468 

   468 

   469   In the extended \texttt{compute3} and \texttt{run3} functions you should

   469   In the extended \texttt{compute3} and \texttt{run3} functions you should

   470   implement this command by writing 0 to \pcode{mem(mp)}, that is use

   470   implement this command by writing 0 to \pcode{mem(mp)}, that is use

   471   \pcode{write(mem, mp, 0)} as the rule for the command \texttt{0}.

   471   \pcode{write(mem, mp, 0)} as the rule for the command \texttt{0}.

   472   The easiest way to modify a string in this way is to use the regular

   472   The easiest way to modify a string in this way is to use the regular

   474   not a bf-command. Similarly, the

   474   not a bf-command. Similarly, the

   475   regular expression \pcode{"""\\[-\\]"""} finds all occurrences of \pcode{[-]}.  By using the Scala method \pcode{.replaceAll} you can replace substrings

   475   regular expression \pcode{"""\\[-\\]"""} finds all occurrences of \pcode{[-]}.  By using the Scala method \pcode{.replaceAll} you can replace substrings

   476   with new strings.\\

   476   with new strings.\\

   477   \mbox{}\hfill{[1 Mark]}

   477   \mbox{}\hfill{[1 Mark]}

   478 

   478