Dumps an object in JSON. Works with circular JSON structures

json_stringify_once.js

// Dumps an object in JSON. Works with circular structures like:
//
//    var o = {};
//    o.o = o;
JSON.stringifyOnce = function(obj, replacer, indent){
    var printedObjects = [];
    var printedObjectKeys = [];

    function printOnceReplacer(key, value){
      if ( printedObjects.length > 2000){ // browsers will not print more than 20K, I don't see the point to allow 2K.. algorithm will not be fast anyway if we have too many objects
        return 'object too long';
      }
      var printedObjIndex = false;
      printedObjects.forEach(function(obj, index){
        if(obj===value){
          printedObjIndex = index;
        }
      });

      if ( key == ''){ //root element
        printedObjects.push(obj);
        printedObjectKeys.push("root");
        return value;
      }

      else if(printedObjIndex+"" != "false" && typeof(value)=="object"){
        if ( printedObjectKeys[printedObjIndex] == "root"){
          return "(pointer to root)";
        } else{
          return "(see " + ((!!value && !!value.constructor) ? value.constructor.name.toLowerCase()  : typeof(value)) + " with key " + printedObjectKeys[printedObjIndex] + ")";
        }
      }else{

        var qualifiedKey = key || "(empty key)";
        printedObjects.push(value);
        printedObjectKeys.push(qualifiedKey);
        if(replacer){
          return replacer(key, value);
        }else{
          return value;
        }
      }
    }
    return JSON.stringify(obj, printOnceReplacer, indent);
  };