import { generate } from 'css-tree'; class Index { constructor() { this.map = new Map(); } resolve(str) { let index = this.map.get(str); if (index === undefined) { index = this.map.size + 1; this.map.set(str, index); } return index; } }; export default function createDeclarationIndexer() { const ids = new Index(); return function markDeclaration(node) { const id = generate(node); node.id = ids.resolve(id); node.length = id.length; node.fingerprint = null; return node; }; };