Path: utzoo!utgpu!news-server.csri.toronto.edu!rutgers!mit-eddie!uw-beaver!fluke!dcd
From: dcd@tc.fluke.COM (David Dyck)
Newsgroups: comp.lang.perl
Subject: a2p generates incorrect code
Keywords: a2p awk perl bug for
Message-ID: <1990Aug2.090725.2029@tc.fluke.COM>
Date: 2 Aug 90 09:07:25 GMT
Organization: John Fluke Mfg. Co., Inc., Everett, WA
Lines: 51

a2p generates incorrect code while translating for loop.

--------- example script  "t1"-------
BEGIN {
    split("a b c", list);
    for (i in list) {
        print i;
    }
}
---------- end of "t1" ----------------

# when run from awk with "awk -f t1 < /dev/null" it prints
# the array indices in 'some' order.
2
3
1

# when translated to perl via "a2p t1 > t1.pl" and executes
# with the command "perl t1.pl < /dev/null" the
# array elements themselves are printed
a
b
c


The awk "for (i in list)" is translated into "foreach $i (@list)"

To get it to run more like awk I changed the perl code to
read "for ($i=1; $i <= $#list; ++$i)", and then perl
prints:
1
2
3

I don't mind perl not simulating the random order that
awk uses, but is there a better way to do this?

PS. (I came upon this while trying to convert the 'Lisp interpreter in Awk'
     that was posted to comp.lang.lisp and alt.sources into
     'Lisp in perl'.  After correcting the bug, perl was only a 
     little slower that awk).

	AWK:  real    0m5.03s 	user    0m4.73s	 sys     0m0.11s
	PERL: real    0m5.10s	user    0m4.78s	 sys     0m0.21s


            David Dyck
    Domain: dcd@tc.fluke.COM
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