Read a structured query — Discover and trace

PART I

Warm-up

Reconnect with a useful idea before starting read a structured query. 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

Replace a native scan with a query contract

For a W developer moving into proposed WS, translate the intended data operation rather than native storage mechanics. The query DSL, object literals and bound-expression forms are proposed extensions. Collections and field names are explicit exercise-host inputs; importing a service neither supplies those resources nor grants access.

Supplied bridge fixture: A W-side exercise loops over three in-memory items: fern stock7,oak stock12,pine stock1. The WS design uses the shown stock<10 query.

A native loop’s concrete memory access is replaced by a host collection contract. On supplied rows, fern and pine pass; ascending stock gives pine1,fern7. This equivalence is a paper model of requested data, not evidence that the proposed WDB DSL executes or exposes native storage.

Record the request, intermediate decisions and final artifact separately. These are paper derivations and platform-contract exercises; .ws and its native services are not implemented or executed by this school. Shared fnc/domain/import vocabulary does not certify parser support for proposed extensions or prove runtime security enforcement.

Worked reasoning and supplied artifact

// PAPER FIXTURE — Replace a native scan with a query contract
// Manual worked artifact; comments below are not executable source.
// INPUT / CONTRACT: Supplied bridge fixture: A W-side exercise loops over three in-memory items: fern
// stock7,oak stock12,pine stock1. The WS design uses the shown stock<10 query.
// DERIVATION / EXPECTED ARTIFACT: A native loop’s concrete memory access is replaced by a host collection
// contract. On supplied rows, fern and pine pass; ascending stock gives pine1,fern7. This equivalence is a
// paper model of requested data, not evidence that the proposed WDB DSL executes or exposes native storage.

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

Guided exercise: reproduce this exact fixture, annotate each native-versus-script responsibility, then explain why the rejected answer “fern7 then oak12” fails.

• 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: Inventory review workspace. Build a small, understandable change around read a structured query.

Use ash11,birch4,cedar0. Produce source rows, predicate outcomes, ordered projected result and required host inputs. Supply different fixture identities/values from the worked case, a complete predicted result or allow/deny artifact, a stepwise trace, one contrasting failure and the required host contract.

What to produce

Use ash11,birch4,cedar0. Produce source rows, predicate outcomes, ordered projected result and required host inputs. Preserve source/implementation status and separate manual predictions from future toolchain evidence.

• 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.

• Replace a native scan with a query contract
• A W-side exercise loops over three in-memory items: fern stock7,oak stock12,pine stock1. The WS design uses the shown stock<10 query.
• Separate source-backed behavior, host requirements and untested predictions.

One small recap task

Change one field,resource scope,lifetime or input value in the bridge fixture. State the new intermediate decisions and final result without assuming a running WS host.

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