step.step_builder

Base class for auto-generated step builders.

A StepBuilder collects constructor arguments via fluent methods and implements StepProtocol so it can be used directly in seq([...]). When executed, it builds the real Step and delegates to it.

Builder classes are generated by raccoon codegen from @dsl_step-decorated Step classes. Each __init__ parameter becomes a fluent setter method, and a snake_case factory function is generated alongside.

Classes

StepBuilder

Base class for generated step builders.

Module Contents

class step.step_builder.StepBuilder

Bases: step.base.Step

Base class for generated step builders.

Subclasses must implement _build() to construct the real Step from the collected parameters.

Since StepBuilder extends Step, it satisfies StepProtocol and can be used anywhere a Step is expected (seq, parallel, mission step lists).

on_anomaly(callback_or_step: StepAnomalyCallback | Step) → StepBuilder

Register a callback or step invoked when a timing anomaly is detected.

Accepts either an async callback (step, robot) -> None or a Step instance to run when the anomaly fires:

drive_forward(25).on_anomaly(my_handler)

async def my_handler(step, robot):
    ...

# Or pass a step directly:
drive_forward(25).on_anomaly(play_sound())

skip_timing() → StepBuilder

Exclude this step from timing anomaly tracking.

Use for steps whose duration is inherently variable (e.g., condition-only drives, user-input waits).

resolve() → step.base.Step

Build the underlying Step and apply any chained options.

Idempotent — composite constructors call this to replace a builder with its real Step at validation time, so resource conflict checks and signature lookups see the actual underlying step rather than an empty builder placeholder. Subsequent calls return the cached instance, so this is safe even if a builder ends up reachable from multiple parents.

Once a builder has been resolved, mutating it via on_anomaly() or skip_timing() is a no-op against the cached step — call those before placing the builder inside a composite.