Consider adding LLM support for draft_validation

[parmsam-pfizer]

Prework

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• Search for duplicates among the existing issues (both open and closed).

Proposal

Describe the new feature clearly and concisely. If applicable, write a minimal example in R code or pseudo-code to show input, usage, and desired output.

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Consider adding ellmer-based LLM support for draft_validation(), similar to Python library capabilities (https://posit-dev.github.io/pointblank/user-guide/draft-validation.html). Similar could apply to future LLM-powered validation data dictionary generation. Please feel free to ignore if this is outside of scope.

[rich-iannone]

Going to do it! Plus there’s another cool LLM feature in Python Pointblank that should be ported over (it’s in development right now) and that’s the .prompt() method, which will be a validation function here.