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From: "Jeffrey R. Carter" <spam.jrcarter.not@acm.nospam.org>
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Subject: Re: Unary operator after binary operator: legal or not?
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Adam Beneschan wrote:
> 
> I think that was a deliberate decision.  See the BNF in 4.4.  The
> operands of "and", "and then", "or", "or else", "xor", "in", or
> relational operators are <simple_expression>.  The definition of a
> <simple_expression> is
> 
>   [unary_adding_operator] term {binary_adding_operator term}
> 
> A unary_adding_operator is part of the syntax of <simple_expression>
> but not of <term>, so the consequences is that the right operator of a
> binary_adding_operator (or a multiplying_operator, or "**" or "abs" or
> "not") can't start with a unary adding operator, unless you
> parenthesize it.  But the right operand of a relational operator or
> one of the logical operators I listed above *can* start with a unary
> adding operator.

I missed that. I knew logical and relational operators were separated 
from other binary operators to get reasonable precedence behavior, but 
didn't remember they had special syntax rules to allow this.

And "abs" and "not" ARE permitted after binary adding and multiplying 
operators, further confusing the issue.

I'd think being consistent would be be preferable.

-- 
Jeff Carter
"All citizens will be required to change their underwear
every half hour. Underwear will be worn on the outside,
so we can check."
Bananas
29