Beefy Boxes and Bandwidth Generously Provided by pair Networks
The stupid question is the question not asked
 
PerlMonks  

comment on

( [id://3333]=superdoc: print w/replies, xml ) Need Help??

Not sure if I would recommend Readonly over constant — at least some people have been bitten by its subtle peculiarities. As an example, see this thread.

BTW, there's also Scalar::Readonly, which is directly manipulating the readonly-flag of scalars (instead of working with tied magic)...

___

Update:  (...it was only a matter of time until someone would post a benchmark, so... :)

use strict; use warnings; use Benchmark 'cmpthese'; use Readonly; use Scalar::Readonly ':all'; use constant NL => "\012"; Readonly my $NL => "\012"; my $nl = "\012"; readonly_on($nl); my $Nl = "\012"; cmpthese 2000000 => { constant => sub { my $s = "abc".NL."def".NL."ghi"; }, constant2 => sub { my $s = "abc${\NL}def${\NL}ghi"; }, Readonly => sub { my $s = "abc${NL}def${NL}ghi"; }, ScalarRO => sub { my $s = "abc${nl}def${nl}ghi"; }, scalarRW => sub { my $s = "abc${Nl}def${Nl}ghi"; }, direct => sub { my $s = "abc\012def\012ghi"; }, }; __END__ Rate Readonly constant2 scalarRW ScalarRO constant + direct Readonly 77851/s -- -84% -85% -85% -96% + -96% constant2 484262/s 522% -- -5% -5% -75% + -75% scalarRW 510204/s 555% 5% -- -0% -74% + -74% ScalarRO 511509/s 557% 6% 0% -- -74% + -74% constant 1960784/s 2419% 305% 284% 283% -- + -0% direct 1960784/s 2419% 305% 284% 283% 0% + --

(as running the benchmark multiple times suggests, differences up to around 5% are insignificant)

___

BTW, I think I remember PBP somewhere saying it's not meant to be treated as a bible...


In reply to Re^3: 2*pi*$r -- constant function without prototype by almut
in thread 2*pi*$r -- constant function without prototype by ambrus

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post; it's "PerlMonks-approved HTML":



  • Are you posting in the right place? Check out Where do I post X? to know for sure.
  • Posts may use any of the Perl Monks Approved HTML tags. Currently these include the following:
    <code> <a> <b> <big> <blockquote> <br /> <dd> <dl> <dt> <em> <font> <h1> <h2> <h3> <h4> <h5> <h6> <hr /> <i> <li> <nbsp> <ol> <p> <small> <strike> <strong> <sub> <sup> <table> <td> <th> <tr> <tt> <u> <ul>
  • Snippets of code should be wrapped in <code> tags not <pre> tags. In fact, <pre> tags should generally be avoided. If they must be used, extreme care should be taken to ensure that their contents do not have long lines (<70 chars), in order to prevent horizontal scrolling (and possible janitor intervention).
  • Want more info? How to link or How to display code and escape characters are good places to start.
Log In?
Username:
Password:

What's my password?
Create A New User
Domain Nodelet?
Chatterbox?
and the web crawler heard nothing...

How do I use this?Last hourOther CB clients
Other Users?
Others making s'mores by the fire in the courtyard of the Monastery: (6)
As of 2024-03-29 10:25 GMT
Sections?
Information?
Find Nodes?
Leftovers?
    Voting Booth?

    No recent polls found