Specify bounded storage, cleanup, and shared-service boundaries — Build the smallest useful slice

PART I

Warm-up

Reconnect with a useful idea before starting specify bounded storage, cleanup, and shared-service boundaries. In one or two sentences, describe the input, output or host boundary from the previous exercise that this lesson builds on. If you are arriving directly, skim the worked example first; there is no locked prerequisite.

A rough note is enough. You can revise it after the example.

PART II

Instruction & guided example

Build a normal release contract

Cleanup must preserve known work under interruption. Temporary data can still be actively owned or important for recovery. Define what becomes replaceable, who authorizes cleanup and what evidence confirms release. Automatic cleanup and crash recovery are policy goals, not guarantees that deletion cannot fail or that bytes are physically erased.

A generated thumbnail T71 is owned by preview P71 and can be recreated from authorized source. When P71 closes normally, T71 should be released. Source records must remain unchanged.

Trace cleanup before initiation, after partial progress and after confirmation. Preserve identity so a retry can recognize already-released resources. Treat crash recovery as reconciliation of an inventory, not permission to delete every unfamiliar file or overwrite newer work. Worked case: The release contract names T71 specifically, verifies P71 ownership and requests cleanup of the thumbnail only. The durable source is not part of the temporary resource set. A confirmed release ends T71 ownership.

Compare the tempting alternative: Deleting the whole containing directory because it includes the thumbnail risks unrelated active or durable data.

Worked reasoning and supplied artifact

// Paper trace / supplied exercise-host contract; no execution claimed.
// A generated thumbnail T71 is owned by preview P71 and can be recreated from authorized source. When P71 closes normally, T71 should be released. Source records must remain unchanged.
// The release contract names T71 specifically, verifies P71 ownership and requests cleanup of the thumbnail only. The durable source is not part of the temporary resource set. A confirmed release ends T71 ownership.

Illustrative example from the proposed WillowScript design. The language and WUIX/WMATH/WDB/WAUDIO/WTMP services are not implemented in the supplied source. This site has no interpreter, VM or native host and does not execute or certify the snippet.

Try the guided change

Reconstruct the supplied worked case first: list its inputs, intermediate decisions and final artifact. Compare each row with the explanation and identify exactly where the rejected alternative fails. Then use the changed inputs in Part IV for independent work.

• Write the supplied inputs and initial state before following the example.
• Reconstruct each intermediate calculation or host decision, then compare with the worked artifact.
• Explain why the contrasting alternative fails before attempting the changed inputs in Part IV.

PART III

Take a breather

Step back after the guided example. Look away from the screen, stretch, or reread your prediction. This is an optional learning pause, not a timer or an assessment gate.

When you return, try to name the lesson’s key idea without copying its wording. If that feels difficult, return to Part II and trace one line rather than restarting the entire lesson.

PART IV

Independent practice

Project context: Temporary asset workflow. Build a small, understandable change around specify bounded storage, cleanup, and shared-service boundaries.

Specify the release scope and trace confirmed release, wrong-owner request and unavailable cleanup service.

What to produce

A named-resource cleanup contract and three outcome rows.

• State the intended behavior in a sentence before editing.
• Use only source-backed syntax and the host services whose contract you have been given.
• Record a normal case and a boundary or unavailable-resource case.
• Label hand predictions separately from anything actually measured in a supplied toolchain.

Syntax colors are a reading aid, not a compiler. The line you are editing stays uncolored until you move to a different line; capitalization is never changed. Drafts stay on this browser and code is not executed.

import wdb;
domain Inventory {
    const lowStock = wdb.query({
        from: products,
        select: [id, name, stock],
        where: [[ stock < 10 ]],
        order: { by: stock, direction: ascending }
    });
}

PART V

Self-check

Use this check to notice what to revisit. It does not award a private course grade, block another page or claim to verify compiled code. Every answer has a learning explanation.

You may keep exploring even if you are unsure. Use the hint, compare the trace, and revise your explanation.

PART VI

Recap & small task

Bring the idea back to the mod feature you are building. A useful recap connects the mechanism to a decision you can make in your own code.

• Build a normal release contract
• Specify the release scope and trace confirmed release, wrong-owner request and unavailable cleanup service.
• Separate source-backed behavior, host requirements and untested predictions.

One small recap task

Write the durable-data invariant preserved by cleanup.

This marks your personal practice record only. It is not a certification or an official workspace assessment.