function jsonStringify(value, replacer, space) {
  const indent = typeof space === 'number' ? ' '.repeat(space) : (space || '');
  function serialize(val, depth) {
    if (val === null) return 'null';
    if (val === undefined || typeof val === 'function') return undefined;
    if (typeof val === 'boolean') return String(val);
    if (typeof val === 'number') return isFinite(val) ? String(val) : 'null';
    if (typeof val === 'string') return '"' + val.replace(/\\/g,'\\\\').replace(/"/g,'\\"').replace(/\n/g,'\\n') + '"';
    if (Array.isArray(val)) {
      if (val.length === 0) return '[]';
      const items = val.map(v => { const s = serialize(v, depth+1); return s === undefined ? 'null' : s; });
      if (!indent) return '[' + items.join(',') + ']';
      const pad = indent.repeat(depth+1);
      return '[\n' + items.map(i => pad + i).join(',\n') + '\n' + indent.repeat(depth) + ']';
    }
    const entries = [];
    for (const [k, v] of Object.entries(val)) {
      let newV = replacer ? replacer(k, v) : v;
      const s = serialize(newV, depth+1);
      if (s !== undefined) entries.push([k, s]);
    }
    if (entries.length === 0) return '{}';
    if (!indent) return '{' + entries.map(([k,v]) => serialize(k,0)+':'+v).join(',') + '}';
    const pad = indent.repeat(depth+1);
    return '{\n' + entries.map(([k,v]) => pad + serialize(k,0)+': '+v).join(',\n') + '\n' + indent.repeat(depth) + '}';
  }
  let v = replacer ? replacer('', value) : value;
  return serialize(v, 0);
}