% Indent
\newcommand{\popline}{\Indm\dosemic}% Undent
\makeatother
\begin{document}
\begin{algorithm}[H]
  \SetAlgoLined
  \KwData{this text}
  \KwResult{how to write algorithm with \LaTeX2e }
    initialization\;
  \While{not at end of this document}{
    read current\;
    \eIf{understand}{
      go to next section\;
      \nosemic this is a very long statement that has to be\;
        \pushline\dosemic wrapped over two lines\;
      \popline current section becomes this one\;
    }{
      go back to the beginning of current section\;
    }
  }
  \caption{How to write algorithms}
\end{algorithm}
\end{document}

如您所见，第 7 行是换行的行，但它被编号了。我想要的是这一行不被编号，而下一行（第 8 行）被编号为 7。

Answer 1

当你加载时algorithm2e使用linesnumbered，它会\nl在每个段落分隔符处执行（取自algorithm2e.sty)：

%
% line numbering
%
\newcommand{\LinesNumbered}{%
  \setboolean{algocf@linesnumbered}{true}%
  \renewcommand{\algocf@linesnumbered}{\everypar={\nl}}}%

所以，\nl这是我们感兴趣调整的事情。

您可以使用以下命令删除单行的行号\nonl：

\let\oldnl\nl% Store \nl in \oldnl
\newcommand{\nonl}{\renewcommand{\nl}{\let\nl\oldnl}}% Remove line number for one line

这是一个显示输出的最小示例：

\documentclass{article}
\usepackage[linesnumbered]{algorithm2e}% http://ctan.org/pkg/algorithm2e
\makeatletter
\newcommand{\nosemic}{\renewcommand{\@endalgocfline}{\relax}}% Drop semi-colon ;
\newcommand{\dosemic}{\renewcommand{\@endalgocfline}{\algocf@endline}}% Reinstate semi-colon ;
\newcommand{\pushline}{\Indp}% Indent
\newcommand{\popline}{\Indm\dosemic}% Undent
\let\oldnl\nl% Store \nl in \oldnl
\newcommand{\nonl}{\renewcommand{\nl}{\let\nl\oldnl}}% Remove line number for one line
\makeatother
\begin{document}
\begin{algorithm}[H]
  \SetAlgoLined
  \KwData{this text}
  \KwResult{how to write algorithm with \LaTeX2e }
    initialization\;
  \While{not at end of this document}{
    read current\;
    \eIf{understand}{
      go to next section\;
      \nosemic this is a very long statement that has to be\;
        \pushline\dosemic\nonl wrapped over two lines\;
      \popline current section becomes this one\;
    }{
      go back to the beginning of current section\;
    }
  }
  \caption{How to write algorithms}
\end{algorithm}
\end{document}

\nonl重新定义\nl一种用法。这种用法只是重新定义自身以使用原始形式（在狡猾的 (La)TeX 技巧）。