Arrange a column and spacing — Flash-check repair

PART I

Warm-up

Reconnect with a useful idea before starting arrange a column and spacing. 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

Repair duplicated outer spacing

Column layout combines ordered children with padding, gaps and available space. The source shows padding [24,32] and gap16 but does not settle every measurement convention. Each exercise supplies its own explicit geometry contract; do not generalize that contract into a universal WUIX guarantee.

A design needs12 units above and below its content. The column already applies vertical padding12. A draft also adds spacer children of height12 at both ends. Gap is zero.

Worked reasoning: With one height20 child, padding alone gives44. Adding the two spacers gives68, doubling the intended outer spacing. Remove the spacers or explicitly change the padding policy, rather than adjusting unrelated text height.

Failed alternative: Reducing the text from20 to negative4 to recover total height corrupts content geometry while hiding the duplicated spacing.

Worked reasoning and supplied artifact

Correct: padding12 + child20 + padding12 =44
Broken: padding12 + spacer12 + child20 + spacer12 + padding12 =68
Repair: remove both outer spacer children; preserve child20

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: Operations dashboard. Build a small, understandable change around arrange a column and spacing.

Audit a column with padding10 plus outer spacers8 around a height30 child. Compute excess height and provide a single-source outer-spacing repair.

What to produce

A segment ledger before and after repair, with content height unchanged.

• 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 wuix.widget.button;
import wuix.layout;
domain Login {
    const screen = {
        layout: { type: "column", padding: [24, 32], gap: 16 },
        components: [{ type: "text", value: "Welcome back" }]
    };
    fnc show() -> void {
        wuix.mount("main", screen);
    }
}

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.

• Repair duplicated outer spacing
• Audit a column with padding10 plus outer spacers8 around a height30 child. Compute excess height and provide a single-source outer-spacing repair.
• Separate source-backed behavior, host requirements and untested predictions.

One small recap task

Assign each spacing requirement to exactly one layout mechanism.

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