/*

 * Copyright (c) 2009, 2012, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

/* @test

 * @summary example code used in javadoc for java.lang.invoke API

 * @compile JavaDocExamplesTest.java

 * @run testng/othervm test.java.lang.invoke.JavaDocExamplesTest

 */

package test.java.lang.invoke;

import java.lang.invoke.*;

import static java.lang.invoke.MethodHandles.*;

import static java.lang.invoke.MethodType.*;

import java.util.*;

import org.testng.*;

import static org.testng.AssertJUnit.*;

import org.testng.annotations.*;

/**

 * @author jrose

 */

public class JavaDocExamplesTest {

    /** Wrapper for running the TestNG tests in this module.

     *  Put TestNG on the classpath!

     */

    public static void main(String... ignore) throws Throwable {

        new JavaDocExamplesTest().run();

    }

    public void run() throws Throwable {

        testFindVirtual();

        testPermuteArguments();

        testDropArguments();

        testFilterArguments();

        testFoldArguments();

        testFoldArguments2();

        testMethodHandlesSummary();

        testAsSpreader();

        testAsCollector();

        testAsVarargsCollector();

        testAsFixedArity();

        testAsTypeCornerCases();

        testMutableCallSite();

    }

    // How much output?

    static final Class<?> THIS_CLASS = JavaDocExamplesTest.class;

    static int verbosity = Integer.getInteger(THIS_CLASS.getSimpleName()+".verbosity", 0);

{}

static final private Lookup LOOKUP = lookup();

// static final private MethodHandle CONCAT_1 = LOOKUP.findVirtual(String.class,

//     "concat", methodType(String.class, String.class));

// static final private MethodHandle HASHCODE_1 = LOOKUP.findVirtual(Object.class,

//     "hashCode", methodType(int.class));

// form required if ReflectiveOperationException is intercepted:

    static final private MethodHandle CONCAT_2, HASHCODE_2, ADD_2, SUB_2;

static {

  try {

    Class<?> THIS_CLASS = LOOKUP.lookupClass();

    CONCAT_2 = LOOKUP.findVirtual(String.class,

      "concat", methodType(String.class, String.class));

    HASHCODE_2 = LOOKUP.findVirtual(Object.class,

      "hashCode", methodType(int.class));

    ADD_2 = LOOKUP.findStatic(THIS_CLASS, "add", methodType(int.class, int.class, int.class));

    SUB_2 = LOOKUP.findStatic(THIS_CLASS, "sub", methodType(int.class, int.class, int.class));

   } catch (ReflectiveOperationException ex) {

     throw new RuntimeException(ex);

   }

}

    static int add(int x, int y) { return x + y; }

    static int sub(int x, int y) { return x - y; }

{}

    @Test public void testFindVirtual() throws Throwable {

{}

MethodHandle CONCAT_3 = LOOKUP.findVirtual(String.class,

  "concat", methodType(String.class, String.class));

MethodHandle HASHCODE_3 = LOOKUP.findVirtual(Object.class,

  "hashCode", methodType(int.class));

//assertEquals("xy", (String) CONCAT_1.invokeExact("x", "y"));

assertEquals("xy", (String) CONCAT_2.invokeExact("x", "y"));

assertEquals("xy", (String) CONCAT_3.invokeExact("x", "y"));

//assertEquals("xy".hashCode(), (int) HASHCODE_1.invokeExact((Object)"xy"));

assertEquals("xy".hashCode(), (int) HASHCODE_2.invokeExact((Object)"xy"));

assertEquals("xy".hashCode(), (int) HASHCODE_3.invokeExact((Object)"xy"));

{}

    }

    @Test public void testPermuteArguments() throws Throwable {

        {{

{} /// JAVADOC

MethodType intfn1 = methodType(int.class, int.class);

MethodType intfn2 = methodType(int.class, int.class, int.class);

MethodHandle sub = SUB_2;// ... {int x, int y => x-y} ...;

assert(sub.type().equals(intfn2));

MethodHandle sub1 = permuteArguments(sub, intfn2, 0, 1);

MethodHandle rsub = permuteArguments(sub, intfn2, 1, 0);

assert((int)rsub.invokeExact(1, 100) == 99);

MethodHandle add = ADD_2;// ... {int x, int y => x+y} ...;

assert(add.type().equals(intfn2));

MethodHandle twice = permuteArguments(add, intfn1, 0, 0);

assert(twice.type().equals(intfn1));

assert((int)twice.invokeExact(21) == 42);

            }}

        {{

{} /// JAVADOC

MethodHandle cat = lookup().findVirtual(String.class,

  "concat", methodType(String.class, String.class));

assertEquals("xy", (String) cat.invokeExact("x", "y"));

MethodHandle d0 = dropArguments(cat, 0, String.class);

assertEquals("yz", (String) d0.invokeExact("x", "y", "z"));

MethodHandle d1 = dropArguments(cat, 1, String.class);

assertEquals("xz", (String) d1.invokeExact("x", "y", "z"));

MethodHandle d2 = dropArguments(cat, 2, String.class);

assertEquals("xy", (String) d2.invokeExact("x", "y", "z"));

MethodHandle d12 = dropArguments(cat, 1, int.class, boolean.class);

assertEquals("xz", (String) d12.invokeExact("x", 12, true, "z"));

            }}

    }

    @Test public void testDropArguments() throws Throwable {

        {{

{} /// JAVADOC

MethodHandle cat = lookup().findVirtual(String.class,

  "concat", methodType(String.class, String.class));

assertEquals("xy", (String) cat.invokeExact("x", "y"));

MethodType bigType = cat.type().insertParameterTypes(0, int.class, String.class);

MethodHandle d0 = dropArguments(cat, 0, bigType.parameterList().subList(0,2));

assertEquals(bigType, d0.type());

assertEquals("yz", (String) d0.invokeExact(123, "x", "y", "z"));

            }}

        {{

{} /// JAVADOC

MethodHandle cat = lookup().findVirtual(String.class,

  "concat", methodType(String.class, String.class));

assertEquals("xy", (String) cat.invokeExact("x", "y"));

MethodHandle d0 = dropArguments(cat, 0, String.class);

assertEquals("yz", (String) d0.invokeExact("x", "y", "z"));

MethodHandle d1 = dropArguments(cat, 1, String.class);

assertEquals("xz", (String) d1.invokeExact("x", "y", "z"));

MethodHandle d2 = dropArguments(cat, 2, String.class);

assertEquals("xy", (String) d2.invokeExact("x", "y", "z"));

MethodHandle d12 = dropArguments(cat, 1, int.class, boolean.class);

assertEquals("xz", (String) d12.invokeExact("x", 12, true, "z"));

            }}

    }

    @Test public void testFilterArguments() throws Throwable {

        {{

{} /// JAVADOC

MethodHandle cat = lookup().findVirtual(String.class,

  "concat", methodType(String.class, String.class));

MethodHandle upcase = lookup().findVirtual(String.class,

  "toUpperCase", methodType(String.class));

assertEquals("xy", (String) cat.invokeExact("x", "y"));

MethodHandle f0 = filterArguments(cat, 0, upcase);

assertEquals("Xy", (String) f0.invokeExact("x", "y")); // Xy

MethodHandle f1 = filterArguments(cat, 1, upcase);

assertEquals("xY", (String) f1.invokeExact("x", "y")); // xY

MethodHandle f2 = filterArguments(cat, 0, upcase, upcase);

assertEquals("XY", (String) f2.invokeExact("x", "y")); // XY

            }}

    }

    @Test public void testFoldArguments() throws Throwable {

        {{

{} /// JAVADOC

MethodHandle trace = publicLookup().findVirtual(java.io.PrintStream.class,

  "println", methodType(void.class, String.class))

    .bindTo(System.out);

MethodHandle cat = lookup().findVirtual(String.class,

  "concat", methodType(String.class, String.class));

assertEquals("boojum", (String) cat.invokeExact("boo", "jum"));

MethodHandle catTrace = foldArguments(cat, trace);

// also prints "boo":

assertEquals("boojum", (String) catTrace.invokeExact("boo", "jum"));

            }}

    }

    static void assertEquals(Object exp, Object act) {

        if (verbosity > 0)

            System.out.println("result: "+act);

        Assert.assertEquals(exp, act);

    }

    @Test public void testMethodHandlesSummary() throws Throwable {

        {{

{} /// JAVADOC

Object x, y; String s; int i;

MethodType mt; MethodHandle mh;

MethodHandles.Lookup lookup = MethodHandles.lookup();

// mt is (char,char)String

mt = MethodType.methodType(String.class, char.class, char.class);

mh = lookup.findVirtual(String.class, "replace", mt);

s = (String) mh.invokeExact("daddy",'d','n');

// invokeExact(Ljava/lang/String;CC)Ljava/lang/String;

assertEquals(s, "nanny");

// weakly typed invocation (using MHs.invoke)

s = (String) mh.invokeWithArguments("sappy", 'p', 'v');

assertEquals(s, "savvy");

// mt is (Object[])List

mt = MethodType.methodType(java.util.List.class, Object[].class);

mh = lookup.findStatic(java.util.Arrays.class, "asList", mt);

assert(mh.isVarargsCollector());

x = mh.invoke("one", "two");

// invoke(Ljava/lang/String;Ljava/lang/String;)Ljava/lang/Object;

assertEquals(x, java.util.Arrays.asList("one","two"));

// mt is (Object,Object,Object)Object

mt = MethodType.genericMethodType(3);

mh = mh.asType(mt);

x = mh.invokeExact((Object)1, (Object)2, (Object)3);

// invokeExact(Ljava/lang/Object;Ljava/lang/Object;Ljava/lang/Object;)Ljava/lang/Object;

assertEquals(x, java.util.Arrays.asList(1,2,3));

// mt is ()int

mt = MethodType.methodType(int.class);

mh = lookup.findVirtual(java.util.List.class, "size", mt);

i = (int) mh.invokeExact(java.util.Arrays.asList(1,2,3));

// invokeExact(Ljava/util/List;)I

assert(i == 3);

mt = MethodType.methodType(void.class, String.class);

mh = lookup.findVirtual(java.io.PrintStream.class, "println", mt);

mh.invokeExact(System.out, "Hello, world.");

// invokeExact(Ljava/io/PrintStream;Ljava/lang/String;)V

{}

            }}

    }

    @Test public void testAsSpreader() throws Throwable {

        {{

{} /// JAVADOC

MethodHandle equals = publicLookup()

  .findVirtual(String.class, "equals", methodType(boolean.class, Object.class));

assert( (boolean) equals.invokeExact("me", (Object)"me"));

assert(!(boolean) equals.invokeExact("me", (Object)"thee"));

// spread both arguments from a 2-array:

MethodHandle eq2 = equals.asSpreader(Object[].class, 2);

assert( (boolean) eq2.invokeExact(new Object[]{ "me", "me" }));

assert(!(boolean) eq2.invokeExact(new Object[]{ "me", "thee" }));

// spread both arguments from a String array:

MethodHandle eq2s = equals.asSpreader(String[].class, 2);

assert( (boolean) eq2s.invokeExact(new String[]{ "me", "me" }));

assert(!(boolean) eq2s.invokeExact(new String[]{ "me", "thee" }));

// spread second arguments from a 1-array:

MethodHandle eq1 = equals.asSpreader(Object[].class, 1);

assert( (boolean) eq1.invokeExact("me", new Object[]{ "me" }));

assert(!(boolean) eq1.invokeExact("me", new Object[]{ "thee" }));

// spread no arguments from a 0-array or null:

MethodHandle eq0 = equals.asSpreader(Object[].class, 0);

assert( (boolean) eq0.invokeExact("me", (Object)"me", new Object[0]));

assert(!(boolean) eq0.invokeExact("me", (Object)"thee", (Object[])null));

// asSpreader and asCollector are approximate inverses:

for (int n = 0; n <= 2; n++) {

    for (Class<?> a : new Class<?>[]{Object[].class, String[].class, CharSequence[].class}) {

        MethodHandle equals2 = equals.asSpreader(a, n).asCollector(a, n);

        assert( (boolean) equals2.invokeWithArguments("me", "me"));

        assert(!(boolean) equals2.invokeWithArguments("me", "thee"));

    }

}

MethodHandle caToString = publicLookup()

  .findStatic(Arrays.class, "toString", methodType(String.class, char[].class));

assertEquals("[A, B, C]", (String) caToString.invokeExact("ABC".toCharArray()));

MethodHandle caString3 = caToString.asCollector(char[].class, 3);

assertEquals("[A, B, C]", (String) caString3.invokeExact('A', 'B', 'C'));

MethodHandle caToString2 = caString3.asSpreader(char[].class, 2);

assertEquals("[A, B, C]", (String) caToString2.invokeExact('A', "BC".toCharArray()));

            }}

    }

    @Test public void testAsCollector() throws Throwable {

        {{

{} /// JAVADOC

MethodHandle deepToString = publicLookup()

  .findStatic(Arrays.class, "deepToString", methodType(String.class, Object[].class));

assertEquals("[won]",   (String) deepToString.invokeExact(new Object[]{"won"}));

MethodHandle ts1 = deepToString.asCollector(Object[].class, 1);

assertEquals(methodType(String.class, Object.class), ts1.type());

//assertEquals("[won]", (String) ts1.invokeExact(         new Object[]{"won"})); //FAIL

assertEquals("[[won]]", (String) ts1.invokeExact((Object) new Object[]{"won"}));

// arrayType can be a subtype of Object[]

MethodHandle ts2 = deepToString.asCollector(String[].class, 2);

assertEquals(methodType(String.class, String.class, String.class), ts2.type());

assertEquals("[two, too]", (String) ts2.invokeExact("two", "too"));

MethodHandle ts0 = deepToString.asCollector(Object[].class, 0);

assertEquals("[]", (String) ts0.invokeExact());

// collectors can be nested, Lisp-style

MethodHandle ts22 = deepToString.asCollector(Object[].class, 3).asCollector(String[].class, 2);

assertEquals("[A, B, [C, D]]", ((String) ts22.invokeExact((Object)'A', (Object)"B", "C", "D")));

// arrayType can be any primitive array type

MethodHandle bytesToString = publicLookup()

  .findStatic(Arrays.class, "toString", methodType(String.class, byte[].class))

  .asCollector(byte[].class, 3);

assertEquals("[1, 2, 3]", (String) bytesToString.invokeExact((byte)1, (byte)2, (byte)3));

MethodHandle longsToString = publicLookup()

  .findStatic(Arrays.class, "toString", methodType(String.class, long[].class))

  .asCollector(long[].class, 1);

assertEquals("[123]", (String) longsToString.invokeExact((long)123));

            }}

    }

    @SuppressWarnings("rawtypes")

    @Test public void testAsVarargsCollector() throws Throwable {

        {{

{} /// JAVADOC

MethodHandle deepToString = publicLookup()

  .findStatic(Arrays.class, "deepToString", methodType(String.class, Object[].class));

MethodHandle ts1 = deepToString.asVarargsCollector(Object[].class);

assertEquals("[won]",   (String) ts1.invokeExact(    new Object[]{"won"}));

assertEquals("[won]",   (String) ts1.invoke(         new Object[]{"won"}));

assertEquals("[won]",   (String) ts1.invoke(                      "won" ));

assertEquals("[[won]]", (String) ts1.invoke((Object) new Object[]{"won"}));

// findStatic of Arrays.asList(...) produces a variable arity method handle:

MethodHandle asList = publicLookup()

  .findStatic(Arrays.class, "asList", methodType(List.class, Object[].class));

assertEquals(methodType(List.class, Object[].class), asList.type());

assert(asList.isVarargsCollector());

assertEquals("[]", asList.invoke().toString());

assertEquals("[1]", asList.invoke(1).toString());

assertEquals("[two, too]", asList.invoke("two", "too").toString());

String[] argv = { "three", "thee", "tee" };

assertEquals("[three, thee, tee]", asList.invoke(argv).toString());

assertEquals("[three, thee, tee]", asList.invoke((Object[])argv).toString());

List ls = (List) asList.invoke((Object)argv);

assertEquals(1, ls.size());

assertEquals("[three, thee, tee]", Arrays.toString((Object[])ls.get(0)));

            }}

    }

    @Test public void testAsFixedArity() throws Throwable {

        {{

{} /// JAVADOC

MethodHandle asListVar = publicLookup()

  .findStatic(Arrays.class, "asList", methodType(List.class, Object[].class))

  .asVarargsCollector(Object[].class);

MethodHandle asListFix = asListVar.asFixedArity();

assertEquals("[1]", asListVar.invoke(1).toString());

Exception caught = null;

try { asListFix.invoke((Object)1); }

catch (Exception ex) { caught = ex; }

assert(caught instanceof ClassCastException);

assertEquals("[two, too]", asListVar.invoke("two", "too").toString());

try { asListFix.invoke("two", "too"); }

catch (Exception ex) { caught = ex; }

assert(caught instanceof WrongMethodTypeException);

Object[] argv = { "three", "thee", "tee" };

assertEquals("[three, thee, tee]", asListVar.invoke(argv).toString());

assertEquals("[three, thee, tee]", asListFix.invoke(argv).toString());

assertEquals(1, ((List) asListVar.invoke((Object)argv)).size());

assertEquals("[three, thee, tee]", asListFix.invoke((Object)argv).toString());

            }}

    }

    @Test public void testAsTypeCornerCases() throws Throwable {

        {{

{} /// JAVADOC

MethodHandle i2s = publicLookup()

  .findVirtual(Integer.class, "toString", methodType(String.class));

i2s = i2s.asType(i2s.type().unwrap());

MethodHandle l2s = publicLookup()

  .findVirtual(Long.class, "toString", methodType(String.class));

l2s = l2s.asType(l2s.type().unwrap());

Exception caught = null;

try { i2s.asType(methodType(String.class, String.class)); }

catch (Exception ex) { caught = ex; }

assert(caught instanceof WrongMethodTypeException);

i2s.asType(methodType(String.class, byte.class));

i2s.asType(methodType(String.class, Byte.class));

i2s.asType(methodType(String.class, Character.class));

i2s.asType(methodType(String.class, Integer.class));

l2s.asType(methodType(String.class, byte.class));

l2s.asType(methodType(String.class, Byte.class));

l2s.asType(methodType(String.class, Character.class));

l2s.asType(methodType(String.class, Integer.class));

l2s.asType(methodType(String.class, Long.class));

caught = null;

try { i2s.asType(methodType(String.class, Long.class)); }

catch (Exception ex) { caught = ex; }

assert(caught instanceof WrongMethodTypeException);

MethodHandle i2sGen = i2s.asType(methodType(String.class, Object.class));

MethodHandle l2sGen = l2s.asType(methodType(String.class, Object.class));

i2sGen.invoke(42);  // int -> Integer -> Object -> Integer -> int

i2sGen.invoke((byte)4);  // byte -> Byte -> Object -> Byte -> byte -> int

l2sGen.invoke(42);  // int -> Integer -> Object -> Integer -> int

l2sGen.invoke((byte)4);  // byte -> Byte -> Object -> Byte -> byte -> int

l2sGen.invoke(0x420000000L);

caught = null;

try { i2sGen.invoke(0x420000000L); } // long -> Long -> Object -> Integer CCE

catch (Exception ex) { caught = ex; }

assert(caught instanceof ClassCastException);

caught = null;

try { i2sGen.invoke("asdf"); } // String -> Object -> Integer CCE

catch (Exception ex) { caught = ex; }

assert(caught instanceof ClassCastException);

{}

            }}

    }

    @Test public void testMutableCallSite() throws Throwable {

        {{

{} /// JAVADOC

MutableCallSite name = new MutableCallSite(MethodType.methodType(String.class));

MethodHandle MH_name = name.dynamicInvoker();

MethodType MT_str1 = MethodType.methodType(String.class);

MethodHandle MH_upcase = MethodHandles.lookup()

    .findVirtual(String.class, "toUpperCase", MT_str1);

MethodHandle worker1 = MethodHandles.filterReturnValue(MH_name, MH_upcase);

name.setTarget(MethodHandles.constant(String.class, "Rocky"));

assertEquals("ROCKY", (String) worker1.invokeExact());

name.setTarget(MethodHandles.constant(String.class, "Fred"));

assertEquals("FRED", (String) worker1.invokeExact());

// (mutation can be continued indefinitely)

/*

 * </pre></blockquote>

 * <p>

 * The same call site may be used in several places at once.

 * <blockquote><pre>

 */

MethodType MT_str2 = MethodType.methodType(String.class, String.class);

MethodHandle MH_cat = lookup().findVirtual(String.class,

  "concat", methodType(String.class, String.class));

MethodHandle MH_dear = MethodHandles.insertArguments(MH_cat, 1, ", dear?");

MethodHandle worker2 = MethodHandles.filterReturnValue(MH_name, MH_dear);

assertEquals("Fred, dear?", (String) worker2.invokeExact());

name.setTarget(MethodHandles.constant(String.class, "Wilma"));

assertEquals("WILMA", (String) worker1.invokeExact());

assertEquals("Wilma, dear?", (String) worker2.invokeExact());

{}

            }}

    }

    @Test public void testSwitchPoint() throws Throwable {

        {{

{} /// JAVADOC

MethodHandle MH_strcat = MethodHandles.lookup()

    .findVirtual(String.class, "concat", MethodType.methodType(String.class, String.class));

SwitchPoint spt = new SwitchPoint();

assert(!spt.hasBeenInvalidated());

// the following steps may be repeated to re-use the same switch point:

MethodHandle worker1 = MH_strcat;

MethodHandle worker2 = MethodHandles.permuteArguments(MH_strcat, MH_strcat.type(), 1, 0);

MethodHandle worker = spt.guardWithTest(worker1, worker2);

assertEquals("method", (String) worker.invokeExact("met", "hod"));

SwitchPoint.invalidateAll(new SwitchPoint[]{ spt });

assert(spt.hasBeenInvalidated());

assertEquals("hodmet", (String) worker.invokeExact("met", "hod"));

{}

            }}

    }

    @Test public void testFoldArguments2() throws Throwable {

        {{

{} /// JAVADOC

// argument-based dispatch for methods of the form boolean x.___(y: String)

Lookup lookup = publicLookup();

// first, a tracing hack:

MethodHandle println = lookup.findVirtual(java.io.PrintStream.class, "println", methodType(void.class, String.class));

MethodHandle arrayToString = lookup.findStatic(Arrays.class, "toString", methodType(String.class, Object[].class));

MethodHandle concat = lookup.findVirtual(String.class, "concat", methodType(String.class, String.class));

MethodHandle arrayToString_DIS = filterReturnValue(arrayToString, concat.bindTo("DIS:"));

MethodHandle arrayToString_INV = filterReturnValue(arrayToString, concat.bindTo("INV:"));