src/vs/workbench/contrib/snippets/browser/snippetsFile.ts/SnippetFile/_scopeSelect
class SnippetFile:	private _scopeSelect(selector: string, bucket: Snippet[]): void {
		// for `my.code-snippets` files we need to look at each snippet
		for (const snippet of this.data) {
			const len = snippet.scopes.length;
			if (len === 0) {
				// always accept
				bucket.push(snippet);

			} else {
				for (let i = 0; i < len; i++) {
					// match
					if (snippet.scopes[i] === selector) {
						bucket.push(snippet);
						break; // match only once!
					}
				}
			}
		}

		const idx = selector.lastIndexOf('.');
		if (idx >= 0) {
			this._scopeSelect(selector.substring(0, idx), bucket);
		}
	}