PART I
Warm-up
Reconnect with a useful idea before starting reading a function from left to right. 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
Review a helper without its author beside you
A reviewable helper explains its role through a clear signature and a small body, while its evidence card makes assumptions visible. Another learner should be able to reconstruct the result without guessing what the inputs mean or whether the code ran.
For remaining(24,9), a review card says capacity = 24 slots, occupied = 9 slots, expression = 24 - 9, expected = 15 slots, validity assumption = 0 ≤ occupied ≤ capacity. A second case remaining(24,24) checks the full boundary and predicts zero. Neither card is a runtime measurement.
A long comment repeating every token does not replace meaningful assumptions. Explain the unit, the valid range and the boundary case instead. If input validation is absent, say so; do not claim that a typed signature guarantees a business rule.
Worked reasoning and supplied artifact
fnc remaining(capacity: i32, occupied: i32) -> i32 {
return capacity - occupied;
}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 remaining(capacity: i32, occupied: i32) -> i32 {Read the function name, its parameter names/types and the result type after ->. This is the contract the body must satisfy.
return capacity - occupied;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 the two worked cards, then underline the assumption the body itself does not enforce.
- 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 reading a function from left to right.
Review a helper for remaining checkpoints from total and completed. Supply normal, complete and over-complete cases. State which expected values are arithmetic and which require a policy decision.
What to produce
A signature/body review and three labelled cases, including an explicit unresolved over-complete policy.
- 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 remaining(24,9), a review card says capacity = 24 slots, occupied = 9 slots, expression = 24 - 9, expected = 15 slots, validity assumption = 0 ≤ occupied ≤ capacity. A second case remaining(24,24) checks the full boundary and predicts zero. Neither card is a runtime measurement.
A long comment repeating every token does not replace meaningful assumptions. Explain the unit, the valid range and the boundary case instead. If input validation is absent, say so; do not claim that a typed signature guarantees a business rule.
Original learning-path task and reference
In a museum exhibit console, demonstrate reading a function from left to right. 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.
- Review a helper without its author beside you
- A reviewable helper explains its role through a clear signature and a small body, while its evidence card makes assumptions visible. Another learner should be able to reconstruct the result without guessing what the inputs mean or whether the code ran.
- Separate source-backed behavior, host requirements and untested predictions.
One small recap task
Write one review comment that adds information beyond repeating the source line.
This marks your personal practice record only. It is not a certification or an official workspace assessment.