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RE: BNF Basics

RBarryYoung — Thu, 13 Aug 2009 11:02:51 GMT

[quote][b]Paul Hunter (8/13/2009)[/b][hr]...<opinion type="humble">The SQL team wrighting BOL should include a link to understanding the BNF convention as a part of BOL. Kind of like you get with a book where they spell out "conventions used in this book".</opinion>...[/quote]Agreed.

RE: BNF Basics

SQLNightOwl — Thu, 13 Aug 2009 07:30:43 GMT

Nice treatment of an unfamiliar topic. I had figured out most of what the syntax/convention was before reading this but didn't know it had a name and defined rules.<opinion type="humble">The SQL team wrighting BOL should include a link to understanding the BNF convention as a part of BOL. Kind of like you get with a book where they spell out "conventions used in this book".</opinion>

RE: BNF Basics

jcrawf02 — Wed, 12 Aug 2009 11:51:04 GMT

[quote][b]sjsubscribe (8/12/2009)[/b][hr] Another would be to make the examples more exhaustive so that all BNF options used in the definition are used in examples. Otherwise BNF just acts as another layer of indirection and not a natural part of composing T-SQL.[/quote]I wouldn't want to be the guy creating all those examples, but good idea, that would help.

RE: BNF Basics

sjsubscribe — Wed, 12 Aug 2009 11:42:45 GMT

Good topic Tom. Speaking of BOL, I think it can be improved by providing a better match between BNF descriptions and examples that follow. One easy way would be to repeat the applicable BNF with each example. Another would be to make the examples more exhaustive so that all BNF options used in the definition are used in examples. Otherwise BNF just acts as another layer of indirection and not a natural part of composing T-SQL.

RE: BNF Basics

Scott-144766 — Wed, 12 Aug 2009 10:06:04 GMT

[quote]And just to clarify, when people refer to braces, they are really talking about orthodontia.[/quote]I'm usually discussing ways of keeping my trousers from falling down. My father-in-law is a carpenter and has a different take on the word altogether. The last time someone really pushed my button on the topic of punctuation was when I told one of my colleagues to use an apostrophe and he asked me if that was the "comma up in the air". I was very impressed with the way that I managed to refrain from comment at the time.

RE: BNF Basics

jcrawf02 — Wed, 12 Aug 2009 09:35:55 GMT

[quote][b]RBarryYoung (8/12/2009)[/b][hr]Nice article. I have a couple of notes though:1) What you are describing is actually a simplified informal version of [i][b]E[/b][/i]BNF, not BNF (though the standards groups do use the formal versions). For instance it adds the ellipsis ("...") as a repetition operator as well as other common conventions. This is the language definition format used almost universally in Language Syntax Manuals since the 60's.2) In English, these ("{ }") are called [b][i]braces[/i][/b], not "brackets" or "curly brackets", or even "squiggly brackets". It seriously undermines the credibility of anyone talking about language definitions if they do not know the proper terms for the language that they themselves are using. (yes, it's a hot button of mine)Still, very nice article.[/quote]And just to clarify, when people refer to braces, they are really talking about orthodontia.

RE: BNF Basics

RBarryYoung — Wed, 12 Aug 2009 09:31:10 GMT

Nice article. I have a couple of notes though:1) What you are describing is actually a simplified informal version of [i][b]E[/b][/i]BNF, not BNF (though the standards groups do use the formal versions). For instance it adds the ellipsis ("...") as a repetition operator as well as other common conventions. This is the language definition format used almost universally in Language Syntax Manuals since the 60's.2) In English, these ("{ }") are called [b][i]braces[/i][/b], not "brackets" or "curly brackets", or even "squiggly brackets". It seriously undermines the credibility of anyone talking about language definitions if they do not know the proper terms for the language that they themselves are using. (yes, it's a hot button of mine)Still, very nice article.

RE: BNF Basics

Tom Fischer — Wed, 12 Aug 2009 08:40:28 GMT

Some formatting didn't transfer from Word to HTML, such as, underlining & bold. Good catch, thank you!

RE: BNF Basics

michael.kjorling — Wed, 12 Aug 2009 08:12:41 GMT

In the second example under BNF ala T-SQL, am I missing something?[quote]Let us also make it a requirement that when calling bar it demands further information, which can be accomplished via squiggly brackets. And if these arguments are not provided, then bar will assume a default value of constant “1” as indicated by an underline.<foo>::= [<foo> |<bar>]<bar>::= {1 | 2}[/quote]Where is the underline? I assume that the second line is really supposed to read:<bar>::= {_1_ | 2}but it would be nice to know.Good writeup, otherwise!Also, a somewhat off-topic question. Should one really be required to manually HTML-escape the less than and greater than signs, or am I doing something wrong?

RE: BNF Basics

jcrawf02 — Wed, 12 Aug 2009 07:34:02 GMT

Disagree with Lambchop in general, but specifically think the comment about requiring additional research was on the mark. However, don't think that's a bad thing. I think you've provided a great springboard for newbies to get their feet wet in BNF/BOL and get comfortable enough to sort out the details. Those who won't bother reading through the article to figure it out will be the ones who don't bother reading BOL either, so no biggy. Good job!Jon

RE: BNF Basics

Lambchop4697 — Wed, 12 Aug 2009 07:03:22 GMT

Excellent subject, but the write up, while well intended, tries to summarize too much information. For most folks, I doubt if they would even bother trying to match up the information into the functional example to really understand much. The foo:bar example really needs expanding and perhaps revised to apply to the example that is initially displayed at the beginning of the article. This article is intended as an application article or an explanation/resolution article. Either way, it misses the mark as it really does not bring the reader forward in logical steps that make sense without further research into the topic. My 2 cents...

BNF Basics

Tom Fischer — Tue, 28 Jul 2009 01:37:10 GMT

Comments posted to this topic are about the item [B]BNF Basics[/B]