> You can't validate an IP packet without having all of it. Your notion > of "streaming" is nonsensical.
Whoa, whoa, hold your horses! "nonsensical" needs a little bit of justification :) It seems you don't understand the difference between words and languages! In my examples, IP _protocol_ is the language, sequences of IP packets are the words in the language. A language is amenable to streaming if the words of the language are repetition of sequences of symbols of the alphabet of fixed length. This is, essentially, like saying that the words themselves are regular. So, the follow-up question from you to me should be: how come strictly context-free languages can still be parsed with streaming parsers? -- And the answer to that is it's possible to approximate context-free languages with regular languages. In fact, this is a very interesting subject, which unfortunately is usually overlooked in automata classes. It's interesting in a sense that it's very accessible to the students who already mastered the understanding of regular and context-free formalisms. So, streaming parsers (eg. SAX) are written for a regular language that approximates XML. This is because in practice we will almost never encounter more than N nesting levels in an XML, more than N characters in an element name etc. (for some large enough N). Something which allows us to create a regular language from a context-free one. NB. "Nonsensical" has a very precise meaning, when it comes to discussing the truth value of a proposition, which I think you also somehow didn't know about. You seem to use "nonsensical" as a synonym to "wrong". But, unbeknownst to you, you said something else. You actually implied that there's no way to tell if my notion of streaming is correct or not. But, for the future reference: my notion of streaming is correct, and you would do better learning some materials about it before jumping to conclusions. -- https://mail.python.org/mailman/listinfo/python-list
