PART I
Warm-up
Reconnect with a useful idea before starting organize related declarations with domain. 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
Read a pricing domain as a responsibility group
A domain groups related declarations in the shown language design. For an experienced Willow learner, use it to make responsibility boundaries readable, while avoiding assumptions about instance creation, automatic public exposure or how an external caller qualifies a name. Exact module/export behavior still needs its documented contract.
The worked group Pricing contains total(price,fee), whose local body adds the two integer inputs. Sample map: Pricing owns the declaration; total owns parameters price/fee; return owns the arithmetic result. For a hypothetical call supplying 100 and 15, the helper predicts 115 cents. The map explains containment without asserting that a Pricing object was constructed.
Do not treat a domain declaration as an Application constructor or an automatic permission grant. It groups the declarations shown. This lesson does not supply an external qualification or export syntax, so write the caller contract in ordinary words rather than inventing Pricing::total.
Worked reasoning and supplied artifact
domain Pricing {
fnc total(price: i32, fee: i32) -> i32 {
return price + fee;
}
}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.
Walk through the example, one line at a time
domain Pricing {Group related declarations under this named boundary. Read the nested declarations as the contents of that group.
fnc total(price: i32, fee: i32) -> i32 {Read the function name, its parameter names/types and the result type after ->. This is the contract the body must satisfy.
return price + fee;Evaluate the following expression using the current values, then send its result to the caller. Explain the value; do not confuse it with printed output.
}Close the nested block or value begun earlier. Match it to its opening boundary to keep the structure readable.
}Close the nested block or value begun earlier. Match it to its opening boundary to keep the structure readable.
Try the guided change
Draw the declaration-containment map and separate it from the paper argument/return trace.
- 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: Shared pricing rules. Build a small, understandable change around organize related declarations with domain.
Group a stock-adjustment helper under an Inventory domain and map its parameters and result. State how an external caller would need a documented public entry contract.
What to produce
A domain/helper draft, ownership tree and explicit external-call question.
- 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.
Need a hint?
The worked group Pricing contains total(price,fee), whose local body adds the two integer inputs. Sample map: Pricing owns the declaration; total owns parameters price/fee; return owns the arithmetic result. For a hypothetical call supplying 100 and 15, the helper predicts 115 cents. The map explains containment without asserting that a Pricing object was constructed.
Do not treat a domain declaration as an Application constructor or an automatic permission grant. It groups the declarations shown. This lesson does not supply an external qualification or export syntax, so write the caller contract in ordinary words rather than inventing Pricing::total.
Original learning-path task and reference
Use your Willow knowledge to implement the .ws host integration, explaining which work remains native and which belongs in the script. In a museum exhibit console, demonstrate organize related declarations with domain. Read the source-grounded example and predict its observable behavior before making changes. Include .ws source and a host-resource contract; compare at least one normal case and one edge case.
fnc add(a: i32, b: i32) -> i32 {
return a + b;
}
fnc main() -> i32 {
return add(2, 3);
}Where the original task needs a host API that is not supplied here, write the contract and predictions. Do not invent a runtime result.
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.
- Read a pricing domain as a responsibility group
- Draw the declaration-containment map and separate it from the paper argument/return trace.
- Separate source-backed behavior, host requirements and untested predictions.
One small recap task
Draw the declaration-containment map and separate it from the paper argument/return trace.
This marks your personal practice record only. It is not a certification or an official workspace assessment.