improve readability

Author: wesleyegberto

java-10/README.md

@@ -22,8 +22,6 @@ java -cp bin <ClassName>
 
 ## Features
 
-### Language
-
 * `var` keyword to declare variables
   * `var universeAnswer = 42`
 * Process API improvements

java-11/README.md

@@ -29,43 +29,44 @@ java -cp bin <ClassName>
 
 ## Features
 
-### Language
-
-* Removal of modules and deprecated API
-  * Removal of Java EE Modules
+* **Removal of Modules and Deprecated API**
+  * removal of Java EE Modules:
     * JAF
     * CORBA
     * JTA
     * JAXB
     * JAX-WS
     * Commons Annotation
   * JavaFX
-* Scripting
-* Shebang
+* **Scripting**
+* **Shebang**
   * `#!/opt/jdk-11/bin/java --source 11`
-* var in lambda expressions
-  * allowing to use annotation without specifying the type: `.filter((@Nonnull var item) -> isAllowed(item))`
-* API improvements
-  * String
-    * `lines()`: to streaming the lines from a string
-    * `strip()`, `stripLeading()` and `stripTrailing()`
-    * `repeat(int)`
-    * `isBlank()`
-  * Path
-    * `of(String, String...)` and `of(URI)`
-  * Files
-    * `readString(Path)`: read the entire content from a file as a String - `Files.readString(Path.of("message.txt"))`
-    * `writeString(Path, CharSequence, OpenOption...)` write a String to a file - `Files.writeString(Path.of("message.txt"), updatedMessage)`
-  * Null I/O
-    * `InputStream.nullInputStream()`: empty input stream
-    * `OutputStream.nullOutputStream()`: output stream that discards input bytes
-    * `Reader.nullReader()`: empty reader
-    * `Writer.nullWriter()`: writer that discards input content
-  * New better way to turn a collection into an array
-    * `String[] array = list.toArray(String[]::new)`
-  * `Optional::isEmpty`
-  * `Predicate::not`
-  * `Pattern::asMatchPredicate`
+* **`var` in Lambda Expressions**
+  * allowing to use annotation without specifying the type
+  * `.filter((@Nonnull var item) -> isAllowed(item))`
+
+### API
+
+* String
+  * `lines()`: to streaming the lines from a string
+  * `strip()`, `stripLeading()` and `stripTrailing()`
+  * `repeat(int)`
+  * `isBlank()`
+* Path
+  * `of(String, String...)` and `of(URI)`
+* Files
+  * `readString(Path)`: read the entire content from a file as a String - `Files.readString(Path.of("message.txt"))`
+  * `writeString(Path, CharSequence, OpenOption...)` write a String to a file - `Files.writeString(Path.of("message.txt"), updatedMessage)`
+* Null I/O
+  * `InputStream.nullInputStream()`: empty input stream
+  * `OutputStream.nullOutputStream()`: output stream that discards input bytes
+  * `Reader.nullReader()`: empty reader
+  * `Writer.nullWriter()`: writer that discards input content
+* New better way to turn a collection into an array
+  * `String[] array = list.toArray(String[]::new)`
+* `Optional::isEmpty`
+* `Predicate::not`
+* `Pattern::asMatchPredicate`
 
 ### JVM
 

java-12/README.md

@@ -16,17 +16,15 @@ To run each example use: `java --enable-preview --source 12 <FileName.java>`
 
 ## Features
 
-### Language
-
-* Switch expression
-* Collectors.teeing
+* Switch Expression (preview)
+* Compact Number Format
+* `Collectors.teeing`
 * More Versatile Error Recovery With CompletableFuture
   * `exceptionallyAsync(Function<Throwable, ? extends T> f)`
   * `exceptionallyAsync(Function<Throwable, ? extends T> f, Executor e)`
   * `exceptionallyCompose(Function<Throwable, ? extends CompletionStage<T>> f)`
   * `exceptionallyComposeAsync(Function<Throwable, ? extends CompletionStage<T>> f)`
   * `exceptionallyComposeAsync(Function<Throwable, ? extends CompletionStage<T>> f, Executor e)`
-* Compact Number Format
 
 ### JVM
 

java-13/README.md

@@ -12,19 +12,20 @@ To run each example use: `java --enable-preview --source 13 <FileName.java>`
 
 ## Features
 
-### Language
-
-* Switch expressions improvements
+* **Switch Expressions (second preview)**
   * Changed `break` from Java 12 to `yield`
-* Text blocks
+* **Text Blocks (preview)**
   * flag to compile: `-Xlint:text-blocks`
-* API improvements
-  * String methods:
-    * `stripIdent`: same operation done by the compiler to strip incidental identation from text block';
-    * `translateEscapes`: same operation done by the compiler to translate escapes in strings;
-    * `formatted`: shortcut to String.format '`"%s years old".formatted(42)`)
-  * NIO improvements
-* Socket and ServerSocket reimplementation (alignment to [Project Loom](https://openjdk.java.net/projects/loom/))
+* **Reimplement Legacy Socket API**
+  * `Socket` and `ServerSocket` reimplementation (alignment to [Project Loom](https://openjdk.java.net/projects/loom/))
+
+### API
+
+* String methods:
+  * `stripIdent`: same operation done by the compiler to strip incidental identation from text block';
+  * `translateEscapes`: same operation done by the compiler to translate escapes in strings;
+  * `formatted`: shortcut to String.format '`"%s years old".formatted(42)`)
+* NIO improvements
 
 ### JVM
 

java-14/README.md

@@ -23,15 +23,13 @@ To run each example use: `java --enable-preview --source 14 <FileName.java>`
 
 ## Features
 
-### Language
-
-* Switch expressions
+* **Switch Expressions**
   * Promotion to standard
-* Text blocks improvements (preview)
+* **Text Blocks (second preview)**
   * added new flags
-* Pattern matching for `instanceof`
+* **Pattern Matching for `instanceof` (preview)**
   * added as Preview
-* Records
+* **Records (preview)**
   * added as Preview
   * Notes:
     * Does not have a `extends` clause, only extends `java.lang.Record`;
@@ -40,7 +38,7 @@ To run each example use: `java --enable-preview --source 14 <FileName.java>`
     * Its components are final and cannot be updated via reflection (throw `IllegalAccessException`);
     * Cannot declare native methods;
     * Local records is always static (local class and enum as never static).
-* JFR Event Streaming
+* **JFR Event Streaming**
   * [Here](https://github.com/flight-recorder/health-report) is a great example of a tool built
 
 ### JVM

java-15/README.md

@@ -21,9 +21,7 @@ To run each example use: `java --enable-preview --source 15 <FileName.java>`
 
 ## Features
 
-### Language
-
-* Sealed types
+* **Sealed Types**
   * Restrict which types can extend/implement a type
   * Constraints:
     * The sealed class and its permitted subclasses must belong to the same module, and, if declared in an unnamed module, the same package.
@@ -32,9 +30,9 @@ To run each example use: `java --enable-preview --source 15 <FileName.java>`
       * `final`
       * `sealed`
       * `non-sealed` (back to a normal class open to extensibility)
-* Pattern matching for `instanceof` (second preview - no changes)
-* Text blocks (standard)
-* Records (second preview)
+* **Pattern Matching for `instanceof` (second preview - no changes)**
+* **Text Blocks (standard)**
+* **Records (second preview)**
   * Integration with sealed types in interfaces
     * The combination of record and sealed types is referred as algebraic data types.
 

java-16/README.md

@@ -24,21 +24,19 @@ To run each example use: `java --enable-preview --source 16 <FileName.java>`
 
 ## Features
 
-### Language
-
-* Pattern matching for `instanceof` (standard)
-* Record
+* **Pattern Matching for `instanceof` (standard)**
+* **Records**
   * now we can declare static class or a record in an inner class
-* Warnings for [Value-Based Classes](https://docs.oracle.com/en/java/javase/15/docs/api/java.base/java/lang/doc-files/ValueBased.html)
+* **Warnings for [Value-Based Classes](https://docs.oracle.com/en/java/javase/15/docs/api/java.base/java/lang/doc-files/ValueBased.html)**
   * starting the preparatives for Project Valhalla (can't wait for it to be fully implemented)
   * warning the using value-based classes in synchronization and flag to force an error (1) or log (2)
     * flag: `-XX:DiagnoseSyncOnValueBasedClasses=1|2`
   * starting with primitive wrappers (but soon might be expanded)
-* Foreign-Memory Access API
+* **Foreign-Memory Access API (third incubator)**
   * change in the API
-* Sealed classes (second preview)
+* **Sealed Classes (second preview)**
   * `sealed`, `non-sealed` and `permits` became contextual keywords (we can use it as var name or method name)
-* Unix-Domain Socket Channels
+* **Unix-Domain Socket Channels**
 
 ### JVM
 

java-17/README.md

@@ -21,14 +21,12 @@ To run each example use: `java --enable-preview --source 17 <FileName.java>`
 
 ## Features
 
-### Language
-
-* Sealed classes (standard)
-* Pattern matching for switch (preview)
+* **Sealed Classes (standard)**
+* **Pattern Matching for `switch` (preview)**
   * improved switch to support pattern matching for types (like `instanceof`)
   * support for `null` case
   * support for guards where we can use a boolean expression like `case String s && s.length > 10:`
-* Pseudo-Random Number Generators (PRNG)
+* **Pseudo-Random Number Generators (PRNG)**
   * created new classes to generate number
   * two groups of PRNG algorithms:
     * splittable (LXM family):

java-18/README.md

@@ -16,9 +16,7 @@ To run each example use: `java --enable-preview --source 18 <FileName.java>`
 
 ## Features
 
-### Language
-
-* chartset UTF-8 will be default for all O.S.
+* **Chartset UTF-8 by Default**
   * to see which is default: `java -XshowSettings:properties -version 2>&1 | grep file.encoding`
   * we can change the chartset with property: `-Dfile.encoding=UTF-8`
   * affected classes:
@@ -28,11 +26,11 @@ To run each example use: `java --enable-preview --source 18 <FileName.java>`
     * `URLEncoder` and `URLDecoder`
   * the `System.out` and `System.err` will use the same charset from the terminal
       * we can see with: `Console.charset()`
-* Pattern matching for `switch`
+* **Pattern Matching for `switch` (second preview)**
   * Minor improvements from JDK 17:
     * refined to use dominance checking that will force constant case label to appear before a guarded pattern of the same type;
     * exhaustiveness checking is now more precise with sealed hierarchies.
-* Code snippet in Java Doc
+* **Code snippet in Java Doc**
   * was introduced the `@snippet` tag to help write code fragments in Java docs
   * the goals is to provide a way to get this fragments (so it can be validated by other tool), enable syntax highlighting and provide better IDE support
   * code snippet suports:

java-19/README.md

@@ -14,15 +14,13 @@ To run each example use: `java --enable-preview --source 19 <FileName.java>`
 
 ## Features
 
-### Language
-
-* Pattern matching for `switch`
+* **Pattern Matching for `switch` (third preview)**
   * minor improvements from JDK 18:
     * changed guarded pattern from `&&` to `when` keyword
     * definition: guard is the boolean expression, guarded pattern is the case with guard
       * guarded pattern: `case Hero h when h.getCity() == Cities.NEW_YORK`
       * guard: `h.getCity() == Cities.NEW_YORK`
-* Record patterns
+* **Record Patterns (preview)**
   * added suport to deconstruct record values in pattern matcher
     * record pattern: `Point(int x, int y)`
     * the variable `int x` is initialized with the result of accessor method `Point.x()`, not directly from the field `x`
@@ -31,7 +29,7 @@ To run each example use: `java --enable-preview --source 19 <FileName.java>`
   * now we can use type pattern and record pattern together
   * we can check the type and extract the record components using `instanceof` operator
     * `o instanceOf Point(int x, int y)`
-* Virtual Threads:
+* **Virtual Threads (preview)**
   * also called user-mode threads or [fiber](https://en.wikipedia.org/wiki/Fiber_(computer_science))
   * more notes about Project Loom [here](../projects/loom/)
   * `Virtual threads are lightweight threads that dramatically reduce the effort of writing, maintaining, and observing high-throughput concurrent applications`
@@ -86,7 +84,7 @@ To run each example use: `java --enable-preview --source 19 <FileName.java>`
     * `Thread.ofPlatform().start(() -> {})`;
     * **do not use** any cached method from `Executors`.
   * [here](platform-thread-vs-virtual-thread.md) is some details about the Platform Thread vs Virtual Thread examples
-* Structured Concurrency
+* **Structured Concurrency (preview)**
   * goal is simplify multithreaded programming;
   * treats multiple tasks running in different threads as a single unit of work:
     * streamlining error handling and cancellation

java-20/README.md

@@ -14,16 +14,16 @@ To run each example use: `java --enable-preview --source 20 <FileName.java>`
 
 ## Features
 
-* Record patterns (second preview)
+* **Record Patterns (second preview)**
   * added support for inference of type arguments of generic record patterns;
     * now it generic type can be inferred
     * given `record Decorator<T>(T t) {}` and variable `Decorator<Decorator<String>> wr`, the record pattern generic type can be inferred in `w insteaceof Decorator(Decorator(var s))`
   * added support for record patterns to appear in the headere of an enhanced for statement;
     * `for (Point(var x, var y) : shapePoints)`
   * remove support for named record pattner.
-* Patteren matching for `switch` (fourth preview)
+* **Patteren Matching for `switch` (fourth preview)**
   * added support for inference of type arguments for generic record patterns
-* Virtual threads (second preview)
+* **Virtual Threads (second preview)**
   * small numbeer of API changes described by JEP 425 were made permanent in JDK 19 and are not proporsed to preview:
     * `Thread.join(Durantion)`
     * `Thread.sleep(Duration)`
@@ -32,7 +32,7 @@ To run each example use: `java --enable-preview --source 20 <FileName.java>`
     * `Future.exceptionNow()`
     * `Future.state()`
     * `ExecutorService` extends `AutoClosable`
-* Scoped values (incubator)
+* **Scoped Values (incubator)**
   * enable the sharing of immutable data within and across threads
   * it were inspired by the way that Lipst dialects provide support for dyanamically scoped free variables
   * they are preferred to thread-local variables (specially using virtual threads)
@@ -86,7 +86,7 @@ To run each example use: `java --enable-preview --source 20 <FileName.java>`
        * the binding will remains until the child thread are finished and we can use `StructuredTaskScoped.join` to ensure
        that the child threads will terminate before `run`/`call`
      * when we try to access a scoped value not shared with current thread an exception `NoSuchElementException` will be thrown
-* Structured concurrency (second incubator)
+* **Structured Concurrency (second incubator)**
   * no changes in API since JDK 19
   * added support to inheritance of scoped values