eval_between_arity

Summary

between/outside requires at least 2 values

Help

between and outside need an array of at least 2 numbers: [low, high]

Details

When this fires

Raised at runtime by the evaluator when a between or outside operator gets an array shorter than two elements. The DSL reads these as range checks of the form x between [low, high], so an empty or single-element array on the right makes no sense.

What to check

# broken
expr = "cpu.usage between [80]"
# fixed
expr = "cpu.usage between [80, 95]"

See @/docs/nanook-expr.md for the full operator list.