node_fork

Static pipeline multi-way branch

Evaluated at pipeline construction time. Takes condition-value pairs and returns the value for the first truthy condition. If no condition matches, returns a null marker (node excluded). Provide .default to control the fallback value. This preserves Nix’s static DAG requirement — the condition is checked before the build. node_fork is only meaningful as the direct value of a node binding inside a pipeline { } block. Using the result outside that context is unsupported.

Parameters

• … (Any): Pairs of condition-value arguments.

• .default (Any): (Optional) Fallback value if no condition matches.

Returns

Examples

p = pipeline {
model = node_fork(
env("MODEL_TYPE") == "lm", rn(script = "lm.R"),
env("MODEL_TYPE") == "nn", pyn(script = "nn.py"),
.default = rn(script = "baseline.R")
)
}