Live demo (code) Some examples using a small DSL of it's own.
Railroad diagrams are a way to represent context-free grammar. Every diagram has exactly one starting- and end-point; everything that belongs to the described language is represented by one of the possible paths between those points.
Using this library, diagrams are created using primitives which implement Node
. Primitives are combined into more complex structures by wrapping simple elements into more complex ones.
use railroad::*;
let mut seq = Sequence::default();
seq.push(Box::new(Start) as Box<dyn Node>)
.push(Box::new(Terminal::new("BEGIN".to_owned())))
.push(Box::new(NonTerminal::new("syntax".to_owned())))
.push(Box::new(End));
let mut dia = Diagram::new(seq);
dia.add_element(svg::Element::new("style")
.set("type", "text/css")
.text(DEFAULT_CSS));
println!("{}", dia);
When adding new Node
-primitives to this library, you may find examples/visual.rs
come in handy to quickly generate special-cases and check if they render properly. Use the visual-debug
feature to add guide-lines to the rendered diagram and extra information to the SVG's code.