Re: [Json] Response to Statement from W3C TAG

[Carsten Bormann <[e-mail]>]

On 05 Dec 2013, at 06:08, Tim Bray <[e-mail]> wrote:

> FWIW, I have never understood what the ECMAnauts mean by the word “semantics” in this context, so I have no idea whether I agree with this statement.

You know this, but just for the record: we could be applying the meaning we have for these terms in CS.

The syntax just tells you which sequences of symbols are part of the language.
(This is what we have ABNF for; ECMA-404 uses racetracks plus some English language that maps the characters to the tokens in the syntax-level racetracks for value, object, and array, and to the English language components of the token-level racetracks for number and string.)

Semantics is needed to describe e.g. that some whitespace is “insignificant” (not contributing to the semantics), describe the intended interpretation of escape sequences in strings, that the sequences of symbols enabled by the production “number” are to be interpreted in base 10, or that “the order of the values is significant” in arrays (which seems to be intended to contrast them to JSON objects, where ECMA-404 weasels out of saying whether the order is significant).

ECMA-404 does quite a bit of of the latter, so indeed I also have trouble interpreting such a statement.
(That doesn’t mean that the chairs’ echo of statements of this kind having been made is incorrect.)

Grüße, Carsten