export function toHalfwidthAscii(str: string): string;
export function toHalfwidthAscii(str: null): null;
export function toHalfwidthAscii(str: undefined): undefined;
export function toHalfwidthAscii(value: string | null | undefined) {
  if (!value) {
    return value;
  }

  return value.replace(/[\u3000\uFF01-\uFF5E]/g, (m) => {
    return m === "\u3000"
      ? " "
      : String.fromCharCode(m.charCodeAt(0) - 0xff01 + 0x21);
  });
}