[VPM] Symbolic references with use strict in effect.

[Peter Scott]

At 1:19 AM -0400 6/4/06, abez wrote:
>no strict "subs";

I beg to differ.

no strict 'refs';

The alternative without violating strict is to maintain a dispatch 
table: hash of names vs subrefs.  However, I have used the 
strict-violating shortcut myself.  It boils down to whether I want to 
validate the routine to be called.  If I find myself writing "if 
defined &$sub2call" I know I'd be better off with the dispatch table.

>On Sat, 3 Jun 2006, Adam Parkin wrote:
>
>>  Hi all, I have a question for the Perl guru's on this list.  What I want
>>  to do is have my Perl script read from a text file some config data that
>>  looks something like:
>>
>>  [DataEntry]
>>  SubRoutineToHandleThisEntry="foo"
>>  ArgumentsToSub="hello world"
>>
>>  The idea is that the string "foo" is supposed to be the name of a
>>  subroutine in my Perl script, and the string "hello world" is the
>>  argument to pass to this subroutine.  I can do something like this:
>>
>>  $nameOfSub = "foo";       # name of sub to call
>>  $args = "hello world!";   # args to pass to sub
>>
>>  &$nameOfSub ($args);      # call foo() via a symbolic reference
>>
>>  sub foo {
>>        print "In foo with args: @_\n";
>>  }
>>
>>  And this works, but there is (IMHO) one very major problem with this: it
>>  is a symbolic reference, and thus if I put "use strict" at the top of my
>>  script, this trick no longer works.  Does anybody have a way of getting
>>  around this limitation?  I *very* much want "use strict" to be in effect
>>  for my script, but I still want the flexibility of being able to read
>>  from a file the name of a subroutine to call.  I could do something like
>>  have a hash in my script which maps string tokens to subroutine
>>  references, like so:
>>
>>  my %tokenToSubHash = ( "foo" => \&foo, "bar" => \&bar);
>>
>>  &{$tokenToSubHash{"foo"}}("hello world");
>>
>>  but this just seems a bit awkward as I now have to make sure I have an
>>  entry in this hash for every subroutine which is "visible" from the
>>  config file.
>>
>>  Anybody have any other creative ideas?
>>
>>  Thanks in advance.
>>
>
>--
>abez ------------------------------------------
>http://www.abez.ca/ Abram Hindle (abez at abez.ca)
>------------------------------------------ abez
>
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