14. The system of claim 13 , wherein the computer program logic further comprises an error indicator configured to be executed by the first thread of execution, the error indicator being further configured to retrieve one or more error checking results from the second queue and, for each retrieved error checking result: determine whether an element currently exists within the document that has an ID that is the same as the ID associated with the retrieved error checking result, and in response to the determining that the element currently exists within the document that has the ID that is the same as the ID associated with retrieved error checking result, generate an indication that the element is m error.
16. The system of claim 14 , wherein the parser is further configured to store each new element in a data structure that stores a plurality of elements that currently exist in the document, an ID associated with each of the plurality of elements, and current position information associated with each of the plurality of elements, and wherein the error indicator is configured to generate the indication that the element is in error by obtaining from the data structure current position information associated with the element and generating the indication based on the current position information associated with the element.