1 /*
2 * Copyright (c) 2015, 2016, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
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19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 /* @test
27 * @bug 8139885
28 * @bug 8150635
29 * @run testng/othervm -ea -esa test.java.lang.invoke.LoopCombinatorTest
30 */
31
32 package test.java.lang.invoke;
33
34 import java.lang.invoke.MethodHandle;
35 import java.lang.invoke.MethodHandles;
36 import java.lang.invoke.MethodHandles.Lookup;
37 import java.lang.invoke.MethodType;
38 import java.util.*;
39
40 import static java.lang.invoke.MethodType.methodType;
41
42 import static org.testng.AssertJUnit.*;
43
44 import org.testng.annotations.*;
45
46 /**
47 * Tests for the loop combinators introduced in JEP 274.
48 */
49 public class LoopCombinatorTest {
50
51 static final Lookup LOOKUP = MethodHandles.lookup();
52
53 @Test
54 public static void testLoopFac() throws Throwable {
55 MethodHandle[] counterClause = new MethodHandle[]{Fac.MH_zero, Fac.MH_inc};
56 MethodHandle[] accumulatorClause = new MethodHandle[]{Fac.MH_one, Fac.MH_mult, Fac.MH_pred, Fac.MH_fin};
57 MethodHandle loop = MethodHandles.loop(counterClause, accumulatorClause);
58 assertEquals(Fac.MT_fac, loop.type());
59 assertEquals(120, loop.invoke(5));
60 }
61
62 @Test
63 public static void testLoopFacNullInit() throws Throwable {
64 // null initializer for counter, should initialize to 0
65 MethodHandle[] counterClause = new MethodHandle[]{null, Fac.MH_inc};
66 MethodHandle[] accumulatorClause = new MethodHandle[]{Fac.MH_one, Fac.MH_mult, Fac.MH_pred, Fac.MH_fin};
67 MethodHandle loop = MethodHandles.loop(counterClause, accumulatorClause);
68 assertEquals(Fac.MT_fac, loop.type());
69 assertEquals(120, loop.invoke(5));
70 }
71
72 @Test
73 public static void testLoopNullInit() throws Throwable {
74 // null initializer for counter, should initialize to 0, one-clause loop
75 MethodHandle[] counterClause = new MethodHandle[]{null, Loop.MH_inc, Loop.MH_pred, Loop.MH_fin};
76 MethodHandle loop = MethodHandles.loop(counterClause);
77 assertEquals(Loop.MT_loop, loop.type());
78 assertEquals(10, loop.invoke(10));
79 }
80
81 @Test
82 public static void testLoopVoid1() throws Throwable {
83 // construct a post-checked loop that only does one iteration and has a void body and void local state
84 MethodHandle loop = MethodHandles.loop(new MethodHandle[]{Empty.MH_f, Empty.MH_f, Empty.MH_pred, null});
85 assertEquals(MethodType.methodType(void.class), loop.type());
86 loop.invoke();
87 }
88
89 @Test
90 public static void testLoopVoid2() throws Throwable {
91 // construct a post-checked loop that only does one iteration and has a void body and void local state,
92 // initialized implicitly from the step type
93 MethodHandle loop = MethodHandles.loop(new MethodHandle[]{null, Empty.MH_f, Empty.MH_pred, null});
94 assertEquals(MethodType.methodType(void.class), loop.type());
95 loop.invoke();
96 }
97
98 @Test
99 public static void testLoopVoid3() throws Throwable {
100 // construct a post-checked loop that only does one iteration and has a void body and void local state,
101 // and that has a void finalizer
102 MethodHandle loop = MethodHandles.loop(new MethodHandle[]{null, Empty.MH_f, Empty.MH_pred, Empty.MH_f});
103 assertEquals(MethodType.methodType(void.class), loop.type());
104 loop.invoke();
105 }
106
107 @Test
108 public static void testLoopFacWithVoidState() throws Throwable {
109 // like testLoopFac, but with additional void state that outputs a dot
110 MethodHandle[] counterClause = new MethodHandle[]{Fac.MH_zero, Fac.MH_inc};
111 MethodHandle[] accumulatorClause = new MethodHandle[]{Fac.MH_one, Fac.MH_mult, Fac.MH_pred, Fac.MH_fin};
112 MethodHandle[] dotClause = new MethodHandle[]{null, Fac.MH_dot};
113 MethodHandle loop = MethodHandles.loop(counterClause, accumulatorClause, dotClause);
114 assertEquals(Fac.MT_fac, loop.type());
115 assertEquals(120, loop.invoke(5));
116 }
117
118 @Test
119 public static void testLoopVoidInt() throws Throwable {
120 // construct a post-checked loop that only does one iteration and has a void body and void local state,
121 // and that returns a constant
122 MethodHandle loop = MethodHandles.loop(new MethodHandle[]{null, Empty.MH_f, Empty.MH_pred, Empty.MH_c});
123 assertEquals(MethodType.methodType(int.class), loop.type());
124 assertEquals(23, loop.invoke());
125 }
126
127 @Test
128 public static void testLoopWithVirtuals() throws Throwable {
129 // construct a loop (to calculate factorial) that uses a mix of static and virtual methods
130 MethodHandle[] counterClause = new MethodHandle[]{null, LoopWithVirtuals.permute(LoopWithVirtuals.MH_inc)};
131 MethodHandle[] accumulatorClause = new MethodHandle[]{
132 // init function must indicate the loop arguments (there is no other means to determine them)
133 MethodHandles.dropArguments(LoopWithVirtuals.MH_one, 0, LoopWithVirtuals.class),
134 LoopWithVirtuals.permute(LoopWithVirtuals.MH_mult),
135 LoopWithVirtuals.permute(LoopWithVirtuals.MH_pred),
136 LoopWithVirtuals.permute(LoopWithVirtuals.MH_fin)
137 };
138 MethodHandle loop = MethodHandles.loop(counterClause, accumulatorClause);
139 assertEquals(LoopWithVirtuals.MT_loop, loop.type());
140 assertEquals(120, loop.invoke(new LoopWithVirtuals(), 5));
141 }
142
143 @DataProvider
144 static Object[][] negativeTestData() {
145 MethodHandle i0 = MethodHandles.constant(int.class, 0);
146 MethodHandle ii = MethodHandles.dropArguments(i0, 0, int.class, int.class);
147 MethodHandle id = MethodHandles.dropArguments(i0, 0, int.class, double.class);
148 MethodHandle i3 = MethodHandles.dropArguments(i0, 0, int.class, int.class, int.class);
149 List<MethodHandle> inits = Arrays.asList(ii, id, i3);
150 List<Class<?>> ints = Arrays.asList(int.class, int.class, int.class);
151 List<MethodHandle> finis = Arrays.asList(Fac.MH_fin, Fac.MH_inc, Counted.MH_step);
152 List<MethodHandle> preds1 = Arrays.asList(null, null, null);
153 List<MethodHandle> preds2 = Arrays.asList(null, Fac.MH_fin, null);
154 MethodHandle eek = MethodHandles.dropArguments(i0, 0, int.class, int.class, double.class);
155 List<MethodHandle> nesteps = Arrays.asList(Fac.MH_inc, eek, Fac.MH_dot);
156 List<MethodHandle> nepreds = Arrays.asList(null, Fac.MH_pred, null);
157 List<MethodHandle> nefinis = Arrays.asList(null, Fac.MH_fin, null);
158 List<MethodHandle> lvsteps = Arrays.asList(LoopWithVirtuals.MH_inc, LoopWithVirtuals.MH_mult);
159 List<MethodHandle> lvpreds = Arrays.asList(null, LoopWithVirtuals.MH_pred);
160 List<MethodHandle> lvfinis = Arrays.asList(null, LoopWithVirtuals.MH_fin);
161 return new Object[][] {
162 {null, "null or no clauses passed"},
163 {new MethodHandle[][]{}, "null or no clauses passed"},
164 {new MethodHandle[][]{{null, Fac.MH_inc}, {Fac.MH_one, null, Fac.MH_mult, Fac.MH_pred, Fac.MH_fin}},
165 "All loop clauses must be represented as MethodHandle arrays with at most 4 elements."},
166 {new MethodHandle[][]{{null, Fac.MH_inc}, null}, "null clauses are not allowed"},
167 {new MethodHandle[][]{{Fac.MH_zero, Fac.MH_dot}},
168 "clause 0: init and step return types must match: int != void"},
169 {new MethodHandle[][]{{ii}, {id}, {i3}},
170 "found non-effectively identical init parameter type lists: " + inits +
171 " (common suffix: " + ints + ")"},
172 {new MethodHandle[][]{{null, Fac.MH_inc, null, Fac.MH_fin}, {null, Fac.MH_inc, null, Fac.MH_inc},
173 {null, Counted.MH_start, null, Counted.MH_step}},
174 "found non-identical finalizer return types: " + finis + " (return type: int)"},
175 {new MethodHandle[][]{{Fac.MH_zero, Fac.MH_inc}, {Fac.MH_one, Fac.MH_mult, null, Fac.MH_fin},
176 {null, Fac.MH_dot}}, "no predicate found: " + preds1},
177 {new MethodHandle[][]{{Fac.MH_zero, Fac.MH_inc}, {Fac.MH_one, Fac.MH_mult, Fac.MH_fin, Fac.MH_fin},
178 {null, Fac.MH_dot}}, "predicates must have boolean return type: " + preds2},
179 {new MethodHandle[][]{{Fac.MH_zero, Fac.MH_inc}, {Fac.MH_one, eek, Fac.MH_pred, Fac.MH_fin},
180 {null, Fac.MH_dot}},
181 "found non-effectively identical parameter type lists:\nstep: " + nesteps +
182 "\npred: " + nepreds + "\nfini: " + nefinis + " (common parameter sequence: " + ints + ")"},
183 {new MethodHandle[][]{{null, LoopWithVirtuals.MH_inc},
184 {LoopWithVirtuals.MH_one, LoopWithVirtuals.MH_mult, LoopWithVirtuals.MH_pred, LoopWithVirtuals.MH_fin}},
185 "found non-effectively identical parameter type lists:\nstep: " + lvsteps +
186 "\npred: " + lvpreds + "\nfini: " + lvfinis + " (common parameter sequence: " + ints + ")"}
187 };
188 }
189
190 static final MethodHandle MH_loop;
191
192 static {
193 try {
194 MH_loop = LOOKUP.findStatic(MethodHandles.class, "loop", methodType(MethodHandle.class, MethodHandle[][].class));
195 } catch (NoSuchMethodException | IllegalAccessException e) {
196 throw new ExceptionInInitializerError(e);
197 }
198 }
199
200 @Test(dataProvider = "negativeTestData")
201 public static void testLoopNegative(MethodHandle[][] clauses, String expectedMessage) throws Throwable {
202 boolean caught = false;
203 try {
204 MH_loop.invokeWithArguments(clauses);
205 } catch (IllegalArgumentException iae) {
206 assertEquals(expectedMessage, iae.getMessage());
207 caught = true;
208 }
209 assertTrue(caught);
210 }
211
212 @Test
213 public static void testWhileLoop() throws Throwable {
214 // int i = 0; while (i < limit) { ++i; } return i; => limit
215 MethodHandle loop = MethodHandles.whileLoop(While.MH_zero, While.MH_pred, While.MH_step);
216 assertEquals(While.MT_while, loop.type());
217 assertEquals(23, loop.invoke(23));
218 }
219
220 @Test
221 public static void testWhileLoopNoIteration() throws Throwable {
222 // a while loop that never executes its body because the predicate evaluates to false immediately
223 MethodHandle loop = MethodHandles.whileLoop(While.MH_initString, While.MH_predString, While.MH_stepString);
224 assertEquals(While.MT_string, loop.type());
225 assertEquals("a", loop.invoke());
226 }
227
228 @Test
229 public static void testDoWhileLoop() throws Throwable {
230 // int i = 0; do { ++i; } while (i < limit); return i; => limit
231 MethodHandle loop = MethodHandles.doWhileLoop(While.MH_zero, While.MH_step, While.MH_pred);
232 assertEquals(While.MT_while, loop.type());
233 assertEquals(23, loop.invoke(23));
234 }
235
236 @Test
237 public static void testWhileZip() throws Throwable {
238 MethodHandle loop = MethodHandles.doWhileLoop(While.MH_zipInitZip, While.MH_zipStep, While.MH_zipPred);
239 assertEquals(While.MT_zip, loop.type());
240 List<String> a = Arrays.asList("a", "b", "c", "d");
241 List<String> b = Arrays.asList("e", "f", "g", "h");
242 List<String> zipped = Arrays.asList("a", "e", "b", "f", "c", "g", "d", "h");
243 assertEquals(zipped, (List<String>) loop.invoke(a.iterator(), b.iterator()));
244 }
245
246 @Test
247 public static void testCountedLoop() throws Throwable {
248 // String s = "Lambdaman!"; for (int i = 0; i < 13; ++i) { s = "na " + s; } return s; => a variation on a well known theme
249 MethodHandle fit13 = MethodHandles.constant(int.class, 13);
250 MethodHandle loop = MethodHandles.countedLoop(fit13, Counted.MH_start, Counted.MH_step);
251 assertEquals(Counted.MT_counted, loop.type());
252 assertEquals("na na na na na na na na na na na na na Lambdaman!", loop.invoke("Lambdaman!"));
253 }
254
255 @Test
256 public static void testCountedArrayLoop() throws Throwable {
257 // int[] a = new int[]{0}; for (int i = 0; i < 13; ++i) { ++a[0]; } => a[0] == 13
258 MethodHandle fit13 = MethodHandles.dropArguments(MethodHandles.constant(int.class, 13), 0, int[].class);
259 MethodHandle loop = MethodHandles.countedLoop(fit13, null, Counted.MH_stepUpdateArray);
260 assertEquals(Counted.MT_arrayCounted, loop.type());
261 int[] a = new int[]{0};
262 loop.invoke(a);
263 assertEquals(13, a[0]);
264 }
265
266 @Test
267 public static void testCountedPrintingLoop() throws Throwable {
268 MethodHandle fit5 = MethodHandles.constant(int.class, 5);
269 MethodHandle loop = MethodHandles.countedLoop(fit5, null, Counted.MH_printHello);
270 assertEquals(Counted.MT_countedPrinting, loop.type());
271 loop.invoke();
272 }
273
274 @Test
275 public static void testCountedRangeLoop() throws Throwable {
276 // String s = "Lambdaman!"; for (int i = -5; i < 8; ++i) { s = "na " + s; } return s; => a well known theme
277 MethodHandle fitm5 = MethodHandles.dropArguments(Counted.MH_m5, 0, String.class);
278 MethodHandle fit8 = MethodHandles.dropArguments(Counted.MH_8, 0, String.class);
279 MethodHandle loop = MethodHandles.countedLoop(fitm5, fit8, Counted.MH_start, Counted.MH_step);
280 assertEquals(Counted.MT_counted, loop.type());
281 assertEquals("na na na na na na na na na na na na na Lambdaman!", loop.invoke("Lambdaman!"));
282 }
283
284 @Test
285 public static void testIterateSum() throws Throwable {
286 // Integer[] a = new Integer[]{1,2,3,4,5,6}; int sum = 0; for (int e : a) { sum += e; } return sum; => 21
287 MethodHandle loop = MethodHandles.iteratedLoop(Iterate.MH_sumIterator, Iterate.MH_sumInit, Iterate.MH_sumStep);
288 assertEquals(Iterate.MT_sum, loop.type());
289 assertEquals(21, loop.invoke(new Integer[]{1, 2, 3, 4, 5, 6}));
290 }
291
292 @Test
293 public static void testIterateReverse() throws Throwable {
294 MethodHandle loop = MethodHandles.iteratedLoop(null, Iterate.MH_reverseInit, Iterate.MH_reverseStep);
295 assertEquals(Iterate.MT_reverse, loop.type());
296 List<String> list = Arrays.asList("a", "b", "c", "d", "e");
297 List<String> reversedList = Arrays.asList("e", "d", "c", "b", "a");
298 assertEquals(reversedList, (List<String>) loop.invoke(list));
299 }
300
301 @Test
302 public static void testIterateLength() throws Throwable {
303 MethodHandle loop = MethodHandles.iteratedLoop(null, Iterate.MH_lengthInit, Iterate.MH_lengthStep);
304 assertEquals(Iterate.MT_length, loop.type());
305 List<Double> list = Arrays.asList(23.0, 148.0, 42.0);
306 assertEquals(list.size(), (int) loop.invoke(list));
307 }
308
309 @Test
310 public static void testIterateMap() throws Throwable {
311 MethodHandle loop = MethodHandles.iteratedLoop(null, Iterate.MH_mapInit, Iterate.MH_mapStep);
312 assertEquals(Iterate.MT_map, loop.type());
313 List<String> list = Arrays.asList("Hello", "world", "!");
314 List<String> upList = Arrays.asList("HELLO", "WORLD", "!");
315 assertEquals(upList, (List<String>) loop.invoke(list));
316 }
317
318 @Test
319 public static void testIteratePrint() throws Throwable {
320 MethodHandle loop = MethodHandles.iteratedLoop(null, null, Iterate.MH_printStep);
321 assertEquals(Iterate.MT_print, loop.type());
322 loop.invoke(Arrays.asList("hello", "world"));
323 }
324
325 @Test
326 public static void testIterateNullBody() {
327 boolean caught = false;
328 try {
329 MethodHandles.iteratedLoop(MethodHandles.identity(int.class), MethodHandles.identity(int.class), null);
330 } catch (IllegalArgumentException iae) {
331 assertEquals("iterated loop body must not be null", iae.getMessage());
332 caught = true;
333 }
334 assertTrue(caught);
335 }
336
337 static class Empty {
338
339 static void f() { }
340
341 static boolean pred() {
342 return false;
343 }
344
345 static int c() {
346 return 23;
347 }
348
349 static final Class<Empty> EMPTY = Empty.class;
350
351 static final MethodType MT_f = methodType(void.class);
352 static final MethodType MT_pred = methodType(boolean.class);
353 static final MethodType MT_c = methodType(int.class);
354
355 static final MethodHandle MH_f;
356 static final MethodHandle MH_pred;
357 static final MethodHandle MH_c;
358
359 static {
360 try {
361 MH_f = LOOKUP.findStatic(EMPTY, "f", MT_f);
362 MH_pred = LOOKUP.findStatic(EMPTY, "pred", MT_pred);
363 MH_c = LOOKUP.findStatic(EMPTY, "c", MT_c);
364 } catch (Exception e) {
365 throw new ExceptionInInitializerError(e);
366 }
367 }
368 }
369
370 static class Fac {
371
372 static int zero(int k) {
373 return 0;
374 }
375
376 static int one(int k) {
377 return 1;
378 }
379
380 static boolean pred(int i, int acc, int k) {
381 return i < k;
382 }
383
384 static int inc(int i, int acc, int k) {
385 return i + 1;
386 }
387
388 static int mult(int i, int acc, int k) {
389 return i * acc;
390 }
391
392 static void dot(int i, int acc, int k) {
393 System.out.print('.');
394 }
395
396 static int fin(int i, int acc, int k) {
397 return acc;
398 }
399
400 static final Class<Fac> FAC = Fac.class;
401
402 static final MethodType MT_init = methodType(int.class, int.class);
403 static final MethodType MT_fn = methodType(int.class, int.class, int.class, int.class);
404 static final MethodType MT_dot = methodType(void.class, int.class, int.class, int.class);
405 static final MethodType MT_pred = methodType(boolean.class, int.class, int.class, int.class);
406
407 static final MethodHandle MH_zero;
408 static final MethodHandle MH_one;
409 static final MethodHandle MH_pred;
410 static final MethodHandle MH_inc;
411 static final MethodHandle MH_mult;
412 static final MethodHandle MH_dot;
413 static final MethodHandle MH_fin;
414
415 static final MethodType MT_fac = methodType(int.class, int.class);
416
417 static {
418 try {
419 MH_zero = LOOKUP.findStatic(FAC, "zero", MT_init);
420 MH_one = LOOKUP.findStatic(FAC, "one", MT_init);
421 MH_pred = LOOKUP.findStatic(FAC, "pred", MT_pred);
422 MH_inc = LOOKUP.findStatic(FAC, "inc", MT_fn);
423 MH_mult = LOOKUP.findStatic(FAC, "mult", MT_fn);
424 MH_dot = LOOKUP.findStatic(FAC, "dot", MT_dot);
425 MH_fin = LOOKUP.findStatic(FAC, "fin", MT_fn);
426 } catch (Exception e) {
427 throw new ExceptionInInitializerError(e);
428 }
429 }
430
431 }
432
433 static class Loop {
434
435 static int inc(int i, int k) {
436 return i + 1;
437 }
438
439 static boolean pred(int i, int k) {
440 return i < k;
441 }
442
443 static int fin(int i, int k) {
444 return k;
445 }
446
447 static final Class<Loop> LOOP = Loop.class;
448
449 static final MethodType MT_inc = methodType(int.class, int.class, int.class);
450 static final MethodType MT_pred = methodType(boolean.class, int.class, int.class);
451 static final MethodType MT_fin = methodType(int.class, int.class, int.class);
452
453 static final MethodHandle MH_inc;
454 static final MethodHandle MH_pred;
455 static final MethodHandle MH_fin;
456
457 static final MethodType MT_loop = methodType(int.class, int.class);
458
459 static {
460 try {
461 MH_inc = LOOKUP.findStatic(LOOP, "inc", MT_inc);
462 MH_pred = LOOKUP.findStatic(LOOP, "pred", MT_pred);
463 MH_fin = LOOKUP.findStatic(LOOP, "fin", MT_fin);
464 } catch (Exception e) {
465 throw new ExceptionInInitializerError(e);
466 }
467 }
468
469 }
470
471 static class LoopWithVirtuals {
472
473 static int one(int k) {
474 return 1;
475 }
476
477 int inc(int i, int acc, int k) {
478 return i + 1;
479 }
480
481 int mult(int i, int acc, int k) {
482 return i * acc;
483 }
484
485 boolean pred(int i, int acc, int k) {
486 return i < k;
487 }
488
489 int fin(int i, int acc, int k) {
490 return acc;
491 }
492
493 static final Class<LoopWithVirtuals> LOOP_WITH_VIRTUALS = LoopWithVirtuals.class;
494
495 static final MethodType MT_one = methodType(int.class, int.class);
496 static final MethodType MT_inc = methodType(int.class, int.class, int.class, int.class);
497 static final MethodType MT_mult = methodType(int.class, int.class, int.class, int.class);
498 static final MethodType MT_pred = methodType(boolean.class, int.class, int.class, int.class);
499 static final MethodType MT_fin = methodType(int.class, int.class, int.class, int.class);
500
501 static final MethodHandle MH_one;
502 static final MethodHandle MH_inc;
503 static final MethodHandle MH_mult;
504 static final MethodHandle MH_pred;
505 static final MethodHandle MH_fin;
506
507 static final MethodType MT_loop = methodType(int.class, LOOP_WITH_VIRTUALS, int.class);
508
509 static {
510 try {
511 MH_one = LOOKUP.findStatic(LOOP_WITH_VIRTUALS, "one", MT_one);
512 MH_inc = LOOKUP.findVirtual(LOOP_WITH_VIRTUALS, "inc", MT_inc);
513 MH_mult = LOOKUP.findVirtual(LOOP_WITH_VIRTUALS, "mult", MT_mult);
514 MH_pred = LOOKUP.findVirtual(LOOP_WITH_VIRTUALS, "pred", MT_pred);
515 MH_fin = LOOKUP.findVirtual(LOOP_WITH_VIRTUALS, "fin", MT_fin);
516 } catch (Exception e) {
517 throw new ExceptionInInitializerError(e);
518 }
519 }
520
521 static MethodHandle permute(MethodHandle h) {
522 // The handles representing virtual methods need to be rearranged to match the required order of arguments
523 // (loop-local state comes first, then loop arguments). As the receiver comes first in the signature but is
524 // a loop argument, it must be moved to the appropriate position in the signature.
525 return MethodHandles.permuteArguments(h,
526 methodType(h.type().returnType(), int.class, int.class, LOOP_WITH_VIRTUALS, int.class), 2, 0, 1, 3);
527 }
528
529 }
530
531 static class While {
532
533 static int zero(int limit) {
534 return 0;
535 }
536
537 static boolean pred(int i, int limit) {
538 return i < limit;
539 }
540
541 static int step(int i, int limit) {
542 return i + 1;
543 }
544
545 static String initString() {
546 return "a";
547 }
548
549 static boolean predString(String s) {
550 return s.length() != 1;
551 }
552
553 static String stepString(String s) {
554 return s + "a";
555 }
556
557 static List<String> zipInitZip(Iterator<String> a, Iterator<String> b) {
558 return new ArrayList<>();
559 }
560
561 static boolean zipPred(List<String> zip, Iterator<String> a, Iterator<String> b) {
562 return a.hasNext() && b.hasNext();
563 }
564
565 static List<String> zipStep(List<String> zip, Iterator<String> a, Iterator<String> b) {
566 zip.add(a.next());
567 zip.add(b.next());
568 return zip;
569 }
570
571 static final Class<While> WHILE = While.class;
572
573 static final MethodType MT_zero = methodType(int.class, int.class);
574 static final MethodType MT_pred = methodType(boolean.class, int.class, int.class);
575 static final MethodType MT_fn = methodType(int.class, int.class, int.class);
576 static final MethodType MT_initString = methodType(String.class);
577 static final MethodType MT_predString = methodType(boolean.class, String.class);
578 static final MethodType MT_stepString = methodType(String.class, String.class);
579 static final MethodType MT_zipInitZip = methodType(List.class, Iterator.class, Iterator.class);
580 static final MethodType MT_zipPred = methodType(boolean.class, List.class, Iterator.class, Iterator.class);
581 static final MethodType MT_zipStep = methodType(List.class, List.class, Iterator.class, Iterator.class);
582
583 static final MethodHandle MH_zero;
584 static final MethodHandle MH_pred;
585 static final MethodHandle MH_step;
586 static final MethodHandle MH_initString;
587 static final MethodHandle MH_predString;
588 static final MethodHandle MH_stepString;
589 static final MethodHandle MH_zipInitZip;
590 static final MethodHandle MH_zipPred;
591 static final MethodHandle MH_zipStep;
592
593 static final MethodType MT_while = methodType(int.class, int.class);
594 static final MethodType MT_string = methodType(String.class);
595 static final MethodType MT_zip = methodType(List.class, Iterator.class, Iterator.class);
596
597 static {
598 try {
599 MH_zero = LOOKUP.findStatic(WHILE, "zero", MT_zero);
600 MH_pred = LOOKUP.findStatic(WHILE, "pred", MT_pred);
601 MH_step = LOOKUP.findStatic(WHILE, "step", MT_fn);
602 MH_initString = LOOKUP.findStatic(WHILE, "initString", MT_initString);
603 MH_predString = LOOKUP.findStatic(WHILE, "predString", MT_predString);
604 MH_stepString = LOOKUP.findStatic(WHILE, "stepString", MT_stepString);
605 MH_zipInitZip = LOOKUP.findStatic(WHILE, "zipInitZip", MT_zipInitZip);
606 MH_zipPred = LOOKUP.findStatic(WHILE, "zipPred", MT_zipPred);
607 MH_zipStep = LOOKUP.findStatic(WHILE, "zipStep", MT_zipStep);
608 } catch (Exception e) {
609 throw new ExceptionInInitializerError(e);
610 }
611 }
612
613 }
614
615 static class Counted {
616
617 static String start(String arg) {
618 return arg;
619 }
620
621 static String step(int counter, String v, String arg) {
622 return "na " + v;
623 }
624
625 static void stepUpdateArray(int counter, int[] a) {
626 ++a[0];
627 }
628
629 static void printHello(int counter) {
630 System.out.print("hello");
631 }
632
633 static final Class<Counted> COUNTED = Counted.class;
634
635 static final MethodType MT_start = methodType(String.class, String.class);
636 static final MethodType MT_step = methodType(String.class, int.class, String.class, String.class);
637 static final MethodType MT_stepUpdateArray = methodType(void.class, int.class, int[].class);
638 static final MethodType MT_printHello = methodType(void.class, int.class);
639
640 static final MethodHandle MH_13;
641 static final MethodHandle MH_m5;
642 static final MethodHandle MH_8;
643 static final MethodHandle MH_start;
644 static final MethodHandle MH_step;
645 static final MethodHandle MH_stepUpdateArray;
646 static final MethodHandle MH_printHello;
647
648 static final MethodType MT_counted = methodType(String.class, String.class);
649 static final MethodType MT_arrayCounted = methodType(void.class, int[].class);
650 static final MethodType MT_countedPrinting = methodType(void.class);
651
652 static {
653 try {
654 MH_13 = MethodHandles.constant(int.class, 13);
655 MH_m5 = MethodHandles.constant(int.class, -5);
656 MH_8 = MethodHandles.constant(int.class, 8);
657 MH_start = LOOKUP.findStatic(COUNTED, "start", MT_start);
658 MH_step = LOOKUP.findStatic(COUNTED, "step", MT_step);
659 MH_stepUpdateArray = LOOKUP.findStatic(COUNTED, "stepUpdateArray", MT_stepUpdateArray);
660 MH_printHello = LOOKUP.findStatic(COUNTED, "printHello", MT_printHello);
661 } catch (Exception e) {
662 throw new ExceptionInInitializerError(e);
663 }
664 }
665
666 }
667
668 static class Iterate {
669
670 static Iterator<Integer> sumIterator(Integer[] a) {
671 return Arrays.asList(a).iterator();
672 }
673
674 static int sumInit(Integer[] a) {
675 return 0;
676 }
677
678 static int sumStep(int s, int e, Integer[] a) {
679 return s + e;
680 }
681
682 static List<String> reverseInit(List<String> l) {
683 return new ArrayList<>();
684 }
685
686 static List<String> reverseStep(String e, List<String> r, List<String> l) {
687 r.add(0, e);
688 return r;
689 }
690
691 static int lengthInit(List<Double> l) {
692 return 0;
693 }
694
695 static int lengthStep(Object o, int len, List<Double> l) {
696 return len + 1;
697 }
698
699 static List<String> mapInit(List<String> l) {
700 return new ArrayList<>();
701 }
702
703 static List<String> mapStep(String e, List<String> r, List<String> l) {
704 r.add(e.toUpperCase());
705 return r;
706 }
707
708 static void printStep(String s, List<String> l) {
709 System.out.print(s);
710 }
711
712 static final Class<Iterate> ITERATE = Iterate.class;
713
714 static final MethodType MT_sumIterator = methodType(Iterator.class, Integer[].class);
715
716 static final MethodType MT_sumInit = methodType(int.class, Integer[].class);
717 static final MethodType MT_reverseInit = methodType(List.class, List.class);
718 static final MethodType MT_lenghInit = methodType(int.class, List.class);
719 static final MethodType MT_mapInit = methodType(List.class, List.class);
720
721 static final MethodType MT_sumStep = methodType(int.class, int.class, int.class, Integer[].class);
722 static final MethodType MT_reverseStep = methodType(List.class, String.class, List.class, List.class);
723 static final MethodType MT_lengthStep = methodType(int.class, Object.class, int.class, List.class);
724 static final MethodType MT_mapStep = methodType(List.class, String.class, List.class, List.class);
725 static final MethodType MT_printStep = methodType(void.class, String.class, List.class);
726
727 static final MethodHandle MH_sumIterator;
728 static final MethodHandle MH_sumInit;
729 static final MethodHandle MH_sumStep;
730 static final MethodHandle MH_printStep;
731
732 static final MethodHandle MH_reverseInit;
733 static final MethodHandle MH_reverseStep;
734
735 static final MethodHandle MH_lengthInit;
736 static final MethodHandle MH_lengthStep;
737
738 static final MethodHandle MH_mapInit;
739 static final MethodHandle MH_mapStep;
740
741 static final MethodType MT_sum = methodType(int.class, Integer[].class);
742 static final MethodType MT_reverse = methodType(List.class, List.class);
743 static final MethodType MT_length = methodType(int.class, List.class);
744 static final MethodType MT_map = methodType(List.class, List.class);
745 static final MethodType MT_print = methodType(void.class, List.class);
746
747 static {
748 try {
749 MH_sumIterator = LOOKUP.findStatic(ITERATE, "sumIterator", MT_sumIterator);
750 MH_sumInit = LOOKUP.findStatic(ITERATE, "sumInit", MT_sumInit);
751 MH_sumStep = LOOKUP.findStatic(ITERATE, "sumStep", MT_sumStep);
752 MH_reverseInit = LOOKUP.findStatic(ITERATE, "reverseInit", MT_reverseInit);
753 MH_reverseStep = LOOKUP.findStatic(ITERATE, "reverseStep", MT_reverseStep);
754 MH_lengthInit = LOOKUP.findStatic(ITERATE, "lengthInit", MT_lenghInit);
755 MH_lengthStep = LOOKUP.findStatic(ITERATE, "lengthStep", MT_lengthStep);
756 MH_mapInit = LOOKUP.findStatic(ITERATE, "mapInit", MT_mapInit);
757 MH_mapStep = LOOKUP.findStatic(ITERATE, "mapStep", MT_mapStep);
758 MH_printStep = LOOKUP.findStatic(ITERATE, "printStep", MT_printStep);
759 } catch (Exception e) {
760 throw new ExceptionInInitializerError(e);
761 }
762 }
763
764 }
765
766 }