在数组循环内，普通 TeX 中的 Accent i 会失败

Question

在 Plain TeX 中，当我尝试创建一个控制序列数组（\word0、\word1等）并使用循环将其打印出来时，TeX 会遇到重音符号 i 的控制序列\'{\i}。我收到此错误：

! Missing number, treated as zero.
<to be read again> 
                   }
\word1 ->r\'{\i }
                 os
\body ->\csname word\the \i \endcsname 
                                       \^^M\advance \i by 1 \ifnum \i < \word 
\next ->\body 
              \let \next \iterate \else \let \next \relax \fi \next 
l.40 Automatic array and printing: \printlist

这让我觉得我可能对扩展有些误解。为什么会出现这个错误？

该图显示了忽略编译过程中的错误所产生的输出。

% This accent macro works.
Spelled out: r\'{\i}os

% It also works inside another macro.
\def\rios{r\'{\i}os}
Macro: \rios

% When I make a quasi-array by hand it works.
\expandafter\def\csname word0\endcsname{river}
\expandafter\def\csname word1\endcsname{r\'{\i}os}

Array by hand:
\csname word0\endcsname\
\csname word1\endcsname

% When I make the array automatically and print the results manually, it works.
\newcount\word
\word=0
\def\addtolist #1{
    \expandafter\def\csname word\the\word\endcsname{#1}
    \advance\word by 1
}
\addtolist{river}
\addtolist{r\'{\i}os}

Automatic array, print by hand:
\csname word0\endcsname\
\csname word1\endcsname

% But when I try to print the list automatically, TeX stumbles over the accented i.
\newcount\i
\def\printlist{
    \i=0
    \loop
        \csname word\the\i\endcsname\
        \advance\i by 1
        \ifnum\i < \word
    \repeat
}
Automatic array and printing: \printlist
\bye

Answer 1

一个控制序列不能同时具有两种含义。

当你这样做时，\newcount\i你只会丢失无点的 i。

修复（一些%在行尾）：

% This accent macro works.
Spelled out: r\'{\i}os

% It also works inside another macro.
\def\rios{r\'{\i}os}
Macro: \rios

% When I make a quasi-array by hand it works.
\expandafter\def\csname word0\endcsname{river}
\expandafter\def\csname word1\endcsname{r\'{\i}os}

Array by hand:
\csname word0\endcsname\
\csname word1\endcsname

% When I make the array automatically and print the results manually, it works.
\newcount\word
\word=0
\def\addtolist #1{%
    \expandafter\def\csname word\the\word\endcsname{#1}%
    \advance\word by 1
}
\addtolist{river}
\addtolist{r\'{\i}os}

Automatic array, print by hand:
\csname word0\endcsname\
\csname word1\endcsname

% But when I try to print the list automatically, TeX stumbles over the accented i.
\newcount\anewcounter
\def\printlist{%
    \anewcounter=0
    \loop
        \csname word\the\anewcounter\endcsname\
        \advance\anewcounter by 1
        \ifnum\anewcounter < \word
    \repeat
}
Automatic array and printing: \printlist
\bye