使用相应的括号注释森林树

Question

为了教人们如何使用它forest来绘制树木，能够展示树木本身和括号之间的关系是很有帮助的。我已经编写了一些代码来做到这一点，但我怀疑还有一种更优雅的方法可以使用它本身来做到这一点forest。有没有更简单/更好的方法来做到这一点？

\documentclass[12pt,border=.5in]{standalone}
\usepackage[T1]{fontenc}
\usepackage[utf8]{inputenc}
\usepackage[linguistics]{forest}
\forestset{nice nodes/.style={for tree={inner sep=0pt,s sep=.4in}},default preamble=nice nodes}
\usepackage{xstring}
\usepackage{amsmath}
\makeatletter
% This code based on a suggestion from Alenanno
\newcommand\nd[1]{%
\noexpandarg
\IfSubStr{#1}{\\}
{\def\nodetext{\StrBefore{#1}{\\}}}
{\def\nodetext{#1}}
\leavevmode\llap{\color{red}[$_{\text{\nodetext}}$}#1}
\makeatletter
% This code due to David Carlisle
\newcommand*\dnx{\textcolor{red}{]}}
\newcommand\dn{\hbox to \z@\bgroup\let\dn\dnxx\dnxx}
\newcommand\dnxx{\dnx\@ifnextchar\dn{}{\hss\egroup}}
\makeatother
\begin{document}
\begin{forest}
[\nd{TP}
    [\nd{DP} [{\nd{D\\the\dn}} ] [\nd{NP} [\nd{N\\man\dn\dn\dn} ]]]
    [\nd{T’}
       [\nd{T\\will\dn} ]
       [\nd{VP}
          [\nd{V\\eat\dn} ]
          [\nd{DP} [\nd{D\\a\dn\dn} ] [\nd{NP} [\nd{N\\burger\dn\dn\dn\dn\dn\dn} ]]]
       ]
    ]
]
\end{forest}
\end{document}

Answer 1

这是全森林版本，感谢Sašo 正在解释如何通过去标记化来测试多行内容中的字符串。否xstring或amsmath必填！

\documentclass[12pt,border=25pt]{standalone}
\usepackage[T1]{fontenc}
\usepackage[utf8]{inputenc}
\usepackage[linguistics]{forest}
\forestset{%
  declare toks={dntoks}{},
  declare toks={ndtoks}{},
  nd/.style={%
    delay={%
      % detokenize to test for string in multi-line content: Sašo Živanović: https://tex.stackexchange.com/questions/330228/annotating-a-forest-tree-with-its-corresponding-bracketing/330237?noredirect=1#comment809615_330237
      temptoksa/.expanded=\detokenize{\\},
      temptoksb/.option=content,
      temptoksb/.wrap value=\detokenize{##1},
      temptoksb/.expanded/.register=temptoksb,
      if={instr(temptoksa,temptoksb)}{%
        split register/.wrap pgfmath arg={{temptoksb}{##1}{ndtoks,temptoksc}}{(temptoksa)},
      }{%
        ndtoks/.option=content,
      },
    },
    before typesetting nodes={%
      content/.wrap value={\llap{\textcolor{red}{[\textsubscript{\foresteoption{ndtoks}}}}##1},
    },
  },
  dn/.style={%
    repeat=#1{%
      dntoks+={]},
    },
    before typesetting nodes={%
      content/.wrap value={##1\rlap{\textcolor{red}{\foresteoption{dntoks}}}},
    },
  },
}
\begin{document}
\begin{forest}
  [TP, nd
    [DP, nd
      [D, nd
      ]
      [NP
        [N\\man, dn=2
        ]
      ]
    ]
    [T', nd
       [T\\will, nd, dn=1
       ]
       [VP, nd
         [V\\eat, nd, dn=1
         ]
         [DP, nd
           [D\\a, nd, dn=1
           ]
           [NP, nd
             [N\\burger, nd, dn=6
             ]
           ]
         ]
       ]
    ]
  ]
\end{forest}
\end{document}

如果所有节点都应采用这种nd风格（如问题中的例子），那么显然可以进一步简化。

\documentclass[12pt,border=25pt]{standalone}
\usepackage[T1]{fontenc}
\usepackage[utf8]{inputenc}
\usepackage[linguistics]{forest}
\forestset{%
  declare toks={dntoks}{},
  declare toks={ndtoks}{},
  nd/.style={%
    delay={%
      % detokenize to test for string in multi-line content: Sašo Živanović: https://tex.stackexchange.com/questions/330228/annotating-a-forest-tree-with-its-corresponding-bracketing/330237?noredirect=1#comment809615_330237
      temptoksa/.expanded=\detokenize{\\},
      temptoksb/.option=content,
      temptoksb/.wrap value=\detokenize{##1},
      temptoksb/.expanded/.register=temptoksb,
      if={instr(temptoksa,temptoksb)}{%
        split register/.wrap pgfmath arg={{temptoksb}{##1}{ndtoks,temptoksc}}{(temptoksa)},
      }{%
        ndtoks/.option=content,
      },
    },
    before typesetting nodes={%
      content/.wrap value={\llap{\textcolor{red}{[\textsubscript{\foresteoption{ndtoks}}}}##1},
    },
  },
  dn/.style={%
    repeat=#1{%
      dntoks+={]},
    },
    before typesetting nodes={%
      content/.wrap value={##1\rlap{\textcolor{red}{\foresteoption{dntoks}}}},
    },
  },
  default preamble={%
    for tree={nd},
  },
}
\begin{document}
\begin{forest}
  [TP
    [DP
      [D
      ]
      [NP
        [N\\man, dn=2
        ]
      ]
    ]
    [T'
       [T\\will, dn=1
       ]
       [VP
         [V\\eat, dn=1
         ]
         [DP
           [D\\a, dn=1
           ]
           [NP
             [N\\burger, dn=6
             ]
           ]
         ]
       ]
    ]
  ]
\end{forest}
\end{document}