A typical diffusion constant for a medium-sized molecule in water is about . If we want the smell to travel a quarter mile, or a little less than , we get a speed of. This speed is fantastically slow, and says that it would take ten million years for blood to diffuse out to a shark a quarter mile away.
XML Parser. A parser is a piece of program that takes a physical representation of some data and converts it into an in-memory form for the program as a whole to use. Parsers are used everywhere in software. An XML Parser is a parser that is designed to read XML and create a way for programs to use XML. There are different types, and each has its advantages. Unless a program simply and blindly copies the whole XML file as a unit, every program must implement or call on an XML parser.
A reference to the XML parser to use. Chunk of data to parse. A document may be parsed piece-wise by calling xml_parse() several times with new data, as long as the is_final parameter is set and TRUE when the last data is parsed. If set and TRUE, data is the last piece of data sent in this parse.