I could only find doc for this in the System Description manual, where it talks about using @ in I-type expressions, where @ is the previous one (just resolved), @1 is result of first "sentence" (separated by ;), @2 is result of 2nd sentence, etc. I could not see an example of using the result from the previous record, but it works.
BTW, with multi-values, ADDS(@1,F26) works. V1 of first record adds to V1 of 2nd, etc. I can't think of where we could use it, but it depends on your file structure. On 4 July 2013 11:47, Peter Cheney <[email protected]> wrote: > I believe the expression in the second example is referred to as a > compound expression? > > Can't put my finger on the exact documentation but I seem to recall that > compound expressions are broken up into "parts" (for want of a better term) > delimited by a ';' and each "part" can be referenced throughout the entire > expression by an @ number e..g. @1 refers to the first part and the nth > part is @n etc. > > So for: > LIST VOC SIZE EVAL "SIZE + @2;@" > > My take on how this works is the the first part of the expression (SIZE + > @2) can be referenced later on as @1, The second part is referenced as @ > (instead of @2) and I believe is used to refer to the result of the entire > expression (sum of all the parts). > > Can @ in this case also be referenced as @2? It probably could but would > break the expression. > > Therefore the reference to @2 is causing the expression to grab the entire > result using contents of @ (via @2 thus keeping it separate to @) and add > it to SIZE which then becomes the new result (@) of the expressions and the > whole thing is repeated. > > Does that sound about tight? Or have I got it way wrong? > > Cheers > Peter > > > > > Peter Cheney > > Universe Engineer > > t 07 3017 8837 | f 07 3002 8400 > > e [email protected] | w www.firstmac.com.au > > > > ________________________________________ > From: [email protected] [ > [email protected]] on behalf of Wjhonson [ > [email protected]] > Sent: Thursday, 4 July 2013 7:31 AM > To: [email protected]; [email protected] > Subject: Re: [U2] Running total > > Can anyone explain this situation better. I've only ever used the @ to > simplify a few I-descriptors. > > I have a dict item SIZE that is just the LEN(@RECORD) > > So in this thread we've seen two EVAL solutions to a running total > > LIST VOC SIZE EVAL "@1+SIZE" > LIST VOC SIZE EVAL "SIZE + @2;@" > > In the first example is the @1 just saving the "previous result of THIS > eval ?" > > And then in the second example does the fact that SIZE is first in the > Eval, effectively *push* the accumulator into position two or something? > So that's why you need @2 ? > > And then what would be the meaning of ";@" at the end of that? > > Pretty confusing stuff! > > > > _______________________________________________ > U2-Users mailing list > [email protected] > http://listserver.u2ug.org/mailman/listinfo/u2-users > > > > ------------------------------------------------------------------------------- > Note: > This email (inc all attachments) is for the use of the intended > recipient(s) only. > Privileged or confidential information may be contained in this > communication. If you have received this email in error, please notify the > sender immediately and then delete all copies of this message from your > computer network. If you are not the intended recipient, you must not keep, > use, disclose, copy or distribute this email without the author's prior > permission. If you are the intended recipient and you do not wish to > receive similar electronic messages from us in future, then please respond > to the sender to this effect. > We have taken precautions to minimise the risk of transmitting software > viruses, but advise you to carry out your own virus checks on this email > and its attachments. We do not accept liability for any loss or damage > caused by software viruses and do not represent that this transmission is > free from viruses or other defects. > Firstmac Limited (ABN 59 094 145 963) (AFSL 290600) > > > ------------------------------------------------------------------------------- > _______________________________________________ > U2-Users mailing list > [email protected] > http://listserver.u2ug.org/mailman/listinfo/u2-users > -- Kate Stanton Walstan Systems Ltd 4 Kelmarna Ave, Herne Bay, Auckland 1011, New Zealand Phone: + 64 9 360 5310 Mobile: + 64 21 400 486 Email: [email protected] _______________________________________________ U2-Users mailing list [email protected] http://listserver.u2ug.org/mailman/listinfo/u2-users
