将参数传递给子例程的名称

Question

Is there a way to choose a subroutine by means of a parameter passed to another subroutine? Something like this:

sub foo1 {
    # does stuff to @_
}

sub foo2 {
    # does other stuff to @_
}

sub foo3 {
    # does other stuff to @_
}

sub foo {
    my $whichsub = shift;
    my @fooed = foo.$whichsub @_;
    # does stuff to @fooed
}

where foo.$whichsub should be foo1 or the like. Except that of course that doesn't work.

Answer 1

You can build a dispatch table of subroutines. Something like this

my @foo_table = \(&foo1, &foo2, &foo3);

foo(2);

sub foo {
    my $whichsub = shift;
    die unless my $foosub = $foo_table[$whichsub-1];
    my @fooed = $foosub->(@_);

    # does stuff to @fooed
}

sub foo1 {
    # does stuff to @_
}

sub foo2 {
    # does other stuff to @_
}

sub foo3 {
    # does other stuff to @_
}

Answer 2

It can be done without a table:

sub foo {
    my $whichsub = shift;
    my $foosub = "foo".$whichsub;
    my @fooed = &$foosub(@_);

    # does stuff to @fooed
}