In working on a web application, I am reaching the point at which I need to provide administrators with some limited scripting capability through a password protected web interface. Capabilities would initially need to include if...elsif...else, return, boolean logic, numeric expressions, retrieving and storing of data from/to a SQL database, and set operations (union, intersection, etc).

I have been exploring several alternatives:

1. represent structure in XML
   • Disadvantage: ugly to edit, verbose
   • Advantage: introspection is easy
2. build an API and allow full use of perl as the scripting language
   • Disadvantage: few limits to power and flexibility; more training required.
   • Advantage: few limits to power and flexibility
3. define a mini-language and write a translator to convert it to perl for execution
   • Disadvantage: additional work over option 2 and less power and flexibility
   • Advantage: introspection easier than option 2, power and flexibility can be limited appropriately; less training required than option 2.

I am leaning toward the third option -- minilanguage with translator to perl. Are there any major pitfalls with such an approach?

I have not found much written about writing a minilanguage translator in perl, though Template Toolkit does serve as an example. Can anyone point me to some good resources as to how to get started down this path?

I envision bulding the parser/translator in something like Parse::RecDescent or Parse::Yapp. Parsing speed is not very critical in this application because code would be parsed once and converted to perl, then used many times.

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