[Adding back python-dev, I don't want this discussion fragmented.] Denis, I am arguing with Mark because he and others claim that it is possible to add capabilities to Python *without* changing the flavor of the language (much), and because he believes that using a subset of Python is somehow helpful for Python programmers (or helps Python programmers transitioning to CapPython). I'm trying to point out the limitations of that approach. In the past capability zealots have also requested forcefully that Python should support capabilities natively. This sounds like an unrealistic evolutionary path for the language, and I'm pointing that out. (Certainly I don't see CapPython as a step in that direction -- perhaps Tav's approach could be.) If they are happy with a different language that happens to resemble Python is some syntactic details that would be fine of course, but then they shouldn't whine that Py3k breaks their implementation. I also suspect that Mark's approach might be easily crackable because he doesn't know the CPython implementation well enough to be aware of all possible attack vectors. --Guido On Tue, Mar 31, 2009 at 4:22 AM, spir <denis.spir@free.fr> wrote:

Le Mon, 30 Mar 2009 16:19:51 -0500, Guido van Rossum <guido@python.org> s'exprima ainsi:

[...]

...

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Fortunately CapPython does not have to make this kind of semantic change.

Well of course it makes a much more severe semantic change by declaring illegal all use of attribute names starting with underscore. [...]

Hello,

I wonder what's the meaning of this exchange. As I understand it, the point of CapPython is precisely to build a different dialect which semantic field is restricted, in order to comply with the so-called "Object-Capability" security guidelines. We may like it or not. So what? I won't use CapPython, but I'm pleased to see people do language experiments on a Python basis. Now, I also understand this: if ever for you CapPython breaks fondamental design choices, then you may not like, as Python inventor, this projects to be called *Python. I would even agree, from a moral point of view, with a demand for a name change.

(Sorry if this sounds a bit rude. Not sure of idiom connotations in english. I prefere clarity to hypocrisy.)

Denis

PS: I had a kind of ProtoPython in mind. If ever someone comments that it's a major semantic change; that it does not let pythonistas use their beloved class-ic idioms; then I'll just laugh... Yes, it's even a major cognitive change. This is precisely the intent. So what?

------ la vita e estrany

-- --Guido van Rossum (home page: http://www.python.org/~guido/)