How to wrap text in a table when there are no spaces at which to break the line?

Question

I have a lot of text in table. I want to wrap it with in 2cm. In the last column, I have [1][2][3].....[89][100] but the column width is only 2 cm. It is supposed be wrapped by itself.

How can I implement that?

Answer 1

I think probably the brackets ought to be in math mode, and that gives the advantage of being able to use mathcode "8000 to insert an active definition for the closing bracket.

\documentclass{article}

\usepackage{array}

\edef\savedbrack{\mathchar\the\mathcode`\] }

\begingroup
\uccode`\~`\]
\uppercase{\endgroup
\def\breakablebracket{%
\mathcode`\]"8000
\def~{\savedbrack\penalty 50 }}}

\begin{document}


\begin{tabular}{|>{\raggedright\arraybackslash\breakablebracket$}p{2.0cm}<{$}|}
[1][7][3][8][5][9][7][8][9][89][100]
\end{tabular}

\end{document}

Answer 2

In this case, using the p{2.0cm} column type is necessary, but not sufficient as there is not a natural break point. This is not related to being in a table, even in normal text, having using content such as [1][1][3][2][5][3][7][8][9][89][100] does not have a natural break point.

So, using just the p{2.0cm} column:

\begin{tabular}{p{2.0cm}}
    [1][7][3][8][5][9][7][8][9][89][100]
\end{tabular}

produces:

---

Manual Solution:

Here is a solution passing the contents to the `\AddBreakableChars{} macro, which allows for a discretionary line breaks following a ]. So with:

\begin{tabular}{p{2.0cm}}
    \AddBreakableChars{[1][7][3][8][5][9][7][8][9][89][100]}
\end{tabular}

we obtain the desired result:

References:

• This is adapted from Automatic line breaking of long lines of text?

---

Automated Solution:

If you include the \usepackage{collcell} in the preamble, then you can define a new column type that automatically passes each entry in this column through the \AddBreakableChars macro via:

\newcolumntype{P}[1]{>{\collectcell\AddBreakableChars}p{#1}<{\endcollectcell}}

and using a P{<width>} column type as in:

\begin{tabular}{P{2.0cm}}
    [1][10][3][11][5][12][7][8][9][89][100]
\end{tabular}

which yields the desired results as above.

---

Code:

\documentclass{article}
\usepackage{hyphenat}
\usepackage{xstring}
\usepackage{forloop}
\usepackage{collcell}

\newsavebox\MyBreakChar%
\sbox\MyBreakChar{}% char to display the break after non char
\newsavebox\MySpaceBreakChar%
\sbox\MySpaceBreakChar{-}% char to display the break after space
\makeatletter%
\newcommand*{\BreakableChar}[1][\MyBreakChar]{%
  \leavevmode%
  \prw@zbreak%
  \discretionary{\usebox#1}{}{}%
  \prw@zbreak%
}%

\newcounter{index}%
\newcommand{\AddBreakableChars}[1]{%
  \StrLen{#1 }[\stringLength]%
  \forloop[1]{index}{1}{\value{index}<\stringLength}{%
    \StrChar{#1}{\value{index}}[\currentLetter]%
    \IfStrEq{\currentLetter}{]}
        {\currentLetter\BreakableChar[\MyBreakChar]}%
        {\currentLetter}%
  }%
}%

\newcolumntype{P}[1]{>{\collectcell\AddBreakableChars}p{#1}<{\endcollectcell}}


\begin{document}
\textbf{Manual Solution:}\par
\begin{tabular}{p{2.0cm}}
    \AddBreakableChars{[1][7][3][8][5][9][7][8][9][89][100]}
\end{tabular}

\bigskip
\textbf{Automatic Solution:}\par
\begin{tabular}{P{2.0cm}}
    [1][2][3][4][5][6][7][8][9][89][100]
\end{tabular}
\end{document}