L06 Pipeline Ergonomics and Composition Antipatterns

Metadata

• Lecture ID: L06
• Track: A (Flow Fundamentals)
• Tier: 1-2
• Duration: 20 minutes
• Prerequisites: L01-L05

Learning Objectives

1. Show equivalence of explicit/context/functional authoring styles.
2. Validate that style choice does not change graph contract.
3. Identify composition antipatterns that hurt readability and maintenance.

Core Concept

• Mental model: choose authoring style for clarity, not behavior changes.
• Key pitfall: accidental implicit pipeline coupling when using functional style carelessly.

Live Demo Mapping

• Primary runnable file: examples/tutorial/a_flow_fundamentals/05_pipeline_ergonomics.py

Runnable Commands

Run from repository root:

pixi run python -m examples.tutorial.a_flow_fundamentals.05_pipeline_ergonomics --mode context --exec step --steps 3
pixi run python -m examples.tutorial.a_flow_fundamentals.05_pipeline_ergonomics --mode functional --exec step --steps 3
pixi run python -m examples.tutorial.a_flow_fundamentals.05_pipeline_ergonomics --mode explicit --exec mp --duration 2

What To Observe

• IR summary line is stable across modes (nodes=3, edges=2).
• Stepper modes print deterministic sink progression (2, 4, 6).
• MP run confirms same contract in runtime backend.

Failure Drill

• Comment out default pipeline reset in functional mode and run multiple times.
• Observe potential hidden coupling from ambient global pipeline state.

Exercise

• Required task: select one preferred authoring mode and justify it for team-scale code review.
• Stretch task: produce a short anti-pattern list from this file for onboarding docs.

Evaluation Rubric

• Pass criteria: learner can switch modes without changing contract-level behavior.
• Common failure signature: learner assumes functional style is always safer/faster.

Follow-up

• Next lecture group: L07-L11 (Debug and Reliability)
• Related tutorials: c_debug_and_replay/01_debug_stepper.py, c_debug_and_replay/06_trace_contract_basics.py