10 my ($name, $rest) = split /: /;
11 my @ops = split /\s+/, $rest;
15 $val{$name} = $ops[0];
20 return $val{$var} if defined $val{$var};
21 my ($arg1, $op, $arg2) = @{ $expr{$var} };
23 return $val{$var} = walk($arg1) + walk($arg2);
24 } elsif ($op eq '-') {
25 return $val{$var} = walk($arg1) - walk($arg2);
26 } elsif ($op eq '*') {
27 return $val{$var} = walk($arg1) * walk($arg2);
28 } elsif ($op eq '/') {
29 return $val{$var} = walk($arg1) / walk($arg2);