[Python-ideas] Statements vs Expressions... why?
Greg Ewing
greg.ewing at canterbury.ac.nz
Tue Sep 16 03:06:02 CEST 2008
Cliff Wells wrote:
> s = 'abc'
> x = for c in s: YIELD c # x = 'a', 'b', 'c'
You mean that the value of (for c in s: YIELD c) is
a tuple? Or that it's an iterator that produces that
series of values?
> I = [ 'spam', 'eggs' ]
>
> for J in I: # J = 'spam' then 'eggs'
> YIELD ( # evaluate to an iterable
> for j in J: YIELD j # j is 's' then 'p' then ...
> )
>
> so we get '-'.join( 's','p','a','m','e','g','g','s' )
I'm still not getting a clear idea of what semantics
you intend for a for-loop-with-YIELD. Neither of the
interpretations I suggested above (sequence or iterator)
seems to produce this result.
> maybe this is clearer as
>
> for J in I:
> tmp = for j in J: YIELD j
> YIELD tmp
No, that's not any clearer. Can you provide a translation
into current, valid Python?
--
Greg
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