Expand description
A library to create syntax (“railroad”) diagrams as Scalable Vector Graphics (SVG).
Railroad diagrams are a graphical way to represent context-free grammar. Every diagram has exactly one starting- and one 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 by primitives which implemented Node.
Primitives are combined into more complex strctures by wrapping simple elements into more
complex ones.
use railroad::*;
// This diagram will be a (horizontal) sequence of simple elements
let mut seq: Sequence<Box<dyn Node>> = Sequence::default();
seq.push(Box::new(Start))
.push(Box::new(Terminal::new("BEGIN".to_owned())))
.push(Box::new(NonTerminal::new("syntax".to_owned())))
.push(Box::new(End));
// The library only computes the diagram's geometry; we use CSS for layout.
let mut dia = Diagram::new_with_stylesheet(seq, &Stylesheet::Light);
// A `Node`'s `fmt::Display` is its SVG.
println!("<html>{}</html>", dia);Re-exports§
pub use crate::notactuallysvg as svg;pub use resvg;
Modules§
- notactuallysvg
- render
- A shorthand for rendering diagrams to images, using
resvg’s default options.
Structs§
- Choice
- A container of elements, drawn vertically, where exactly one element has to be picked
- Comment
- A label / verbatim text, drawn in-line
- Diagram
- Empty
- A dummy-element which has no size and draws nothing.
- End
- A symbol indicating the logical end of a syntax-diagram via two vertical bars.
- Horizontal
Grid - A horizontal group of unconnected elements.
- Labeled
Box - A box drawn around the given element and a label placed inside the box, above the element.
- Link
- Wraps another primitive, making it a clickable link to some URI.
- NonTerminal
- A
NonTerminal, drawn as a rectangle. - Optional
- Wraps another element to make that element logically optional.
- Repeat
- Wraps one element by providing a backwards-path through another element.
- Sequence
- A horizontal group of elements, connected from left to right.
- Simple
End - A symbol indicating the logical end of a syntax-diagram via a circle
- Simple
Start - A symbol indicating the logical start of a syntax-diagram via a circle
- Stack
- A vertical group of elements, drawn from top to bottom.
- Start
- A symbol indicating the logical start of a syntax-diagram via two vertical bars.
- Terminal
- A
Terminal-symbol, drawn as a rectangle with rounded corners. - Vertical
Grid - A vertical group of unconnected elements.
Enums§
- Link
Target - Possible targets for
Link. - Stylesheet
- Pre-defined stylesheets
Constants§
- DEFAULT_
CSS - Default Cascading Style Sheets for the resuling SVG.
Traits§
- Node
- A diagram is built from a set of primitives which implement
Node. - Node
Collection - Helper trait for collections of nodes.