Re: slurping styles

Yes.

The do uses twice as much memory.
The second uses a global variable (*FILE{IO}) without localizing it.

Cleaned up (with do ⇒ elegant):

my $raw = do {
   open(my $fh, '<', $file)
      or die("Could not read file: $!\n");
   binmode $fh;
   local $/;
   <$fh>
};
[download]

Cleaned up (without do ⇒ saves memory):

my $raw;
{
   open(my $fh, '<', $file)
      or die("Could not read file: $!\n");
   binmode $fh;
   local $/;
   $raw = <$fh>;
}
[download]

Comment on Re: slurping styles Select or Download Code

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Re^2: slurping styles by BrowserUk (Patriarch) on Aug 01, 2008 at 12:01 UTC
There's a simple solution to the memory doubling problem: `my $raw = do { open(my $fh, '<', $file) or die("Could not read file: $!\n"); binmode $fh; local $/; \<$fh> }; $$raw =~ ...; ## etc.` [download] Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error. "Science is about questioning the status quo. Questioning authority". In the absence of evidence, opinion is indistinguishable from prejudice. "Too many [] have been sedated by an oppressive environment of political correctness and risk aversion."	[reply] [d/l]
Re^2: slurping styles by massa (Hermit) on Aug 01, 2008 at 11:30 UTC
Do you care to explain why does the `do` version uses 2x as much memory? []s, HTH, Massa (κς,πμ,πλ)	[reply] [d/l]
Re^3: slurping styles by ikegami (Patriarch) on Aug 01, 2008 at 11:36 UTC
No can do. I don't know why. Update: Actually, it's quite basic. The assignment of `do`'s return value causes it to be copied. You'll notice the same effect from subroutines. use Devel::Peek qw( Dump ); { my $x = do { my $y = 'abcdef'; Dump($y); $y }; Dump($x); } { my $x = sub { my $y = 'abcdef'; Dump($y); $y }->(); Dump($x); } __END__ SV = PV(0x226df4) at 0x226ce0 REFCNT = 1 FLAGS = (PADBUSY,PADMY,POK,pPOK) PV = 0x1822b04 "abcdef"\0 CUR = 6 LEN = 8 SV = PV(0x226e24) at 0x226d34 REFCNT = 1 FLAGS = (PADBUSY,PADMY,POK,pPOK) PV = 0x187a93c "abcdef"\0 <-- new buffer CUR = 6 LEN = 8 SV = PV(0x226e0c) at 0x1830320 REFCNT = 1 FLAGS = (PADBUSY,PADMY,POK,pPOK) PV = 0x182c84c "abcdef"\0 CUR = 6 LEN = 8 SV = PV(0x226e60) at 0x226d70 REFCNT = 1 FLAGS = (PADBUSY,PADMY,POK,pPOK) PV = 0x1855fac "abcdef"\0 <-- new buffer CUR = 6 LEN = 8 [download]	[reply] [d/l] [select]
Re^3: slurping styles by moritz (Cardinal) on Aug 01, 2008 at 11:44 UTC
I'd think that `do` block creates an anonymous lexical variable to hold the last value, and its content is being copies to the caller. Try to measure the memory for returning something like `[ <$handle> ]`, if my theory holds it won't use twice as much memory then because only the array reference is copied.	[reply] [d/l] [select]