unary star

[Steven Taschuk]

Quoth David Eppstein:
> If f(a, b, *(c, d)) is always equivalent to f(a, b, c, d), then why 
> isn't (a, b, *(c, d)) always equivalent to (a, b, c, d)?
> 
> That is, since (non-keyworded) function arguments are a lot like tuples, 
> why isn't there a unary star pseudo-operator to expand a sequence into 
> the end of a tuple or list expression?
  [...]

At first blush, I like the idea of unary * being more widely
applicable.

I see one difficulty: what if you want to expand a sequence of
sequences?  That is, what if you have
    S = ((c, d), (e, f))
and want to produce
    (a, b, c, d, e, f)
?  If unary * worked, this would (I presume) be
    (a, b, **S)
which looks misleadingly like the **kwargs syntax.  A reader might
expect that S is a dict.  Moreover, you couldn't use this in a
function call; you'd have to add whitespace: * *S.  Ick.

-- 
Steven Taschuk                           staschuk at telusplanet.net
"I'm always serious, never more so than when I'm being flippant."
                            -- _Look to Windward_, Iain M. Banks