循環遍歷字串數組（實際上是字串數組的數組，例如 `{{black, ab}, {white, cd}}`）

Question

我正在圍棋（遊戲）棋盤上畫棋子肝細胞生長因子座標（我只能從人們給我的幫助中做到這個問題） 像這樣\drawStoneFromSgfCoords{ab}。

但是，每個圖表可能有很多石頭，因此也可以使用另一個像這樣的巨集：（\drawStonesFromSgfCoords{{black, ab}, {white, cd}}顏色通常會交替，但有時會先列出黑色座標，然後列出白色座標更實用）。

這是我現在正在嘗試的，儘管它不起作用（我的意思是，它確實有效，只是不適用於新巨集）：

\documentclass{article}

\usepackage{tikz}

% From [this answer by @DavidCarlisle](https://tex.stackexchange.com/a/708876/64441).
\newcommand\notwhite{black}
\newcommand\notblack{white}

% From [this answer by @DavidCarlisle](https://tex.stackexchange.com/a/708893/64441).
\ExplSyntaxOn
  \cs_generate_variant:Nn \int_from_alph:n {e}

  \newcommand\stringToCoordX[1]{
    \int_from_alph:e{\use_i:nn#1}
  }
  \newcommand\stringToCoordY[1]{
    ~\int_from_alph:e{\use_ii:nn#1}
  }
\ExplSyntaxOff

\newcommand{\drawStoneFromSgfCoords}[2]{
  \pgfmathsetmacro{\x}{\stringToCoordX{#2} - 1}
  \pgfmathsetmacro{\y}{\stringToCoordY{#2} - 1}

  \draw[draw = \UseName{not#1}, fill = #1, line width = 0.1mm]
    (\x * 10cm / 18, \y * 10cm / 18)
    circle [radius = 0.2575cm];
    node[color = white] {1};
}

% Example usage: `drawStonesFromSgfCoords{{black, ab}, {white, cd}}`
\newcommand{\drawStonesFromSgfCoords}[1]{
  \foreach \coords in {#1}{
    \drawStoneFromSgfCoords{{\coords}[0]}{{\coords}[1]}
  }
}

\begin{document}
  \begin{tikzpicture}
    \pgfmathsetmacro{\step}{10 / 18}

    \draw[step=\step] (0, 0) grid (10, 10);

    \drawStoneFromSgfCoords{black}{ab}
    \drawStoneFromSgfCoords{white}{cd}
    
    % \drawStonesFromSgfCoords{{black, ab}, {white, cd}}
  \end{tikzpicture}
\end{document}

存取或傳遞數組（在循環內）的正確方法是什麼？

（我使用 PGF 是\foreach因為我知道這一點。）

Answer 1

我認為，透過 expl 工具處理嵌套clist（逗號分隔的清單）是一個更好的主意，因為那裡已經存在處理此類清單的工具：

\documentclass{article}
\usepackage{tikz}

% From [this answer by @DavidCarlisle](https://tex.stackexchange.com/a/708876/64441).
\newcommand\notwhite{black}
\newcommand\notblack{white}

% From [this answer by @DavidCarlisle](https://tex.stackexchange.com/a/708893/64441).
\ExplSyntaxOn
  \cs_generate_variant:Nn \int_from_alph:n {e}

  \NewExpandableDocumentCommand{\stringToCoordX}{ m }{
    \int_from_alph:e { \use_i:nn #1 }
  }
  \NewExpandableDocumentCommand{\stringToCoordY}{ m }{
    \int_from_alph:e { \use_ii:nn #1 }
  }
\ExplSyntaxOff

\newcommand{\drawStoneFromSgfCoords}[2]{
  \pgfmathsetmacro{\x}{\stringToCoordX{#2} - 1}
  \pgfmathsetmacro{\y}{\stringToCoordY{#2} - 1}

  \draw[draw = \UseName{not#1}, fill = #1, line width = 0.1mm]
    (\x * 10cm / 18, \y * 10cm / 18)
    circle [radius = 0.2575cm];
}

\ExplSyntaxOn
  % Example usage: `drawStonesFromSgfCoords{{black, ab}, {white, cd}}`
  \NewExpandableDocumentCommand{\drawStonesFromSgfCoords}{ m }{
    \clist_set:Nn \l_tmpa_clist { #1 }
    \clist_map_inline:Nn \l_tmpa_clist {
      \clist_set:Nn \l_tmpb_clist { ##1 }
      \clist_pop:NN \l_tmpb_clist \l_tmpa_tl 
      \clist_pop:NN \l_tmpb_clist \l_tmpb_tl 
      \exp_args:Noo \drawStoneFromSgfCoords { \l_tmpa_tl } { \l_tmpb_tl }
      
    }
  }
\ExplSyntaxOff

\begin{document}
  \begin{tikzpicture}
    \pgfmathsetmacro{\step}{10 / 18}

    \draw[step=\step] (0, 0) grid (10, 10);

    %\drawStoneFromSgfCoords{black}{ab}
    %\drawStoneFromSgfCoords{white}{cd}
    \drawStonesFromSgfCoords{{black, ab}, {white, cd}}
    
  \end{tikzpicture}
\end{document}

---

關於所使用命令的一些註釋（可以在以下位置找到很好的概述和詳盡的文檔）L3 介面 PDF）：

• \clist_set:Nn \l_tmpa_clist { #1 }將clist（逗號分隔的清單）儲存在令牌變數中以使其可存取。在本例中，{{black, ab}, {white, cd}}儲存clist在標記變數 中\l_tmpa_clist。
• \clist_map_inline:Nn \l_tmpa_clist { ... }迴圈遍歷clist(儲存在 token 變數中) 中的每個項目並執行大括號之間的程式碼。當前專案透過#1(##1在程式碼範例中，因為它嵌套得更深一層) 來存取。
• \clist_pop:NN \l_tmpb_clist \l_tmpa_tl取得 的第一項clist並將其儲存在標記變數 ( l_tmpa_tl) 中。然後它會從 中刪除此項目clist。
• \exp_args:Noo \drawStoneFromSgfCoords { \l_tmpa_tl } { \l_tmpb_tl }首先擴展兩個標記變數並將結果作為參數插入到\drawStoneFromSgfCoords.

那麼，讓我們看看如果我們說\drawStonesFromSgfCoords{{black, ab}, {white, cd}}：

\NewExpandableDocumentCommand{\drawStonesFromSgfCoords}{ m }{

    % store {{black, ab}, {white, cd}} in \l_tmpa_clist 
    \clist_set:Nn \l_tmpa_clist { #1 }

    % loop over items in \l_tmpa_clist 
    \clist_map_inline:Nn \l_tmpa_clist {

      % store {black, ab} in \l_tmpb_clist
      \clist_set:Nn \l_tmpb_clist { ##1 }

      % store black in \l_tmpa_tl and remove item from clist
      \clist_pop:NN \l_tmpb_clist \l_tmpa_tl 

      % store ab in \l_tmpb_tl and remove item from clist
      \clist_pop:NN \l_tmpb_clist \l_tmpb_tl 

      % expand \l_tmpa_tl and \l_tmpb_tl so that we get
      % \drawStoneFromSgfCoords{black}{ab}
      \exp_args:Noo \drawStoneFromSgfCoords { \l_tmpa_tl } { \l_tmpb_tl }

      % repeat this loop for the next item in the clist in \l_tmpa_clist

    }
}