You are viewing a plain text version of this content. The canonical link for it is here.
Posted to users@groovy.apache.org by Søren Berg Glasius <so...@glasius.dk> on 2015/09/29 09:54:17 UTC
A @CompileStatic bug, or is it just me: [].withDefault { 0 }
Hi Fellows,
I stumbled upon this today.
This code runs:
class Test {
private List<Integer> x = [].withDefault { 0 }
Integer getValue(int n) {
return x[n]
}
}
assert new Test().getValue(5) == 0
where as when I compile static:
@CompileStatic
class Test {
private List<Integer> x = [].withDefault { 0 }
Integer getValue(int n) {
return x[n]
}
}
assert new Test().getValue(5) == 0
I get an assertion failed, because new Test().getValue(5) == null
Is this expected behavior or a bug?
Best regards / Med venlig hilsen,
Søren Berg Glasius
Hedevej 1, Gl. Rye, 8680 Ry, Denmark
Mobile: +45 40 44 91 88, Skype: sbglasius
--- Press ESC once to quit - twice to save the changes.
RE: A @CompileStatic bug, or is it just me: [].withDefault { 0 }
Posted by "Winnebeck, Jason" <Ja...@windstream.com>.
This is an interesting one, you are right about the method selection, because static compiler doesn't know that it's a ListWithDefault, it calls DGM.getAt instead of ListWithDefault.getAt. I think this is reasonable and static compiler has selected the proper method.
But, I also agree it could be considered a bug in DGM.getAt, or with ListWithDefault. If I implement my own class that does the same as withDefault, it will have the same bug even in dynamic Groovy. The DGM.getAt method checks, using List.size() method, if the index is valid, if so it calls List.get else it returns null without trying get. ListWithDefault has an interesting behavior that get at an index past the end extends the list. The contract of List.get states that index out of range produces IndexOutOfBoundsException, ListWithDefault doesn't, so it doesn't obey List's contract.
Here is an example where I am simulating what withDefault does, but from the perspective of a non-Groovy developer that doesn't know about getAt (i.e. ListWrapper maybe is implemented in Java or Scala):
class ListWrapper implements List {
@Delegate List delegate
def get(int index) {
if (index >= size())
"past the end"
}
}
x = new ListWrapper(delegate: [])
assert x[1] == null
assert x.get(1) == "past the end"
As I see it, there are two solutions to this:
1. Argue that ListWithDefault is not obeying List contract and have its size method return Integer.MAX_VALUE
2. DGM.getAt(List, int) should be written to replace the if (index < size) check with always calling List.get returning null if catching IndexOutOfBoundsException (or perhaps on any exception).
The second option is definitely the safer and acts like a developer would expect. I'm not sure try/catch has a significant performance impact in Java when the exception is not thrown, though. It still can represent a breaking change if any code relies on get not having been called (but before I saw code or docs I would expect x[0] on a List type to always attempt x.get(0)).
Jason
-----Original Message-----
From: Jochen Theodorou [mailto:blackdrag@gmx.org]
Sent: Wednesday, September 30, 2015 2:05 AM
To: users@groovy.incubator.apache.org
Subject: Re: A @CompileStatic bug, or is it just me: [].withDefault { 0 }
This actually highlights a general problem with static compilation and extension methods.
Extension methods are not part of the class in the Java sense. Thus there is no virtual method call. This means that if the compiler assumes the wrong type, it will call the wrong method. In Java everything is fine as long as the "wrongly" assumed type is a super type and defines the method. Example:
class Foo {
int foo(){1}
}
class Bar extends Foo {
int foo(){2}
}
def method(Foo f) {
return f.foo()
}
assert method(new Foo()) == 1
assert method(new Bar()) == 2
A static compiler will select Foo#foo() for the call, but since the method call is done virtual, you still end up doing Bar#foo() if f is Bar. But with extension methods:
class Foo{}
class ExtensionMethodsForFoo { // placed so compiler knows this
static int foo(Foo f){1}
}
class Bar extends Foo{
int foo(){2}
}
assert method(new Foo()) == 1
assert method(new Bar()) == 1
Again the compiler will only see Foo#foo, because he cannot know better.
But since the call cannot be virtual, there is no way of calling Bar#foo this way. It would also be the same if Bar#foo is defined as extension method as well.
In general: inheritance with extension methods does not work properly for static compiled Groovy. It cannot imho.
For the case here, it might be a workaround to let the withDefault method not return List (which will let the compiler then later select List#getAt from DGM), but to use the specific type (ListWithDefault or something). Then the compiler can select the proper method through flow typing. Of course, as soon as you moves parts of the code in another method, you may end up with the same problem. So it is not a really refactoring-safe solution. But better than nothing I guess.
Anyway... just wanted to confirm you guys why this is no static compilation bug.
Of course you could think about doing double dispatch in the DGM method, but either you do dynamic calls from there and loose the advantage of static compilation, or
bye blackdrag
Am 29.09.2015 23:58, schrieb Shil Sinha:
> The bytecode for x[n] is:
>
> ILOAD 1
> INVOKESTATIC
> org/codehaus/groovy/runtime/DefaultGroovyMethods.getAt
> (Ljava/util/List;I)Ljava/lang/Object;
>
> The implementation of DGM.getAt(List, int) returns null if the given
> index is >= the size of the list, so this makes sense. Seems like a
> bug in the DGM implementation more than @CompileStatic.
>
> On Tue, Sep 29, 2015 at 5:17 PM, Søren Berg Glasius <soeren@glasius.dk
> <ma...@glasius.dk>> wrote:
>
> Should I file a bug report?
>
>
> Best regards / Med venlig hilsen,
> Søren Berg Glasius
>
> Hedevej 1, Gl. Rye, 8680 Ry, Denmark
> Mobile: +45 40 44 91 88 <tel:%2B45%2040%2044%2091%2088>, Skype:
> sbglasius
> --- Press ESC once to quit - twice to save the changes.
>
> On 29 September 2015 at 10:17, Dinko Srkoč <dinko.srkoc@gmail.com
> <ma...@gmail.com>> wrote:
>
> On 29 September 2015 at 10:12, Cédric Champeau
> <cedric.champeau@gmail.com <ma...@gmail.com>>
> wrote:
> > That's because it's withDefault { 1 } ;)
>
> Argh! Still morning for me. :-(
>
> >
> > 2015-09-29 10:05 GMT+02:00 Dinko Srkoč <dinko.srkoc@gmail.com
> <ma...@gmail.com>>:
> >>
> >> On 29 September 2015 at 09:58, Cédric Champeau
> >> <cedric.champeau@gmail.com
> <ma...@gmail.com>> wrote:
> >> > This looks like a bug. Would be interesting to look at the
> bytecode to
> >> > check
> >> > what method is called for x[n].
> >>
> >> Curiously, I tried to do just that in the Groovy AST Browser
> and, for
> >> the following piece of code:
> >>
> >> @groovy.transform.CompileStatic
> >> def foo() {
> >> [].withDefault(1)
> >> }
> >>
> >> got this:
> >>
> >> Unable to produce AST for this phase due to earlier
> compilation error:
> >> startup failed:
> >> script1443513793544.groovy: 3: [Static type checking] -
> Cannot find
> >> matching method java.util.List#withDefault(int). Please
> check if the
> >> declared type is right and if the method exists.
> >> @ line 3, column 5.
> >> [].withDefault(1)
> >> ^
> >>
> >> That's Groovy 2.4.4
> >>
> >> Cheers,
> >> Dinko
> >>
> >> >
> >> > 2015-09-29 9:54 GMT+02:00 Søren Berg Glasius
> <soeren@glasius.dk <ma...@glasius.dk>>:
> >> >>
> >> >> Hi Fellows,
> >> >>
> >> >> I stumbled upon this today.
> >> >>
> >> >> This code runs:
> >> >>
> >> >> class Test {
> >> >> private List<Integer> x = [].withDefault { 0 }
> >> >> Integer getValue(int n) {
> >> >> return x[n]
> >> >> }
> >> >> }
> >> >> assert new Test().getValue(5) == 0
> >> >>
> >> >> where as when I compile static:
> >> >>
> >> >> @CompileStatic
> >> >> class Test {
> >> >> private List<Integer> x = [].withDefault { 0 }
> >> >> Integer getValue(int n) {
> >> >> return x[n]
> >> >> }
> >> >> }
> >> >> assert new Test().getValue(5) == 0
> >> >>
> >> >> I get an assertion failed, because new Test().getValue(5)
> == null
> >> >>
> >> >> Is this expected behavior or a bug?
> >> >>
> >> >>
> >> >> Best regards / Med venlig hilsen,
> >> >> Søren Berg Glasius
> >> >>
> >> >> Hedevej 1, Gl. Rye, 8680 Ry, Denmark
> >> >> Mobile: +45 40 44 91 88 <tel:%2B45%2040%2044%2091%2088>,
> Skype: sbglasius
> >> >> --- Press ESC once to quit - twice to save the changes.
> >> >
> >> >
> >
> >
>
>
>
--
Jochen "blackdrag" Theodorou
blog: http://blackdragsview.blogspot.com/
----------------------------------------------------------------------
This email message and any attachments are for the sole use of the intended recipient(s). Any unauthorized review, use, disclosure or distribution is prohibited. If you are not the intended recipient, please contact the sender by reply email and destroy all copies of the original message and any attachments.
Re: A @CompileStatic bug, or is it just me: [].withDefault { 0 }
Posted by Jochen Theodorou <bl...@gmx.org>.
This actually highlights a general problem with static compilation and
extension methods.
Extension methods are not part of the class in the Java sense. Thus
there is no virtual method call. This means that if the compiler assumes
the wrong type, it will call the wrong method. In Java everything is
fine as long as the "wrongly" assumed type is a super type and defines
the method. Example:
class Foo {
int foo(){1}
}
class Bar extends Foo {
int foo(){2}
}
def method(Foo f) {
return f.foo()
}
assert method(new Foo()) == 1
assert method(new Bar()) == 2
A static compiler will select Foo#foo() for the call, but since the
method call is done virtual, you still end up doing Bar#foo() if f is
Bar. But with extension methods:
class Foo{}
class ExtensionMethodsForFoo { // placed so compiler knows this
static int foo(Foo f){1}
}
class Bar extends Foo{
int foo(){2}
}
assert method(new Foo()) == 1
assert method(new Bar()) == 1
Again the compiler will only see Foo#foo, because he cannot know better.
But since the call cannot be virtual, there is no way of calling Bar#foo
this way. It would also be the same if Bar#foo is defined as extension
method as well.
In general: inheritance with extension methods does not work properly
for static compiled Groovy. It cannot imho.
For the case here, it might be a workaround to let the withDefault
method not return List (which will let the compiler then later select
List#getAt from DGM), but to use the specific type (ListWithDefault or
something). Then the compiler can select the proper method through flow
typing. Of course, as soon as you moves parts of the code in another
method, you may end up with the same problem. So it is not a really
refactoring-safe solution. But better than nothing I guess.
Anyway... just wanted to confirm you guys why this is no static
compilation bug.
Of course you could think about doing double dispatch in the DGM method,
but either you do dynamic calls from there and loose the advantage of
static compilation, or
bye blackdrag
Am 29.09.2015 23:58, schrieb Shil Sinha:
> The bytecode for x[n] is:
>
> ILOAD 1
> INVOKESTATIC org/codehaus/groovy/runtime/DefaultGroovyMethods.getAt
> (Ljava/util/List;I)Ljava/lang/Object;
>
> The implementation of DGM.getAt(List, int) returns null if the given
> index is >= the size of the list, so this makes sense. Seems like a bug
> in the DGM implementation more than @CompileStatic.
>
> On Tue, Sep 29, 2015 at 5:17 PM, Søren Berg Glasius <soeren@glasius.dk
> <ma...@glasius.dk>> wrote:
>
> Should I file a bug report?
>
>
> Best regards / Med venlig hilsen,
> Søren Berg Glasius
>
> Hedevej 1, Gl. Rye, 8680 Ry, Denmark
> Mobile: +45 40 44 91 88 <tel:%2B45%2040%2044%2091%2088>, Skype:
> sbglasius
> --- Press ESC once to quit - twice to save the changes.
>
> On 29 September 2015 at 10:17, Dinko Srkoč <dinko.srkoc@gmail.com
> <ma...@gmail.com>> wrote:
>
> On 29 September 2015 at 10:12, Cédric Champeau
> <cedric.champeau@gmail.com <ma...@gmail.com>>
> wrote:
> > That's because it's withDefault { 1 } ;)
>
> Argh! Still morning for me. :-(
>
> >
> > 2015-09-29 10:05 GMT+02:00 Dinko Srkoč <dinko.srkoc@gmail.com
> <ma...@gmail.com>>:
> >>
> >> On 29 September 2015 at 09:58, Cédric Champeau
> >> <cedric.champeau@gmail.com
> <ma...@gmail.com>> wrote:
> >> > This looks like a bug. Would be interesting to look at the
> bytecode to
> >> > check
> >> > what method is called for x[n].
> >>
> >> Curiously, I tried to do just that in the Groovy AST Browser
> and, for
> >> the following piece of code:
> >>
> >> @groovy.transform.CompileStatic
> >> def foo() {
> >> [].withDefault(1)
> >> }
> >>
> >> got this:
> >>
> >> Unable to produce AST for this phase due to earlier
> compilation error:
> >> startup failed:
> >> script1443513793544.groovy: 3: [Static type checking] -
> Cannot find
> >> matching method java.util.List#withDefault(int). Please
> check if the
> >> declared type is right and if the method exists.
> >> @ line 3, column 5.
> >> [].withDefault(1)
> >> ^
> >>
> >> That's Groovy 2.4.4
> >>
> >> Cheers,
> >> Dinko
> >>
> >> >
> >> > 2015-09-29 9:54 GMT+02:00 Søren Berg Glasius
> <soeren@glasius.dk <ma...@glasius.dk>>:
> >> >>
> >> >> Hi Fellows,
> >> >>
> >> >> I stumbled upon this today.
> >> >>
> >> >> This code runs:
> >> >>
> >> >> class Test {
> >> >> private List<Integer> x = [].withDefault { 0 }
> >> >> Integer getValue(int n) {
> >> >> return x[n]
> >> >> }
> >> >> }
> >> >> assert new Test().getValue(5) == 0
> >> >>
> >> >> where as when I compile static:
> >> >>
> >> >> @CompileStatic
> >> >> class Test {
> >> >> private List<Integer> x = [].withDefault { 0 }
> >> >> Integer getValue(int n) {
> >> >> return x[n]
> >> >> }
> >> >> }
> >> >> assert new Test().getValue(5) == 0
> >> >>
> >> >> I get an assertion failed, because new Test().getValue(5)
> == null
> >> >>
> >> >> Is this expected behavior or a bug?
> >> >>
> >> >>
> >> >> Best regards / Med venlig hilsen,
> >> >> Søren Berg Glasius
> >> >>
> >> >> Hedevej 1, Gl. Rye, 8680 Ry, Denmark
> >> >> Mobile: +45 40 44 91 88 <tel:%2B45%2040%2044%2091%2088>,
> Skype: sbglasius
> >> >> --- Press ESC once to quit - twice to save the changes.
> >> >
> >> >
> >
> >
>
>
>
--
Jochen "blackdrag" Theodorou
blog: http://blackdragsview.blogspot.com/
Re: A @CompileStatic bug, or is it just me: [].withDefault { 0 }
Posted by Shil Sinha <sh...@gmail.com>.
The bytecode for x[n] is:
ILOAD 1
INVOKESTATIC org/codehaus/groovy/runtime/DefaultGroovyMethods.getAt
(Ljava/util/List;I)Ljava/lang/Object;
The implementation of DGM.getAt(List, int) returns null if the given index
is >= the size of the list, so this makes sense. Seems like a bug in the
DGM implementation more than @CompileStatic.
On Tue, Sep 29, 2015 at 5:17 PM, Søren Berg Glasius <so...@glasius.dk>
wrote:
> Should I file a bug report?
>
>
> Best regards / Med venlig hilsen,
> Søren Berg Glasius
>
> Hedevej 1, Gl. Rye, 8680 Ry, Denmark
> Mobile: +45 40 44 91 88, Skype: sbglasius
> --- Press ESC once to quit - twice to save the changes.
>
> On 29 September 2015 at 10:17, Dinko Srkoč <di...@gmail.com> wrote:
>
>> On 29 September 2015 at 10:12, Cédric Champeau
>> <ce...@gmail.com> wrote:
>> > That's because it's withDefault { 1 } ;)
>>
>> Argh! Still morning for me. :-(
>>
>> >
>> > 2015-09-29 10:05 GMT+02:00 Dinko Srkoč <di...@gmail.com>:
>> >>
>> >> On 29 September 2015 at 09:58, Cédric Champeau
>> >> <ce...@gmail.com> wrote:
>> >> > This looks like a bug. Would be interesting to look at the bytecode
>> to
>> >> > check
>> >> > what method is called for x[n].
>> >>
>> >> Curiously, I tried to do just that in the Groovy AST Browser and, for
>> >> the following piece of code:
>> >>
>> >> @groovy.transform.CompileStatic
>> >> def foo() {
>> >> [].withDefault(1)
>> >> }
>> >>
>> >> got this:
>> >>
>> >> Unable to produce AST for this phase due to earlier compilation error:
>> >> startup failed:
>> >> script1443513793544.groovy: 3: [Static type checking] - Cannot find
>> >> matching method java.util.List#withDefault(int). Please check if the
>> >> declared type is right and if the method exists.
>> >> @ line 3, column 5.
>> >> [].withDefault(1)
>> >> ^
>> >>
>> >> That's Groovy 2.4.4
>> >>
>> >> Cheers,
>> >> Dinko
>> >>
>> >> >
>> >> > 2015-09-29 9:54 GMT+02:00 Søren Berg Glasius <so...@glasius.dk>:
>> >> >>
>> >> >> Hi Fellows,
>> >> >>
>> >> >> I stumbled upon this today.
>> >> >>
>> >> >> This code runs:
>> >> >>
>> >> >> class Test {
>> >> >> private List<Integer> x = [].withDefault { 0 }
>> >> >> Integer getValue(int n) {
>> >> >> return x[n]
>> >> >> }
>> >> >> }
>> >> >> assert new Test().getValue(5) == 0
>> >> >>
>> >> >> where as when I compile static:
>> >> >>
>> >> >> @CompileStatic
>> >> >> class Test {
>> >> >> private List<Integer> x = [].withDefault { 0 }
>> >> >> Integer getValue(int n) {
>> >> >> return x[n]
>> >> >> }
>> >> >> }
>> >> >> assert new Test().getValue(5) == 0
>> >> >>
>> >> >> I get an assertion failed, because new Test().getValue(5) == null
>> >> >>
>> >> >> Is this expected behavior or a bug?
>> >> >>
>> >> >>
>> >> >> Best regards / Med venlig hilsen,
>> >> >> Søren Berg Glasius
>> >> >>
>> >> >> Hedevej 1, Gl. Rye, 8680 Ry, Denmark
>> >> >> Mobile: +45 40 44 91 88, Skype: sbglasius
>> >> >> --- Press ESC once to quit - twice to save the changes.
>> >> >
>> >> >
>> >
>> >
>>
>
>
Re: A @CompileStatic bug, or is it just me: [].withDefault { 0 }
Posted by Søren Berg Glasius <so...@glasius.dk>.
Should I file a bug report?
Best regards / Med venlig hilsen,
Søren Berg Glasius
Hedevej 1, Gl. Rye, 8680 Ry, Denmark
Mobile: +45 40 44 91 88, Skype: sbglasius
--- Press ESC once to quit - twice to save the changes.
On 29 September 2015 at 10:17, Dinko Srkoč <di...@gmail.com> wrote:
> On 29 September 2015 at 10:12, Cédric Champeau
> <ce...@gmail.com> wrote:
> > That's because it's withDefault { 1 } ;)
>
> Argh! Still morning for me. :-(
>
> >
> > 2015-09-29 10:05 GMT+02:00 Dinko Srkoč <di...@gmail.com>:
> >>
> >> On 29 September 2015 at 09:58, Cédric Champeau
> >> <ce...@gmail.com> wrote:
> >> > This looks like a bug. Would be interesting to look at the bytecode to
> >> > check
> >> > what method is called for x[n].
> >>
> >> Curiously, I tried to do just that in the Groovy AST Browser and, for
> >> the following piece of code:
> >>
> >> @groovy.transform.CompileStatic
> >> def foo() {
> >> [].withDefault(1)
> >> }
> >>
> >> got this:
> >>
> >> Unable to produce AST for this phase due to earlier compilation error:
> >> startup failed:
> >> script1443513793544.groovy: 3: [Static type checking] - Cannot find
> >> matching method java.util.List#withDefault(int). Please check if the
> >> declared type is right and if the method exists.
> >> @ line 3, column 5.
> >> [].withDefault(1)
> >> ^
> >>
> >> That's Groovy 2.4.4
> >>
> >> Cheers,
> >> Dinko
> >>
> >> >
> >> > 2015-09-29 9:54 GMT+02:00 Søren Berg Glasius <so...@glasius.dk>:
> >> >>
> >> >> Hi Fellows,
> >> >>
> >> >> I stumbled upon this today.
> >> >>
> >> >> This code runs:
> >> >>
> >> >> class Test {
> >> >> private List<Integer> x = [].withDefault { 0 }
> >> >> Integer getValue(int n) {
> >> >> return x[n]
> >> >> }
> >> >> }
> >> >> assert new Test().getValue(5) == 0
> >> >>
> >> >> where as when I compile static:
> >> >>
> >> >> @CompileStatic
> >> >> class Test {
> >> >> private List<Integer> x = [].withDefault { 0 }
> >> >> Integer getValue(int n) {
> >> >> return x[n]
> >> >> }
> >> >> }
> >> >> assert new Test().getValue(5) == 0
> >> >>
> >> >> I get an assertion failed, because new Test().getValue(5) == null
> >> >>
> >> >> Is this expected behavior or a bug?
> >> >>
> >> >>
> >> >> Best regards / Med venlig hilsen,
> >> >> Søren Berg Glasius
> >> >>
> >> >> Hedevej 1, Gl. Rye, 8680 Ry, Denmark
> >> >> Mobile: +45 40 44 91 88, Skype: sbglasius
> >> >> --- Press ESC once to quit - twice to save the changes.
> >> >
> >> >
> >
> >
>
Re: A @CompileStatic bug, or is it just me: [].withDefault { 0 }
Posted by Dinko Srkoč <di...@gmail.com>.
On 29 September 2015 at 10:12, Cédric Champeau
<ce...@gmail.com> wrote:
> That's because it's withDefault { 1 } ;)
Argh! Still morning for me. :-(
>
> 2015-09-29 10:05 GMT+02:00 Dinko Srkoč <di...@gmail.com>:
>>
>> On 29 September 2015 at 09:58, Cédric Champeau
>> <ce...@gmail.com> wrote:
>> > This looks like a bug. Would be interesting to look at the bytecode to
>> > check
>> > what method is called for x[n].
>>
>> Curiously, I tried to do just that in the Groovy AST Browser and, for
>> the following piece of code:
>>
>> @groovy.transform.CompileStatic
>> def foo() {
>> [].withDefault(1)
>> }
>>
>> got this:
>>
>> Unable to produce AST for this phase due to earlier compilation error:
>> startup failed:
>> script1443513793544.groovy: 3: [Static type checking] - Cannot find
>> matching method java.util.List#withDefault(int). Please check if the
>> declared type is right and if the method exists.
>> @ line 3, column 5.
>> [].withDefault(1)
>> ^
>>
>> That's Groovy 2.4.4
>>
>> Cheers,
>> Dinko
>>
>> >
>> > 2015-09-29 9:54 GMT+02:00 Søren Berg Glasius <so...@glasius.dk>:
>> >>
>> >> Hi Fellows,
>> >>
>> >> I stumbled upon this today.
>> >>
>> >> This code runs:
>> >>
>> >> class Test {
>> >> private List<Integer> x = [].withDefault { 0 }
>> >> Integer getValue(int n) {
>> >> return x[n]
>> >> }
>> >> }
>> >> assert new Test().getValue(5) == 0
>> >>
>> >> where as when I compile static:
>> >>
>> >> @CompileStatic
>> >> class Test {
>> >> private List<Integer> x = [].withDefault { 0 }
>> >> Integer getValue(int n) {
>> >> return x[n]
>> >> }
>> >> }
>> >> assert new Test().getValue(5) == 0
>> >>
>> >> I get an assertion failed, because new Test().getValue(5) == null
>> >>
>> >> Is this expected behavior or a bug?
>> >>
>> >>
>> >> Best regards / Med venlig hilsen,
>> >> Søren Berg Glasius
>> >>
>> >> Hedevej 1, Gl. Rye, 8680 Ry, Denmark
>> >> Mobile: +45 40 44 91 88, Skype: sbglasius
>> >> --- Press ESC once to quit - twice to save the changes.
>> >
>> >
>
>
Re: A @CompileStatic bug, or is it just me: [].withDefault { 0 }
Posted by Cédric Champeau <ce...@gmail.com>.
That's because it's withDefault { 1 } ;)
2015-09-29 10:05 GMT+02:00 Dinko Srkoč <di...@gmail.com>:
> On 29 September 2015 at 09:58, Cédric Champeau
> <ce...@gmail.com> wrote:
> > This looks like a bug. Would be interesting to look at the bytecode to
> check
> > what method is called for x[n].
>
> Curiously, I tried to do just that in the Groovy AST Browser and, for
> the following piece of code:
>
> @groovy.transform.CompileStatic
> def foo() {
> [].withDefault(1)
> }
>
> got this:
>
> Unable to produce AST for this phase due to earlier compilation error:
> startup failed:
> script1443513793544.groovy: 3: [Static type checking] - Cannot find
> matching method java.util.List#withDefault(int). Please check if the
> declared type is right and if the method exists.
> @ line 3, column 5.
> [].withDefault(1)
> ^
>
> That's Groovy 2.4.4
>
> Cheers,
> Dinko
>
> >
> > 2015-09-29 9:54 GMT+02:00 Søren Berg Glasius <so...@glasius.dk>:
> >>
> >> Hi Fellows,
> >>
> >> I stumbled upon this today.
> >>
> >> This code runs:
> >>
> >> class Test {
> >> private List<Integer> x = [].withDefault { 0 }
> >> Integer getValue(int n) {
> >> return x[n]
> >> }
> >> }
> >> assert new Test().getValue(5) == 0
> >>
> >> where as when I compile static:
> >>
> >> @CompileStatic
> >> class Test {
> >> private List<Integer> x = [].withDefault { 0 }
> >> Integer getValue(int n) {
> >> return x[n]
> >> }
> >> }
> >> assert new Test().getValue(5) == 0
> >>
> >> I get an assertion failed, because new Test().getValue(5) == null
> >>
> >> Is this expected behavior or a bug?
> >>
> >>
> >> Best regards / Med venlig hilsen,
> >> Søren Berg Glasius
> >>
> >> Hedevej 1, Gl. Rye, 8680 Ry, Denmark
> >> Mobile: +45 40 44 91 88, Skype: sbglasius
> >> --- Press ESC once to quit - twice to save the changes.
> >
> >
>
Re: A @CompileStatic bug, or is it just me: [].withDefault { 0 }
Posted by Dinko Srkoč <di...@gmail.com>.
On 29 September 2015 at 09:58, Cédric Champeau
<ce...@gmail.com> wrote:
> This looks like a bug. Would be interesting to look at the bytecode to check
> what method is called for x[n].
Curiously, I tried to do just that in the Groovy AST Browser and, for
the following piece of code:
@groovy.transform.CompileStatic
def foo() {
[].withDefault(1)
}
got this:
Unable to produce AST for this phase due to earlier compilation error:
startup failed:
script1443513793544.groovy: 3: [Static type checking] - Cannot find
matching method java.util.List#withDefault(int). Please check if the
declared type is right and if the method exists.
@ line 3, column 5.
[].withDefault(1)
^
That's Groovy 2.4.4
Cheers,
Dinko
>
> 2015-09-29 9:54 GMT+02:00 Søren Berg Glasius <so...@glasius.dk>:
>>
>> Hi Fellows,
>>
>> I stumbled upon this today.
>>
>> This code runs:
>>
>> class Test {
>> private List<Integer> x = [].withDefault { 0 }
>> Integer getValue(int n) {
>> return x[n]
>> }
>> }
>> assert new Test().getValue(5) == 0
>>
>> where as when I compile static:
>>
>> @CompileStatic
>> class Test {
>> private List<Integer> x = [].withDefault { 0 }
>> Integer getValue(int n) {
>> return x[n]
>> }
>> }
>> assert new Test().getValue(5) == 0
>>
>> I get an assertion failed, because new Test().getValue(5) == null
>>
>> Is this expected behavior or a bug?
>>
>>
>> Best regards / Med venlig hilsen,
>> Søren Berg Glasius
>>
>> Hedevej 1, Gl. Rye, 8680 Ry, Denmark
>> Mobile: +45 40 44 91 88, Skype: sbglasius
>> --- Press ESC once to quit - twice to save the changes.
>
>
Re: A @CompileStatic bug, or is it just me: [].withDefault { 0 }
Posted by Cédric Champeau <ce...@gmail.com>.
This looks like a bug. Would be interesting to look at the bytecode to
check what method is called for x[n].
2015-09-29 9:54 GMT+02:00 Søren Berg Glasius <so...@glasius.dk>:
> Hi Fellows,
>
> I stumbled upon this today.
>
> This code runs:
>
> class Test {
> private List<Integer> x = [].withDefault { 0 }
> Integer getValue(int n) {
> return x[n]
> }
> }
> assert new Test().getValue(5) == 0
>
> where as when I compile static:
>
> @CompileStatic
> class Test {
> private List<Integer> x = [].withDefault { 0 }
> Integer getValue(int n) {
> return x[n]
> }
> }
> assert new Test().getValue(5) == 0
>
> I get an assertion failed, because new Test().getValue(5) == null
>
> Is this expected behavior or a bug?
>
>
> Best regards / Med venlig hilsen,
> Søren Berg Glasius
>
> Hedevej 1, Gl. Rye, 8680 Ry, Denmark
> Mobile: +45 40 44 91 88, Skype: sbglasius
> --- Press ESC once to quit - twice to save the changes.
>