[jira] [Created] (GROOVY-9977) @CompileStatic does not work for when a class field has a lambda initializer

["Lyuben Atanasov (Jira)" <ji...@apache.org>]

Lyuben Atanasov created GROOVY-9977:
---------------------------------------

             Summary: @CompileStatic does not work for when a class field has a lambda initializer
                 Key: GROOVY-9977
                 URL: https://issues.apache.org/jira/browse/GROOVY-9977
             Project: Groovy
          Issue Type: Bug
          Components: Static compilation, Static Type Checker
    Affects Versions: 4.0.0-alpha-2, 3.0.7
         Environment: OpenJDK8
            Reporter: Lyuben Atanasov


Using {{@CompileStatic}} when a field is initialized with a lambda:
{code}
class LambdaAssignedToField
{
	private Comparator<Integer> myComparator = (int1, int2) -> Integer.compare(int1, int2);
}
{code}
causes compilation errors:
{noformat}
Exception in thread "main" org.codehaus.groovy.control.MultipleCompilationErrorsException: startup failed:
Script_28800dd8352617dbb4fe2e1957614875.groovy: 3: [Static type checking] - Cannot find matching method java.lang.Integer#compare(java.lang.Object, java.lang.Object). Please check if the declared type is correct and if the method exists.
 @ line 3, column 61.
   yComparator = (int1, int2) -> Integer.co
                                 ^

Script_28800dd8352617dbb4fe2e1957614875.groovy: 3: [Static type checking] - Cannot assign value of type groovy.lang.Closure <java.lang.Object> to variable of type java.util.Comparator <Integer>
 @ line 3, column 45.
   rator<Integer> myComparator = (int1, int
{noformat}

The same code, used in the context of a method, works fine:
{code}
class LambdaAssignedToVariable
{
	public void test()
	{
		Comparator<Integer> myComparator = (int1, int2) -> Integer.compare(int1, int2);
	}
}
{code}

In order to make the first example compile, I have to manually specify the types of the lambda parameters and also cast it to the correct type:
{code}
class LambdaAssignedToFieldCast
{
	private Comparator<Integer> myComparator = (Comparator<Integer>) (Integer int1, Integer int2) -> Integer.compare(int1, int2);
}
{code}

The issue seems to exist since Groovy 3.0.0.



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