Introduce UNUSED_ANONYMOUS_PARAMETER for anonymous functions

It is not reported for 1.0 language version because
renaming to _ is not possible. It has weak warning severity

So #KT-8813 Fixed
So #KT-16875 Fixed

compiler/frontend/src/org/jetbrains/kotlin/cfg/ControlFlowInformationProvider.kt

@@ -646,8 +646,8 @@ class ControlFlowInformationProvider private constructor(
                 }
             }
             is KtFunction -> {
-                if (owner is KtFunctionLiteral &&
+                val anonymous = owner is KtFunctionLiteral || owner is KtNamedFunction && owner.name == null
-                    !languageVersionSettings.supportsFeature(LanguageFeature.SingleUnderscoreForParameterName)) {
+                if (anonymous && !languageVersionSettings.supportsFeature(LanguageFeature.SingleUnderscoreForParameterName)) {
                     return
                 }
                 val mainFunctionDetector = MainFunctionDetector(trace.bindingContext)
@@ -666,7 +666,12 @@ class ControlFlowInformationProvider private constructor(
                     || OperatorNameConventions.PROVIDE_DELEGATE == functionName) {
                     return
                 }
-                report(UNUSED_PARAMETER.on(element, variableDescriptor), ctxt)
+                if (anonymous) {
+                    report(UNUSED_ANONYMOUS_PARAMETER.on(element, variableDescriptor), ctxt)
+                }
+                else {
+                    report(UNUSED_PARAMETER.on(element, variableDescriptor), ctxt)
+                }
             }
         }
     }
@@ -1121,6 +1126,7 @@ class ControlFlowInformationProvider private constructor(
         private fun mustBeReportedOnAllCopies(diagnosticFactory: DiagnosticFactory<*>) =
                 diagnosticFactory === UNUSED_VARIABLE
                 || diagnosticFactory === UNUSED_PARAMETER
+                || diagnosticFactory === UNUSED_ANONYMOUS_PARAMETER
                 || diagnosticFactory === UNUSED_CHANGED_VALUE
     }
 }

compiler/frontend/src/org/jetbrains/kotlin/diagnostics/Errors.java

@@ -744,6 +744,7 @@ public interface Errors {
 
     DiagnosticFactory1<KtNamedDeclaration, VariableDescriptor> UNUSED_VARIABLE = DiagnosticFactory1.create(WARNING, DECLARATION_NAME);
     DiagnosticFactory1<KtParameter, VariableDescriptor> UNUSED_PARAMETER = DiagnosticFactory1.create(WARNING, DECLARATION_NAME);
+    DiagnosticFactory1<KtParameter, VariableDescriptor> UNUSED_ANONYMOUS_PARAMETER = DiagnosticFactory1.create(WARNING, DECLARATION_NAME);
     DiagnosticFactory1<KtDestructuringDeclarationEntry, VariableDescriptor> UNUSED_DESTRUCTURED_PARAMETER_ENTRY =
             DiagnosticFactory1.create(WARNING, DECLARATION_NAME);
     DiagnosticFactory2<KtTypeParameter, TypeParameterDescriptor, KotlinType> UNUSED_TYPEALIAS_PARAMETER =

compiler/frontend/src/org/jetbrains/kotlin/diagnostics/rendering/DefaultErrorMessages.java

@@ -288,6 +288,7 @@ public class DefaultErrorMessages {
         MAP.put(UNINITIALIZED_ENUM_COMPANION, "Companion object of enum class ''{0}'' is uninitialized here", NAME);
         MAP.put(UNUSED_VARIABLE, "Variable ''{0}'' is never used", NAME);
         MAP.put(UNUSED_PARAMETER, "Parameter ''{0}'' is never used", NAME);
+        MAP.put(UNUSED_ANONYMOUS_PARAMETER, "Parameter ''{0}'' is never used, could be renamed to _", NAME);
         MAP.put(UNUSED_DESTRUCTURED_PARAMETER_ENTRY, "Destructured parameter ''{0}'' is never used", NAME);
         MAP.put(ASSIGNED_BUT_NEVER_ACCESSED_VARIABLE, "Variable ''{0}'' is assigned but never accessed", NAME);
         MAP.put(VARIABLE_WITH_REDUNDANT_INITIALIZER, "Variable ''{0}'' initializer is redundant", NAME);

compiler/testData/diagnostics/tests/AutoCreatedIt.kt

@@ -4,7 +4,7 @@ fun text() {
     "direct:a" on {it -> it.body == "<hello/>"} to "mock:a"
     bar <!EXPECTED_PARAMETERS_NUMBER_MISMATCH!>{<!>1}
     bar <!EXPECTED_PARAMETERS_NUMBER_MISMATCH!>{<!><!UNRESOLVED_REFERENCE!>it<!> <!DEBUG_INFO_ELEMENT_WITH_ERROR_TYPE!>+<!> 1}
-    bar {it, <!UNUSED_PARAMETER!>it1<!> -> it}
+    bar {it, <!UNUSED_ANONYMOUS_PARAMETER!>it1<!> -> it}
 
     bar1 {1}
     bar1 {it + 1}

compiler/testData/diagnostics/tests/BacktickNames.kt

@@ -1,4 +1,4 @@
-//  !DIAGNOSTICS: -UNUSED_VARIABLE -UNUSED_PARAMETER
+//  !DIAGNOSTICS: -UNUSED_VARIABLE -UNUSED_PARAMETER -UNUSED_ANONYMOUS_PARAMETER
 // TODO Uncomment all the examples when there will be no problems with light classes
 //package `foo.bar`
 

compiler/testData/diagnostics/tests/FunctionCalleeExpressions.kt

@@ -36,8 +36,8 @@ fun main(args : Array<String>) {
     foo2()({})
     foo2()<!TOO_MANY_ARGUMENTS!>{}<!>
     (foo2()){}
-    (foo2()){<!EXPECTED_PARAMETERS_NUMBER_MISMATCH, CANNOT_INFER_PARAMETER_TYPE, UNUSED_PARAMETER!>x<!> -> }
+    (foo2()){<!EXPECTED_PARAMETERS_NUMBER_MISMATCH, CANNOT_INFER_PARAMETER_TYPE, UNUSED_ANONYMOUS_PARAMETER!>x<!> -> }
-    foo2()({<!EXPECTED_PARAMETERS_NUMBER_MISMATCH, CANNOT_INFER_PARAMETER_TYPE, UNUSED_PARAMETER!>x<!> -> })
+    foo2()({<!EXPECTED_PARAMETERS_NUMBER_MISMATCH, CANNOT_INFER_PARAMETER_TYPE, UNUSED_ANONYMOUS_PARAMETER!>x<!> -> })
 
     val a = fooT1(1)()
     checkSubtype<Int>(a)
@@ -72,7 +72,7 @@ fun main1() {
 }
 
 fun test() {
-    {<!UNUSED_PARAMETER!>x<!> : Int -> 1}(<!NO_VALUE_FOR_PARAMETER!>)<!>;
+    {<!UNUSED_ANONYMOUS_PARAMETER!>x<!> : Int -> 1}(<!NO_VALUE_FOR_PARAMETER!>)<!>;
     (fun Int.() = 1)(<!NO_VALUE_FOR_PARAMETER!>)<!>
     <!TYPE_MISMATCH!>"sd"<!>.(fun Int.() = 1)()
     val i : Int? = null

compiler/testData/diagnostics/tests/FunctionParameterWithoutType.kt

@@ -1,4 +1,4 @@
-// !DIAGNOSTICS: -UNUSED_PARAMETER -UNUSED_VARIABLE
+// !DIAGNOSTICS: -UNUSED_PARAMETER -UNUSED_ANONYMOUS_PARAMETER -UNUSED_VARIABLE
 fun test(<!VALUE_PARAMETER_WITH_NO_TYPE_ANNOTATION!>a<!>) {
 
 }

compiler/testData/diagnostics/tests/ReserveYield2.kt

@@ -1,4 +1,4 @@
-// !DIAGNOSTICS: -UNUSED_PARAMETER -UNUSED_EXPRESSION -UNREACHABLE_CODE -UNUSED_VARIABLE -WRONG_ANNOTATION_TARGET -UNUSED_LAMBDA_EXPRESSION
+// !DIAGNOSTICS: -UNUSED_PARAMETER -UNUSED_ANONYMOUS_PARAMETER -UNUSED_EXPRESSION -UNREACHABLE_CODE -UNUSED_VARIABLE -WRONG_ANNOTATION_TARGET -UNUSED_LAMBDA_EXPRESSION
 
 // FILE: 1.kt
 

compiler/testData/diagnostics/tests/Underscore.kt

@@ -14,7 +14,7 @@ fun <!UNDERSCORE_IS_RESERVED!>__<!>(<!UNDERSCORE_IS_RESERVED!>___<!>: Int, y: <!
     // in backquotes: allowed
     val `_` = <!UNDERSCORE_USAGE_WITHOUT_BACKTICKS!>__________<!>
 
-    val q = fun(_: Int, <!UNDERSCORE_IS_RESERVED, UNUSED_PARAMETER!>__<!>: Int) {}
+    val q = fun(_: Int, <!UNDERSCORE_IS_RESERVED, UNUSED_ANONYMOUS_PARAMETER!>__<!>: Int) {}
     q(1, 2)
 
     val <!UNDERSCORE_IS_RESERVED!>_<!> = 56

compiler/testData/diagnostics/tests/annotations/onFunctionParameter.kt

@@ -4,4 +4,4 @@ fun test(@ann <!UNUSED_PARAMETER!>p<!>: Int) {
 
 }
 
-val bar = fun(@ann <!UNUSED_PARAMETER!>g<!>: Int) {}
+val bar = fun(@ann <!UNUSED_ANONYMOUS_PARAMETER!>g<!>: Int) {}

compiler/testData/diagnostics/tests/controlFlowAnalysis/unusedInAnonymous.kt

@@ -0,0 +1,9 @@
+// !LANGUAGE: -SingleUnderscoreForParameterName
+// See KT-8813, KT-9631
+
+fun someApi(f: (Int) -> Unit) = f(42)
+
+fun test() {
+    someApi(fun(p: Int) {})
+    // Apparently "p" cannot be removed because the signature is fixed by "someApi
+}

compiler/testData/diagnostics/tests/controlFlowAnalysis/unusedInAnonymous.txt

@@ -0,0 +1,4 @@
+package
+
+public fun someApi(/*0*/ f: (kotlin.Int) -> kotlin.Unit): kotlin.Unit
+public fun test(): kotlin.Unit

compiler/testData/diagnostics/tests/declarationChecks/anonymousFunAsLastExpressionInBlock.kt

@@ -1,4 +1,4 @@
-// !DIAGNOSTICS: -UNUSED_PARAMETER -UNUSED_VARIABLE
+// !DIAGNOSTICS: -UNUSED_PARAMETER -UNUSED_ANONYMOUS_PARAMETER -UNUSED_VARIABLE
 // !CHECK_TYPE
 fun foo(block: () -> (() -> Int)) {}
 

compiler/testData/diagnostics/tests/declarationChecks/namedFunAsLastExpressionInBlock.kt

@@ -1,4 +1,4 @@
-// !DIAGNOSTICS: -UNUSED_PARAMETER -UNUSED_VARIABLE
+// !DIAGNOSTICS: -UNUSED_PARAMETER -UNUSED_ANONYMOUS_PARAMETER -UNUSED_VARIABLE
 // !CHECK_TYPE
 fun foo(block: () -> (() -> Int)) {}
 

compiler/testData/diagnostics/tests/functionAsExpression/AutoLabels.kt

@@ -1,4 +1,4 @@
-// !DIAGNOSTICS: -UNUSED_PARAMETER -UNUSED_VARIABLE
+// !DIAGNOSTICS: -UNUSED_PARAMETER -UNUSED_ANONYMOUS_PARAMETER -UNUSED_VARIABLE
 
 fun <T, R> Iterable<T>.map(transform: (T) -> R): List<R> = null!!
 

compiler/testData/diagnostics/tests/functionAsExpression/FunctionType.kt

@@ -1,5 +1,5 @@
 // !CHECK_TYPE
-// !DIAGNOSTICS: -UNUSED_PARAMETER -UNUSED_VARIABLE
+// !DIAGNOSTICS: -UNUSED_ANONYMOUS_PARAMETER -UNUSED_VARIABLE
 
 fun testReturnType(foo: String) {
     val bar = fun () = foo

compiler/testData/diagnostics/tests/functionAsExpression/InferenceParametersTypes.kt

@@ -1,5 +1,5 @@
 // !CHECK_TYPE
-// !DIAGNOSTICS: -UNUSED_PARAMETER -UNUSED_VARIABLE
+// !DIAGNOSTICS: -UNUSED_PARAMETER -UNUSED_ANONYMOUS_PARAMETER -UNUSED_VARIABLE
 fun <T> listOf(): List<T> = null!!
 
 fun test(a: (Int) -> Int) {

compiler/testData/diagnostics/tests/functionAsExpression/MissingParameterTypes.kt

@@ -1,5 +1,5 @@
 // !CHECK_TYPE
-// !DIAGNOSTICS: -UNUSED_PARAMETER -UNUSED_VARIABLE
+// !DIAGNOSTICS: -UNUSED_PARAMETER -UNUSED_ANONYMOUS_PARAMETER -UNUSED_VARIABLE
 
 val a = fun (<!CANNOT_INFER_PARAMETER_TYPE!>x<!>) = <!DEBUG_INFO_ELEMENT_WITH_ERROR_TYPE!>x<!>
 

compiler/testData/diagnostics/tests/functionAsExpression/Parameters.kt

@@ -1,4 +1,4 @@
-// !DIAGNOSTICS: -UNUSED_PARAMETER -UNUSED_VARIABLE
+// !DIAGNOSTICS: -UNUSED_PARAMETER -UNUSED_ANONYMOUS_PARAMETER -UNUSED_VARIABLE
 
 val bar = fun(p: Int = <!ANONYMOUS_FUNCTION_PARAMETER_WITH_DEFAULT_VALUE!>3<!>) {}
 val bas = fun(<!USELESS_VARARG_ON_PARAMETER!>vararg p: Int<!>) {}

compiler/testData/diagnostics/tests/functionAsExpression/WithGenericParameters.kt

@@ -1,4 +1,4 @@
-// !DIAGNOSTICS: -UNUSED_PARAMETER
+// !DIAGNOSTICS: -UNUSED_PARAMETER -UNUSED_ANONYMOUS_PARAMETER
 
 interface A
 fun devNull(a: Any?){}

compiler/testData/diagnostics/tests/functionLiterals/DeprecatedSyntax.kt

@@ -17,8 +17,8 @@ val none = { -> }
 
 val parameterWithFunctionType = { a: ((Int) -> Int) -> <!SYNTAX!><!>} // todo fix parser
 
-val newSyntax = { <!UNUSED_PARAMETER!>a<!>: Int -> }
+val newSyntax = { <!UNUSED_ANONYMOUS_PARAMETER!>a<!>: Int -> }
-val newSyntax1 = { <!CANNOT_INFER_PARAMETER_TYPE, UNUSED_PARAMETER!>a<!>, <!CANNOT_INFER_PARAMETER_TYPE, UNUSED_PARAMETER!>b<!> -> }
+val newSyntax1 = { <!CANNOT_INFER_PARAMETER_TYPE, UNUSED_ANONYMOUS_PARAMETER!>a<!>, <!CANNOT_INFER_PARAMETER_TYPE, UNUSED_ANONYMOUS_PARAMETER!>b<!> -> }
-val newSyntax2 = { <!UNUSED_PARAMETER!>a<!>: Int, <!UNUSED_PARAMETER!>b<!>: Int -> }
+val newSyntax2 = { <!UNUSED_ANONYMOUS_PARAMETER!>a<!>: Int, <!UNUSED_ANONYMOUS_PARAMETER!>b<!>: Int -> }
-val newSyntax3 = { <!CANNOT_INFER_PARAMETER_TYPE, UNUSED_PARAMETER!>a<!>, <!UNUSED_PARAMETER!>b<!>: Int -> }
+val newSyntax3 = { <!CANNOT_INFER_PARAMETER_TYPE, UNUSED_ANONYMOUS_PARAMETER!>a<!>, <!UNUSED_ANONYMOUS_PARAMETER!>b<!>: Int -> }
-val newSyntax4 = { <!UNUSED_PARAMETER!>a<!>: Int, <!CANNOT_INFER_PARAMETER_TYPE, UNUSED_PARAMETER!>b<!> -> }
+val newSyntax4 = { <!UNUSED_ANONYMOUS_PARAMETER!>a<!>: Int, <!CANNOT_INFER_PARAMETER_TYPE, UNUSED_ANONYMOUS_PARAMETER!>b<!> -> }

compiler/testData/diagnostics/tests/functionLiterals/ExpectedParameterTypeMismatchVariance.kt

@@ -1,4 +1,4 @@
-// !DIAGNOSTICS: -UNUSED_PARAMETER
+// !DIAGNOSTICS: -UNUSED_ANONYMOUS_PARAMETER
 package a
 
 interface Super

compiler/testData/diagnostics/tests/functionLiterals/ExpectedParametersTypesMismatch.kt

@@ -9,20 +9,20 @@ fun test1() {
         ""
     }
     foo0 {
-        <!EXPECTED_PARAMETERS_NUMBER_MISMATCH!><!UNUSED_PARAMETER!>s<!>: String<!>-> ""
+        <!EXPECTED_PARAMETERS_NUMBER_MISMATCH!><!UNUSED_ANONYMOUS_PARAMETER!>s<!>: String<!>-> ""
     }
     foo0 {
-        <!EXPECTED_PARAMETERS_NUMBER_MISMATCH!><!CANNOT_INFER_PARAMETER_TYPE, UNUSED_PARAMETER!>x<!>, <!CANNOT_INFER_PARAMETER_TYPE, UNUSED_PARAMETER!>y<!><!> -> ""
+        <!EXPECTED_PARAMETERS_NUMBER_MISMATCH!><!CANNOT_INFER_PARAMETER_TYPE, UNUSED_ANONYMOUS_PARAMETER!>x<!>, <!CANNOT_INFER_PARAMETER_TYPE, UNUSED_ANONYMOUS_PARAMETER!>y<!><!> -> ""
     }
 
     foo1 {
         ""
     }
     foo1 {
-        <!EXPECTED_PARAMETER_TYPE_MISMATCH!><!UNUSED_PARAMETER!>s<!>: String<!> -> ""
+        <!EXPECTED_PARAMETER_TYPE_MISMATCH!><!UNUSED_ANONYMOUS_PARAMETER!>s<!>: String<!> -> ""
     }
     foo1 {
-        <!EXPECTED_PARAMETERS_NUMBER_MISMATCH!><!UNUSED_PARAMETER!>x<!>, <!CANNOT_INFER_PARAMETER_TYPE, UNUSED_PARAMETER!>y<!><!> -> ""
+        <!EXPECTED_PARAMETERS_NUMBER_MISMATCH!><!UNUSED_ANONYMOUS_PARAMETER!>x<!>, <!CANNOT_INFER_PARAMETER_TYPE, UNUSED_ANONYMOUS_PARAMETER!>y<!><!> -> ""
     }
     foo1 {
         <!EXPECTED_PARAMETERS_NUMBER_MISMATCH!><!>-> <!CONSTANT_EXPECTED_TYPE_MISMATCH!>42<!>
@@ -33,10 +33,10 @@ fun test1() {
         ""
     }
     foo2 {
-        <!EXPECTED_PARAMETERS_NUMBER_MISMATCH, EXPECTED_PARAMETER_TYPE_MISMATCH!><!UNUSED_PARAMETER!>s<!>: String<!> -> ""
+        <!EXPECTED_PARAMETERS_NUMBER_MISMATCH, EXPECTED_PARAMETER_TYPE_MISMATCH!><!UNUSED_ANONYMOUS_PARAMETER!>s<!>: String<!> -> ""
     }
     foo2 {
-        <!EXPECTED_PARAMETERS_NUMBER_MISMATCH, UNUSED_PARAMETER!>x<!> -> ""
+        <!EXPECTED_PARAMETERS_NUMBER_MISMATCH, UNUSED_ANONYMOUS_PARAMETER!>x<!> -> ""
     }
     foo2 {
          <!EXPECTED_PARAMETERS_NUMBER_MISMATCH!><!>-> <!CONSTANT_EXPECTED_TYPE_MISMATCH!>42<!>

compiler/testData/diagnostics/tests/functionLiterals/destructuringInLambdas/redeclaration.kt

@@ -1,5 +1,5 @@
 // !CHECK_TYPE
-// !DIAGNOSTICS: -UNUSED_PARAMETER
+// !DIAGNOSTICS: -UNUSED_PARAMETER -UNUSED_ANONYMOUS_PARAMETER
 data class A(val x: Int, val y: String)
 data class B(val u: Double, val w: Short)
 

compiler/testData/diagnostics/tests/functionLiterals/destructuringInLambdas/unusedParameters.kt

@@ -1,5 +1,5 @@
 // !CHECK_TYPE
-// !DIAGNOSTICS: -UNUSED_PARAMETER
+// !DIAGNOSTICS: -UNUSED_PARAMETER -UNUSED_ANONYMOUS_PARAMETER
 data class A(val x: Int, val y: String)
 data class B(val u: Double, val w: Short)
 

compiler/testData/diagnostics/tests/functionLiterals/underscopeParameters.kt

@@ -40,9 +40,9 @@ fun bar() {
         _ checkType { _<String>() }
     }
 
-    foo { <!REDECLARATION, REDECLARATION, UNUSED_PARAMETER!>`_`<!>, <!REDECLARATION, REDECLARATION!>`_`<!> ->
+    foo { <!REDECLARATION, REDECLARATION, UNUSED_ANONYMOUS_PARAMETER!>`_`<!>, <!REDECLARATION, REDECLARATION!>`_`<!> ->
         _ checkType { _<String>() }
     }
 
-    foo(fun(<!UNUSED_PARAMETER!>x<!>: Int, _: String) {})
+    foo(fun(<!UNUSED_ANONYMOUS_PARAMETER!>x<!>: Int, _: String) {})
 }

compiler/testData/diagnostics/tests/generics/projectionsScope/flexibleProjectedScope.kt

@@ -1,4 +1,4 @@
-// !DIAGNOSTICS: -UNUSED_PARAMETER
+// !DIAGNOSTICS: -UNUSED_PARAMETER -UNUSED_ANONYMOUS_PARAMETER
 // !CHECK_TYPE
 
 // FILE: Clazz.java

compiler/testData/diagnostics/tests/inference/cannotCompleteResolveFunctionLiteralsNoUse.kt

@@ -3,4 +3,4 @@ package f
 fun <R> h(<!UNUSED_PARAMETER!>i<!>: Int, <!UNUSED_PARAMETER!>a<!>: Any, <!UNUSED_PARAMETER!>r<!>: R, <!UNUSED_PARAMETER!>f<!>: (Boolean) -> Int) = 1
 fun <R> h(<!UNUSED_PARAMETER!>a<!>: Any, <!UNUSED_PARAMETER!>i<!>: Int, <!UNUSED_PARAMETER!>r<!>: R, <!UNUSED_PARAMETER!>f<!>: (Boolean) -> Int) = 1
 
-fun test() = <!CANNOT_COMPLETE_RESOLVE!>h<!>(1, 1, 1, { <!CANNOT_INFER_PARAMETER_TYPE, UNUSED_PARAMETER!>b<!> -> 42 })
+fun test() = <!CANNOT_COMPLETE_RESOLVE!>h<!>(1, 1, 1, { <!CANNOT_INFER_PARAMETER_TYPE, UNUSED_ANONYMOUS_PARAMETER!>b<!> -> 42 })

compiler/testData/diagnostics/tests/inference/cannotCompleteResolveWithFunctionLiterals.kt

@@ -4,7 +4,7 @@ package f
 fun <R> h(<!UNUSED_PARAMETER!>f<!>: (Boolean) -> R) = 1
 fun <R> h(<!UNUSED_PARAMETER!>f<!>: (String) -> R) = 2
 
-fun test() = <!CANNOT_COMPLETE_RESOLVE!>h<!>{ <!CANNOT_INFER_PARAMETER_TYPE, UNUSED_PARAMETER!>i<!> -> getAnswer() }
+fun test() = <!CANNOT_COMPLETE_RESOLVE!>h<!>{ <!CANNOT_INFER_PARAMETER_TYPE, UNUSED_ANONYMOUS_PARAMETER!>i<!> -> getAnswer() }
 
 fun getAnswer() = 42
 

compiler/testData/diagnostics/tests/inference/dependantOnVarianceNullable.kt

@@ -5,7 +5,7 @@ import java.util.*
 import java.util.Collections.*
 
 fun foo(list: List<String>) : String {
-    val w : String = max(list, comparator<String?> {<!UNUSED_PARAMETER!>o1<!>, <!UNUSED_PARAMETER!>o2<!> -> 1
+    val w : String = max(list, comparator<String?> {<!UNUSED_ANONYMOUS_PARAMETER!>o1<!>, <!UNUSED_ANONYMOUS_PARAMETER!>o2<!> -> 1
     })
     return w
 }

compiler/testData/diagnostics/tests/inference/kt6175.kt

@@ -1,4 +1,4 @@
-// !DIAGNOSTICS: -UNUSED_PARAMETER
+// !DIAGNOSTICS: -UNUSED_PARAMETER -UNUSED_ANONYMOUS_PARAMETER
 
 fun <T, R : Any> foo(body: (R?) -> T): T = fail()
 

compiler/testData/diagnostics/tests/inference/regressions/kt2283.kt

@@ -9,5 +9,5 @@ fun <A, B> Foo<A>.map(<!UNUSED_PARAMETER!>f<!>: (A) -> B): Foo<B> = object : Foo
 
 fun foo() {
     val l: Foo<String> = object : Foo<String> {}
-    val <!UNUSED_VARIABLE!>m<!>: Foo<String> = l.<!TYPE_INFERENCE_EXPECTED_TYPE_MISMATCH!>map { <!UNUSED_PARAMETER!>ppp<!> -> 1 }<!>
+    val <!UNUSED_VARIABLE!>m<!>: Foo<String> = l.<!TYPE_INFERENCE_EXPECTED_TYPE_MISMATCH!>map { <!UNUSED_ANONYMOUS_PARAMETER!>ppp<!> -> 1 }<!>
 }

compiler/testData/diagnostics/tests/inference/regressions/kt2741.kt

@@ -7,5 +7,5 @@ fun <T> _arrayList(vararg <!UNUSED_PARAMETER!>values<!>: T) : List<T> = throw Ex
 class _Pair<A>(val a: A)
 
 fun test() {
-    _arrayList(_Pair(1))._sortBy { <!UNUSED_PARAMETER!>it<!> -> <!UNRESOLVED_REFERENCE!>xxx<!> }
+    _arrayList(_Pair(1))._sortBy { <!UNUSED_ANONYMOUS_PARAMETER!>it<!> -> <!UNRESOLVED_REFERENCE!>xxx<!> }
 }

compiler/testData/diagnostics/tests/inference/regressions/kt2841.kt

@@ -9,7 +9,7 @@ public inline fun <T: Closeable, R> T.use1(block: (T)-> R) : R {
 
 fun main(args: Array<String>) {
     C().use1 {
-        <!UNUSED_PARAMETER!>w<!> ->  // ERROR here
+        <!UNUSED_ANONYMOUS_PARAMETER!>w<!> ->  // ERROR here
         <!UNRESOLVED_REFERENCE!>x<!>
     }
 }

compiler/testData/diagnostics/tests/inference/regressions/kt3007.kt

@@ -8,7 +8,7 @@ enum class SomeEnum {
 
 // Doesn't work
 fun Iterable<Int>.some() {
-    this.fold(SomeEnum.FIRST, {res : SomeEnum, <!UNUSED_PARAMETER!>value<!> ->
+    this.fold(SomeEnum.FIRST, {res : SomeEnum, <!UNUSED_ANONYMOUS_PARAMETER!>value<!> ->
         if (res == SomeEnum.FIRST) SomeEnum.FIRST else SomeEnum.SECOND
     })
 }
@@ -19,7 +19,7 @@ fun tempFun() : SomeEnum {
 
 // Doesn't work
 fun Iterable<Int>.someSimpleWithFun() {
-    this.fold(SomeEnum.FIRST, {<!UNUSED_PARAMETER!>res<!> : SomeEnum, <!UNUSED_PARAMETER!>value<!> ->
+    this.fold(SomeEnum.FIRST, {<!UNUSED_ANONYMOUS_PARAMETER!>res<!> : SomeEnum, <!UNUSED_ANONYMOUS_PARAMETER!>value<!> ->
         tempFun()
     })
 }
@@ -27,14 +27,14 @@ fun Iterable<Int>.someSimpleWithFun() {
 
 // Works
 fun Iterable<Int>.someSimple() {
-    this.fold(SomeEnum.FIRST, {<!UNUSED_PARAMETER!>res<!> : SomeEnum, <!UNUSED_PARAMETER!>value<!> ->
+    this.fold(SomeEnum.FIRST, {<!UNUSED_ANONYMOUS_PARAMETER!>res<!> : SomeEnum, <!UNUSED_ANONYMOUS_PARAMETER!>value<!> ->
         SomeEnum.FIRST
     })
 }
 
 // Works
 fun Iterable<Int>.someInt() {
-    this.fold(0, {res : Int, <!UNUSED_PARAMETER!>value<!> ->
+    this.fold(0, {res : Int, <!UNUSED_ANONYMOUS_PARAMETER!>value<!> ->
         if (res == 0) 1 else 0
     })
 }

compiler/testData/diagnostics/tests/inference/regressions/kt3150.kt

@@ -15,10 +15,10 @@ fun SomeTemplate.query(f: (i: Int) -> Unit) = f
 fun SomeTemplate.query1(f: (i: Int) -> Unit) = f
 
 fun test() {
-    val mapperFunction = { <!UNUSED_PARAMETER!>i<!>: Int -> }
+    val mapperFunction = { <!UNUSED_ANONYMOUS_PARAMETER!>i<!>: Int -> }
     SomeTemplate().query(mapperFunction)
 
     // TYPE_MISMATCH: Required Class<[ERROR: CANT_INFER]>, Found (kotlin.Int) -> Unit
-    SomeTemplate().query { <!UNUSED_PARAMETER!>i<!>: Int -> }
+    SomeTemplate().query { <!UNUSED_ANONYMOUS_PARAMETER!>i<!>: Int -> }
-    SomeTemplate().query1 { <!UNUSED_PARAMETER!>i<!>: Int -> }
+    SomeTemplate().query1 { <!UNUSED_ANONYMOUS_PARAMETER!>i<!>: Int -> }
 }

compiler/testData/diagnostics/tests/inference/regressions/kt8132.kt

@@ -1,4 +1,4 @@
-// !DIAGNOSTICS: -UNUSED_PARAMETER
+// !DIAGNOSTICS: -UNUSED_PARAMETER -UNUSED_ANONYMOUS_PARAMETER
 // KT-8132 Can't omit lambda parameter types
 
 fun <T> test(foo: List<T>): T {

compiler/testData/diagnostics/tests/inference/reportingImprovements/ErrorTypeAsGenericParameter.kt

@@ -3,7 +3,7 @@ package a
 fun <T, R, S> foo(block: (T)-> R, <!UNUSED_PARAMETER!>second<!>: (T)-> S) = block
 
 fun main(args: Array<String>) {
-    val fff = { <!UNUSED_PARAMETER!>x<!>: Int -> <!UNRESOLVED_REFERENCE!>aaa<!> }
+    val fff = { <!UNUSED_ANONYMOUS_PARAMETER!>x<!>: Int -> <!UNRESOLVED_REFERENCE!>aaa<!> }
     foo(<!DEBUG_INFO_ELEMENT_WITH_ERROR_TYPE!>fff<!>, { x -> x + 1 })
 }
 

compiler/testData/diagnostics/tests/inference/reportingImprovements/NoAmbiguityForDifferentFunctionTypes.kt

@@ -9,7 +9,7 @@ fun <T: Closeable, R> T.foo(block: (T, T)-> R) = block
 
 fun main(args: Array<String>) {
     C().foo { // no ambiguity here
-        <!UNUSED_PARAMETER!>www<!> ->
+        <!UNUSED_ANONYMOUS_PARAMETER!>www<!> ->
         <!UNRESOLVED_REFERENCE!>xs<!>
     }
 }

compiler/testData/diagnostics/tests/inference/reportingImprovements/cannotInferParameterTypeWithInference.kt

@@ -4,7 +4,7 @@ fun <T, R> foo(block: (T)-> R) = block
 
 fun test1() {
     <!TYPE_INFERENCE_NO_INFORMATION_FOR_PARAMETER!>foo<!> {
-        <!CANNOT_INFER_PARAMETER_TYPE, UNUSED_PARAMETER!>x<!> ->  // here we have 'cannot infer parameter type' error
+        <!CANNOT_INFER_PARAMETER_TYPE, UNUSED_ANONYMOUS_PARAMETER!>x<!> ->  // here we have 'cannot infer parameter type' error
         43
     }
 }
@@ -12,5 +12,5 @@ fun test1() {
 fun bar(<!UNUSED_PARAMETER!>f<!>: (<!UNRESOLVED_REFERENCE!>A<!>)->Unit) {}
 
 fun test2() {
-    bar { <!UNUSED_PARAMETER!>a<!> -> } // here we don't have 'cannot infer parameter type' error
+    bar { <!UNUSED_ANONYMOUS_PARAMETER!>a<!> -> } // here we don't have 'cannot infer parameter type' error
 }

compiler/testData/diagnostics/tests/j+k/sam/typeInferenceOnSamAdapters.kt

@@ -1,4 +1,4 @@
-// !DIAGNOSTICS: -UNUSED_PARAMETER
+// !DIAGNOSTICS: -UNUSED_ANONYMOUS_PARAMETER
 // FILE: A.java
 public class A<K, V> {
     public void foo(K key, BiFunction<? super K, ? super V, ? extends V> remappingFunction) {

compiler/testData/diagnostics/tests/j+k/samByProjectedType/noAdapterBecuaseOfRecursiveUpperBound.kt

@@ -16,12 +16,12 @@ public class A {
 // FILE: main.kt
 fun main() {
     A().foo <!TYPE_MISMATCH!>{
-        <!CANNOT_INFER_PARAMETER_TYPE, UNUSED_PARAMETER!>x<!> ->
+        <!CANNOT_INFER_PARAMETER_TYPE, UNUSED_ANONYMOUS_PARAMETER!>x<!> ->
         ""
     }<!>
 
     A.bar <!TYPE_MISMATCH!>{
-        <!CANNOT_INFER_PARAMETER_TYPE, UNUSED_PARAMETER!>x<!> ->
+        <!CANNOT_INFER_PARAMETER_TYPE, UNUSED_ANONYMOUS_PARAMETER!>x<!> ->
         ""
     }<!>
 }

compiler/testData/diagnostics/tests/platformTypes/samAdapterInConstructor.kt

@@ -1,4 +1,4 @@
-// !DIAGNOSTICS: -UNUSED_VARIABLE -UNUSED_PARAMETER
+// !DIAGNOSTICS: -UNUSED_VARIABLE -UNUSED_ANONYMOUS_PARAMETER
 
 // FILE: A.java
 import java.util.Comparator;

compiler/testData/diagnostics/tests/regressions/Jet124.kt

@@ -3,6 +3,6 @@ fun foo1() :  (Int) -> Int = { x: Int -> x }
 fun foo() {
   val h :  (Int) -> Int = foo1();
   h(1)
-  val m :  (Int) -> Int = {<!UNUSED_PARAMETER!>a<!> : Int -> 1}//foo1()
+  val m :  (Int) -> Int = {<!UNUSED_ANONYMOUS_PARAMETER!>a<!> : Int -> 1}//foo1()
   m(1)
 }

compiler/testData/diagnostics/tests/resolve/invoke/invokeNonExtensionLambdaInContext.kt

@@ -1,4 +1,4 @@
-// !DIAGNOSTICS: -UNUSED_PARAMETER
+// !DIAGNOSTICS: -UNUSED_PARAMETER -UNUSED_ANONYMOUS_PARAMETER
 
 class C {
     fun f() {}

compiler/testData/diagnostics/tests/syntheticExtensions/samAdapters/GenericClass.kt

@@ -1,6 +1,6 @@
 // FILE: KotlinFile.kt
 fun foo(javaClass: JavaClass<String>): String {
-    return javaClass.doSomething("", 1) { <!UNUSED_PARAMETER!>s<!>: String -> "" }
+    return javaClass.doSomething("", 1) { <!UNUSED_ANONYMOUS_PARAMETER!>s<!>: String -> "" }
 }
 
 // FILE: JavaClass.java

compiler/testData/diagnostics/tests/when/whenAndLambdaWithExpectedType.kt

@@ -12,13 +12,13 @@ val test2: (String) -> Boolean =
 
 val test3: (String) -> Boolean =
         when {
-            true -> { <!UNUSED_PARAMETER!>s<!> -> true }
+            true -> { <!UNUSED_ANONYMOUS_PARAMETER!>s<!> -> true }
             else -> null!!
         }
 
 val test4: (String) -> Boolean =
         when {
-            true -> { <!EXPECTED_PARAMETERS_NUMBER_MISMATCH!><!UNUSED_PARAMETER!>s1<!>, <!CANNOT_INFER_PARAMETER_TYPE, UNUSED_PARAMETER!>s2<!><!> -> true }
+            true -> { <!EXPECTED_PARAMETERS_NUMBER_MISMATCH!><!UNUSED_ANONYMOUS_PARAMETER!>s1<!>, <!CANNOT_INFER_PARAMETER_TYPE, UNUSED_ANONYMOUS_PARAMETER!>s2<!><!> -> true }
             else -> null!!
         }
 

compiler/testData/diagnostics/testsWithJsStdLib/dynamicTypes/dynamicCallsWithLambdas.kt

@@ -1,4 +1,4 @@
-// !DIAGNOSTICS: -UNUSED_PARAMETER
+// !DIAGNOSTICS: -UNUSED_ANONYMOUS_PARAMETER
 // !CHECK_TYPE
 
 fun test(d: dynamic) {

compiler/testData/diagnostics/testsWithJsStdLib/noImpl.kt

@@ -1,4 +1,4 @@
-// !DIAGNOSTICS: -UNUSED_PARAMETER, -UNREACHABLE_CODE
+// !DIAGNOSTICS: -UNUSED_ANONYMOUS_PARAMETER -UNUSED_PARAMETER, -UNREACHABLE_CODE
 
 val prop: String = <!CALL_TO_DEFINED_EXTERNALLY_FROM_NON_EXTERNAL_DECLARATION!>definedExternally<!>
 

compiler/testData/diagnostics/testsWithStdLib/annotations/JvmSyntheticOnDelegate.kt

@@ -1,4 +1,4 @@
-// !DIAGNOSTICS: -UNUSED_PARAMETER
+// !DIAGNOSTICS: -UNUSED_ANONYMOUS_PARAMETER
 import kotlin.properties.Delegates
 
 class My {

compiler/testData/diagnostics/testsWithStdLib/annotations/Volatile.kt

@@ -1,4 +1,4 @@
-// !DIAGNOSTICS: -UNUSED_PARAMETER
+// !DIAGNOSTICS: -UNUSED_ANONYMOUS_PARAMETER
 import kotlin.jvm.Volatile
 import kotlin.properties.Delegates
 

compiler/testData/diagnostics/testsWithStdLib/coroutines/inference/withUninferredParameter.kt

@@ -1,4 +1,4 @@
-// !DIAGNOSTICS: -UNUSED_EXPRESSION -UNUSED_PARAMETER -UNUSED_VARIABLE
+// !DIAGNOSTICS: -UNUSED_EXPRESSION -UNUSED_PARAMETER -UNUSED_ANONYMOUS_PARAMETER -UNUSED_VARIABLE
 
 class GenericController<T> {
     suspend fun yield(t: T) {}

compiler/testData/diagnostics/testsWithStdLib/coroutines/tailCalls/forbidden.kt

@@ -1,4 +1,4 @@
-// !DIAGNOSTICS: -UNUSED_PARAMETER
+// !DIAGNOSTICS: -UNUSED_ANONYMOUS_PARAMETER
 import kotlin.coroutines.experimental.*
 import kotlin.coroutines.experimental.intrinsics.*
 

compiler/testData/diagnostics/testsWithStdLib/coroutines/tailCalls/tryCatch.kt

@@ -1,4 +1,4 @@
-// !DIAGNOSTICS: -UNUSED_PARAMETER
+// !DIAGNOSTICS: -UNUSED_ANONYMOUS_PARAMETER
 import kotlin.coroutines.experimental.*
 import kotlin.coroutines.experimental.intrinsics.*
 

compiler/testData/diagnostics/testsWithStdLib/coroutines/tailCalls/valid.kt

@@ -1,4 +1,4 @@
-// !DIAGNOSTICS: -UNUSED_PARAMETER
+// !DIAGNOSTICS: -UNUSED_ANONYMOUS_PARAMETER
 import kotlin.coroutines.experimental.*
 import kotlin.coroutines.experimental.intrinsics.*
 

compiler/testData/diagnostics/testsWithStdLib/functionLiterals/pseudocodeMemoryOverhead.kt

@@ -33,8 +33,8 @@ private val STRING = CompileTimeType<String>()
 private val ANY = CompileTimeType<Any>()
 
 
-private val emptyBinaryFun: Function2<BigInteger, BigInteger, BigInteger> = { <!UNUSED_PARAMETER!>a<!>, <!UNUSED_PARAMETER!>b<!> -> BigInteger("0") }
+private val emptyBinaryFun: Function2<BigInteger, BigInteger, BigInteger> = { <!UNUSED_ANONYMOUS_PARAMETER!>a<!>, <!UNUSED_ANONYMOUS_PARAMETER!>b<!> -> BigInteger("0") }
-private val emptyUnaryFun: Function1<Long, Long> = { <!UNUSED_PARAMETER!>a<!> -> 1.toLong() }
+private val emptyUnaryFun: Function1<Long, Long> = { <!UNUSED_ANONYMOUS_PARAMETER!>a<!> -> 1.toLong() }
 
 private val unaryOperations: HashMap<UnaryOperationKey<*>, Pair<Function1<Any?, Any>, Function1<Long, Long>>>
         = hashMapOf<UnaryOperationKey<*>, Pair<Function1<Any?, Any>, Function1<Long, Long>>>(

compiler/testData/diagnostics/testsWithStdLib/regression/ea70485_functionTypeInheritor.kt

@@ -4,7 +4,7 @@ class O : Function2<Int, String, Unit> {
 }
 
 fun test() {
-    val a = fun(<!UNUSED_PARAMETER!>o<!>: O) {
+    val a = fun(<!UNUSED_ANONYMOUS_PARAMETER!>o<!>: O) {
     }
     a <!TYPE_MISMATCH!>{}<!>
 }

compiler/tests/org/jetbrains/kotlin/checkers/DiagnosticsTestGenerated.java

@@ -4048,6 +4048,12 @@ public class DiagnosticsTestGenerated extends AbstractDiagnosticsTest {
                 doTest(fileName);
             }
 
+            @TestMetadata("unusedInAnonymous.kt")
+            public void testUnusedInAnonymous() throws Exception {
+                String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/diagnostics/tests/controlFlowAnalysis/unusedInAnonymous.kt");
+                doTest(fileName);
+            }
+
             @TestMetadata("useUninitializedInLambda.kt")
             public void testUseUninitializedInLambda() throws Exception {
                 String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/diagnostics/tests/controlFlowAnalysis/useUninitializedInLambda.kt");

idea/idea-analysis/src/org/jetbrains/kotlin/idea/highlighter/KotlinPsiChecker.kt

@@ -239,11 +239,16 @@ private class ElementAnnotator(private val element: PsiElement,
 
                 AnnotationPresentationInfo(
                         ranges,
-                        textAttributes = if (factory == Errors.DEPRECATION) CodeInsightColors.DEPRECATED_ATTRIBUTES else null,
+                        textAttributes = when (factory) {
-                        highlightType = if (factory in Errors.UNUSED_ELEMENT_DIAGNOSTICS)
+                            Errors.DEPRECATION -> CodeInsightColors.DEPRECATED_ATTRIBUTES
-                            ProblemHighlightType.LIKE_UNUSED_SYMBOL
+                            Errors.UNUSED_ANONYMOUS_PARAMETER -> CodeInsightColors.WEAK_WARNING_ATTRIBUTES
-                        else
+                            else -> null
-                            null
+                        },
+                        highlightType = when (factory) {
+                            in Errors.UNUSED_ELEMENT_DIAGNOSTICS -> ProblemHighlightType.LIKE_UNUSED_SYMBOL
+                            Errors.UNUSED_ANONYMOUS_PARAMETER -> ProblemHighlightType.WEAK_WARNING
+                            else -> null
+                        }
                 )
             }
             Severity.INFO -> return // Do nothing
@@ -278,14 +283,22 @@ private class AnnotationPresentationInfo(
         val ranges: List<TextRange>,
         val nonDefaultMessage: String? = null,
         val highlightType: ProblemHighlightType? = null,
-        val textAttributes: TextAttributesKey? = null) {
+        val textAttributes: TextAttributesKey? = null
+) {
 
     fun create(diagnostic: Diagnostic, range: TextRange, holder: AnnotationHolder): Annotation {
         val defaultMessage = nonDefaultMessage ?: getDefaultMessage(diagnostic)
 
         val annotation = when (diagnostic.severity) {
             Severity.ERROR -> holder.createErrorAnnotation(range, defaultMessage)
-            Severity.WARNING -> holder.createWarningAnnotation(range, defaultMessage)
+            Severity.WARNING -> {
+                if (highlightType == ProblemHighlightType.WEAK_WARNING) {
+                    holder.createWeakWarningAnnotation(range, defaultMessage)
+                }
+                else {
+                    holder.createWarningAnnotation(range, defaultMessage)
+                }
+            }
             else -> throw IllegalArgumentException("Only ERROR and WARNING diagnostics are supported")
         }
 

idea/src/org/jetbrains/kotlin/idea/quickfix/QuickFixRegistrar.kt

@@ -284,8 +284,8 @@ class QuickFixRegistrar : QuickFixContributor {
         TOO_MANY_ARGUMENTS.registerFactory(ChangeFunctionSignatureFix)
         NO_VALUE_FOR_PARAMETER.registerFactory(ChangeFunctionSignatureFix)
         UNUSED_PARAMETER.registerFactory(RemoveUnusedFunctionParameterFix)
-        UNUSED_PARAMETER.registerFactory(RenameToUnderscoreFix.Factory)
+        UNUSED_ANONYMOUS_PARAMETER.registerFactory(RenameToUnderscoreFix.Factory)
-        UNUSED_PARAMETER.registerFactory(RemoveSingleLambdaParameterFix)
+        UNUSED_ANONYMOUS_PARAMETER.registerFactory(RemoveSingleLambdaParameterFix)
         EXPECTED_PARAMETERS_NUMBER_MISMATCH.registerFactory(ChangeFunctionLiteralSignatureFix)
 
         EXPECTED_PARAMETER_TYPE_MISMATCH.registerFactory(ChangeTypeFix)

idea/src/org/jetbrains/kotlin/idea/quickfix/RenameToUnderscoreFix.kt

@@ -36,7 +36,7 @@ class RenameToUnderscoreFix(element: KtCallableDeclaration) : KotlinQuickFixActi
     companion object Factory : KotlinSingleIntentionActionFactory() {
         override fun createAction(diagnostic: Diagnostic): IntentionAction? {
             val declaration: KtCallableDeclaration? = when (diagnostic.factory) {
-                Errors.UNUSED_PARAMETER -> {
+                Errors.UNUSED_ANONYMOUS_PARAMETER -> {
                     val parameter = diagnostic.psiElement as? KtParameter
                     val owner = parameter?.parent?.parent
 

idea/testData/checker/regression/Jet124.kt

@@ -3,6 +3,6 @@ fun foo1() :  (Int) -> Int = { x: Int -> x }
 fun foo() {
   val h :  (Int) -> Int = foo1();
   h(1)
-  val m :  (Int) -> Int = {<warning descr="[UNUSED_PARAMETER] Parameter 'a' is never used">a</warning> : Int -> 1}//foo1()
+  val m :  (Int) -> Int = {a : Int -> 1}//foo1()
   m(1)
 }

plugins/sam-with-receiver/sam-with-receiver-cli/testData/diagnostics/noReturnType.kt

@@ -1,4 +1,4 @@
-// !DIAGNOSTICS: -UNUSED_PARAMETER,-UNUSED_VARIABLE
+// !DIAGNOSTICS: -UNUSED_ANONYMOUS_PARAMETER,-UNUSED_VARIABLE
 
 // FILE: Sam.java
 @SamWithReceiver

plugins/sam-with-receiver/sam-with-receiver-cli/testData/diagnostics/samWithAnnotation.kt

@@ -1,4 +1,4 @@
-// !DIAGNOSTICS: -UNUSED_PARAMETER,-UNUSED_VARIABLE
+// !DIAGNOSTICS: -UNUSED_ANONYMOUS_PARAMETER,-UNUSED_VARIABLE
 
 // FILE: Sam.java
 @SamWithReceiver

plugins/sam-with-receiver/sam-with-receiver-cli/testData/diagnostics/samWithoutAnnotation.kt

@@ -1,4 +1,4 @@
-// !DIAGNOSTICS: -UNUSED_PARAMETER,-UNUSED_VARIABLE
+// !DIAGNOSTICS: -UNUSED_ANONYMOUS_PARAMETER,-UNUSED_VARIABLE
 
 // FILE: Sam.java
 public interface Sam {