EBNF 2 RailRoad


A command line tool to create great documentation including railroad diagrams
based on the ISO/IEC 14977 specification

Features

- Creates optimized visual syntax diagrams based on the EBNF syntax
- Quick navigation using references of used declarations
- Nice comment markup using markdown
- Validates if document is complete and has no duplicate declarations
- Shows pretty printed text syntax in the document
- Pretty printing of the sourcefile
- Table of contents indicating root elements, character sets, common elements
and recursion
- Generation of large overview diagrams for root elements

Installation

``
npm install -g ebnf2railroad
`

Usage from command line

`
Usage: ebnf2railroad [options]

Converts an ISO/IEC 14977 EBNF file to a HTML/Markdown file with SVG railroad diagrams

Options:

-V, --version output the version number
-q, --quiet suppress output to STDOUT
-o, --target [target] output the file to target destination.
--no-target skip writing output HTML
-t, --title [title] title to use for HTML document
--lint exit with status code 2 if EBNF document has warnings
--write-style rewrites the source document with styled text
--no-optimizations does not try to optimize the diagrams
--no-overview-diagram skip creating overview diagrams for root elements
--no-diagram-wrap does not wrap diagrams for width minimization
--no-text-formatting does not format the output text version (becomes single line)
--dump-ast dump EBNF file AST to target destination for further processing
--read-ast input file is in the AST format
-h, --help output usage information
`

$3

To generate HTML documentation of the EBNF file:

`
ebnf2railroad --title 'My Title' inputfile.ebnf -o outputfile.html
`

To only verify the EBNF file:

`
ebnf2railroad --lint inputfile.ebnf --no-target
`

To prettify the source EBNF file:

`
ebnf2railroad --write-style inputfile.ebnf --no-target
`

$3

Check the examples folder for an example input file and the generated result
page.

- EBNF ebnf2railroad examples/ebnf.ebnf --title EBNF
[View html result online][example-ebnf] View source
- JSON ebnf2railroad examples/json.ebnf --title JSON
[View html result online][example-json] View source

$3

The following optimizations are applied:

- Ungrouping of groups that do not affect meaning of syntax
- Untangling of nested choice elements
- Duplicate choices are removed
- Pretty printing of original syntax, with wrapping, column alignment

[View html result online][example-optimizations] View source
View markdown result

Usage as module

`javascript
const { parseEbnf, createDocumentation } = require("ebnf2railroad");

const ebnf = "definition = 'a', other, { other } | item, 'b';";
const ast = parseEbnf(ebnf); // can throw parse error exceptions
const htmlOutput = createDocumentation(ast);
``

Licence

The code is licensed under MIT (see LICENSE file).

Contributing

Thanks for your interest in contributing! There are many ways to contribute to
this project. Get started here

Acknowledgements

- All SVG railroad diagrams are generated through:
https://github.com/tabatkins/railroad-diagrams
- All UTF railroad diagrams are generated through:
https://github.com/matthijsgroen/utf-railroad
- The EBNF parser is generated by http://zaa.ch/jison/
- All markdown is parsed with http://showdownjs.com/

[example-ebnf]: https://htmlpreview.github.io/?https://github.com/matthijsgroen/ebnf2railroad/blob/master/examples/ebnf.html
[example-json]: https://htmlpreview.github.io/?https://github.com/matthijsgroen/ebnf2railroad/blob/master/examples/json.html
[example-optimizations]: https://htmlpreview.github.io/?https://github.com/matthijsgroen/ebnf2railroad/blob/master/examples/optimizations.html