Re^2: Extending Perl::PIE - how to have Perl snippets executed ?

Hi,

I guess it would be too much to include code. You can find Perl::Pie here :
http://www.pre-emptive.net/doco/pie-perl-inference-engine

The problem is that I do eval from Perl::PIE package extensions and it doesn't work, while it works in main program when used directly without eval...

Small Example:
main program:

...
use Pie::KnowledgeBase;
use Pie::Engine;
use Pie::KnowledgeBase::Dumper;
use Data::Dumper;
require 'time_utilities.pl';       # For misc. functions (e.g. time/da
+te stamp routines)
use Time::HiRes('gettimeofday');




use vars qw($Time $Second $Minute $Hour $Mday $Wday $Day $Month $Year)
+;

...
[download]

then I have somewhere in Perl::PIE packages snippet:

...
                print " ----------------- " . $ref->{attribute} . "\n"
+;

...
[download]

where $ref->{attribute} includes string to print that is defined in xml config :

  <rule name="print status every 5 secs">
   <condition attribute='main::new_second(5)' type="time" trigger="1">
+1</condition>
   <action attribute="\n****************print status every 5 secs: New
+_Second: Weekday:$Wday Time:$Hour:$Minute:$Second Time_Now:$Time_Now 
+Date:$Mday/$Month/$Year" type="print">1</action>
  </rule>
[download]

and I don't get variables substituted in printed text by their value, so I get exactly literally the same string back :
"\n****************print status every 5 secs: New_Second: Weekday:$Wday Time:$Hour:$Minute:$Second Time_Now:$Time_Now Date:$Mday/$Month/$Year"

What should I do to print real values of variables and not literally their names ?

Thanks in advance,

Rob.

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Re^3: Extending Perl::PIE - how to have Perl snippets executed ? by spazm (Monk) on Jul 13, 2009 at 18:02 UTC
Rob, Thanks for the update. I don't have time to look at it currently, but a perl rules engine sounds interesting. It looks like you need something to interpolate your string. So, something like changing your print routine to include an eval of the string? I don't think the code below works, but may prove helpful? You may also find yourself doing a search on the returned string to fill in values... blech. `$string =~ s/\$(\w+)/ ${$1} /xeg;` [download] orig: `print " ----------------- " . $ref->{attribute} . "\n"` [download] new: `my $string = $ref->{attribute}; my $output = eval $string; if($@){ die "problem with eval: $@"; } print " ----------------- $output\n";` [download]	[reply] [d/l] [select]

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Re^3: Extending Perl::PIE - how to have Perl snippets executed ?
by spazm (Monk) on Jul 13, 2009 at 18:02 UTC

Thanks for the update. I don't have time to look at it currently, but a perl rules engine sounds interesting.

It looks like you need something to interpolate your string. So, something like changing your print routine to include an eval of the string?

I don't think the code below works, but may prove helpful? You may also find yourself doing a search on the returned string to fill in values... blech.

$string =~ s/\$(\w+)/ ${$1} /xeg;
[download]

                print " ----------------- " . $ref->{attribute} . "\n"
[download]

my $string = $ref->{attribute};
my $output = eval $string;
if($@){
  die "problem with eval: $@";
}
 print " ----------------- $output\n";
[download]

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