On Mon, May 16, 2011 at 03:45:08PM -0400, Parrot Raiser wrote: > The following piece of trivial code, (drastically simplified from an > example I was trying to convert), produces different results (3rd > line) under Perl 5 and Perl 6. (Saved as t_f_int2) > > print sqrt (1.5 * 1) ; > print "\n"; > print ((1 / 2.7) ** 1); > print "\n"; > > print sqrt (1.5 * 1) * > ((1 / 2.7) ** 1); > > print "\n"; > [...] > $>perl6 t_f_int2 > 1.22474487139159 > 0.37037037037037 > 0.74535599249993 > > Have I found a bug or merely revealed my ignorance of a change in > precedence somewhere?
You've found the difference in how Perl 5 and Perl 6 handles whitespace+parentheses following a function name. In Perl 5, only the parenthesized part is passed to C<sqrt>; in Perl 6, the entire expression will be passed as an argument to the sqrt listop. Removing the space between "sqrt" and the parenthesized part will cause sqrt to act like a normal function on just the value in the parentheses instead of the full expression: $ ./perl6 -e 'say sqrt (1.5 * 1) * ((1 / 2.7) ** 1);' 0.74535599249993 $ ./perl6 -e 'say sqrt(1.5 * 1) * ((1 / 2.7) ** 1);' 0.453609211626514 In general, a paren immediately following an identifier is treated as a function call, while whitespace indicates it's a listop or some other construct. Pm
