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 minimal bounded preview cache

Bound storage before admitting new work. A temporary-storage design needs an owner, placement, quota, lifetime and pressure response. WTMP is a proposed ecosystem; a configuration policy is not proof of implemented allocation or cleanup. Keep units consistent and distinguish reserved capacity, used capacity and a new operation’s estimated peak.

A preview cache stores at most four 5 MB previews. Each preview belongs to a draft revision. The first slice needs one 5 MB preview for revision 1; no sharing or disk persistence is required.

Write current use plus required peak before admitting the operation. Identify which existing data is active, replaceable or durable. A mathematical fit does not prove a host allocation will succeed, so the contract must still describe failure without claiming a completed artifact. Worked case: Specify owner, revision key, 20 MB maximum and a documented admission-failure response. After the first preview confirms, predicted use is 5 MB. The slice does not need a database or an invented eviction callback.

Compare the tempting alternative: Calling the cache temporary without a limit leaves growth undefined; adding unrelated persistence requirements obscures the smallest useful contract.

Worked reasoning and supplied artifact

// Paper trace / supplied exercise-host contract; no execution claimed.
// A preview cache stores at most four 5 MB previews. Each preview belongs to a draft revision. The first slice needs one 5 MB preview for revision 1; no sharing or disk persistence is required.
// Specify owner, revision key, 20 MB maximum and a documented admission-failure response. After the first preview confirms, predicted use is 5 MB. The slice does not need a database or an invented eviction callback.

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 the one-preview contract and trace additions of previews two through five without assuming automatic eviction.

What to produce

A four-slot capacity ledger and a fifth-preview pressure decision.

• 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 minimal bounded preview cache
• Write the one-preview contract and trace additions of previews two through five without assuming automatic eviction.
• Separate source-backed behavior, host requirements and untested predictions.

One small recap task

State the response when the fifth preview is requested.

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