- From: Doug Schepers <schepers@w3.org>
- Date: Tue, 10 Jul 2007 20:54:52 -0400
- To: www-archive@w3.org
Hi, Philip- Philip TAYLOR wrote: > >> A browser does not need a doctype to be present to define for it the >> HTML dialect. So your last sentence could just as well be written, >> "Even without a doctype, a document can be parsed and converted >> into meaning and/or rendering". > > And ungrammatical utterances can still communicate meaning. > But they usually do so with a marked lack of precision, whence > the need for puncutation words such as "like" and punctuation > phrases such as "you know what I'm saying". The whole point > is that the meaning/rendering of "an arbitrary mixture of > angle brackets, ampersands, semi-colons and prose" can only be > guessed at; with a DOCTYPE, it is known. Even were I to agree with your larger point (I'm not sure I do), you're making a fallacy here. You want there to be a DOCTYPE because it serves as an identifier of a particular instantiation of a strict grammar, but one of your criteria for that strict grammar is that it has a DOCTYPE. DOCTYPE, ipso facto, is not necessary to satisfy your requirement; the presence of an identifier is. That identifier could be a DOCTYPE, or it could be a namespace in the root (as SVG uses), or it could even be a validation of the set of elements that serves as a hash (though the latter is not very robust). To illustrate: you don't require that everyone who speaks to you first identifies the spoken language that they will use. You identify it by the lexicon and the grammar. If you speak more than one language (English and French), you are capable of using the linguistic signature of the speech to decide if you can understand that language (it might be Spanish or Chinese), and to correctly interpret it if so. Sure, people are much more powerful than computers in this respect, but in the real world, there are only a very few grammars that begin <html ...>; browsers can do some inferring. In fact, it's not even absolutely necessary that identifier the be unique, only that it serve to differentiate on points where there may be confusion between e.g. 2 similar grammars. To continue the earlier example, to distinguish between American and British English, the spelling or pronunciation of a single word is enough (a shibboleth); by analogy, the presence or absence of any given non-shared element or attribute could be enough to distinguish between grammars. But that's going too far, and doesn't bode well for extensibility and mixed namespaces. I'm not calling for an abolition of identifiers, I'm just saying that DOCTYPE doesn't have to be the one true identifier. (I'm going to suppress my linguistic training, and not hold forth on description vs. prescription.) You know what I'm saying? Regards- -Doug Schepers (unofficially) W3C Staff Contact, SVG, CDF, and WebAPI
Received on Wednesday, 11 July 2007 06:17:23 UTC