Re^2: elsif chain vs. dispatch

For me, it is that the codebase is becoming unwieldy, so I wanted to switch to the dispatch style, and I was (honest) going to be putting it outside a sub so it only gets compiled once!

Have you ever considered using the symbol table as the hash, would this be any good:

$::{"handle_fieldcode_$code"}->($args);  # for $code = 'A'..'Z'
[download]

??
SSF

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Re^3: elsif chain vs. dispatch by ikegami (Patriarch) on Apr 27, 2009 at 02:57 UTC
The slow bit is the function call, not the hash lookup which you'd also have to do with the symtab anyway. With a hash, you have better control over what inputs are allowed and how they are dispatched. With symtab: `my $handler = do { no strict 'refs'; \&{"handle_fieldcode_$code"} }; ...handle expections somehow?... die if !$handler; $handler->(@args);` [download] With hash; `my $handler = $lookup{$code}; die if !$handler; $handler->(@args);` [download] with a one-time setup of `my %lookup = map { no warnings 'refs'; $_ => \&{"handle_fieldcode_$_"} } 'A'..'Z'; ...modify %lookup for expections...` [download]	[reply] [d/l] [select]

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Re^3: elsif chain vs. dispatch
by ikegami (Patriarch) on Apr 27, 2009 at 02:57 UTC

The slow bit is the function call, not the hash lookup which you'd also have to do with the symtab anyway. With a hash, you have better control over what inputs are allowed and how they are dispatched.

With symtab:

my $handler = do { no strict 'refs'; \&{"handle_fieldcode_$code"} };
...handle expections somehow?...
die if !$handler;
$handler->(@args);
[download]

With hash;

my $handler = $lookup{$code};
die if !$handler;
$handler->(@args);
[download]

with a one-time setup of

my %lookup = map {
   no warnings 'refs';
   $_ => \&{"handle_fieldcode_$_"}
} 'A'..'Z';
...modify %lookup for expections...
[download]

[reply]
[d/l]
[select]