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Adding a built-in function

Adding a built-in or "Standard Library Function" is usually straight-forward involving implementation and testing only in the backend.

(This document is in-progress and needs work)

Define the function​

  • Determine where the function should live
    • If the function is required to be run in the backend (e.g. to connect to a database), then BackendOnlyStdLib is appropriate
    • Otherwise the function may live within LibExecutionStdLib. This is where most pure functions live, such as Int::absoluteValue
  • Implement the function generally speaking, you should be able to copy/paste an existing function and adjust from there intuitively
    • name
    • params and return type
    • description/docs
    • function implementation
    • sqlSpec. (usually ok to NotImplementedTodo)
    • previewable - Pure, Impure, or ImpurePreviewable?
    • deprecated - NotDeprecated
  • Should some other function be deprecated in favor of this? If you're creating a new version of an existing function, probably yes.

Add tests covering the function​

  • Most pure functions are testable solely with execution test files they don't require recompilation consider test file. Refer to backend/testfiles/execution.
  • Other functions may require more nuanced testing in backend/tests/Tests.

Test the function in the editor​

  • try it out! Does it generally work as expected?
  • if it's a Pure (or ImpurePreviewable?) function, check to see if Analysis behaves appropriately (e.g. does evaluating the function require a you clicking the 'Play' button in the Editor?)