src/vs/editor/common/languages/supports/inplaceReplaceSupport.ts/BasicInplaceReplace/numberReplace
class BasicInplaceReplace:	private numberReplace(value: string, up: boolean): string | null {
		const precision = Math.pow(10, value.length - (value.lastIndexOf('.') + 1));
		let n1 = Number(value);
		let n2 = parseFloat(value);

		if (!isNaN(n1) && !isNaN(n2) && n1 === n2) {

			if (n1 === 0 && !up) {
				return null; // don't do negative
				//			} else if(n1 === 9 && up) {
				//				return null; // don't insert 10 into a number
			} else {
				n1 = Math.floor(n1 * precision);
				n1 += up ? precision : -precision;
				return String(n1 / precision);
			}
		}

		return null;
	}