Another very text format is XML. Unfortunately, there is no stable serialization/deserialization library to manage XML format. However, this is not necessarily a shortcoming. In actual fact, XML format is often used to store large datasets; so large, in fact, that it would be inefficient to load them all before we start converting the data into an internal format. In these cases, it may be more efficient to scan the file or incoming stream and process it as long as it is read.
The xml_example project is a rather convoluted program that scans the XML file specified on the command line and, in a procedural fashion, loads information from the file into a Rust data structure. It is meant to read the ../data/sales.xml file. This file has a structure corresponding to the JSON file we sought in the previous section. The following lines show an excerpt of that file:
<?xml version="1.0" encoding="utf-8"?>
<sales-and-products>
<product>...