Date:         Fri, 25 Jun 1999 17:15:59 -0400
Reply-To:     GORRELP1 <GORRELP1@WESTAT.COM>
Sender:       "SAS(r) Discussion" <SAS-L@LISTSERV.UGA.EDU>
From:         GORRELP1 <GORRELP1@WESTAT.COM>
Subject:      Re: SOLVED: Omitting "OF" with SUM function
Comments: To: Jack Hamilton <JackHamilton@FIRSTHEALTH.COM>
Content-Type: text/plain; charset=US-ASCII

We all want SAS to be as user friendly as possible.  But we don't want the LOG
cluttered with 'just in case' WARNINGS.  If you submit a syntactically-valid
statement for execution, it's expecting a bit much for SAS to 'know what you
meant' or to warn you that you might not have submitted what you meant (it's
also a mean parsing problem to compute the alternatives).  It's often all too
easy to get in trouble, just type "IF X = Y" instead of "IF X ^= Y".

Paul Gorrell
gorrelp1@westat.com

____________________Reply Separator____________________
Subject:    Re: SOLVED: Omitting "OF" with SUM function
Author: Jack Hamilton <JackHamilton@FIRSTHEALTH.COM>
Date:       06/25/1999 2:12 PM

Yes, but I'm not sure what else SAS should do.  Should it give an error message
if you have two minus signs in a row without intervening parentheses?  That
wouldn't match standard mathematical notation (which the data step language
usually does, being based on PL/I syntax).


--
JackHamilton@FirstHealth.com
Development Manager, METRICS
First Health, West Sacramento, California USA


>>> Tom Frenkel <taf2@IS8.NYU.EDU> 25Jun1999 11:58 AM >>>
To SAS-L:

With Ian Whitlock's help, I now understand why I didn't get an error
message.  SAS interprets

        sum(x--y)

as

        sum(x-(-y))

i.e.

        sum(x+y)

In other words, the sum of x and y.

With hindsight, this seems very clear.  However, I *still* think it's too
easy for someone to get into trouble, if they mean to write "sum(of x--y)"
but instead write "sum(x--y)" !

        --Tom

Tom Frenkel
Assoc. Research Scientist
Center for Health & Public Service Research
New York University
taf2@is8.nyu.edu