Assigning anonymous hash to a list
Abigail
abigail at abigail.be
Tue Jul 30 20:49:35 BST 2013
On Tue, Jul 30, 2013 at 03:34:48PM -0400, Joseph Werner wrote:
> I disagree.
>
> This is a straightforward assignment to the first element of a list.
> Precedence is not involved. A scalar assignment vs a list assignment
> is the issue.
>
Thank you for playing.
You are right it's straighforward, but you're wrong that it's scalar
assignment vs list assignment.
The fact there's "my ($str, $ref)" on the LHS of the assignment makes
that Perl considers this a list assignment:
$ perl -MO=Terse -e 'my ($str, $ref) = "text", {a => 1, b => 2, c => 3}'
LISTOP (0x100324de0) leave [1]
OP (0x100324e20) enter
COP (0x100324d90) nextstate
LISTOP (0x100301f10) list
OP (0x100301ee0) pushmark
BINOP (0x1003093c0) aassign [3]
UNOP (0x100309950) null [148]
OP (0x100309390) pushmark
SVOP (0x100309d90) const PV (0x1008143c0) "text"
UNOP (0x100329530) null [148]
OP (0x100329570) pushmark
OP (0x1003096e0) padsv [1]
OP (0x100309600) padsv [2]
LISTOP (0x100309460) anonhash
OP (0x1003094a0) pushmark
SVOP (0x100309400) const PV (0x100814408) "a"
SVOP (0x100309430) const IV (0x1008143f0) 1
SVOP (0x1003094d0) const PV (0x100814048) "b"
SVOP (0x100309500) const IV (0x1008143a8) 2
SVOP (0x100309530) const PV (0x100814378) "c"
SVOP (0x100309560) const IV (0x100814390) 3
-e syntax OK
$
Note the line: BINOP (0x1003093c0) aassign [3], and compare:
$ perl -MO=Terse -e 'my ($str, $ref) = ("text", {a => 1, b => 2, c => 3})'
LISTOP (0x100324d90) leave [1]
OP (0x100324dd0) enter
COP (0x100324d40) nextstate
BINOP (0x100309570) aassign [3]
UNOP (0x100301f10) null [148]
OP (0x100301ee0) pushmark
SVOP (0x100309d90) const PV (0x1008143c0) "text"
LISTOP (0x1003093c0) anonhash
OP (0x100309400) pushmark
SVOP (0x100309950) const PV (0x100814450) "a"
SVOP (0x100309390) const IV (0x100814408) 1
SVOP (0x100309430) const PV (0x1008143f0) "b"
SVOP (0x100309460) const IV (0x100814048) 2
SVOP (0x100309490) const PV (0x1008143a8) "c"
SVOP (0x1003094c0) const IV (0x100814378) 3
UNOP (0x100329530) null [148]
OP (0x100329570) pushmark
OP (0x1003096e0) padsv [1]
OP (0x100309600) padsv [2]
-e syntax OK
$
Abigail
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