rouge-ddot

Rouge lexer for the ddot.it knowledge graph notation (https://ddot.it).

Usage

require 'rouge-ddot'

Rouge::Lexers::Ddot.new.lex("Project Eagle ..started in.. 2024") do |tok, val|
  puts [tok.qualname, val].inspect
end

Rouge does not auto-discover third-party lexers, so the gem has to be required before a ddot.it block can be highlighted. Requiring it by name is enough (since 0.1.3); require 'rouge/lexers/ddot' also works.

In Jekyll, put it in the :jekyll_plugins group and Bundler requires it at startup — no _plugins/ file needed:

# Gemfile
group :jekyll_plugins do
  gem 'rouge-ddot', '~> 0.1.3'
end

In Asciidoctor with :source-highlighter: rouge set, [source,ddot] blocks are dispatched here automatically — no extra wiring per document. The lexer registers under the tag ddot, with the aliases ddotit and ddot.it.

Token mapping

The lexer emits standard Rouge tokens; they map to the canonical ddot.it token vocabulary in ../../ddot.it/test-data/tokens.md:

Rouge	Canonical
Name::Class	subject
Name::Function	relation
Literal::String::Symbol	object
Operator	doubledot
Keyword::Pseudo	command
Name::Attribute	command-param
Name::Label	block-end
Comment::Preproc	meta-delim
Punctuation	meta-separator
Comment::Hashbang	meta-doubledot
Comment::Doc	meta-relation
Comment::Special	meta-object
Comment::Multiline	meta-text
Comment::Single	excluded
Literal::String::Backtick	verbatim

Conformance

The lexer is asserted byte-equal to the corpus at ../../ddot.it/test-data/cases/*/expected.tokens.json (after the mapping above). To run:

# from the ddot.it-syntax-tools/ root
ruby tools/conformance-rouge.rb       # exits non-zero on any case diverging
npm run conformance:rouge             # npm-wrapped form

The same corpus also feeds npm run conformance:textmate. Any change to the canonical vocabulary or adding a case must keep both implementations in lockstep.

Layout

rouge/
├── lib/
│   ├── rouge-ddot.rb            # entry point: require 'rouge-ddot'
│   └── rouge/
│       └── lexers/
│           └── ddot.rb          # the lexer
├── CHANGELOG.md
├── README.md
└── rouge-ddot.gemspec

License

MIT.