Pseudocode

The documentation embeds some algorithms written using pseudocode.js whose syntax is mostly compatible with LaTeX package algorithmic.

The complete documentation and grammar is available at pseudocode.js grammar reference.

In order to display pseudocode properly you have to use [.pseudocode] on a literal block.

1. Basic Structure

Every pseudocode block follows this basic structure:

AsciiDoc Source

[.pseudocode]
....
\begin{algorithm}
\caption{Simple Example}
\begin{algorithmic}
\STATE $x \leftarrow 0$
\STATE $y \leftarrow 1$
\RETURN{$x + y$}
\end{algorithmic}
\end{algorithm}
....

Rendered Result

\begin{algorithm}
\caption{Simple Example}
\begin{algorithmic}
\STATE $x \leftarrow 0$
\STATE $y \leftarrow 1$
\RETURN{$x + y$}
\end{algorithmic}
\end{algorithm}

2. Available Commands

2.1. Control Structures

Command Syntax Description

Command	Syntax	Description
`\IF{condition}`	`\IF{condition} … \ENDIF`	Conditional statement
`\ELSIF{condition}`	`\ELSIF{condition} …`	Else-if branch
`\ELSE`	`\ELSE …`	Else branch
`\ENDIF`	`\ENDIF`	End of if block
`\FOR{loop}`	`\FOR{loop} … \ENDFOR`	For loop
`\FORALL{condition}`	`\FORALL{condition} … \ENDFOR`	For-all loop
`\WHILE{condition}`	`\WHILE{condition} … \ENDWHILE`	While loop
`\REPEAT`	`\REPEAT … \UNTIL{condition}`	Repeat-until loop
`\UNTIL{condition}`	`\UNTIL{condition}`	Until condition

\IF{condition}

\IF{condition} … \ENDIF

Conditional statement

\ELSIF{condition}

\ELSIF{condition} …

Else-if branch

\ELSE

\ELSE …

Else branch

\ENDIF

End of if block

\FOR{loop}

\FOR{loop} … \ENDFOR

For loop

\FORALL{condition}

\FORALL{condition} … \ENDFOR

For-all loop

\WHILE{condition}

\WHILE{condition} … \ENDWHILE

While loop

\REPEAT

\REPEAT … \UNTIL{condition}

Repeat-until loop

\UNTIL{condition}

Until condition

2.2. Statements and Actions

Command Syntax Description

Command	Syntax	Description
`\STATE`	`\STATE statement`	General statement
`\PRINT{text}`	`\PRINT{text}`	Print statement
`\RETURN{value}`	`\RETURN{value}`	Return statement
`\CALL{name}{args}`	`\CALL{name}{args}`	Function call
`\COMMENT{text}`	`\COMMENT{text}`	Add comment

\STATE

\STATE statement

General statement

\PRINT{text}

Print statement

\RETURN{value}

Return statement

\CALL{name}{args}

Function call

\COMMENT{text}

Add comment

2.3. Procedures and Functions

Command Syntax Description

Command	Syntax	Description
`\PROCEDURE{name}{args}`	`\PROCEDURE{name}{args} … \ENDPROCEDURE`	Define procedure
`\FUNCTION{name}{args}`	`\FUNCTION{name}{args} … \ENDFUNCTION`	Define function
`\ENDPROCEDURE`	`\ENDPROCEDURE`	End procedure
`\ENDFUNCTION`	`\ENDFUNCTION`	End function

\PROCEDURE{name}{args}

\PROCEDURE{name}{args} … \ENDPROCEDURE

Define procedure

\FUNCTION{name}{args}

\FUNCTION{name}{args} … \ENDFUNCTION

Define function

\ENDPROCEDURE

End procedure

\ENDFUNCTION

End function

2.4. Loop Keywords

Command Syntax Description

Command	Syntax	Description
`\TO`	`\FOR{$i = 1$ \TO $n$}`	Range operator
`\DOWNTO`	`\FOR{$i = n$ \DOWNTO $1$}`	Reverse range
`\STEP`	`\FOR{$i = 1$ \TO $n$ \STEP $2$}`	Step size

\TO

\FOR{$i = 1$ \TO $n$}

Range operator

\DOWNTO

\FOR{$i = n$ \DOWNTO $1$}

Reverse range

\STEP

\FOR{$i = 1$ \TO $n$ \STEP $2$}

Step size

3. Complete Examples

3.1. Example 1: Quicksort Algorithm

AsciiDoc Source

[.pseudocode]
....
% Quicksort from Introduction to Algorithms (3rd edition)
\begin{algorithm}
\caption{Quicksort}
\begin{algorithmic}
\PROCEDURE{Quicksort}{$A, p, r$}
    \IF{$p < r$}
        \STATE $q = $ \CALL{Partition}{$A, p, r$}
        \STATE \CALL{Quicksort}{$A, p, q - 1$}
        \STATE \CALL{Quicksort}{$A, q + 1, r$}
    \ENDIF
\ENDPROCEDURE
\PROCEDURE{Partition}{$A, p, r$}
    \STATE $x = A[r]$
    \STATE $i = p - 1$
    \FOR{$j = p$ \TO $r - 1$}
        \IF{$A[j] < x$}
            \STATE $i = i + 1$
            \STATE exchange $A[i]$ with $A[j]$
        \ENDIF
    \ENDFOR
    \STATE exchange $A[i + 1]$ with $A[r]$
    \RETURN{$i + 1$}
\ENDPROCEDURE
\end{algorithmic}
\end{algorithm}
....

Rendered Result

% Quicksort from Introduction to Algorithms (3rd edition)
\begin{algorithm}
\caption{Quicksort}
\begin{algorithmic}
\PROCEDURE{Quicksort}{$A, p, r$}
    \IF{$p < r$}
        \STATE $q = $ \CALL{Partition}{$A, p, r$}
        \STATE \CALL{Quicksort}{$A, p, q - 1$}
        \STATE \CALL{Quicksort}{$A, q + 1, r$}
    \ENDIF
\ENDPROCEDURE
\PROCEDURE{Partition}{$A, p, r$}
    \STATE $x = A[r]$
    \STATE $i = p - 1$
    \FOR{$j = p$ \TO $r - 1$}
        \IF{$A[j] < x$}
            \STATE $i = i + 1$
            \STATE exchange $A[i]$ with $A[j]$
        \ENDIF
    \ENDFOR
    \STATE exchange $A[i + 1]$ with $A[r]$
    \RETURN{$i + 1$}
\ENDPROCEDURE
\end{algorithmic}
\end{algorithm}

3.2. Example 2: Binary Search

AsciiDoc Source

[.pseudocode]
....
\begin{algorithm}
\caption{Binary Search}
\begin{algorithmic}
\FUNCTION{BinarySearch}{$A, target, low, high$}
    \WHILE{$low \leq high$}
        \STATE $mid \leftarrow \lfloor (low + high) / 2 \rfloor$
        \IF{$A[mid] = target$}
            \RETURN{$mid$}
        \ELSIF{$A[mid] < target$}
            \STATE $low \leftarrow mid + 1$
        \ELSE
            \STATE $high \leftarrow mid - 1$
        \ENDIF
    \ENDWHILE
    \RETURN{$-1$} \COMMENT{Not found}
\ENDFUNCTION
\end{algorithmic}
\end{algorithm}
....

Rendered Result

\begin{algorithm}
\caption{Binary Search}
\begin{algorithmic}
\FUNCTION{BinarySearch}{$A, target, low, high$}
    \WHILE{$low \leq high$}
        \STATE $mid \leftarrow \lfloor (low + high) / 2 \rfloor$
        \IF{$A[mid] = target$}
            \RETURN{$mid$}
        \ELSIF{$A[mid] < target$}
            \STATE $low \leftarrow mid + 1$
        \ELSE
            \STATE $high \leftarrow mid - 1$
        \ENDIF
    \ENDWHILE
    \RETURN{$-1$} \COMMENT{Not found}
\ENDFUNCTION
\end{algorithmic}
\end{algorithm}

3.3. Example 3: Graph Traversal

AsciiDoc Source

[.pseudocode]
....
\begin{algorithm}
\caption{Breadth-First Search}
\begin{algorithmic}
\PROCEDURE{BFS}{$G, s$}
    \FORALL{$u \in V[G] \setminus \{s\}$}
        \STATE $color[u] \leftarrow WHITE$
        \STATE $d[u] \leftarrow \infty$
        \STATE $\pi[u] \leftarrow NIL$
    \ENDFOR
    \STATE $color[s] \leftarrow GRAY$
    \STATE $d[s] \leftarrow 0$
    \STATE $\pi[s] \leftarrow NIL$
    \STATE $Q \leftarrow \emptyset$
    \STATE \CALL{Enqueue}{$Q, s$}
    \WHILE{$Q \neq \emptyset$}
        \STATE $u \leftarrow$ \CALL{Dequeue}{$Q$}
        \FORALL{$v \in Adj[u]$}
            \IF{$color[v] = WHITE$}
                \STATE $color[v] \leftarrow GRAY$
                \STATE $d[v] \leftarrow d[u] + 1$
                \STATE $\pi[v] \leftarrow u$
                \STATE \CALL{Enqueue}{$Q, v$}
            \ENDIF
        \ENDFOR
        \STATE $color[u] \leftarrow BLACK$
    \ENDWHILE
\ENDPROCEDURE
\end{algorithmic}
\end{algorithm}
....

Rendered Result

\begin{algorithm}
\caption{Breadth-First Search}
\begin{algorithmic}
\PROCEDURE{BFS}{$G, s$}
    \FORALL{$u \in V[G] \setminus \{s\}$}
        \STATE $color[u] \leftarrow WHITE$
        \STATE $d[u] \leftarrow \infty$
        \STATE $\pi[u] \leftarrow NIL$
    \ENDFOR
    \STATE $color[s] \leftarrow GRAY$
    \STATE $d[s] \leftarrow 0$
    \STATE $\pi[s] \leftarrow NIL$
    \STATE $Q \leftarrow \emptyset$
    \STATE \CALL{Enqueue}{$Q, s$}
    \WHILE{$Q \neq \emptyset$}
        \STATE $u \leftarrow$ \CALL{Dequeue}{$Q$}
        \FORALL{$v \in Adj[u]$}
            \IF{$color[v] = WHITE$}
                \STATE $color[v] \leftarrow GRAY$
                \STATE $d[v] \leftarrow d[u] + 1$
                \STATE $\pi[v] \leftarrow u$
                \STATE \CALL{Enqueue}{$Q, v$}
            \ENDIF
        \ENDFOR
        \STATE $color[u] \leftarrow BLACK$
    \ENDWHILE
\ENDPROCEDURE
\end{algorithmic}
\end{algorithm}

3.4. Example 4: Simple Loop Constructs

AsciiDoc Source

[.pseudocode]
....
\begin{algorithm}
\caption{Loop Examples}
\begin{algorithmic}
\PROCEDURE{LoopExamples}{$n$}
    \FOR{$i = 0$ \TO $n$}
        \PRINT{$i$}
    \ENDFOR

    \FOR{$j = n$ \DOWNTO $1$}
        \PRINT{$j$}
    \ENDFOR

    \STATE $x \leftarrow 0$
    \REPEAT
        \STATE $x \leftarrow x + 1$
        \PRINT{$x$}
    \UNTIL{$x = n$}
\ENDPROCEDURE
\end{algorithmic}
\end{algorithm}
....

Rendered Result

\begin{algorithm}
\caption{Loop Examples}
\begin{algorithmic}
\PROCEDURE{LoopExamples}{$n$}
    \FOR{$i = 0$ \TO $n$}
        \PRINT{$i$}
    \ENDFOR

    \FOR{$j = n$ \DOWNTO $1$}
        \PRINT{$j$}
    \ENDFOR

    \STATE $x \leftarrow 0$
    \REPEAT
        \STATE $x \leftarrow x + 1$
        \PRINT{$x$}
    \UNTIL{$x = n$}
\ENDPROCEDURE
\end{algorithmic}
\end{algorithm}

4. Mathematical Expressions

Pseudocode.js supports full LaTeX mathematical notation within $…$ delimiters:

Variables: $x, y, z$
Subscripts/Superscripts: $A[i], x^2, log_2(n)$
Greek letters: $\alpha, \beta, \gamma, \pi$
Set notation: $\{1, 2, 3\}, \emptyset, \in, \subset$
Mathematical operators: $\leftarrow, \rightarrow, \leq, \geq, \neq$
Functions: $\lfloor x \rfloor, \lceil x \rceil, \max(a,b)$

5. Comments and Formatting

Use % for single-line comments
Use \COMMENT{text} for inline comments
Mathematical expressions are automatically rendered with MathJax
Indentation is handled automatically based on control structures

6. Usage Tips

Always use the .pseudocode class on your literal block
Wrap math in dollar signs for proper rendering
Use proper nesting of control structures
End blocks explicitly with appropriate \END… commands
Mathematical expressions are automatically processed by MathJax after pseudocode rendering