SuperiorStreams

It is possible to have your cake and eat it too.

The Streams API in Java 8 doesn't handle exceptions or resources properly. Superior Streams are a wrapper around the JDK Streams API that adds proper exception passing and resource management without complicating the API.

New: Experimental Collections API replacement featuring regular and immutable versions of Map, Set and List. This is integrated to a new version of the Stream API.

Superior examples

Lambda expressions throwing IOExceptions are just as simple to use as those throwing unchecked exceptions:

//*/
static Object[] example1(IOStream<File> s3, Stream<File> s33) {

	IOFunction<File, JarFile> toJarFile1 = JarFile::new;
	IOStream<JarFile> s4 = s3.map(toJarFile1);

	// Using JDK Streams requires twisting and turning:

	Function<File, JarFile> toJarFile2 = (File file) -> {
		try {
			return new JarFile(file);
		} catch(IOException e) {
			throw new UncheckedIOException(e);
		}
	};
	Stream<JarFile> s43 = s33.map(toJarFile2);

return new Object[] {s4,s43}; }/*/

Resources are released as soon as they are no longer needed, automatically and transparently:

//*/
static void example2(Path install, Predicate<Path> isJdk) throws IOException {

	IOStream<Path> s1 = Files.list(install);
	IOStream<Path> s2 = s1.filter(isJdk);
	for(Path path : s1.iterable()) {
		System.out.println(path);
	}
	for(Path path : s2.iterable()) {
		System.out.println(path);
	}

	// JDK Streams need to be manually tracked at each use site:

	try(java.util.stream.Stream<Path> s11 = java.nio.file.Files.list(install);
		java.util.stream.Stream<Path> s12 = java.nio.file.Files.list(install);) {

		java.util.stream.Stream<Path> s22 = s12.filter(isJdk);
		for(Path path : (Iterable<Path>) () -> s11.iterator()) {
			System.out.println(path);
		}
		for(Path path : (Iterable<Path>) () -> s22.iterator()) {
			System.out.println(path);
		}
	}
}/*/

Superior Streams can be freely reused as many times as needed:

//*/
static Object[] example3(List<String> JDK_PROJECTS1, java.util.List<String> JDK_PROJECTS2) {

	Stream<String> projects1 = JDK_PROJECTS1.stream();
	Predicate<String> isPrefix1 = (String path) -> projects1.anyMatch(path::startsWith);

	// Each Stream from JDK can only be used once or the result is an exception at runtime:

	Supplier<java.util.stream.Stream<String>> projects2 = () -> JDK_PROJECTS2.stream();
	Predicate<String> isPrefix2 = (String path) -> projects2.get().anyMatch(path::startsWith);

return new Object[] {isPrefix1,isPrefix2}; }/*/

Extra Features

Replacements for standard library ArrayList, HashSet and HashMap collections

Mutable and immutable versions:

//*/
static Object[] example4() {
	ArrayList<String> list = new ArrayList<>();
	HashSet<String> set = list.add("1").add("2").toHashSet();

	// Immutable versions use the same API but return copies when changed:

	List<String> immutableList = list.toList();
	Set<String> immutableSet = set.toSet().replaceAll(s -> "log: " + s);

return new Object[] {immutableList,immutableSet}; }/*/

With exceptions passing through as expected:

//*/
static FileTime getLastModifiedTime(Path path) throws IOException {
	return lastModifiedCache.computeIfAbsent(path, p -> Files.getLastModifiedTime(path)).get(path);
}
private static HashMap<Path, FileTime> lastModifiedCache = new HashMap<>();

// Standard library version requires lots of catching and re-throwing:

static FileTime getLastModifiedTime2(Path path) throws IOException {
	try {
		return lastModifiedCache2.computeIfAbsent(path, p -> {
			try {
				return Files.getLastModifiedTime(path);
			} catch(IOException e) {
				throw new UncheckedIOException(e);
			}
		});
	} catch(UncheckedIOException e) {
		throw e.getCause();
	}
}
private static java.util.Map<Path, FileTime> lastModifiedCache2 = new java.util.HashMap<>();
/*/

Streams of RGB pixels for image manipulation

Image manipulation using red, green, blue channels:

//*/
static void example6() throws IOException {
	RGBStream stream = Streams.loadImageInRGB("pagoda.jpg");
	stream.swapRedAndGreen().save("pagoda_rg.jpg");
	stream.swapRedAndBlue().save("pagoda_rb.jpg");
	stream.swapAlphaAndBlue().save("pagoda_ab.png");
	stream.setRed(255).save("pagoda_bright_red.png");
}/*/

Image color manipulation in HSB changing hue, saturation and brightness values:

//*/
static void example7() throws IOException {
	HSBStream hsb = Streams.loadImageInHSB("pagoda.jpg");
	hsb.mapBrightness((h, s, b, a) -> b * 0.25).save("pagoda_dark.jpg");
	hsb.mapHue((h, s, b, a) -> h + 60).save("pagoda_altered_hue.jpg");
}/*/

Gamma adjustments:

//*/
static void example8() throws IOException {
	RGBStream stream = Streams.loadImageInRGB("pagoda.jpg");
	stream.gammaExpand(2.4).save("pagoda_texture.jpg");
	HSBStream bw = stream.toBlackAndWhite();
	bw.save("pagoda_bw.jpg");
	bw.gammaCompress(0.5).save("pagoda_bw2.jpg");
}/*/

Helper methods for WHERE clauses over Lists, Maps and Sets

//*/
static ArrayList<String> removeBadWords(List<String> list) {
  return Streams.where(list, s -> s.contains("fuck") == false);
}/*/