Suppose you have a program consisting of just >. What happens to it when you run your code:
- s/>/\t\t++k;\n/g; transforms it into \t\t++k;\n
- s/</\t\t--k;\n/g; does nothing, it's still \t\t++k;\n
- s/\+/\t\t++*k;\n/g; transforms each + present in the program into \t\t++*k;\n, leaving you with \t\t\t\t++*k;\n\t\t++*k;\nk;\n
One way to solve it would be to create a hash of all possible replacements:
my %sub = {
">" => "\t\t++k;\n",
"+" => "\t\t++*k;\n",
... # fill as needed
}
Then run the substitution only once, on each symbol:
s/(.)/$sub{$1}/ge
Fixing the warnings about undefined hash elements (when do they happen?) and/or constructing a regular expression that would only match brainf*ck characters is left as an exercise for the reader.
A faster, but less elegant solution would be to replace + and - first, then consider other characters which might produce their own [+-].