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Add demo script for printSalesForecasts (Split Loop with Lambda)

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Demo on the messier sibling of the exercise method: three unwanted
dependencies in one loop (Scorer incl. static field write, System.out,
clock — clock stripped in 2-min prep). Same six mechanics with SVGs in
the storyboard style, ends green via overload + pure-lambda approval
test. Pointer added to the learning hour's demo section.
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2026-09-28 07:42:33 +00:00
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commit 558ad54516
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ideas/split-loop-with-lambda/storyboard/svg/d4-extract.svg
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<text x="24" y="34" font-size="20" font-weight="bold" fill="#0f172a">Step 4 — extract the loop; the lambda becomes a parameter</text>
<text x="24" y="56" font-size="13" fill="#475569">collectSalesScores is static and scorer-free. The printing loop stays behind — one split at a time.</text>
<!-- left: composed method -->
<rect x="50" y="74" width="300" height="356" rx="10" fill="#f8fafc" stroke="#64748b" stroke-width="1.5"/>
<text x="66" y="96" font-size="14" font-weight="bold" fill="#0f172a">printSalesForecasts()</text>
<!-- lambda -->
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<text x="78" y="126" font-size="12" font-weight="bold" fill="#9333ea">λ nameToSalesScore</text>
<text x="78" y="146" font-size="10" font-family="Menlo, Consolas, monospace" fill="#dc2626">static write + updateSelection +</text>
<text x="78" y="162" font-size="10" font-family="Menlo, Consolas, monospace" fill="#dc2626">getSalesForecast()</text>
<!-- call site -->
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<text x="78" y="208" font-size="11" font-family="Menlo, Consolas, monospace" fill="#0f172a">var scores =</text>
<text x="78" y="226" font-size="11" font-family="Menlo, Consolas, monospace" fill="#0f172a">collectSalesScores(names, <tspan fill="#9333ea" font-weight="bold">λ</tspan>)</text>
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<text x="78" y="276" font-size="11" font-family="Menlo, Consolas, monospace" font-weight="bold" fill="#d97706">for (entry : scores)</text>
<text x="78" y="296" font-size="11" font-family="Menlo, Consolas, monospace" font-weight="bold" fill="#d97706">System.out.println(...)</text>
<text x="78" y="316" font-size="10" fill="#d97706">IO stays — next time</text>
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<text x="396" y="188" font-size="10" font-weight="bold" fill="#9333ea" text-anchor="middle" transform="rotate(-48 396 188)">λ becomes a parameter</text>
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<text x="456" y="96" font-size="13" font-weight="bold" fill="#0f172a">collectSalesScores</text>
<text x="456" y="112" font-size="11" fill="#475569">static — no fields, all inputs are parameters</text>
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<text x="585" y="142" font-size="11" font-weight="bold" fill="#9333ea" text-anchor="middle">λ Function&lt;String, Integer&gt; nameToSalesScore</text>
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<text x="470" y="190" font-size="11" font-family="Menlo, Consolas, monospace" fill="#1e1b4b">for (String name : names)</text>
<text x="470" y="214" font-size="11" font-family="Menlo, Consolas, monospace" fill="#1e1b4b">scores.put(name,</text>
<text x="470" y="234" font-size="11" font-family="Menlo, Consolas, monospace" fill="#1e1b4b"> <tspan fill="#9333ea" font-weight="bold">λ</tspan>.apply(name))</text>
<text x="470" y="260" font-size="10" fill="#64748b">LinkedHashMap — keeps the order</text>
<text x="456" y="308" font-size="11" font-family="Menlo, Consolas, monospace" fill="#0f172a">return scores;</text>
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<text x="640" y="426" font-size="10" fill="#7f1d1d" text-anchor="middle">out of reach from in here</text>
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<text x="650" y="376" font-size="10" font-weight="bold" fill="#dc2626">✗ cannot reach in</text>
<!-- System.out note -->
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<text x="64" y="378" font-size="10" font-weight="bold" fill="#d97706">…but System.out is still on this side</text>
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