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<div class="moz-cite-prefix">On 10/09/2013 04:26 PM, Georg Brandl
wrote:<br>
</div>
<blockquote cite="mid:l33p0b$u88$1@ger.gmane.org" type="cite">
<blockquote type="cite">
<pre wrap="">I realize you are -1 on the proposal in general, but I'd be very interested if
you could propose an alternate approach where I didn't need "a new spelling for
None" as you put it.
</pre>
</blockquote>
<pre wrap="">
I think I would make Steven's proposed syntax mandatory: let the implementor
of the function decide which value stands for "not given" -- just like we do
in the C version, BTW.
</pre>
</blockquote>
<br>
But that's not how addch works. addch counts how many arguments it
received; if it is called with one or two, it does one thing, and if
it's called with three or four it does something else. You can't
duplicate these semantics with <br>
<br>
Similarly, you can't accurately express the semantics of range's
arguments using default values. PyPy's approach is approximately
like this:<br>
<blockquote>def range(x, y=None, step=None):<br>
step = 1 if step is None else step<br>
if y is not None:<br>
start, stop = x, y<br>
else:<br>
start, stop = 0, x<br>
</blockquote>
But now introspection information on range() is inaccurate and
unhelpful. (Not to mention, they allow specifying step without
specifying y, by using keyword arguments.)<br>
<br>
My goal in writing the PEP was to codify existing practice, which
meant reflecting these (annoying!) corner cases accurately.<br>
<br>
<br>
<i>/arry</i><br>
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