Hello Dan;
The more comments you use to justify dd, the less attractive I find it.
Dan Bron wrote:
I wrote:
I don't understand
Regarding your comment:
dd ,:1 2 NB. The result exceeds ":
1+i.1 2
Ah, I see. You're saying (dd >&# ":) ,: 1 2 . Well, keep two things in mind:
(A) For large arguments, dd will either dramatically beat or tie with ":
. For small arguments, the differences will be
minute and probably overshadowed by the mechanism of communication [1]. Take
my example where two J servers are connected via
sockets for this case: Nagel's algorithm (and the size of a TCP/IP packet)
virtually guaruntee neither message will arrive sooner
[1]. Which brings me to my second point.
(B) These two verbs do different things. The point of my J IPC protocol
was to send data from one J session to another, such
that the receiving J server received an exact copy of the noun sent by the
sending J server. Now note:
(-: ".@:":) ,: 1
0
(-: ".@:dd) ,: 1
1
the result of ".":y is not guarunteed to be the same as y (for the reasons
discussed elsewhere in this thread). Which just
means we're not really comparing apples-to-apples in the first place.
And, in the interests of full disclosure, I will note that while our initial J
IPC protocol leveraged this feature of 5!:5 , we
changed it in a later release to use 3!:1 . The cost of sending large nouns
when 5!:5 couldn't find a terse J expression
which resulted in that noun far outstripped the gains from the cases where it could.
-Dan
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|\/| Randy A MacDonald | APL: If you can say it, it's done.. (ram)
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