How do I create an aligned column of text before the numbers in a "pseudo" environment?

Question

I want to create a "diff" effect using the pseudo package, inspired by GitHub/Gerrit diffs. However, the symbols at the start of the line aren't lined up - they move when the digits go from 9 to 10. How can I get this to look nice? Can I force the numbers to be fixed-width, or set a tabular prelude that gives me a column for the "+"/"-" symbols?

Example:

\documentclass{article}
\usepackage{xcolor}
\usepackage{pseudo}
\pseudodefinestyle{rm}{bol-prepend=\rowcolor{red!30!white}{--}\quad}
\pseudodefinestyle{gp}{bol-prepend=\rowcolor{green!30!white}+\quad}
\begin{document}
\begin{pseudo}[start=7]
    foo \[rm]
    bar \[gp]
    baz \[gp]
    quuz \[gp]
    snoz \
    blep
\end{pseudo}
\end{document}

score 1 · Accepted Answer · answered Oct 06 '23 at 14:08

Using the prefix and preamble options you can add a column separator before the numbers:

\documentclass{article}
\usepackage{pseudo}
\pseudodefinestyle{rm}{bol-prepend=\rowcolor{red}{--}}
\pseudodefinestyle{gp}{bol-prepend=\rowcolor{green}+}
\begin{document}
\begin{pseudo}[
    start=7,
    prefix={\pseudobol & \stepcounter* \pseudolabel &},
    preamble={
        >{ \pseudohpad }
        c
        >{ \pseudohpad }
        \pseudolabelalign
        >{ \pseudosetup }
        l
        <{ \pseudohpad }
    },
]
    foo \[rm]
    bar \[gp]
    baz \[gp]
    quuz \+[gp]
    snoz \-
    blep
\end{pseudo}
\end{document}

I started writing this post because I was stumped, but then before posting it I found out what the solution was, so I thought I'd share both! — Paul Crowley, Oct 06 '23 at 14:19

How do I create an aligned column of text before the numbers in a "pseudo" environment?

1 Answers1