Re: Perl Script Engine

I was wondering if a module existed to help with custom script language parsing and execution.

I doubt that this is the right way to look at the issue you have. A better design or a better way to look at the problem, is to allow the user to configue the action. If the action is complex enough, XML could be a good idea.

Your script simply parse the XML file, and call various functions you already implemented as instructed.

This really should not resolve to the creation of some one-time only mini-language, when a general tool like XML is available.

Comment on Re: Perl Script Engine

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Re^2: Perl Script Engine by adrianh (Chancellor) on Jan 23, 2004 at 15:24 UTC
I doubt that this is the right way to look at the issue you have. A better design or a better way to look at the problem, is to allow the user to configue the action. If the action is complex enough, XML could be a good idea. I wouldn't be so sure myself. What exactly is wrong with a domain specific scripting language? Will it really be easier for a non-technical user to edit XML in all cases? Yes there are instances where static configuration using XML files makes sense. There are also many cases when it doesn't. As soon as you start getting close to a declarative or procedural language that needs to be written by normal people then I think a domain specific language is an excellent solution. For example, look at Ant - which I find a royal PITA for non-trivial systems. I'm sure it seemed a good idea at the time to configure builds using XML, but what you end up with is verbose hard to maintain configuration files as soon as you start doing something vaguely complex. I much prefer systems like Ruby's Rake and Perl's Module::Build that allow you to use a proper scripting language. Not many people write programs in XML. This is mostly a good thing :-) Update: Of course on the day I write this I hear that Ant is adding scripting features - one less thing to complain about I guess ;-)	[reply]

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Re^2: Perl Script Engine
by adrianh (Chancellor) on Jan 23, 2004 at 15:24 UTC

I doubt that this is the right way to look at the issue you have. A better design or a better way to look at the problem, is to allow the user to configue the action. If the action is complex enough, XML could be a good idea.

I wouldn't be so sure myself.

What exactly is wrong with a domain specific scripting language? Will it really be easier for a non-technical user to edit XML in all cases?

Yes there are instances where static configuration using XML files makes sense. There are also many cases when it doesn't. As soon as you start getting close to a declarative or procedural language that needs to be written by normal people then I think a domain specific language is an excellent solution.

For example, look at Ant - which I find a royal PITA for non-trivial systems. I'm sure it seemed a good idea at the time to configure builds using XML, but what you end up with is verbose hard to maintain configuration files as soon as you start doing something vaguely complex. I much prefer systems like Ruby's Rake and Perl's Module::Build that allow you to use a proper scripting language.

Not many people write programs in XML. This is mostly a good thing :-)

Update: Of course on the day I write this I hear that Ant is adding scripting features - one less thing to complain about I guess ;-)

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