SAMP MType BNF change

[Mark Taylor]

The existing version of the standard has the following BNF
in section 3.7 for MType syntax:

   <mchar>  ::= [0-9a-z] | "-" | "_"
   <atom>   ::= <mchar> | <atom> <mchar>
   <mtype>  ::= <atom> | <mtype> "." <atom>

this has the effect that only lower-case MTypes are permitted.
This was probably the intention, but at least two MTypes in common 
use use mixed case:

   table.select.rowList
   coord.pointAt.sky

(see http://www.ivoa.net/cgi-bin/twiki/bin/view/IVOA/SampMTypes).

I have therefore changed the <mchar> production to read:

   <mchar> ::= [0-9A-Za-z] | "-" | "_"

(http://code.google.com/p/volute/source/detail?spec=svn1536&r=1536)
since this is unlikely to break anything, and will certainly be less
disruptive than trying to fix all use of mixed-case MTypes in existing
code to match the older definition.

Any objections, please post.

Mark

--
Mark Taylor   Astronomical Programmer   Physics, Bristol University, UK
m.b.taylor at bris.ac.uk +44-117-928-8776 http://www.star.bris.ac.uk/~mbt/