Re: bin/52623: nonsense error message in awk

[Robert Elz <kre%munnari.OZ.AU@localhost>]

The following reply was made to PR bin/52623; it has been noted by GNATS.

From: Robert Elz <kre%munnari.OZ.AU@localhost>
To: gnats-bugs%NetBSD.org@localhost
Cc: 
Subject: Re: bin/52623: nonsense error message in awk
Date: Mon, 16 Oct 2017 14:15:07 +0700

     Date:        Mon, 16 Oct 2017 02:05:00 +0000 (UTC)
     From:        dholland%eecs.harvard.edu@localhost
     Message-ID:  <20171016020500.E6C587A269%mollari.NetBSD.org@localhost>
 
   | Accidentally writing index[array] instead of array[index] in awk
   | causes a nonsense error message.
 
 Not really nonsense...
 
   |    awk -F: < /etc/passwd '{ a[$1] = $3; } END { for (k in a) print k[a]; }'
 
 When that is compiled, awk can see from the reference to k[a] that k is
 an array.   The syntax is all OK, so the compile succeeds.
 
 When it is executed, and we get to the "for (k in a)" we need to assign
 the indexes of array a to k, which can't be done, as k is an array.
 
 Hence:
   |    awk: can't assign to k; it's an array name.
 
 What would you have it do differently?
 
 kre