Re: (expression)

[Bill Allombert <Bill.Allombert@math.u-bordeaux.fr>]

On Wed, Feb 07, 2024 at 10:42:10AM +0100, Ruud H.G. van Tol wrote:
> 
> Just an innocent example:
> 
> ? my(i=3, n=3); n + (while(i--, n++);n)
>   ***   syntax error, unexpected ')', expecting )-> or ',':
> ...,n=3);n+(while(i--,n++);n)
> *** ^-
> 
> ? my(i=3, n=3); n + if(1, while(i--, n++);n )
> %2 = 8
> 
> 
> Would it be useful to allow/support (expression)s like in the first format?

It is customary to use if(1,...) for that:
my(i=3, n=3); n + if(1,while(i--, n++);n)

The drawback of your suggestion is that users sometime forget to close parenthesis
and allowing ";" inside parenthesis makes that very hard to detect.

Also your example modify a variable inside an expression already involving this
variable.  This copy optimiser does not work well with such code.

Cheers,
Bill