Specify bounded storage, cleanup, and shared-service boundaries — Connect the previous skills

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

Connect sharing with expiry and active leases

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.

Shared S83 expires for new leases at 18:00. Owner A holds a lease until 18:02; owner B holds one until 18:05. A releases at 18:01. No new lease is allowed after 18:00.

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: At 18:01 logical expiry still blocks new users, A’s reference ends, and B remains protected until 18:05. Cleanup eligibility must consider B’s valid lease even though the resource is expired for new access.

Compare the tempting alternative: Using either “expired” or “A released” as a global deletion trigger overlooks the still-owned B lease.

Worked reasoning and supplied artifact

// Paper trace / supplied exercise-host contract; no execution claimed.
// Shared S83 expires for new leases at 18:00. Owner A holds a lease until 18:02; owner B holds one until 18:05. A releases at 18:01. No new lease is allowed after 18:00.
// At 18:01 logical expiry still blocks new users, A’s reference ends, and B remains protected until 18:05. Cleanup eligibility must consider B’s valid lease even though the resource is expired for new access.

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.

Draw per-owner and shared-object state at 17:59, 18:00, 18:01 and 18:05.

What to produce

A four-time, two-owner lifetime table.

• 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.

• Connect sharing with expiry and active leases
• Draw per-owner and shared-object state at 17:59, 18:00, 18:01 and 18:05.
• Separate source-backed behavior, host requirements and untested predictions.

One small recap task

State when new leases stop and when the last existing lease ends.

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