[
https://issues.apache.org/jira/browse/GROOVY-12756?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Scott Murphy Heiberg updated GROOVY-12756:
------------------------------------------
Description:
Anything can be assigned to a variable of type {{Class}}, {{String}} or
{{Boolean}}: the value is converted at run time, so {{Class c =
'java.lang.String'}} loads the class. That still compiles for a raw {{Class}}.
Since GROOVY-12714 (GROOVY_6_0_X and master) static type checking rejects it
when the variable's type has a type argument, even {{Class<?>}}:
{code:groovy}
import java.lang.reflect.ParameterizedType
import java.lang.reflect.Type
@groovy.transform.CompileStatic
abstract class Editor<T> {
final Class<T> targetType
Editor() {
Type[] types = ((ParameterizedType)
getClass().genericSuperclass).actualTypeArguments
targetType = types[0]
}
}
@groovy.transform.CompileStatic
void test(Type type, Object object) {
Class raw = type // compiles
Class<?> any = type // error
Class<String> string = 'java.lang.String' // error
Class<? extends Number> number = object // error
}
{code}
{noformat}
[Static type checking] - Incompatible generic argument types. Cannot assign
java.lang.reflect.Type to: java.lang.Class<T>
[Static type checking] - Incompatible generic argument types. Cannot assign
java.lang.reflect.Type to: java.lang.Class<?>
[Static type checking] - Incompatible generic argument types. Cannot assign
java.lang.String to: java.lang.Class<java.lang.String>
[Static type checking] - Incompatible generic argument types. Cannot assign
java.lang.Object to: java.lang.Class<? extends java.lang.Number>
{noformat}
All of these compiled on GROOVY_6_0_X before GROOVY-12714 (a5d10dd198). The
first is {{AbstractStructuredBindingEditor}} in Grails, which no longer
compiles against GROOVY_6_0_X.
For an assignment to a {{Class}}, {{String}} or {{Boolean}} variable,
{{getResultType}} returned the variable's type. GROOVY-12714 made it keep the
type of the value when the variable is a parameterized {{Class}}, so that
{{Class<?>}} is no longer accepted for {{Class<? extends CharSequence>}}. That
is right when the value is a {{Class}}. When it is not, there are no type
arguments to compare, and {{checkTypeGenerics}} reports the value's type as an
incompatible generic argument.
The value's type should be kept only when it is a {{Class}}.
Pull request: https://github.com/apache/groovy/pull/3289
was:
Anything can be assigned to a variable of type {{Class}}, {{String}} or
{{Boolean}}: the value is converted at run time, so {{Class c =
'java.lang.String'}} loads the class. That still compiles for a raw {{Class}}.
Since GROOVY-12714 (GROOVY_6_0_X and master) static type checking rejects it
when the variable's type has a type argument, even {{Class<?>}}:
{code:groovy}
import java.lang.reflect.ParameterizedType
import java.lang.reflect.Type
@groovy.transform.CompileStatic
abstract class Editor<T> {
final Class<T> targetType
Editor() {
Type[] types = ((ParameterizedType)
getClass().genericSuperclass).actualTypeArguments
targetType = types[0]
}
}
@groovy.transform.CompileStatic
void test(Type type, Object object) {
Class raw = type // compiles
Class<?> any = type // error
Class<String> string = 'java.lang.String' // error
Class<? extends Number> number = object // error
}
{code}
{noformat}
[Static type checking] - Incompatible generic argument types. Cannot assign
java.lang.reflect.Type to: java.lang.Class<T>
[Static type checking] - Incompatible generic argument types. Cannot assign
java.lang.reflect.Type to: java.lang.Class<?>
[Static type checking] - Incompatible generic argument types. Cannot assign
java.lang.String to: java.lang.Class<java.lang.String>
[Static type checking] - Incompatible generic argument types. Cannot assign
java.lang.Object to: java.lang.Class<? extends java.lang.Number>
{noformat}
All of these compiled on GROOVY_6_0_X before GROOVY-12714 (a5d10dd198). The
first is {{AbstractStructuredBindingEditor}} in Grails, which no longer
compiles against GROOVY_6_0_X.
For an assignment to a {{Class}}, {{String}} or {{Boolean}} variable,
{{getResultType}} returned the variable's type. GROOVY-12714 made it keep the
type of the value when the variable is a parameterized {{Class}}, so that
{{Class<?>}} is no longer accepted for {{Class<? extends CharSequence>}}. That
is right when the value is a {{Class}}. When it is not, there are no type
arguments to compare, and {{checkTypeGenerics}} reports the value's type as an
incompatible generic argument.
The value's type should be kept only when it is a {{Class}}.
> STC: since GROOVY-12714 a value that is not a Class cannot be assigned to a
> parameterized Class variable
> --------------------------------------------------------------------------------------------------------
>
> Key: GROOVY-12756
> URL: https://issues.apache.org/jira/browse/GROOVY-12756
> Project: Groovy
> Issue Type: Bug
> Components: Static Type Checker
> Affects Versions: 7.0.0-alpha-1, 6.0.1
> Reporter: Scott Murphy Heiberg
> Priority: Major
>
> Anything can be assigned to a variable of type {{Class}}, {{String}} or
> {{Boolean}}: the value is converted at run time, so {{Class c =
> 'java.lang.String'}} loads the class. That still compiles for a raw
> {{Class}}. Since GROOVY-12714 (GROOVY_6_0_X and master) static type checking
> rejects it when the variable's type has a type argument, even {{Class<?>}}:
> {code:groovy}
> import java.lang.reflect.ParameterizedType
> import java.lang.reflect.Type
> @groovy.transform.CompileStatic
> abstract class Editor<T> {
> final Class<T> targetType
> Editor() {
> Type[] types = ((ParameterizedType)
> getClass().genericSuperclass).actualTypeArguments
> targetType = types[0]
> }
> }
> @groovy.transform.CompileStatic
> void test(Type type, Object object) {
> Class raw = type // compiles
> Class<?> any = type // error
> Class<String> string = 'java.lang.String' // error
> Class<? extends Number> number = object // error
> }
> {code}
> {noformat}
> [Static type checking] - Incompatible generic argument types. Cannot assign
> java.lang.reflect.Type to: java.lang.Class<T>
> [Static type checking] - Incompatible generic argument types. Cannot assign
> java.lang.reflect.Type to: java.lang.Class<?>
> [Static type checking] - Incompatible generic argument types. Cannot assign
> java.lang.String to: java.lang.Class<java.lang.String>
> [Static type checking] - Incompatible generic argument types. Cannot assign
> java.lang.Object to: java.lang.Class<? extends java.lang.Number>
> {noformat}
> All of these compiled on GROOVY_6_0_X before GROOVY-12714 (a5d10dd198). The
> first is {{AbstractStructuredBindingEditor}} in Grails, which no longer
> compiles against GROOVY_6_0_X.
> For an assignment to a {{Class}}, {{String}} or {{Boolean}} variable,
> {{getResultType}} returned the variable's type. GROOVY-12714 made it keep the
> type of the value when the variable is a parameterized {{Class}}, so that
> {{Class<?>}} is no longer accepted for {{Class<? extends CharSequence>}}.
> That is right when the value is a {{Class}}. When it is not, there are no
> type arguments to compare, and {{checkTypeGenerics}} reports the value's type
> as an incompatible generic argument.
> The value's type should be kept only when it is a {{Class}}.
> Pull request: https://github.com/apache/groovy/pull/3289
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