This is how I usually do it. But I am C-damaged and also wonder how you do it with maps etc.

my($actions) = " ABCDEFG";
my($bits) = 0x37;

my($bplace) = 1;
my($index) = length($actions);

while(--$index >= 0) {
    substr($actions, $index, 1, " ")    if !($bplace & $bits);
    $bplace += $bplace;
}

print $actions, "\n";
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