Subj : baja.c / unbaja.c
To   : Deuce
From : Angus McLeod
Date : Thu Sep 08 2005 01:42 pm

  Re: baja.c / unbaja.c
  By: Deuce to Angus McLeod on Thu Sep 08 2005 10:54:00

 >  > I've always wondered at baja.c's not using Dijkstra's algorithm to
 >  > simplify ARS, but I guess it pays off, now that unbaja.c is recovering th
 >  > nested expression again.....
 > 
 > Not sre I understand what you mean exactly... an ARS isn't really a good tar
 > for a shortest path evaluation.

I meant the use of Dijkstra's *shunting* algorithm or a variant thereof, 
to convert infix with nested sub-expressions to postfix, for simplified 
evaluation by the low level processor (in this instance, the BAJA 
low-level execution code).  I've always found it a little strange seeing 
parenthesis actually embedded in the low level code as they are (in 
tokenized form) in Sync's .BIN files.  These are usually removed by the 
(semi-)compiler by application of some variation of Dijkstra's 
shunting algorithm.  It's a very basic sort of code-optimization.

It wasn't a criticism, just an observation.

And obviously, to de-compile postfix back into infix with nested 
sub-expressions whould be, at best, non-trivial.  So as I said -- that 
original decision by DM seems to be bearing fruit, what with unbaja.c 
recently introduced.


---
 þ Synchronet þ Great programs on the Synchronet Channel at The ANJO BBS

.