Re: PLUS SIGN character in value of a pkey column

It's fine by me to have %-encoding (space characters encoded as “%20”
instead of “+”)

Eric, do you agree?

Juan Sequeda
+1-575-SEQ-UEDA
www.juansequeda.com


On Wed, Nov 2, 2011 at 9:54 AM, Richard Cyganiak <richard@cyganiak.de>wrote:

> On 1 Nov 2011, at 18:33, Souripriya Das wrote:
> > In Section 3 [1] of Direct Mapping LC Working draft (reproduced below),
> do we need to replace PLUS SIGN character in the value of a key column with
> its percent encoding?
> >
> > ---------------
> > Definition percent-encode: (a subset of HTML5 form dataset encoding):
> >
> >    * Replace each PERCENT SIGN character ('%', U+0025) with the string
> "%25".
> >    * For table names, replace each NUMBER SIGN character ('#', U+0023)
> with the string "%23".
> >    * For table names, replace each SOLIDUS character ('/', U+002f) with
> the string "%2f".
> >    * For attribute names, replace each HYPHEN-MINUS character ('-',
> U+003d) with the string "%3D".
> >    * For attribute values, replace each FULL STOP character ('.',
> U+002e) with the string "%2E".
> >    * Replace each SPACE character (U+0020) with the PLUS SIGN character
> (+, U+002B).
> > -----------------
> >
> > [1] http://www.w3.org/TR/rdb-direct-mapping/#definition
>
> Hm, this definition has at least two problems:
>
> 1. It is lossy, because – as you correctly note – the strings “ ” and “+”
> end up with the same encoded representation, making it impossible to
> reconstruct the original string.
>
> 2. It doesn't escape many characters that are forbidden in IRIs, making
> the results potentially violate the IRI (and RDF) specs.
>
> To me it's also not clear why HTML form-encoding is used here instead of
> %-encoding as defined in RFC 3986. In other words, why are space characters
> encoded as “+” and not as “%20”? Form-encoding would clearly be appropriate
> if the URIs had the form ...?foo=this&bar=that, but since this is not the
> case, normal %-encoding seems to make more sense.
>
> Best,
> Richard
>