On Nov 12, 2005, at 2:56 AM, James Reynolds wrote:
Is there someway to execute this code like this:
$subroutine_name = "something"; # can't change
$hashref->{'key'}='value'; # can't change
eval "$subroutine_name($hashref)"; # how do I eval this? It
doesn't eval.
Essentially I get the subroutine names to execute from a text file,
and there will be thousands of differently named subroutines. I
simplified the reason why the hash exists in this example.
Needless to say I can't get out of using it that way easily, if at
all.
Block eval() is useful for exception handling, but string eval() is
just evil misspelled.
Use a dispatch table instead:
#!/usr/bin/perl
use strict;
use warnings;
my %dispatch = (
'a' => \&a,
'b' => \&b,
'c' => \&c,
);
my $hashref = {
'foo' => 1,
'bar' => 2,
'baz' => 3,
};
for my $sub_name ('a', 'b', 'c') {
$dispatch{$sub_name}->($hashref);
}
sub a {
my ($hr) = @_;
print "A called\n";
print "\t", join(",", keys(%$hr)), "\n";
}
sub b {
my ($hr) = @_;
print "B called\n";
print "\t", join(",", keys(%$hr)), "\n";
}
sub c {
my ($hr) = @_;
print "C called\n";
print "\t", join(",", keys(%$hr)), "\n";
}
Have a look in the archives for comp.lang.perl.misc at Google Groups
- the subject of "dispatch tables" has been covered at great length:
http://groups.google.com/group/comp.lang.perl.misc/search?
group=comp.lang.perl.misc&q=dispatch+table
sherm--
Cocoa programming in Perl: http://camelbones.sourceforge.net
Hire me! My resume: http://www.dot-app.org
