if (condition1) {
  code_for_condition1($data)
} elsif (condition2) {
  code_for_condition2($data)
} else {
  default_condition($data)
}

##</code><code>##

%despatcher = (
  ident_1 => \*code_for_condition1,
  ident_2 => \*code_for_condition2,
  ...
};

&$despatcher{$identifier}($data);

sub code_for_condition1 {
  ...
}

sub code_for_condition2 {
  ...
}