src/vs/platform/contextkey/common/contextkey.ts/ContextKeyRegexExpr/cmp
class ContextKeyRegexExpr:	public cmp(other: ContextKeyExpression): number {
		if (other.type !== this.type) {
			return this.type - other.type;
		}
		if (this.key < other.key) {
			return -1;
		}
		if (this.key > other.key) {
			return 1;
		}
		const thisSource = this.regexp ? this.regexp.source : '';
		const otherSource = other.regexp ? other.regexp.source : '';
		if (thisSource < otherSource) {
			return -1;
		}
		if (thisSource > otherSource) {
			return 1;
		}
		return 0;
	}