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.
BTW, cygwin only has bison 1.875b, not the allowed 1.875 or 1.875c,
but it seemed to work. I also note that Debian stable has 1.875d;
would it make sense to just allow any 1.875* version?
--- p/regen_perly.pl.orig 2005-05-07 04:36:14.000000000 -0700
+++ p/regen_perly.pl 2005-08-31 11:16:02.869920000 -0700
@@ -65,7 +65,7 @@
# the test below to allow that version too. DAPM Feb 04.
my $version = `$bison -V`;
-unless ($version =~ /\b(1\.875c?|2\.0)\b/) { die <<EOF; }
+unless ($version =~ /\b(1\.875[a-z]?|2\.0)\b/) { die <<EOF; }
You have the wrong version of bison in your path; currently 1.875
or 2.0 is required. Try installing
End of Patch.
