1. Modifying a variable you use several times within an expression is begging for problems. Don't!
2. You can't use a state variable for something like this! As soon as that line gets evaluated twice, you end up in deep sh^B^Bproblems:
use feature qw(say state);
my @widths = (2, 6, 5, 7);
foreach (1 .. 2) {
my @partitions = map { state $c = 0; [$c, $c += $_] } @widths;
say '[', join(', ', @$_), ']' for @partitions;
print "\n";
}
State variables are too global. The simplest solution I can think of is:
use feature qw(say);
my @widths = (2, 6, 5, 7);
foreach (1 .. 2) {
my @partitions = do { my $c = 0; map { $c += $_; [$c - $_, $c] } @
+widths};
say '[', join(', ', @$_), ']' for @partitions;
print "\n";
}
or
use feature qw(say);
my @widths = (2, 6, 5, 7);
foreach (1 .. 2) {
my @partitions = do { my $c = 0; map { my $old = $c; [$old, $c+=$_
+] } @widths};
say '[', join(', ', @$_), ']' for @partitions;
print "\n";
}
Jenda
Enoch was right!
Enjoy the last years of Rome.
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