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
Map positional arguments to named roles
A parameter’s position determines which supplied argument it receives in these examples. Descriptive names make the role easier for a reader to track, but the caller still passes values in the declared order. A correct-looking pair of integers can be semantically reversed.
cost(quantity,unitPrice) receives 3 and 80 in cost(3,80), then returns 240 cents. remaining(total,used) receives 10 and 4, then returns 6. Multiplication happens to give the same numeric result if cost’s arguments are reversed, but that does not make the meanings interchangeable: 80 items at 3 cents is a different order.
Do not rely on commutative arithmetic to prove that an argument order is right. A future quantity limit or price validation would care about the roles. Record units alongside each argument even when an accidental swap produces the same product.
Worked reasoning and supplied artifact
fnc cost(quantity: i32, unitPrice: i32) -> i32 {
return quantity * unitPrice;
}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 cost(quantity: i32, unitPrice: 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;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
Annotate cost(3,80) with quantity = 3 items and unitPrice = 80 cents/item, then trace the product.
- 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.
Create a helper for total points from rounds and points per round. Document the call order and compare two calls with swapped arguments, describing their different meanings even if totals agree.
What to produce
A role-labelled signature and two same-total/different-meaning call descriptions.
- 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?
cost(quantity,unitPrice) receives 3 and 80 in cost(3,80), then returns 240 cents. remaining(total,used) receives 10 and 4, then returns 6. Multiplication happens to give the same numeric result if cost’s arguments are reversed, but that does not make the meanings interchangeable: 80 items at 3 cents is a different order.
Do not rely on commutative arithmetic to prove that an argument order is right. A future quantity limit or price validation would care about the roles. Record units alongside each argument even when an accidental swap produces the same product.
Original learning-path task and reference
In a rhythm-game audio editor, demonstrate names, parameters, and return types. 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.
- Map positional arguments to named roles
- A parameter’s position determines which supplied argument it receives in these examples. Descriptive names make the role easier for a reader to track, but the caller still passes values in the declared order. A correct-looking pair of integers can be semantically reversed.
- Separate source-backed behavior, host requirements and untested predictions.
One small recap task
Label the units in cost(4,125) without calculating the result.
This marks your personal practice record only. It is not a certification or an official workspace assessment.