'for every' and 'for any'

[Oren Tirosh]

Here's an idea for a possible language enhancement.  I'd like to hear your
comments about it.  It's inspired by list comprehensions and I think the
examples are pretty self-explanatory:

if not isinstance(x, str) for any x in args:
  raise TypeError, "arguments must be of type str"

valid = i>0 for every i in vector

if dict2.has_key(k) for any k in dict1:
  ...

The words 'any' and 'every' can be non-reserved keywords (like the word 'as' 
in "import foo as bar").  They are valid only after the keyword 'for' when 
it's used in a non-statement context. 

	Oren