Version: 1.1.0

Docstrings

A docstring is a string literal placed as the first statement of a function, struct, or trait. mojo doc collects them.

Essentials

• Triple double quotes are the usual form.
• The first sentence is the summary.
• Later sections name Parameters, Args, Returns, and Raises.
• Docstrings are data, not comments, so they exist in the program.
• Keep the summary shorter than one line.

Example

fn area(w: Int, h: Int) -> Int:
    """Return the area of a rectangle.

    Args:
        w: Width.
        h: Height.
    """
    return w * h

Keep in mind

Write the docstring for a caller who has not opened the file.