PART II
Instruction & guided example
Trace a reusable price adjustment
The shared fnc/parameter/return grammar can make a Willow learner feel immediately at home, but familiar arithmetic does not establish that a proposed .ws program has a runtime. Treat each helper as a typed input/result contract and keep the caller’s units and role assumptions explicit. This bridge separates portable reasoning from unverified execution.
A shared pricing helper returns price + fee. For price 180 cents and fee 25 cents, the worked call binds price=180 and fee=25, evaluates 205 and returns that integer to the caller. Sample trace artifact: caller request → two parameter bindings → 180+25 → returned 205 cents. This source-level reasoning carries across the language paths, while the execution claim does not.
A matching function keyword does not mean the experimental .w compiler accepts this .ws file or provides its host. Likewise, return is not a console output operation. State the hypothetical caller observation separately from the arithmetic.
Worked reasoning and supplied artifact
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
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.
Try the guided change
Rebuild the call/return trace for price 180 and fee 25, then mark the point where the caller receives 205.
- 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 functions as reusable contracts.
Write a typed total helper for a 240-cent item plus a 35-cent service fee. Include a zero-fee case and distinguish hand prediction from a future toolchain observation.
What to produce
A helper, cases (240,35)→275 and (240,0)→240, unit annotations and an explicit unexecuted label.
- 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?
A shared pricing helper returns price + fee. For price 180 cents and fee 25 cents, the worked call binds price=180 and fee=25, evaluates 205 and returns that integer to the caller. Sample trace artifact: caller request → two parameter bindings → 180+25 → returned 205 cents. This source-level reasoning carries across the language paths, while the execution claim does not.
A matching function keyword does not mean the experimental .w compiler accepts this .ws file or provides its host. Likewise, return is not a console output operation. State the hypothetical caller observation separately from the arithmetic.
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 community library utility, demonstrate functions as reusable contracts. 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.
- Trace a reusable price adjustment
- Rebuild the call/return trace for price 180 and fee 25, then mark the point where the caller receives 205.
- Separate source-backed behavior, host requirements and untested predictions.
One small recap task
Rebuild the call/return trace for price 180 and fee 25, then mark the point where the caller receives 205.
This marks your personal practice record only. It is not a certification or an official workspace assessment.