× The internal search function is temporarily non-functional. The current search engine is no longer viable and we are researching alternatives.
As a stop gap measure, we are using Google's custom search engine service.
If you know of an easy to use, open source, search engine ... please contact support@midrange.com.



I don't think xlate will compare. More likely, it will use the value of each "badchar" as an offset in the tranlation table, and move the character it founds there to the "goodchar".

Albert York wrote:

That reduces the source code but increases the amount of work being done.
Under the covers, %xlate would have to compare each character in the srcdata field with each character in the badchar field, one at a time. Most of the time it would not find a match, which means it would have searched the entire badchar field. Somewhere around 100,000 comparisons per srcdata field. Then there is the additional overhead for subsetting within the badchar field.

Contrast that with simply comparing each character to X'40', which is only 1920 comparisons.

Albert


----- Original Message -----
From: "Rory Hewitt" <roryhewitt@xxxxxxxxx>
To: "RPG programming on the IBM i / System i" <rpg400-l@xxxxxxxxxxxx>
Subject: Re: Pointer vs. BIF performance (was: Getting into pointers)
Date: Wed, 12 Aug 2009 09:53:29 -0700


Probably a very slight improvement. But on a string this long, is it worth
it?

Of course, you could simply use %xlate, specifying a string of control
characters for arg 1 and a string of blanks for arg 2:

D badchars C
x'0102030405060708090A0B0C0D10111213141516171819'

srcdta = %xlate( badchars : *blanks : SRCDTA );

I didn't put all of the badchars string in there, but you'd include all the
characters from x'01' to x'39' (not including x'0E' and x'0F', since they
are shift-in and shift-out DBCS characters).

I *think* using *blanks for arg 2 works, but you might need to define a
string of blanks the same length as badchars.

Rory

On Wed, Aug 12, 2009 at 7:42 AM, David Gibbs <david@xxxxxxxxxxxx> wrote:


This question is mostly out of idle curiosity ...

I've got a simple routine that is designed to replace any 5250 control
characters in a RPG source file with blank.

for p = 1 to %len(%trim(SRCDATA));
if %subst(SRCDATA:p:1) < x'40';
%subst(SRCDATA:p:1) = *blank;
endif;
endfor;

Would there be any performance benefit if I used a pointer to update the
field?

D charPtr S *
D char S 1A based(charPtr)

.
.
.

for p = 0 to %len(%trim(SRCDATA));
charPtr = %addr(SRCDATA)+p;
if char < x'40';
char = *blank;
endif;
endfor;

Thanks!

david


--
This is the RPG programming on the IBM i / System i (RPG400-L) mailing list
To post a message email: RPG400-L@xxxxxxxxxxxx
To subscribe, unsubscribe, or change list options,
visit: http://lists.midrange.com/mailman/listinfo/rpg400-l
or email: RPG400-L-request@xxxxxxxxxxxx
Before posting, please take a moment to review the archives
at http://archive.midrange.com/rpg400-l.






As an Amazon Associate we earn from qualifying purchases.

This thread ...

Replies:

Follow On AppleNews
Return to Archive home page | Return to MIDRANGE.COM home page

This mailing list archive is Copyright 1997-2024 by midrange.com and David Gibbs as a compilation work. Use of the archive is restricted to research of a business or technical nature. Any other uses are prohibited. Full details are available on our policy page. If you have questions about this, please contact [javascript protected email address].

Operating expenses for this site are earned using the Amazon Associate program and Google Adsense.