qclone/qcloneCircular.js

the fastest function for deep clone js objects compatible with es6

'use strict';

function qcloneCircular(o){
  const __qhop__ = Object.prototype.hasOwnProperty;
  const {
          getPrototypeOf: __gpo__,
          create: __cr__
        } = Object;
  const __Generator__ = __gpo__(function*(){});
  let __o__ = [], __c__ = [];

  function qclone(o){
    if(typeof o !== 'object' || o === null)return o;
    switch(o.constructor){
      case Object:
        let i,l,c = {};
        __o__.push(o);__c__.push(c);
        for(i in o){
          if(__qhop__.call(o, i)){
            l = o[i];
            if(typeof l !== 'object' || l === null){
              c[i] = l;
            }else{
              let pi = __o__.indexOf(l);
              c[i] = (~pi) ? __c__[pi] : qclone(l);
            }
          }
        }
        __o__.pop();__c__.pop();
        return c;
      case Array:
        let p,j = o.length, a = new Array(j);
        for(let i = 0; i < j; i++){
          p = o[i];
          if(typeof p !== 'object' || p === null){
            a[i] = p;
          }else{
            let pi = __o__.indexOf(p);
            a[i] = (~pi) ? __c__[pi] : qclone(p);
          }
        }
        return a;
      case undefined:
        __o__.push(o);__c__.push(c);
        let q,y,d = Object.create(null);
        for(q in o){
          y = o[q];
          if(typeof y !== 'object' || y === null){
            d[q] = y;
          }else{
            let pi = __o__.indexOf(y);
            d[q] = (~pi) ? __c__[pi] : qclone(y);
          }
        }
        __o__.pop();__c__.pop();
        return d;
      case Map:
        let b,m,x = new Map();
        for(b of o){
          m = b[1];
          (typeof m !== 'object' || m === null) ? x.set(b[0], m) : x.set(b[0], qclone(m));
        }
        return x;
      case Set:
        let v,n = new Set();
        for(v of o){
          (typeof v !== 'object' || v === null) ? n.add(v) : n.add(qclone(v));
        }
        return n;
      case Promise:
      case Symbol:
      case WeakMap:
      case WeakSet:
      case __Generator__:
        return o;
      case String:
        return String(o);
      case Number:
        return Number(o);
      case Date:
        return new Date(o);
      case Boolean:
        return Boolean(o);
      case RegExp:
        let r = new RegExp(o.source,
          o.flags &&
          (o.global ? 'g':'') +
          (o.ignoreCase ? 'i':'') +
          (o.multiline ? 'm':'')  +
          (o.unicode ? 'u':'') +
          (o.sticky ? 'y':''));
        r.lastIndex = o.lastIndex;
        return r;
      // case BigInt:
      //   return Object(o.valueOf());
      case DataView:
        return new DataView(new Uint8Array(new Uint8Array(o.buffer)).buffer, o.byteOffset, o.byteLength);
      case ArrayBuffer:
        //case SharedArrayBuffer:
        return new Uint8Array(new Uint8Array(o)).buffer;
      case Error:
      case RangeError:
      case EvalError:
      case ReferenceError:
      case SyntaxError:
      case TypeError:
      case URIError:
        //case InternalError:
        //case AggregateError:
        return o;
      default:
        if(o.BYTES_PER_ELEMENT)return new o.constructor(o);
        let s,u,f = __cr__(__gpo__(o));
        __o__.push(o);__c__.push(f);
        for(s in o){
          if(__qhop__.call(o, s)){
            u = o[s];
            if(typeof u !== 'object' || u === null){
              f[s] = u;
            }else{
              let pi = __o__.indexOf(u);
              f[s] = (~pi) ? __c__[pi] : qclone(u);
            }
          }
        }
        __o__.pop();__c__.pop();
        return f;
    }
  };
  return qclone(o);
}

module.exports = qcloneCircular;