Beefy Boxes and Bandwidth Generously Provided by pair Networks
Pathologically Eclectic Rubbish Lister
 
PerlMonks  

Comment on

( #3333=superdoc: print w/ replies, xml ) Need Help??
Another note (hope I haven't bothered you enough yet :-))

Last time I checked with the Parrot docs (the tutorial mainly), there was no mention of jumps to computed values (which is what you said you need for implementing call/cc). So the question is: how can one do proper tail recursion without jumps? (Parrot does have jump LABEL though)

Another question is: if your C compiler doesn't do proper tail recursion (C compilers are not required to), then can you still do proper tail recursion in C?

Just for the record, here is the definition of proper tail recursion according to the Scheme Revised^5 Report:

Implementations of Scheme are required to be properly tail-recursive. ... . A Scheme implementation is properly tail-recursive if it supports an unbounded number of active tail calls. A call is active if the called procedure may still return.

I don't think scheme implementations are required to support call/cc, but they are required to support proper tail recursion.

The reason I'm blabbering about this is that I just finished a course in compilers where we implemented a good subset of scheme. The compiler translates scheme to Sparc assembly code, and at some time we targeted C. So, I know proper tail recursion is possible, even in VB :-).

Aziz,,,

Update: Thanks Elian for the reply. I guess the docs might be out of date since development there is going very fast.


In reply to Re: Pure Perl tail call optimization by abstracts
in thread Pure Perl tail call optimization by pdcawley

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



  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • Outside of code tags, you may need to use entities for some characters:
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.
  • Log In?
    Username:
    Password:

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

    How do I use this? | Other CB clients
    Other Users?
    Others browsing the Monastery: (10)
    As of 2014-07-24 17:51 GMT
    Sections?
    Information?
    Find Nodes?
    Leftovers?
      Voting Booth?

      My favorite superfluous repetitious redundant duplicative phrase is:









      Results (163 votes), past polls