= Reddit Suggestion for visual pure functional programming

The Reddit user 'Jameshfisher' suggested a style of pure visual programming
@reddit_visual_fp. It is only theoretical and, therefore, not an existing
tool. A picture of the suggestion is shown in @screenshot_reddit_visual_fp. 

#figure(
    image("../../../static/reddit_suggestion_visual_fp.png", width: 80%),
    caption: [
        Suggestion for visual pure function programming by Reddit user Jameshfisher
        Source: Adapted from @reddit_visual_fp
    ]
)<screenshot_reddit_visual_fp>

But the proposed concept is very intriguing. Instead of drawing a function from
the outside, functions are drawn from the inside.

A function's input is displayed on the top, and the output on the bottom.
The arrows show how the output is composed of other expressions.

Out of all the researched tools, this suggestion shows functional
programming concepts best.