By "just fine" do you mean "not quite"? You missed the part about the first job of a parser being "check for correct syntax": http://en.wikipedia.org/wiki/Par

By "just fine" do you mean "not quite"? You missed the part about the first job of a parser being "check for correct syntax": http://en.wikipedia.org/wiki/Parser http://en.wikipedia.org/wiki/Parser Parser In computing, a parser is one of the components in an interpreter or compiler, which checks for correct syntax and builds a data structure (often some kind of parse tree, abstract syntax tree or other hierarchical structure) implicit in the input tokens. The parser often uses a separate lexical analyser to create tokens from the sequence of input characters. Parsers may be programmed by hand or may be (semi-)automatically generated (in some programming languages) by a tool.