IWETHEY v. 0.3.0 | TODO
1,095 registered users | 0 active users | 0 LpH | Statistics
Login | Create New User
IWETHEY Banner

Welcome to IWETHEY!

IWETHEY Home / IWETHEY Board / Theory and Practice of Programming Forum / Method Dispatch in Smalltalk
Post #95,609
by JimWeirich
Picture of JimWeirich
4/9/03 11:33:43 PM
Reply
New Method Dispatch in Smalltalk
Smaltalk (if I get it right) uses hashing on actual function signature. For most cases. My head is still spinning.

Strickly speaking, you are correct. However, most modern Smalltalks will optimize that lookup quite heavily. A Cincom developer once described to me the mechanism they use to make method lookups (on the average) faster than the typical implementation of C++ virtual method dispatch. Fascinating stuff!
--
-- Jim Weirich jweirich@one.net [link|http://w3.one.net/~jweirich|http://w3.one.net/~jweirich]
---------------------------------------------------------------------
"Beware of bugs in the above code; I have only proved it correct,
not tried it." -- Donald Knuth (in a memo to Peter van Emde Boas)
Post #95,782
by tuberculosis
Picture of tuberculosis
4/10/03 1:39:03 PM
Reply
New Yep - pretty amazing stuff
It totally depends on the implementation and there are a lot of really clever tricks. It might not seem like it - but ST actually (sometimes) gets you closer to the metal in a lot of nifty ways than something like C. Its very freaky.

For instance, the opencroquet guys are moving a huge amount of rendering into graphics hardware despite the fact that you're calling it from Smalltalk with ST data structures.



"Packed like lemmings into shiny metal boxes.
Contestants in a suicidal race."
    - Synchronicity II - The Police
     OO Design in C - (Ovid) - (12) - April 4, 2003, 01:37:43 PM EST
         Hmm...If I were doing ObjectOrienteed in C - (Simon_Jester) - April 4, 2003, 01:52:47 PM EST
         Take a look at the source-code to Ruby - (ben_tilly) - April 4, 2003, 06:40:50 PM EST
         Lots of ways - (tuberculosis) - (8) - April 8, 2003, 04:00:07 PM EDT
             That reminds me of another thread here. - (Another Scott) - (1) - April 8, 2003, 04:54:20 PM EDT
                 Re: That reminds me of another thread here. - (neelk) - April 16, 2003, 11:01:27 AM EDT
             Hold on here - (Arkadiy) - (5) - April 9, 2003, 10:31:29 AM EDT
                 Not too slow - (tuberculosis) - (4) - April 9, 2003, 01:42:28 PM EDT
                     C++ also uses lookups... - (ChrisR) - (3) - April 9, 2003, 03:53:39 PM EDT
                         No - (Arkadiy) - (2) - April 9, 2003, 08:24:38 PM EDT
                             Method Dispatch in Smalltalk - (JimWeirich) - (1) - April 9, 2003, 11:33:43 PM EDT
                                 Yep - pretty amazing stuff - (tuberculosis) - April 10, 2003, 01:39:03 PM EDT
         Free Book - (systems) - May 3, 2003, 07:14:54 AM EDT

Unintended consequences.
60 ms