Re: Shortcut logicals (was: Re: F200x )

[Adrien Plisson <aplisson-news@stochastique.net>]

Martin Krischik wrote:
> Christoph Grein wrote:
>>You'll find
>>relation and relation gives an expression,
>>relation and then relation also gives an expression.
>>But there is no syntax rule to combine an expression with a relation.
>>You can only combine a parenthesized expression (a primary) with a
>>relation.
> 
> 
> Sure, you are right. But that rule means that:
> 
>  X or Y and Z
> 
> is not valid either. Not that I ever noticed - I would always use '()' on
> such a term.

it isn't valid. GNAT 3.15p says: mixed logical operators in expression.

See RM Introduction - design goals (§7):
"error-prone notations have been avoided"

and this construct is error-prone (especially if you are used to code 
in other languages than Ada, since each language has its own different 
operator precedence). the use of parenthesis clarifies the expression 
and leverages any ambiguities.

-- 
rien