src/vs/platform/quickinput/browser/quickAccess.ts/QuickAccessController/adjustValueSelection
class QuickAccessController:	private adjustValueSelection(picker: IQuickPick<IQuickPickItem>, descriptor?: IQuickAccessProviderDescriptor, options?: IQuickAccessOptions): void {
		let valueSelection: [number, number];

		// Preserve: just always put the cursor at the end
		if (options?.preserveValue) {
			valueSelection = [picker.value.length, picker.value.length];
		}

		// Otherwise: select the value up until the prefix
		else {
			valueSelection = [descriptor?.prefix.length ?? 0, picker.value.length];
		}

		picker.valueSelection = valueSelection;
	}