On Thu, Sep 01, 2005 at 05:41:36PM -0700, Yitzchak Scott-Thoennes wrote:
> On Wed, Aug 31, 2005 at 06:07:11AM -0700, japhy @ perlmonk. org wrote:
> > In 'perlref', item #3 of 'Using References' says
> >
> > One more thing here. The arrow is optional between brackets sub-
> > scripts, so you can shrink the above down to
> >
> > $array[$x]{"foo"}[0] = "January";
> >
> > This led me to believe I could write:
> >
> > sub foo { ...; return @data }
> >
> > my $x = (foo())[0][1];
> >
> > which would have the same effect as
> >
> > my @return = foo();
> > my $x = $return[0][1];
> >
> > However, it's a syntax error. This can be fixed with an arrow:
> >
> > my $x = (foo())[0]->[1];
> >
> > The problem is that (foo())[0] is NOT analogous to $array[$x]; one is a
> > list slice, the other is a single element from an array. But the
> > documentation does not distinguish when it says "optional between brackets
> > subscripts [sic]".
> >
> > I think the language there should be polished a bit.
>
> I don't see any reason not to just make it legal syntax instead:
>
> --- p/perly.y.orig 2005-06-08 01:32:12.000000000 -0700
> +++ p/perly.y 2005-08-31 11:02:57.520643200 -0700
> @@ -487,6 +487,10 @@ subscripted: star '{' expr ';' '}'
> | subscripted '(' ')' /* $foo->{bar}->() */
> { $$ = newUNOP(OP_ENTERSUB, OPf_STACKED,
> newCVREF(0, scalar($1))); }
> + | '(' expr ')' '[' expr ']' /* list slice */
> + { $$ = newSLICEOP(0, $5, $2); }
> + | '(' ')' '[' expr ']' /* empty list slice! */
> + { $$ = newSLICEOP(0, $4, Nullop); }
> ;
>
> /* Binary operators between terms */
> @@ -622,10 +626,6 @@ term : termbinop
> { $$ = newUNOP(OP_AV2ARYLEN, 0, ref($1,
> OP_AV2ARYLEN));}
> | subscripted
> { $$ = $1; }
> - | '(' expr ')' '[' expr ']' /* list slice */
> - { $$ = newSLICEOP(0, $5, $2); }
> - | '(' ')' '[' expr ']' /* empty list slice! */
> - { $$ = newSLICEOP(0, $4, Nullop); }
> | ary '[' expr ']' /* array slice */
> { $$ = prepend_elem(OP_ASLICE,
> newOP(OP_PUSHMARK, 0),
> End of Patch.
Any other feedback on making
(LIST)[LIST]->
not need the ->?
