[Python-Dev] Adding C ternary select (a?b:c) to Python?

[Ka-Ping Yee]

On Mon, 31 Jan 2000, Tim Peters wrote:
> If I didn't know better <wink>, I'd say there's an actual consensus here:
> it seems we would all agree to "(if cond then true else false)" spelling.

Actually, i'm afraid i don't.  I initially chose the "then/else"
spelling specifically because "if" flags the eye to the beginning
of a statement.  My line of thinking was, "'then' for expressions,
'if' for statements."

> I had already channeled that for the group's benefit <wink>.  For 1.6,
> without absurd overloading of some other keyword (like "if cond def true
> ..."), that seems to leave
> 
>     (if cond: true else false)

Sorry, i like that even less.  It seems to abuse the colon, for the
colon (to me) signals both (a) This Is A Statement and (b) This Begins
A Block, neither of which are true here.

> How much is that hated?  I hate it myself, not least because I'd have to
> change IDLE's parser to guarantee it couldn't get confused by the colon
> here:
> 
>    big = (
>        if x >= y:
>          x else y)

I consider this a symptom of the colon-abuse i just described...

> BTW, I'm not entirely convinced "then" would have to be a keyword to make
> "if x then y else z" work:  couldn't the grammar use WORD and verify it's
> specifically "then" later?

Quite possibly, yes -- though i figured it wouldn't be *too*
large an issue to make "then" a keyword, since i can't imagine
anyone naming a symbol "then" except under the most freakish
of circumstances.  A quick check shows no symbol by that name
in any of the Python scripts or modules we have here.


-- ?!ng