On Tue, Oct 22, 2013 at 8:04 AM, Mark Janssen <dreamingforw...@gmail.com> wrote: > I love it. Watch this... > > [context] >>>> A language specification in BNF is just syntax. It doesn't say anything >>>> about semantics. So how could this be used to produce executable C code >>>> for a program? BNF is used to produce parsers. But a parser isn't >>>> sufficient. >>> >>> A C program is just syntax also. How does the compiler generate >>> executable machine code? Extrapolate into a Python front-end to C. > > [Dave Angel responds:] >> Did you even read the paragraph you quoted above? The BNF specification >> does NOT completely describe a language, it only defines its syntax. > > [Steven D'Aprano responds:] >> Like every other language, C programs are certainly not *just* syntax. >> Here is some syntax: >> >> &foo bar^ := > > Now, I don't know where y'all were taught Computer Science, but BNF > specifies not only syntax (which would be the *tokens* of a language), > but also its *grammar*; how syntax relates to linguistic categories > like keywords, and tokens relate to each other. > > Dave is claiming that BNF only defines the syntax of a language, but > then Stephen goes on to supply some syntax that a BNF specification of > the language would not allow (even though Steven calls it "syntax" > which is what BNF in Dave's claim parses). > > So which of you is confused? I ask that in the inclusive (not > exclusive OR) sense.... ;^) <-- face says "both". >
I don't know where you were taught English, but syntax is " the way in which linguistic elements (as words) are put together to form constituents (as phrases or clauses) ", not the set of valid words (tokens) in a language. A grammar, such as those grammars written in BNF, describe the rules for the syntax of a language. And, as Steven said, it still doesn't describe the semantics of a language, which is the set of instructions described by the syntax. -- https://mail.python.org/mailman/listinfo/python-list
