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Nix Functions Reference

This reference documents the public API exposed by repx.lib.

Experiment Definition​

repx.mkLab​

Creates the top-level Lab derivation. This is the entry point for your experiment definition in flake.nix.

Arguments:

  • pkgs (Attribute Set): The Nixpkgs package set.
  • repx-lib (Attribute Set): The RepX library instance.
  • runs (Attribute Set): A dictionary where keys are run names and values are Run objects (created by import).

Returns:

  • (Derivation): The built Lab derivation containing the experiment graph.

repx.mkRun​

Defines a parameterized run.

Arguments:

  • name (String): The unique name of the run.
  • pipelines (List): A list of paths to pipeline definition files.
  • params (Attribute Set): A dictionary of parameter lists for parameter sweeping.
    • Example: { seed = [ 1 2 3 ]; model = [ "A" "B" ]; }
    • RepX generates the Cartesian product of these lists.

Returns:

  • (Attribute Set): A Run definition object.

Pipeline Construction​

repx.mkPipe​

Constructs a pipeline from a set of stages. Used inside a pipeline file.

Arguments:

  • stages (Attribute Set): A recursive attribute set (rec) where each key is a stage name and value is a Stage object (returned by callStage).

Returns:

  • (Attribute Set): A Pipeline definition object.

repx.callStage​

Instantiates a stage from a file, resolving dependencies and parameters.

Arguments:

  • path (Path): The path to the stage definition file (.nix).
  • dependencies (List): A list of dependencies. Elements can be:
    • Stage Object: Implicit mapping. Matches output names to input names.
    • List [stage source target]: Explicit mapping. Maps source output of stage to target input of the current stage.

Returns:

  • (Derivation): The instantiated Stage derivation.