@calpano/ddot-highlightjs

highlight.js language definition for ddot.it — a minimal text format for typed knowledge graphs.

Install

npm install @calpano/ddot-highlightjs highlight.js

highlight.js is a peer dependency.

Use

import hljs from 'highlight.js/lib/core';
import ddot from '@calpano/ddot-highlightjs';

hljs.registerLanguage('ddot.it', ddot);

const html = hljs.highlight(code, { language: 'ddot.it' }).value;

Aliases registered: ddot.it, ddot, ddotit.

Theme styling

This language uses ddot-specific scopes (hljs-subject, hljs-relation, hljs-object, hljs-operator, hljs-command, hljs-meta-delim, hljs-meta-operator, hljs-meta-relation, hljs-meta-object, hljs-meta-text, hljs-disabled). To get reasonable colours from a generic hljs theme, supply CSS that maps these to themed properties:

.hljs-subject  { color: var(--hljs-name); font-weight: 600; }
.hljs-relation { color: var(--hljs-attr); }
.hljs-object   { color: var(--hljs-string); }
.hljs-operator { color: var(--hljs-punctuation); }
.hljs-command  { color: var(--hljs-keyword); }
.hljs-meta-delim, .hljs-meta-operator,
.hljs-meta-relation, .hljs-meta-object,
.hljs-meta-text { color: var(--hljs-comment); font-style: italic; }
.hljs-disabled { color: var(--hljs-comment); opacity: 0.6; }

Conformance

The lexer is verified against the cross-implementation golden corpus — identical to the TextMate, Shiki, Pygments, Chroma, and Rouge ports. See tools/conformance-highlightjs.mjs.

npm run conformance:highlightjs

Implementation note

highlight.js's bygroups (match: [r1,r2,...] + scope: {1:'a',2:'b'}) keys scope by array position, not capture-group index. There's no way to express "this slot is either a command OR a name" with one rule — so each line shape is split into two variants (command-subject vs name-subject). The corpus only ever places commands in the subject slot (or as standalone off/on markers), so this stays tractable.

A subtler hljs quirk: in a begin/end mode, the inner contains rules can match the end marker before the END regex fires. Our DISABLED mode's inner content rule uses a negative lookahead (?![ \t]*(?:ddot\.it\/on|!!on)[ \t]*$) to avoid swallowing the on-marker line.

License

MIT