PART I
Warm-up
Reconnect with a useful idea before starting names, parameters, and return types. 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
Audit the entire caller-to-return contract
Review a complete helper by checking four links: the caller’s argument roles, the parameter declarations, the expression’s meaning, and the returned value’s unit. A defect in any link can produce a misleading result even when other links look correct.
For total(2,125,30), quantity = 2 items, unitPrice = 125 cents/item, fee = 30 cents. Multiplication gives 250 cents, addition gives 280 cents, and main returns 280 under the hypothetical host contract. A zero-fee case checks the subtotal route; a zero-quantity case exposes the fee policy.
The source does not implement payment, stock updates or receipt display. Keep the review focused on the calculation and clearly list those future host responsibilities. Do not turn an arithmetic demonstration into a claim that an order was placed.
Worked reasoning and supplied artifact
fnc total(quantity: i32, unitPrice: i32, fee: i32) -> i32 {
return quantity * unitPrice + fee;
}
fnc main() -> i32 {
return total(2, 125, 30);
}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
fnc total(quantity: i32, unitPrice: 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 quantity * unitPrice + 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.
fnc main() -> i32 {Read the function name, its parameter names/types and the result type after ->. This is the contract the body must satisfy.
return total(2, 125, 30);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.
Try the guided change
Write a four-link contract audit for the worked call and add its zero-fee prediction of 250.
- 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: Snack-shop calculator. Build a small, understandable change around names, parameters, and return types.
Review a 3-ticket purchase at 140 cents with a 25-cent fee. Provide normal, zero-fee and zero-quantity cards; distinguish arithmetic outputs from empty-order policy and host-side payment behavior.
What to produce
The source draft, predictions 445/420/25, argument units, valid-input assumptions and host limitations.
- 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?
For total(2,125,30), quantity = 2 items, unitPrice = 125 cents/item, fee = 30 cents. Multiplication gives 250 cents, addition gives 280 cents, and main returns 280 under the hypothetical host contract. A zero-fee case checks the subtotal route; a zero-quantity case exposes the fee policy.
The source does not implement payment, stock updates or receipt display. Keep the review focused on the calculation and clearly list those future host responsibilities. Do not turn an arithmetic demonstration into a claim that an order was placed.
Original learning-path task and reference
In a small-shop operations tool, demonstrate names, parameters, and return types. Submit source, acceptance cases, and an explanation proving the section objective. 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.
- Audit the entire caller-to-return contract
- Review a complete helper by checking four links: the caller’s argument roles, the parameter declarations, the expression’s meaning, and the returned value’s unit. A defect in any link can produce a misleading result even when other links look correct.
- Separate source-backed behavior, host requirements and untested predictions.
One small recap task
Identify one missing host responsibility before this calculator could place an order.
This marks your personal practice record only. It is not a certification or an official workspace assessment.