On 1 Nov 2008, at 17:09, Terry Reedy wrote:

Zaur Shibzoukhov wrote:

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) Python 2.6/3.0 now has a module ast. This opens up new opportunities. One of them is the possibility of introducing human readable/writable literal object notation, based on the syntax of

Python Object Notation (PyON <http://code.google.com/p/pyon/wiki/GettingStarted the python language.

Other than syntax details, how is PyON different from json, yaml (3rd party module), and anything else?

Looking at the page, it seems to me that it aims to: * be able to give a string representation of any(*) object like pickle and unlike json * produce human readable output like json and unlike pickle (*) for a suitable definition of 'any', ideally the same as pickle I guess. That would be good. There are several examples of pyon.loads, but none of pyon.dumps, which would be interesting. E.g. can pyon.dumps dump obj accurately for the following value of obj? lst = [1, 2] obj = [lst, lst] I would expect pyon.dumps(obj) to give something like: """ sym0 = [1, 2] obj = [sym0, sym0] """ -- Arnaud

On 1 Nov 2008, at 19:49, Mathias Panzenböck wrote:

Arnaud Delobelle schrieb:

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E.g. can pyon.dumps dump obj accurately for the following value of obj?

lst = [1, 2] obj = [lst, lst]

I would expect pyon.dumps(obj) to give something like: """ sym0 = [1, 2] obj = [sym0, sym0] """

I wonder what it would yield in this case: lst = ['foo'] lst.append(lst)

I guess it could be: """ sym0 = ['foo', sym0] sym0 """ I.e, one could allow 'assignments' to be made in any order as long as all names are eventually defined. E.g. == pyon form == """ a = [1, b] b = [a, 2] a, b """ Which would describe the following two objects: == python form == a = [1, None] b = [None, 2] a[1] = b b[0] = 1 The conversion between the two forms seems doable. Or maybe the 'python form' should be the 'pyon form', there would b a need for extending the syntax so that foo[bar] and foo.bar can appear on the left hand side of an assignment. In that case your 'lst' above could be: """ sym0 = ['foo', None] sym0[1] = sym0 sym0 """ -- Arnaud