Beefy Boxes and Bandwidth Generously Provided by pair Networks
good chemistry is complicated,
and a little bit messy -LW
 
PerlMonks  

comment on

( #3333=superdoc: print w/replies, xml ) Need Help??
Your program is already heavily invested in the performance of hashes. Most objects use hashes as their underlying data structure. Every reference to a package variable results in multiple hash lookups (I think). And every call to a subroutine results in multiple hash lookups (I think).
Well, then, think again. :)

To the first approximation, only packages use hashes for their internal structure, and most package symbol lookups happen only at compile time. (Any stored GV* is post-hash-lookup.) Apart from symbolic references (which are discouraged), the only major operation that historically used hash lookups implicitly at run time was method calls, and I think even that has been heavily optimized these days when the method name is known in advance.

There are other implicit uses of hashes, but these typically come into play only when you start using higher Unicodes characters in patterns, and even there the internals typically try to avoid using the hash in the common cases.

In any event, normal sub calls don't use any implicit hashes. They're already too slow as it is...


In reply to Re^4: Could we save the memory occupied by "undef" in an array? by TimToady
in thread Could we save the memory occupied by "undef" in an array? by lightoverhead

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 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? | Other CB clients
Other Users?
Others musing on the Monastery: (1)
As of 2021-12-03 06:48 GMT
Sections?
Information?
Find Nodes?
Leftovers?
    Voting Booth?
    R or B?



    Results (28 votes). Check out past polls.

    Notices?