SIA 2.0 POS parameters

[Patrick Dowler]

While it is nice if param values do not have to be encoded/decoded, good 
web software always encodes and decodes just-in-case. Yes, it makes it 
hard to type URLs and (more importantly to me) very hard to read/check 
the encoded ones.

I have implemented the current POS parsing and it works.

I have implemented the functional syntax in the past (service no longer 
operational). The parser was uglier and the error messages were more 
opaque, but it worked. In some previous exploratory work on PQL by 
Daniel Durand, the functional style seemed to be more generally useful 
beyond structured values, but that was just blue-sky thinking :-)


So, I'm rather ambivalent on this but I don't see it as compelling 
enough to change from what is written.

Pat

PS-Yes, you have to encode spaces, but you don't have to use +; that was 
a horrible shortcut that causes endless pain.

On 27/06/14 01:24 PM, Walter Landry wrote:
> 1) POS uses spaces as semantically important elements as in
>
>       POS=Circle 10 10 1
>
>     This makes it annoying to create URL's because you must URL encode
>     the spaces as '+'.  Otherwise my web server (Apache) will strip out
>     the rest of the parameters.  If we instead used ADQL'ish syntax
>
>       POS=Circle(10,10,1)
>
>     with explicit, visible separators, that is not as prone to being
>     mangled.

-- 

Patrick Dowler
Canadian Astronomy Data Centre
National Research Council Canada
5071 West Saanich Road
Victoria, BC V9E 2E7

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