Recursive update exception: assignment to a cage with lazy right hand side is a problem! #462

dours · 2021-11-29T18:18:54Z

[] > infinite-loop
  cage > x
  seq > @
    x.write 0
    x.write (x.add 1)
    x.eq 1

fails.

Of course: x.write (x.add 1) is implemented basically as x := (lambda nothing -> x + 1). Any attempt to calculate x leads to endless recursion.

The text was updated successfully, but these errors were encountered:

dours · 2021-11-29T18:20:59Z

The previous eaxmple only uses dataizable objects, so it does not need cage. But here is an example, which is not implementable with memory:

[] > infinite-loop-2
  [first second] > pair
  [head list] > addHead
    pair head list > @
  cage > lst
  seq > @
    lst.write (pair 1 0)
    lst.write (addHead 2 lst)
    lst.second.second.eq 0

yegor256 · 2021-12-01T04:35:52Z

@dours it seems that we should get back to the "dataized" idea, which was abandoned some time ago: #354 Your code would be:

[] > infinite-loop
  cage > x
  seq > @
    x.write 0
    x.write (dataized (x.add 1))
    x.eq 1

Will this work?

yegor256 · 2021-12-01T04:41:57Z

@dours on second thought, it seems that this won't help, since dataized would be yet another object in the recursion chain...

yegor256 · 2021-12-01T04:58:40Z

@dours another option is this:

[] > infinite-loop
  cage > x
  seq > @
    x.write 0
    x.add 1 > a!
    x.write a
    x.eq 1

yegor256 · 2021-12-01T09:04:21Z

@dours or this one:

[] > infinite-loop
  cage > x
  seq > @
    x.write 0
    x.write (x.add 1).@
    x.eq 1

dours · 2021-12-01T12:53:32Z

@yegor256 what does .@ mean? Does it also call dataization?

What about the second example, infinite-loop-2?

[] > infinite-loop-2
  [first second] > pair
  [head list] > addHead
    pair head list > @
  cage > lst
  seq > @
    lst.write (pair 1 0)
    lst.write (addHead 2 lst).@
    lst.second.second.eq 0

does not work (StillAbstract exception)

yegor256 · 2021-12-01T18:22:51Z

@dours yes, .@ is basically a dataization. For example, random.@ > x means: "x is the object which is decorated by random". In order to find out who it is, we have to ask random this question. And the answer will be, for example, 0.4738383. We will not ask random again. We will assign x to the float number.

yegor256 · 2021-12-01T18:26:23Z

@dours try this:

lst.write ((addHead 2 lst).@)

Maybe it's a syntax problem. But I doubt it. Please, post your entire stack trace.

dours · 2021-12-01T19:03:04Z

@yegor256 I don't think that it is a syntax problem. I just don't want to dataize the right hand side of assignment in this example, because it is not dataizable. I try to express a list as a pair of head (the first element of a list) and tail (the rest of the list, which is a list itself).

I construct a list with two elements by adding a head to a list with one element (lst.write (addHead 2 lst)).

But if I'm forced to dataize the right hand side of that assignment, then the representation of my list is changed in the middle of construction, that's the problem! (I mean, even if I make my list implementation dataizable, a dataization of a list is not the list itself, how can I add an element to it?).

Is this stack trace entire enough? I don't know how to get rid of "... 88 more". Maybe, you don't need the trace to answer my question.

�[1;34mINFO�[m] Running EOorg.EOeolang.EOgray.�[1mEOinfinite_loop_2Test�[m
·𝔻( seq.steps ≡ array(Δ ↦ ⟦ι0 ↦ infinite-loop-2.lst.write(#0 ↦ infinite-loop-2.pair(#0 ↦ int(Δ ↦ 1))(#1 ↦ int(Δ ↦ 0))), ι1 ↦ infinite-loop-2.lst.write(#0 ↦ infinite-loop-2.addHead(#0 ↦ int(Δ ↦ 2))(#1 ↦ infinite-loop-2.lst).φ), ι2 ↦ infinite-loop-2.lst.second.second.eq(#0 ↦ int(Δ ↦ 0))⟧) ) ➜ ⟦ι0 ↦ infinite-loop-2.lst.write(#0 ↦ infinite-loop-2.pair(#0 ↦ int(Δ ↦ 1))(#1 ↦ int(Δ ↦ 0))), ι1 ↦ infinite-loop-2.lst.write(#0 ↦ infinite-loop-2.addHead(#0 ↦ int(Δ ↦ 2))(#1 ↦ infinite-loop-2.lst).φ), ι2 ↦ infinite-loop-2.lst.second.second.eq(#0 ↦ int(Δ ↦ 0))⟧
·𝔻( infinite-loop-2.lst.write(#0 ↦ infinite-loop-2.pair(#0 ↦ int(Δ ↦ 1))(#1 ↦ int(Δ ↦ 0))) ) ➜ true
·𝔻( infinite-loop-2.lst.write(#0 ↦ infinite-loop-2.addHead(#0 ↦ int(Δ ↦ 2))(#1 ↦ infinite-loop-2.lst).φ) ) ➜ true
[�[1;31mERROR�[m] �[1;31mTests �[0;1mrun: �[0;1m1�[m, Failures: 0, �[1;31mErrors: �[0;1;31m1�[m, Skipped: 0, Time elapsed: 0.012 s�[1;31m <<< FAILURE!�[m - in EOorg.EOeolang.EOgray.�[1mEOinfinite_loop_2Test�[m
[�[1;31mERROR�[m] EOorg.EOeolang.EOgray.EOinfinite_loop_2Test.testWorks  Time elapsed: 0.004 s  <<< ERROR!
org.eolang.Attr$StillAbstractException: Error at "EOorg.EOeolang.EOgray.EOinfinite_loop_2Test.EOinfinite_loop_2Test$EOpair#eq" attribute
	at org.eolang.AtNamed.get(AtNamed.java:79)
	at org.eolang.PhDefault.attr(PhDefault.java:209)
	at org.eolang.PhNamed.attr(PhNamed.java:82)
	at org.eolang.PhNamed.attr(PhNamed.java:82)
	at org.eolang.PhNamed.attr(PhNamed.java:82)
	at org.eolang.PhOnce.attr(PhOnce.java:86)
	at org.eolang.PhMethod.lambda$new$0(PhMethod.java:42)
	at org.eolang.Data$Once.take(Data.java:90)
	at org.eolang.PhOnce.copy(PhOnce.java:71)
	at org.eolang.Data$Once.take(Data.java:90)
	at org.eolang.PhOnce.attr(PhOnce.java:81)
	at org.eolang.PhWith.lambda$new$3(PhWith.java:72)
	at org.eolang.Data$Once.take(Data.java:90)
	at org.eolang.PhOnce.attr(PhOnce.java:86)
	at org.eolang.PhDefault.attr(PhDefault.java:209)
	at org.eolang.PhOnce.attr(PhOnce.java:86)
	at org.eolang.PhOnce.attr(PhOnce.java:86)
	at org.eolang.PhOnce.attr(PhOnce.java:86)
	at org.eolang.PhOnce.attr(PhOnce.java:86)
	at org.eolang.PhDefault.attr(PhDefault.java:209)
	at org.eolang.Dataized.take(Dataized.java:71)
	at org.eolang.Dataized.take(Dataized.java:107)
	at EOorg.EOeolang.EOgray.EOinfinite_loop_2Test.testWorks(EOinfinite_loop_2Test.java:76)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.base/java.lang.reflect.Method.invoke(Method.java:567)
	at org.junit.platform.commons.util.ReflectionUtils.invokeMethod(ReflectionUtils.java:686)
	at org.junit.jupiter.engine.execution.MethodInvocation.proceed(MethodInvocation.java:60)
	at org.junit.jupiter.engine.execution.InvocationInterceptorChain$ValidatingInvocation.proceed(InvocationInterceptorChain.java:131)
	at org.junit.jupiter.engine.extension.TimeoutExtension.intercept(TimeoutExtension.java:149)
	at org.junit.jupiter.engine.extension.TimeoutExtension.interceptTestableMethod(TimeoutExtension.java:140)
	at org.junit.jupiter.engine.extension.TimeoutExtension.interceptTestMethod(TimeoutExtension.java:84)
	at org.junit.jupiter.engine.execution.ExecutableInvoker$ReflectiveInterceptorCall.lambda$ofVoidMethod$0(ExecutableInvoker.java:115)
	at org.junit.jupiter.engine.execution.ExecutableInvoker.lambda$invoke$0(ExecutableInvoker.java:105)
	at org.junit.jupiter.engine.execution.InvocationInterceptorChain$InterceptedInvocation.proceed(InvocationInterceptorChain.java:106)
	at org.junit.jupiter.engine.execution.InvocationInterceptorChain.proceed(InvocationInterceptorChain.java:64)
	at org.junit.jupiter.engine.execution.InvocationInterceptorChain.chainAndInvoke(InvocationInterceptorChain.java:45)
	at org.junit.jupiter.engine.execution.InvocationInterceptorChain.invoke(InvocationInterceptorChain.java:37)
	at org.junit.jupiter.engine.execution.ExecutableInvoker.invoke(ExecutableInvoker.java:104)
	at org.junit.jupiter.engine.execution.ExecutableInvoker.invoke(ExecutableInvoker.java:98)
	at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.lambda$invokeTestMethod$6(TestMethodTestDescriptor.java:212)
	at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
	at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.invokeTestMethod(TestMethodTestDescriptor.java:208)
	at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.execute(TestMethodTestDescriptor.java:137)
	at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.execute(TestMethodTestDescriptor.java:71)
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$5(NodeTestTask.java:135)
	at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$7(NodeTestTask.java:125)
	at org.junit.platform.engine.support.hierarchical.Node.around(Node.java:135)
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$8(NodeTestTask.java:123)
	at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.executeRecursively(NodeTestTask.java:122)
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:80)
	at java.base/java.util.ArrayList.forEach(ArrayList.java:1508)
	at org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService.invokeAll(SameThreadHierarchicalTestExecutorService.java:38)
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$5(NodeTestTask.java:139)
	at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$7(NodeTestTask.java:125)
	at org.junit.platform.engine.support.hierarchical.Node.around(Node.java:135)
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$8(NodeTestTask.java:123)
	at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.executeRecursively(NodeTestTask.java:122)
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:80)
	at java.base/java.util.ArrayList.forEach(ArrayList.java:1508)
	at org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService.invokeAll(SameThreadHierarchicalTestExecutorService.java:38)
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$5(NodeTestTask.java:139)
	at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$7(NodeTestTask.java:125)
	at org.junit.platform.engine.support.hierarchical.Node.around(Node.java:135)
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$8(NodeTestTask.java:123)
	at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.executeRecursively(NodeTestTask.java:122)
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:80)
	at org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService.submit(SameThreadHierarchicalTestExecutorService.java:32)
	at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor.execute(HierarchicalTestExecutor.java:57)
	at org.junit.platform.engine.support.hierarchical.HierarchicalTestEngine.execute(HierarchicalTestEngine.java:51)
	at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:248)
	at org.junit.platform.launcher.core.DefaultLauncher.lambda$execute$5(DefaultLauncher.java:211)
	at org.junit.platform.launcher.core.DefaultLauncher.withInterceptedStreams(DefaultLauncher.java:226)
	at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:199)
	at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:132)
	at org.apache.maven.surefire.junitplatform.JUnitPlatformProvider.execute(JUnitPlatformProvider.java:188)
	at org.apache.maven.surefire.junitplatform.JUnitPlatformProvider.invokeAllTests(JUnitPlatformProvider.java:154)
	at org.apache.maven.surefire.junitplatform.JUnitPlatformProvider.invoke(JUnitPlatformProvider.java:128)
	at org.apache.maven.surefire.booter.ForkedBooter.runSuitesInProcess(ForkedBooter.java:428)
	at org.apache.maven.surefire.booter.ForkedBooter.execute(ForkedBooter.java:162)
	at org.apache.maven.surefire.booter.ForkedBooter.run(ForkedBooter.java:562)
	at org.apache.maven.surefire.booter.ForkedBooter.main(ForkedBooter.java:548)
Caused by: org.eolang.Attr$StillAbstractException: Can't get(), attribute "eq" is absent among other 4 attrs (ρ, σ, first, second) and φ is absent
	at org.eolang.AtAbsent.get(AtAbsent.java:70)
	at org.eolang.AtNamed.get(AtNamed.java:75)
	... 88 more

yegor256 · 2021-12-02T04:34:18Z

@dours you understand the error message? It says that it can't find eq in the object. Thus, lst.second.second is pair. Does this information help?

yegor256 · 2021-12-09T08:13:39Z

@rultor release, tag is 0.20.0

rultor · 2021-12-09T08:14:46Z

@rultor release, tag is 0.20.0

@yegor256 OK, I will release it now. Please check the progress here

rultor · 2021-12-09T08:40:07Z

@rultor release, tag is 0.20.0

@yegor256 Done! FYI, the full log is here (took me 25min)

yegor256 · 2021-12-09T08:40:51Z

@dours I believe this problem is fixed in version 0.20.0. Try this code:

[] > avoid-infinite-loop
  cage > x
  x' > copy
  seq > @
    x.write 42
    copy.<
    x.write (7.add copy)
    x.eq 49

The new syntax introduced is x' -- it explicitly makes a copy of an object. Also, in order to make sure the copy is ready before the write is happening, we do this:

copy.<

This line, when being dataized by seq, makes sure the copy is alive. More tests here: https://github.com/cqfn/eo/blob/master/eo-runtime/src/test/eo/org/eolang/gray/cage-tests.eo

0crat · 2021-12-09T14:29:29Z

Job gh:cqfn/eo#462 is not assigned, can't get performer

0crat added the 0crat/new label Nov 29, 2021

dours mentioned this issue Nov 29, 2021

generate a more elegant EO with the help of org.eolang.gray.cage object polystat/py2eo#36

Closed

dours changed the title ~~Recursive update exception: assignment with lazy right hand side is a problem!~~ Recursive update exception: assignment to a cage with lazy right hand side is a problem! Nov 29, 2021

yegor256 added a commit that referenced this issue Dec 7, 2021

#462 reset caching

2b59f71

yegor256 added a commit that referenced this issue Dec 7, 2021

#462 still broken test

4955e33

yegor256 added a commit that referenced this issue Dec 9, 2021

#462 fixed and explicit copy introduced

2834f3b

yegor256 closed this as completed Dec 9, 2021

yegor256 added a commit that referenced this issue Dec 9, 2021

#462 explained

77dbd0a

yegor256 added a commit that referenced this issue Dec 9, 2021

#462 tests enabled

02e6fa2

yegor256 added a commit that referenced this issue Dec 9, 2021

#462 sandbox up

db44746

yegor256 added a commit that referenced this issue Dec 9, 2021

#462 typo

f1ab98b

yegor256 mentioned this issue Dec 12, 2021

Problem when using cage with nested memory #481

Closed

dours mentioned this issue May 31, 2022

Complicated translation result polystat/py2eo#257

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Recursive update exception: assignment to a cage with lazy right hand side is a problem! #462

Recursive update exception: assignment to a cage with lazy right hand side is a problem! #462

dours commented Nov 29, 2021

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0crat commented Dec 9, 2021

Recursive update exception: assignment to a cage with lazy right hand side is a problem! #462

Recursive update exception: assignment to a cage with lazy right hand side is a problem! #462

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