Re^3: A way to avoid repeated conditional loops

in reply to Re^2: A way to avoid repeated conditional loops
in thread A way to avoid repeated conditional loops

Are you assuming that 'alpha' is also always the first line in the file?

Also, the posted flipflop doesn't behave the same as the OP

A simpler way to just use a flag and short circuit the regex work:

    my $seen = 0;
    while (<$fh>)
    {
        if ( !$seen and m/^alpha$/)
        {
            $seen = 'yes indeed';
            print "true\n";
        }else{
            print "false\n";
        }
    }
[download]

Given a test file of:

foo
bar
alpha
beta
gamma
delta
[download]

The results I got are:

Original:
false
false
true
false
false
false

Flipflop:
Argument "" isn't numeric in numeric gt (>) at test.pl line 21, <$fh> 
+line 1.
false
Argument "" isn't numeric in numeric gt (>) at test.pl line 21, <$fh> 
+line 2.
false
false
true
true
true

Flag:
false
false
true
false
false
false
[download]

Comment on Re^3: A way to avoid repeated conditional loops Select or Download Code
Re^4: A way to avoid repeated conditional loops by Deus Ex (Beadle) on Aug 24, 2011 at 14:43 UTC
No, "alpha" might be anywhere in the middle of the file (but it will appear only once). Actually the flip-flop operator may work only after "alpha" matched. Many thanks though for the short-circuiting thing :)	[reply]
Re^4: A way to avoid repeated conditional loops by tinita (Parson) on Aug 24, 2011 at 15:10 UTC
hm, if I add `no warnings "numeric";` to the flip-flop code, the output seems to be fine. output all lines after "alpha". at least that's how I understood the task.	[reply] [d/l]
Re^5: A way to avoid repeated conditional loops by Anonymous Monk on Aug 24, 2011 at 16:27 UTC
The OP code has an else condition on the match for alpha. That should execute for every line of the file except the 'alpha', regardless of before or after.	[reply]


Think about Loose Coupling
	PerlMonks

Re^3: A way to avoid repeated conditional loops

How many continents have you visited?