Translate content to Spanish. Move from JSON to YAML

.gitignore

@@ -18,7 +18,8 @@ site/data/snippets.json
 site/index.html
 
 # Generated locale directories (built by html-generators/ for non-English locales)
-site/pt-BR/
+site/[a-z][a-z]/
+site/[a-z][a-z]-[A-Z][A-Z]/
 
 # Platform-specific CDS/AOT intermediate files (generated by build-cds.sh)
 html-generators/generate.aot

CONTRIBUTING.md

@@ -0,0 +1,56 @@
+# Contributing
+
+Contributions are welcome! Content is managed as YAML files — never edit generated HTML.
+
+## Adding a new pattern
+
+1. Fork the repo
+2. Create a new YAML file in the appropriate `content/<category>/` folder (e.g. `content/language/my-feature.yaml`)
+3. Copy [`content/template.json`](content/template.json) as a starting point for all required fields (see the [snippet schema](.github/copilot-instructions.md) for details)
+4. Update the `prev`/`next` fields in adjacent pattern files to maintain navigation
+5. Run `jbang html-generators/generate.java` to verify your changes build correctly
+6. Open a pull request
+
+Please ensure JDK version labels only reference the version where a feature became **final** (non-preview).
+
+## Translating the site
+
+The site supports multiple languages. See [`specs/i18n/i18n-spec.md`](specs/i18n/i18n-spec.md) for the full specification.
+
+### Adding a new locale
+
+1. Add the locale to `html-generators/locales.properties` (e.g. `ja=日本語`)
+2. Create `translations/strings/<locale>.yaml` with all UI strings translated (copy `translations/strings/en.yaml` as a starting point)
+3. Create content translation files under `translations/content/<locale>/<category>/<slug>.yaml`
+4. Run `jbang html-generators/generate.java` and verify the build succeeds
+5. Open a pull request
+
+### Translating content files
+
+Translation files contain **only** translatable fields — the generator merges them onto the English base at build time. This prevents translated files from diverging structurally from the English source of truth.
+
+A translation file should contain exactly these fields:
+
+```yaml
+title: "Inferencia de tipos con var"
+oldApproach: "Tipos explícitos"
+modernApproach: "Palabra clave var"
+summary: "Usa var para inferencia de tipos..."
+explanation: "Desde Java 10, el compilador infiere..."
+whyModernWins:
+  - icon: "⚡"
+    title: "Menos código repetitivo"
+    desc: "No es necesario repetir tipos genéricos..."
+  - icon: "👁"
+    title: "Mejor legibilidad"
+    desc: "..."
+  - icon: "🔒"
+    title: "Igualmente seguro"
+    desc: "..."
+support:
+  description: "Ampliamente disponible desde JDK 10 (marzo 2018)"
+```
+
+Do **not** include `id`, `slug`, `category`, `difficulty`, `jdkVersion`, `oldCode`, `modernCode`, `prev`, `next`, `related`, or `docs` — these are always taken from the English source.
+
+**Important:** If your text contains colons (`:`), ensure the value is properly quoted in YAML to avoid parse errors. Always validate with `jbang html-generators/generate.java` before submitting.

README.md

@@ -74,16 +74,7 @@ For development on the generator itself, you can use JBang or Python — see [ht
 
 ## Contributing
 
-Contributions are welcome! Content is managed as JSON files — never edit generated HTML.
-
-1. Fork the repo
-2. Create a new JSON file in the appropriate `content/<category>/` folder (e.g. `content/language/my-feature.json`)
-3. Copy [`content/template.json`](content/template.json) to the new file as a starting point for all required fields (see the [snippet JSON schema](.github/copilot-instructions.md) for details)
-4. Update the `prev`/`next` fields in adjacent pattern JSON files to maintain navigation
-5. Run `jbang html-generators/generate.java` to verify your changes build correctly
-6. Open a pull request
-
-Please ensure JDK version labels only reference the version where a feature became **final** (non-preview).
+Contributions are welcome! See [CONTRIBUTING.md](CONTRIBUTING.md) for details on adding patterns and translating the site.
 
 ## Tech stack
 

content/collections/collectors-teeing.yaml

@@ -0,0 +1,51 @@
+---
+id: 26
+slug: "collectors-teeing"
+title: "Collectors.teeing()"
+category: "collections"
+difficulty: "intermediate"
+jdkVersion: "12"
+oldLabel: "Java 8"
+modernLabel: "Java 12+"
+oldApproach: "Two Passes"
+modernApproach: "teeing()"
+oldCode: |
+  long count = items.stream().count();
+  double sum = items.stream()
+      .mapToDouble(Item::price)
+      .sum();
+  var result = new Stats(count, sum);
+modernCode: |
+  var result = items.stream().collect(
+      Collectors.teeing(
+          Collectors.counting(),
+          Collectors.summingDouble(Item::price),
+          Stats::new
+      )
+  );
+summary: "Compute two aggregations in a single stream pass."
+explanation: "Collectors.teeing() sends each element to two downstream collectors\
+  \ and merges the results. This avoids streaming the data twice or using a mutable\
+  \ accumulator."
+whyModernWins:
+- icon: "⚡"
+  title: "Single pass"
+  desc: "Process the stream once instead of twice."
+- icon: "🧩"
+  title: "Composable"
+  desc: "Combine any two collectors with a merger function."
+- icon: "🔒"
+  title: "Immutable result"
+  desc: "Merge into a record or value object directly."
+support:
+  state: "available"
+  description: "Widely available since JDK 12 (March 2019)"
+prev: "collections/sequenced-collections"
+next: "collections/stream-toarray-typed"
+related:
+- "collections/copying-collections-immutably"
+- "collections/unmodifiable-collectors"
+- "collections/stream-toarray-typed"
+docs:
+- title: "Collectors.teeing()"
+  href: "https://docs.oracle.com/en/java/javase/25/docs/api/java.base/java/util/stream/Collectors.html#teeing(java.util.stream.Collector,java.util.stream.Collector,java.util.function.BiFunction)"

content/collections/copying-collections-immutably.yaml

@@ -0,0 +1,45 @@
+---
+id: 22
+slug: "copying-collections-immutably"
+title: "Copying collections immutably"
+category: "collections"
+difficulty: "beginner"
+jdkVersion: "10"
+oldLabel: "Java 8"
+modernLabel: "Java 10+"
+oldApproach: "Manual Copy + Wrap"
+modernApproach: "List.copyOf()"
+oldCode: |-
+  List<String> copy =
+      Collections.unmodifiableList(
+          new ArrayList<>(original)
+      );
+modernCode: |-
+  List<String> copy =
+      List.copyOf(original);
+summary: "Create an immutable copy of any collection in one call."
+explanation: "List.copyOf(), Set.copyOf(), and Map.copyOf() create immutable snapshots\
+  \ of existing collections. If the source is already an immutable collection, no\
+  \ copy is made."
+whyModernWins:
+- icon: "⚡"
+  title: "Smart copy"
+  desc: "Skips the copy if the source is already immutable."
+- icon: "📏"
+  title: "One call"
+  desc: "No manual ArrayList construction + wrapping."
+- icon: "🛡️"
+  title: "Defensive copy"
+  desc: "Changes to the original don't affect the copy."
+support:
+  state: "available"
+  description: "Widely available since JDK 10 (March 2018)"
+prev: "collections/immutable-set-creation"
+next: "collections/map-entry-factory"
+related:
+- "collections/immutable-set-creation"
+- "collections/map-entry-factory"
+- "collections/immutable-list-creation"
+docs:
+- title: "List.copyOf()"
+  href: "https://docs.oracle.com/en/java/javase/25/docs/api/java.base/java/util/List.html#copyOf(java.util.Collection)"

content/collections/immutable-list-creation.yaml

@@ -0,0 +1,49 @@
+---
+id: 19
+slug: "immutable-list-creation"
+title: "Immutable list creation"
+category: "collections"
+difficulty: "beginner"
+jdkVersion: "9"
+oldLabel: "Java 8"
+modernLabel: "Java 9+"
+oldApproach: "Verbose Wrapping"
+modernApproach: "List.of()"
+oldCode: |-
+  List<String> list =
+      Collections.unmodifiableList(
+          new ArrayList<>(
+              Arrays.asList("a", "b", "c")
+          )
+      );
+modernCode: |-
+  List<String> list =
+      List.of("a", "b", "c");
+summary: "Create immutable lists in one clean expression."
+explanation: "List.of() creates a truly immutable list — no wrapping, no defensive\
+  \ copy. It's null-hostile (rejects null elements) and structurally immutable. The\
+  \ old way required three nested calls."
+whyModernWins:
+- icon: "📏"
+  title: "One call"
+  desc: "Replace three nested calls with a single factory method."
+- icon: "🔒"
+  title: "Truly immutable"
+  desc: "Not just a wrapper — the list itself is immutable."
+- icon: "🛡️"
+  title: "Null-safe"
+  desc: "Rejects null elements at creation time, failing fast."
+support:
+  state: "available"
+  description: "Widely available since JDK 9 (Sept 2017)"
+prev: "language/exhaustive-switch"
+next: "collections/immutable-map-creation"
+related:
+- "collections/immutable-map-creation"
+- "collections/immutable-set-creation"
+- "collections/sequenced-collections"
+docs:
+- title: "List.of()"
+  href: "https://docs.oracle.com/en/java/javase/25/docs/api/java.base/java/util/List.html#of()"
+- title: "Collections Factory Methods (JEP 269)"
+  href: "https://openjdk.org/jeps/269"