Pseudocode to LaTeX

This repository provides a script to format Pseudocode using LaTeX.

Requirements

Programs

• Python
• LaTeX

Packages

For Python:

• Pygments --- For code tokenisation

For LaTeX:

• minted --- For typesetting code listings
• tikZ --- For drawing curly braces

Getting Started

1. Copy pseudocode-preamble.sty and Pseudocode.py to your project directory.

2. Add the following line of code to the preamble of your *.tex file.

   \input{pseudocode-preamble.sty}

3. Place pseudocode in independent files with glob pattern *.pseudo or *.pseudocode, ensuring that filenames do not contain numbers. Place these code files inside a folder called Pseudocode/. (You may specify another directory by modifying the command in pseudocode-preamble.sty).

4. Place an \input{<filename>.tex} macro where you would like your code to appear.

5. Compile your program.

   • If a pseudocode file is modified or a new file is included, you must compile the document twice for all marker locations to be updated.

Note if you have not specified an aux directory, you will need to modify line 1 in pseudocode-preamble.sty and line 150 in pseudocode.py.

Pseudocode Fie Conventions

Pseudocode can be placed in files with the glob pattern *.pseudo or *.pseudocode.

Warning: file names cannot contain numbers. Special characters will be ignored.

Recognised keywords are automatically formatted as bold. All other text is formatted as plain text.

For typesetting mathematical expressions, operators, and variables, surround text with dollar signs ($).

Comments are typeset as plain text, and can be invoked using double-forwardslashes (//). These may be placed anywhere in the code. To enter Math mode, place dollar signs within comments as previously stated.

For description braces, use the following syntax.

# Pseudocode
ALGORITHM AlgorithmName()
...

# The following code must be placed at the end of the file
# 1. Brace definitions (separate multiple definitions by a new line)
:{<level>}{<start line number>:<end line number>}<label>
# 2. Brace horizontal offsets
>{<initial offset>}{<additional offsets>}

• If 1. is omitted, 2. will be ignored and can also be omitted.
• If 1. is present, 2. must also be present.

Brace Definition Guide

Specifying a level allows us to control the horizontal offset of braces that appear above other braces.

• Levels start at 0, and take positive integer values.

The distance between two levels is controlled by initial offset and additional offsets.

• Distances can be positive or negative floating point values.
• additional offsets must appear as comma separated values. If the number of supplied additional offsets is less than the maximum level, the program will automatically choose the last supplied offset.

For example:

...
:{0}{1:2}...
:{1}{2:3}...
:{2}{3:4}...
:{3}{4:5}...
>{7}{1.5, 1.0}

In the above code:

• Level 0 will be horizontally offset by 7cm (as specified).
• Level 1 will be horizontally offset by 7cm + 1.5cm (as specified).
• Level 2 will be horizontally offset by 7cm + 1.5cm + 1.0cm (as specified).
• Level 3 will be horizontally offset by 7cm + 1.5cm + 1.0cm + 1.0cm (the program chooses a 1.0cm offset for level 3 as it could not find a 3rd offset).

Minimal Reproduceable Example

Pseudocode/select-sort-A.pseudocode:

ALGORITHM SelectSort($A\left[0..n - 1\right]$)
// Selection sort algorithm.
for $i \leftarrow 0$ to $n - 1$ do
    $SmallSub \leftarrow i$
    for $j \leftarrow i + 1$ to $n - 1$ do
        if $A[j] < A[SmallSub]$ then
            $SmallSub \leftarrow j$

    $temp \leftarrow A[i]$
    $A[SmallSub] \leftarrow temp$

return $A$
:{0}{6:6}\(O\left( 1 \right)\)
:{1}{5:7}\(O\left( n \right)\)
:{2}{3:10}\(O\left( n^2 \right)\)
>{7}{1.5, 1.5}

Command-line (produces .tex file):

python Pseudocode.py Pseudocode

Within LaTeX:

%!TEX TS-program = xelatex
%!TEX options = -aux-directory=aux -shell-escape -interaction=nonstopmode -synctex=1 "%DOC%"
\documentclass{article}
\input{pseudocode-preamble.sty}

\setminted{linenos} % Style your minted environments here

\begin{document}
\input{Pseudocode/select-sort-A.tex}
\input{Pseudocode/select-sort-B.tex}
\end{document}

Note that if you are using the LaTeX Workshop extension in VSCode, the magic comments (TeX directives) used in this example are disabled by default. To enable them, please see this issue.

Example Output

Debugging

The provided script accepts both files and folders.

python Pseudocode.py <file | folder> [files | folders]...

This will generate a file within the same directory as the specified file with the .tex extension.

To optimise workflow, the above command has been placed within LaTeX using:

\immediate\write18{<command>}

where <command> is a shell command.

If the program does not produce the desired output, please check the output of the PseudocodeLexer in the aux directory.

Certain constants such as the output directory and the debugging flag can be modified from this file also. See line 149.