Specify bounded storage, cleanup, and shared-service boundaries — Review and demonstrate

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

Review shared-service fairness under pressure

Shared resources require scoped owners and permissions. A shared temporary service serves several consumers with separate identities, quotas and lifetimes. Sharing a storage backend does not merge resource authority. A host contract must validate handles, prevent cross-owner effects and say how aggregate pressure interacts with per-owner promises.

A 120 MB service gives each team a guaranteed 30 MB active reservation. A uses 70 MB including 40 MB replaceable cache; B uses 30 MB active. B requests 20 MB new active work.

Draw owner→resource edges and trace one operation through identity, scope, quota and lifetime checks. Separate releasing one consumer’s reference from deleting an object still needed by others. Unknown sharing semantics must remain explicit requirements, not guessed reference-count or cancellation APIs. Worked case: Current total is 100 MB, and B’s request reaches 120 MB. If another request later needs space, policy may consider A’s replaceable 40 MB before threatening B’s active reservation. Fairness and eviction order need explicit guarantees beyond arithmetic fit.

Compare the tempting alternative: Deleting the smallest team’s active files because it is easiest violates the reservation promise even if total use drops below quota.

Worked reasoning and supplied artifact

// Paper trace / supplied exercise-host contract; no execution claimed.
// A 120 MB service gives each team a guaranteed 30 MB active reservation. A uses 70 MB including 40 MB replaceable cache; B uses 30 MB active. B requests 20 MB new active work.
// Current total is 100 MB, and B’s request reaches 120 MB. If another request later needs space, policy may consider A’s replaceable 40 MB before threatening B’s active reservation. Fairness and eviction order need explicit guarantees beyond arithmetic fit.

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.

Write fit and fairness decisions separately, then add A requesting another 10 MB after B’s admission.

What to produce

A capacity ledger and a reservation-preserving pressure policy.

• 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.

• Review shared-service fairness under pressure
• Write fit and fairness decisions separately, then add A requesting another 10 MB after B’s admission.
• Separate source-backed behavior, host requirements and untested predictions.

One small recap task

Name one guarantee a pressure policy must preserve.

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