Code Highlighting with minted

Minted is a package that allows formatting and highlighting source code in LaTeX. This article explains how to use it.

Introduction

Using the package minted is straightforward.

\documentclass{article}
\usepackage[utf8]{inputenc}
\usepackage[english]{babel}

\usepackage{minted}

\begin{document}
\begin{minted}{python}
import numpy as np
    
def incmatrix(genl1,genl2):
    m = len(genl1)
    n = len(genl2)
    M = None #to become the incidence matrix
    VT = np.zeros((n*m,1), int)  #dummy variable
    
    #compute the bitwise xor matrix
    M1 = bitxormatrix(genl1)
    M2 = np.triu(bitxormatrix(genl2),1) 

    for i in range(m-1):
        for j in range(i+1, m):
            [r,c] = np.where(M2 == M1[i,j])
            for k in range(len(r)):
                VT[(i)*n + r[k]] = 1;
                VT[(i)*n + c[k]] = 1;
                VT[(j)*n + r[k]] = 1;
                VT[(j)*n + c[k]] = 1;
                
                if M is None:
                    M = np.copy(VT)
                else:
                    M = np.concatenate((M, VT), 1)
                
                VT = np.zeros((n*m,1), int)
    
    return M
\end{minted}
\end{document}

There are two important commands here. In the preamble the package is imported by

\usepackage{minted}

then the tags \begin{minted}{python} and \end{minted} delimit an environment that print the text verbatim in monospaced fonts and also colour comments, keywords and functions. The parameter python is the programming language the source code is written in. minted supports over 150 programming and markup languages as well as configuration files, see the reference guide for a list of supported languages.

Note: For minted to work with you local LaTeX distribution an additional program called Pygments must be installed, Overleaf can save you the trouble of installing it and having to run special commands to compile your document. Documents that use minted work "out of the box" in Overelaf.

  Open an example of the minted package in Overeaf

Basic usage

There are some options in the minted environment that change the visual aspect of the code.

\begin{minted}
[
frame=lines,
framesep=2mm,
baselinestretch=1.2,
bgcolor=LightGray,
fontsize=\footnotesize,
linenos
]
{python}
import numpy as np
    
def incmatrix(genl1,genl2):
    m = len(genl1)
    n = len(genl2)
    M = None #to become the incidence matrix
    VT = np.zeros((n*m,1), int)  #dummy variable
    
    #compute the bitwise xor matrix
    M1 = bitxormatrix(genl1)
    M2 = np.triu(bitxormatrix(genl2),1) 

    for i in range(m-1):
        for j in range(i+1, m):
            [r,c] = np.where(M2 == M1[i,j])
            for k in range(len(r)):
                VT[(i)*n + r[k]] = 1;
                VT[(i)*n + c[k]] = 1;
                VT[(j)*n + r[k]] = 1;
                VT[(j)*n + c[k]] = 1;
                
                if M is None:
                    M = np.copy(VT)
                else:
                    M = np.concatenate((M, VT), 1)
                
                VT = np.zeros((n*m,1), int)
    
    return M
\end{minted}

This is the example presented in the introduction, but the opening delimiter for the environment now has the syntax \begin{minted}[...]{python}. Inside the brackets several comma-separated parameters in the form key=value are set:

frame=lines

Draws two lines, one on top and one at the bottom of the code to frame it. Other possible values are leftline, topline, bottomline and single.

framesep=2mm

The frame separation is set to 2mm. Other length units can be used.

baselinestretch=1.2

Interlining of the code set to 1.2.

bgcolor=LightGray

Background colour set to light grey. You need to import xcolor for this to work. See Using colours in LaTeX to learn more about colour manipulation.

fontsize=\footnotesize

Font size set to footnotesize. Any other font size can be set.

linenos

Enables line numbers.

Other options that may be useful are:

• mathscape. Enables math mode in code comments.
• rulecolor. Changes the colour of the frame.
• showspaces. Enables a special character to make spaces visible.

  Open an example of the minted package in Overleaf

Including code from a file

Code is usually stored in a source file, therefore a command that automatically pulls code from a file becomes very handy.

\documentclass{article}
\usepackage[utf8]{inputenc}
\usepackage[english]{babel}

\usepackage{minted}

\begin{document}
The next code will be directly imported from a file:

\inputminted{octave}{BitXorMatrix.m}
\end{document}

The command \inputminted{octave}{BitXorMatrix.m} imports the code from the file BitXorMatrix.m, the parameter octave tells LaTeX the programming language of the code. This command can take two extra parameters to import only part of the file; for instance, to import code from the line 2 to the line 12, the command becomes:

\inputminted[firstline=2, lastline=12]{octave}{BitXorMatrix.m}

  Open an example of the minted package in Overleaf

One-line code

If you need to input only a line of code, the command \mint, whose syntax is presented in the next example, will do the trick.

One-line code formatting also works with minted. For instance, a simple html 
sample like this:
\mint{html}|<h2>Something <b>here</b></h2>|
can be properly 
formatted.

The parameter in between braces set the programming language (markup language in this case), the actual text to be formatted is delimited by the character |.

  Open an example of the minted package in Overleaf

Custom lexers

By default, minted supports only languages with lexers that are already installed or registered with pygmentize. If you have written a custom lexer, or want to use a lexer for a language that's not yet been installed on Overleaf, you can still use it in your own Overleaf project using the approach mentioned here.

Say for example you have defined a lexer in the file nl-lexer.py, containing the class NetLogoLexer for the NetLogo language. Upload nl-lexer.py to your Overleaf project, and then specify nl-lexer.py:NetLogoLexer as the "language name" when using minted. For example:

\begin{minted}{nl-lexer.py:NetLogoLexer -x}
   ... your code here ...
\end{minted}

Here's another example for the ImageJ Macro language.

Colours and style sheets

The colour schemes for code highlighting are saved in style sheets. You can create your own or use one already available in your LaTeX distribution. See the reference guide for a list of stylesheets included in Overleaf.

\documentclass{article}
\usepackage[utf8]{inputenc}
\usepackage[english]{babel}

\usepackage{minted}
\usemintedstyle{borland}

\begin{document}
\begin{minted}{python}
import numpy as np
    
def incmatrix(genl1,genl2):
    m = len(genl1)
    n = len(genl2)
    M = None #to become the incidence matrix
    VT = np.zeros((n*m,1), int)  #dummy variable
    
    #compute the bitwise xor matrix
    M1 = bitxormatrix(genl1)
    M2 = np.triu(bitxormatrix(genl2),1) 
...
\end{minted}
\end{document}

The syntax to set a colouring style is easy, the command \usemintedstyle{borland} uses the colour theme borland to format the source code. You can find more colour schemes in the reference guide.

  Open an example of the minted package in Overleaf

Captions, labels and the list of listings

Code listings formatted with minted can be included in a float element, just like figures and tables. Captions and labels can be assigned to code listings, and then later be referenced and included in a "List of listings".

\begin{listing}[ht]
\inputminted{octave}{BitXorMatrix.m}
\caption{Example from external file}
\label{listing:3}
\end{listing}

To print the list with all listing elements use \listoflistings

\renewcommand\listoflistingscaption{List of source codes}
\listoflistings

In the example above, the default title "List of listings" is changed to "List of source codes" by

\renewcommand\listoflistingscaption{List of source codes}

  Open an example of the minted package in Overleaf

Reference guide

Colour styles for minted

name	output	name	output
manni		fruity
rrt		autumn
perldoc		bw
borland		emacs
colorful		vim
murphy		pastie
vs		friendly
trac		native
tango		monokai

Some colour schemes need a dark background to be readable.

Main supported programming languages and configuration files

Further reading

For more information see:

• Lengths in LaTeX
• Code listing
• Counters
• Using colours in LaTeX
• Font sizes, families, and styles
• Font typefaces
• Management in a large project
• Multi-file LaTeX projects
• Table of contents
• Single sided and double sided documents
• The minted package documentation