I'm solving exercise 15-1 in the Llama, and I've run across a peculiarity I don't understand. In my program, I use the following loop:

for (
        print "Please enter your guess from " . MINGUESS . " to " . MA
+XGUESS . ":  ";
        <>;
        print "Try again.  Please enter your new guess from " . MINGUE
+SS . " to " . MAXGUESS . ":  ") {
    chomp;
    when ( '' ) { last; }
    when ( 'quit' ) { last; }
    when ( $iTarget ) { last; }
    default { print "\tYour guess of $_ was too " . ($_ < $iTarget ? "
+small." : "large.") . "\n"; }
    }

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The first time through the loop, the code executes as expected. If a second time through is necessary, the program immediately dies with "Can't use when() outside a topicalizer at (line number corresponding to 'default' line).", before the third section of the for loop conditions is able to execute. Is a for loop not a sufficiently good topicalizer? What gives?

In reply to When in the course of Perl topicalizers by piezocuttlefish

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