diff --git a/src/QsCompiler/DataStructures/Diagnostics.fs b/src/QsCompiler/DataStructures/Diagnostics.fs
index 50e77301e3..e4476b0977 100644
--- a/src/QsCompiler/DataStructures/Diagnostics.fs
+++ b/src/QsCompiler/DataStructures/Diagnostics.fs
@@ -369,6 +369,7 @@ type WarningCode =
     | [<Obsolete("This diagnostic is no longer in use. The error InvalidUseOfUnderscorePattern is given instead.")>] UseOfUnderscorePattern = 3305
     | DeprecatedTupleBrackets = 3306
     | DeprecatedQubitBindingKeyword = 3307
+    | DeprecatedNewArray = 3308
     | DeprecatedRUSloopInFunction = 4001
 
     | DiscardingItemInAssignment = 5001
@@ -954,6 +955,8 @@ type DiagnosticItem =
             | WarningCode.DeprecatedQubitBindingKeyword ->
                 "The \"{0}\" keyword has been replaced with \"{1}\", and qubits may now be allocated without a block. "
                 + "Consider \"{1} q = Qubit();\" or \"{1} q = Qubit() {{ ... }}\"."
+            | WarningCode.DeprecatedNewArray ->
+                "Deprecated syntax. Use [] to construct an empty array, or [x, size = n] to construct an array of x repeated n times."
             | WarningCode.DeprecatedRUSloopInFunction ->
                 "The use of repeat-until-success-loops within functions may not be supported in the future. Please use a while-loop instead."
 
diff --git a/src/QsCompiler/Tests.Compiler/AccessModifierTests.fs b/src/QsCompiler/Tests.Compiler/AccessModifierTests.fs
index 60d67d1cbf..bfa56e5677 100644
--- a/src/QsCompiler/Tests.Compiler/AccessModifierTests.fs
+++ b/src/QsCompiler/Tests.Compiler/AccessModifierTests.fs
@@ -27,8 +27,12 @@ type AccessModifierTests() =
 
     [<Fact>]
     member this.Types() =
-        this.Expect "TypeUseOK" []
-        this.Expect "TypeReferenceInternalInaccessible" [ Error ErrorCode.InaccessibleType ]
+        this.Expect "TypeUseOK" (Warning WarningCode.DeprecatedNewArray |> List.replicate 3)
+
+        this.Expect
+            "TypeReferenceInternalInaccessible"
+            [ Error ErrorCode.InaccessibleType; Warning WarningCode.DeprecatedNewArray ]
+
         this.Expect "TypeConstructorReferenceInternalInaccessible" [ Error ErrorCode.InaccessibleCallable ]
 
     [<Fact>]
diff --git a/src/QsCompiler/Tests.Compiler/GlobalVerificationTests.fs b/src/QsCompiler/Tests.Compiler/GlobalVerificationTests.fs
index 585d659e1e..e1b57eab2a 100644
--- a/src/QsCompiler/Tests.Compiler/GlobalVerificationTests.fs
+++ b/src/QsCompiler/Tests.Compiler/GlobalVerificationTests.fs
@@ -35,12 +35,12 @@ type GlobalVerificationTests() =
         this.Expect "LocalNamespaceShortNames1" []
         this.Expect "LocalNamespaceShortNames2" []
         this.Expect "LocalNamespaceShortNames3" [ Error ErrorCode.UnknownType ]
-        this.Expect "LocalNamespaceShortNames4" [ Error ErrorCode.UnknownType ]
+        this.Expect "LocalNamespaceShortNames4" [ Error ErrorCode.UnknownType; Warning WarningCode.DeprecatedNewArray ]
         this.Expect "LocalNamespaceShortNames5" [ Error ErrorCode.UnknownIdentifier ]
         this.Expect "LocalNamespaceShortNames6" [ Error ErrorCode.TypeMismatch; Error ErrorCode.TypeMismatch ]
         this.Expect "LocalNamespaceShortNames7" [ Error ErrorCode.UnknownIdentifier ]
         this.Expect "LocalNamespaceShortNames8" []
-        this.Expect "LocalNamespaceShortNames9" []
+        this.Expect "LocalNamespaceShortNames9" [ Warning WarningCode.DeprecatedNewArray ]
         this.Expect "LocalNamespaceShortNames10" []
         this.Expect "LocalNamespaceShortNames11" [ Error ErrorCode.UnknownType; Error ErrorCode.UnknownIdentifier ]
         this.Expect "LocalNamespaceShortNames12" [ Error ErrorCode.UnknownIdentifier ]
@@ -53,7 +53,7 @@ type GlobalVerificationTests() =
         this.Expect "LocalNamespaceShortNames19" []
         this.Expect "LocalNamespaceShortNames20" []
         this.Expect "LocalNamespaceShortNames21" []
-        this.Expect "LocalNamespaceShortNames22" []
+        this.Expect "LocalNamespaceShortNames22" (Warning WarningCode.DeprecatedNewArray |> List.replicate 2)
         this.Expect "LocalNamespaceShortNames23" []
         this.Expect "LocalNamespaceShortNames24" []
 
@@ -533,7 +533,7 @@ type GlobalVerificationTests() =
         this.Expect "ValidAttributes1" []
         this.Expect "ValidAttributes2" []
         this.Expect "ValidAttributes3" []
-        this.Expect "ValidAttributes4" []
+        this.Expect "ValidAttributes4" [ Warning WarningCode.DeprecatedNewArray ]
         this.Expect "ValidAttributes5" []
         this.Expect "ValidAttributes6" []
         this.Expect "ValidAttributes7" []
@@ -555,7 +555,14 @@ type GlobalVerificationTests() =
         this.Expect "InvalidAttributes5" [ Error ErrorCode.UnknownTypeInNamespace ]
         this.Expect "InvalidAttributes6" [ Error ErrorCode.AttributeArgumentTypeMismatch ]
         this.Expect "InvalidAttributes7" [ Error ErrorCode.InvalidAttributeArgument ]
-        this.Expect "InvalidAttributes8" [ Error ErrorCode.ArgumentOfUserDefinedTypeInAttribute ]
+
+        this.Expect
+            "InvalidAttributes8"
+            [
+                Error ErrorCode.ArgumentOfUserDefinedTypeInAttribute
+                Warning WarningCode.DeprecatedNewArray
+            ]
+
         this.Expect "InvalidAttributes9" [ Error ErrorCode.MisplacedDeclarationAttribute ]
         this.Expect "InvalidAttributes10" [ Error ErrorCode.MisplacedDeclarationAttribute ]
         this.Expect "InvalidAttributes11" [ Error ErrorCode.MisplacedDeclarationAttribute ]
diff --git a/src/QsCompiler/Tests.Compiler/LocalVerificationTests.fs b/src/QsCompiler/Tests.Compiler/LocalVerificationTests.fs
index 58a0245e11..a3d0273f10 100644
--- a/src/QsCompiler/Tests.Compiler/LocalVerificationTests.fs
+++ b/src/QsCompiler/Tests.Compiler/LocalVerificationTests.fs
@@ -47,25 +47,25 @@ type LocalVerificationTests() =
 
         this.Expect "TypeArgumentsInference6" []
         this.Expect "TypeArgumentsInference7" []
-        this.Expect "TypeArgumentsInference8" []
-        this.Expect "TypeArgumentsInference9" []
+        this.Expect "TypeArgumentsInference8" [ Warning WarningCode.DeprecatedNewArray ]
+        this.Expect "TypeArgumentsInference9" [ Warning WarningCode.DeprecatedNewArray ]
         this.Expect "TypeArgumentsInference10" []
         this.Expect "TypeArgumentsInference11" []
         this.Expect "TypeArgumentsInference12" []
         this.Expect "TypeArgumentsInference13" []
         this.Expect "TypeArgumentsInference14" []
         this.Expect "TypeArgumentsInference15" []
-        this.Expect "TypeArgumentsInference16" []
-        this.Expect "TypeArgumentsInference17" []
-        this.Expect "TypeArgumentsInference18" []
+        this.Expect "TypeArgumentsInference16" [ Warning WarningCode.DeprecatedNewArray ]
+        this.Expect "TypeArgumentsInference17" [ Warning WarningCode.DeprecatedNewArray ]
+        this.Expect "TypeArgumentsInference18" [ Warning WarningCode.DeprecatedNewArray ]
         this.Expect "TypeArgumentsInference19" []
         this.Expect "TypeArgumentsInference20" []
         this.Expect "TypeArgumentsInference21" [ Error ErrorCode.TypeMismatch ]
         this.Expect "TypeArgumentsInference22" [ Error ErrorCode.TypeMismatch ]
         this.Expect "TypeArgumentsInference23" []
         this.Expect "TypeArgumentsInference24" []
-        this.Expect "TypeArgumentsInference25" []
-        this.Expect "TypeArgumentsInference26" []
+        this.Expect "TypeArgumentsInference25" [ Warning WarningCode.DeprecatedNewArray ]
+        this.Expect "TypeArgumentsInference26" [ Warning WarningCode.DeprecatedNewArray ]
         this.Expect "TypeArgumentsInference27" [ Error ErrorCode.TypeMismatch ]
         this.Expect "TypeArgumentsInference28" [ Error ErrorCode.TypeMismatch ]
         this.Expect "TypeArgumentsInference29" [ Error ErrorCode.InvalidCyclicTypeParameterResolution ]
@@ -88,8 +88,8 @@ type LocalVerificationTests() =
         this.Expect "TypeArgumentsInference33" [ Error ErrorCode.TypeMismatch ]
         this.Expect "TypeArgumentsInference34" []
         this.Expect "TypeArgumentsInference35" []
-        this.Expect "TypeArgumentsInference36" []
-        this.Expect "TypeArgumentsInference37" []
+        this.Expect "TypeArgumentsInference36" [ Warning WarningCode.DeprecatedNewArray ]
+        this.Expect "TypeArgumentsInference37" [ Warning WarningCode.DeprecatedNewArray ]
         this.Expect "TypeArgumentsInference38" [ Error ErrorCode.TypeMismatch ]
         this.Expect "TypeArgumentsInference39" [ Error ErrorCode.TypeMismatch ]
         this.Expect "TypeArgumentsInference40" []
@@ -134,10 +134,10 @@ type LocalVerificationTests() =
 
         this.Expect "VariableDeclaration15" []
         this.Expect "VariableDeclaration16" []
-        this.Expect "VariableDeclaration17" []
-        this.Expect "VariableDeclaration18" []
-        this.Expect "VariableDeclaration19" []
-        this.Expect "VariableDeclaration20" []
+        this.Expect "VariableDeclaration17" [ Warning WarningCode.DeprecatedNewArray ]
+        this.Expect "VariableDeclaration18" [ Warning WarningCode.DeprecatedNewArray ]
+        this.Expect "VariableDeclaration19" [ Warning WarningCode.DeprecatedNewArray ]
+        this.Expect "VariableDeclaration20" [ Warning WarningCode.DeprecatedNewArray ]
         this.Expect "VariableDeclaration21" []
         this.Expect "VariableDeclaration22" []
         this.Expect "VariableDeclaration23" []
@@ -157,7 +157,7 @@ type LocalVerificationTests() =
         this.Expect "CopyAndUpdateArray1" []
         this.Expect "CopyAndUpdateArray2" []
         this.Expect "CopyAndUpdateArray3" []
-        this.Expect "CopyAndUpdateArray4" []
+        this.Expect "CopyAndUpdateArray4" [ Warning WarningCode.DeprecatedNewArray ]
         this.Expect "CopyAndUpdateArray5" [ Error ErrorCode.TypeMismatchInCopyAndUpdateExpr ]
         this.Expect "CopyAndUpdateArray6" [ Error ErrorCode.TypeMismatchInCopyAndUpdateExpr ]
         this.Expect "CopyAndUpdateArray7" [ Error ErrorCode.TypeMismatchInCopyAndUpdateExpr ]
@@ -179,11 +179,23 @@ type LocalVerificationTests() =
         this.Expect "UpdateAndReassign3" []
         this.Expect "UpdateAndReassign4" [ Error ErrorCode.TypeMismatchInCopyAndUpdateExpr ]
         this.Expect "UpdateAndReassign5" [ Error ErrorCode.TypeMismatchInCopyAndUpdateExpr ]
-        this.Expect "UpdateAndReassign6" []
-        this.Expect "UpdateAndReassign7" []
-        this.Expect "UpdateAndReassign8" []
-        this.Expect "UpdateAndReassign9" [ Error ErrorCode.TypeMismatchInCopyAndUpdateExpr ]
-        this.Expect "UpdateAndReassign10" [ Error ErrorCode.TypeMismatchInCopyAndUpdateExpr ]
+        this.Expect "UpdateAndReassign6" [ Warning WarningCode.DeprecatedNewArray ]
+        this.Expect "UpdateAndReassign7" [ Warning WarningCode.DeprecatedNewArray ]
+        this.Expect "UpdateAndReassign8" [ Warning WarningCode.DeprecatedNewArray ]
+
+        this.Expect
+            "UpdateAndReassign9"
+            [
+                Error ErrorCode.TypeMismatchInCopyAndUpdateExpr
+                Warning WarningCode.DeprecatedNewArray
+            ]
+
+        this.Expect
+            "UpdateAndReassign10"
+            [
+                Error ErrorCode.TypeMismatchInCopyAndUpdateExpr
+                Warning WarningCode.DeprecatedNewArray
+            ]
 
 
     [<Fact>]
@@ -234,7 +246,7 @@ type LocalVerificationTests() =
         this.Expect "ItemAccess16" []
         this.Expect "ItemAccess17" []
         this.Expect "ItemAccess18" []
-        this.Expect "ItemAccess19" []
+        this.Expect "ItemAccess19" [ Warning WarningCode.DeprecatedNewArray ]
         this.Expect "ItemAccess20" []
 
 
@@ -255,22 +267,29 @@ type LocalVerificationTests() =
                 Error ErrorCode.TypeMismatchInCopyAndUpdateExpr
             ]
 
-        this.Expect "ItemUpdate9" []
+        this.Expect "ItemUpdate9" [ Warning WarningCode.DeprecatedNewArray ]
 
         this.Expect
             "ItemUpdate10"
             [
                 Error ErrorCode.InvalidIdentifierExprInUpdate
                 Error ErrorCode.ExcessContinuation
+                Warning WarningCode.DeprecatedNewArray
             ]
 
-        this.Expect "ItemUpdate11" [ Error ErrorCode.UpdateOfArrayItemExpr ]
+        this.Expect
+            "ItemUpdate11"
+            [
+                Error ErrorCode.UpdateOfArrayItemExpr
+                Warning WarningCode.DeprecatedNewArray
+            ]
 
         this.Expect
             "ItemUpdate12"
             [
                 Error ErrorCode.TypeMismatchInCopyAndUpdateExpr
                 Error ErrorCode.TypeMismatchInCopyAndUpdateExpr
+                Warning WarningCode.DeprecatedNewArray
             ]
 
         this.Expect "ItemUpdate13" []
@@ -294,7 +313,7 @@ type LocalVerificationTests() =
         this.Expect "ItemUpdate18" [ Error ErrorCode.MissingFunctorForAutoGeneration ]
         this.Expect "ItemUpdate19" [ Error ErrorCode.MissingFunctorForAutoGeneration ]
         this.Expect "ItemUpdate20" []
-        this.Expect "ItemUpdate21" []
+        this.Expect "ItemUpdate21" [ Warning WarningCode.DeprecatedNewArray ]
         this.Expect "ItemUpdate22" []
 
 
@@ -374,7 +393,13 @@ type LocalVerificationTests() =
         this.Expect "UsingDepAttrInDepCall" [ Warning WarningCode.DeprecationWithoutRedirect ]
         this.Expect "UsingDepTypeInDepCall" [ Warning WarningCode.DeprecationWithoutRedirect ]
 
-        this.Expect "UsingDeprecatedType1" [ Warning WarningCode.DeprecationWithoutRedirect ]
+        this.Expect
+            "UsingDeprecatedType1"
+            [
+                Warning WarningCode.DeprecationWithoutRedirect
+                Warning WarningCode.DeprecatedNewArray
+            ]
+
         this.Expect "UsingDeprecatedType2" [ Warning WarningCode.DeprecationWithoutRedirect ]
         this.Expect "UsingDeprecatedType3" [ Warning WarningCode.DeprecationWithoutRedirect ]
 
@@ -392,7 +417,13 @@ type LocalVerificationTests() =
                 Warning WarningCode.DeprecationWithoutRedirect
             ]
 
-        this.Expect "UsingRenamedType1" [ Warning WarningCode.DeprecationWithRedirect ]
+        this.Expect
+            "UsingRenamedType1"
+            [
+                Warning WarningCode.DeprecationWithRedirect
+                Warning WarningCode.DeprecatedNewArray
+            ]
+
         this.Expect "UsingRenamedType2" [ Warning WarningCode.DeprecationWithRedirect ]
         this.Expect "UsingRenamedType3" [ Warning WarningCode.DeprecationWithRedirect ]
 
diff --git a/src/QsCompiler/Tests.Compiler/SyntaxTests.fs b/src/QsCompiler/Tests.Compiler/SyntaxTests.fs
index 4c5b8ffb63..816440e452 100644
--- a/src/QsCompiler/Tests.Compiler/SyntaxTests.fs
+++ b/src/QsCompiler/Tests.Compiler/SyntaxTests.fs
@@ -889,12 +889,16 @@ let ``Function type tests`` () =
         "new (Int -> Int)[0]",
         true,
         toNewArray (toTupleType [ Function(toType Int, toType Int) |> toType ]) (toInt 0),
-        []
+        [ Warning WarningCode.DeprecatedNewArray ]
 
         "new Int -> Int[0]",
         true,
         toNewArray (Function(toType Int, toType Int) |> toType) (toInt 0),
-        [ Error ErrorCode.MissingLTupleBracket; Error ErrorCode.MissingRTupleBracket ]
+        [
+            Error ErrorCode.MissingLTupleBracket
+            Error ErrorCode.MissingRTupleBracket
+            Warning WarningCode.DeprecatedNewArray
+        ]
     ]
     |> List.iter testExpr
 
@@ -986,45 +990,86 @@ let ``Operation type tests`` () =
         "new (Qubit => Unit is Adj)[0]",
         true,
         toNewArray (toTupleType [ toOpType qubitType unitType adjSet ]) (toInt 0),
-        []
+        [ Warning WarningCode.DeprecatedNewArray ]
 
         "new Qubit => Unit is Adj[0]",
         true,
         toNewArray (toOpType qubitType unitType adjSet) (toInt 0),
-        [ Error ErrorCode.MissingLTupleBracket; Error ErrorCode.MissingRTupleBracket ]
+        [
+            Error ErrorCode.MissingLTupleBracket
+            Error ErrorCode.MissingRTupleBracket
+            Warning WarningCode.DeprecatedNewArray
+        ]
 
-        "new (Qubit => Unit) is Adj[0]", true, toExpr InvalidExpr, [ Error ErrorCode.InvalidConstructorExpression ]
+        "new (Qubit => Unit) is Adj[0]",
+        true,
+        toExpr InvalidExpr,
+        [
+            Error ErrorCode.InvalidConstructorExpression
+            Warning WarningCode.DeprecatedNewArray
+        ]
 
         "new (Qubit => Unit : Adjoint)[0]",
         true,
         toNewArray (toTupleType [ toOpType qubitType unitType emptySet ]) (toInt 0),
-        [ Error ErrorCode.ExcessContinuation ]
+        [ Error ErrorCode.ExcessContinuation; Warning WarningCode.DeprecatedNewArray ]
 
-        "new Qubit => Unit : Adjoint[0]", true, toExpr InvalidExpr, [ Error ErrorCode.InvalidConstructorExpression ]
-        "new (Qubit => Unit) : Adjoint[0]", true, toExpr InvalidExpr, [ Error ErrorCode.InvalidConstructorExpression ]
+        "new Qubit => Unit : Adjoint[0]",
+        true,
+        toExpr InvalidExpr,
+        [
+            Error ErrorCode.InvalidConstructorExpression
+            Warning WarningCode.DeprecatedNewArray
+        ]
+        "new (Qubit => Unit) : Adjoint[0]",
+        true,
+        toExpr InvalidExpr,
+        [
+            Error ErrorCode.InvalidConstructorExpression
+            Warning WarningCode.DeprecatedNewArray
+        ]
 
         "new (Qubit => Unit : Adj)[0]",
         true,
         toNewArray (toTupleType [ toOpType qubitType unitType emptySet ]) (toInt 0),
-        [ Error ErrorCode.ExcessContinuation ]
+        [ Error ErrorCode.ExcessContinuation; Warning WarningCode.DeprecatedNewArray ]
 
-        "new Qubit => Unit : Adj[0]", true, toExpr InvalidExpr, [ Error ErrorCode.InvalidConstructorExpression ]
-        "new (Qubit => Unit) : Adj[0]", true, toExpr InvalidExpr, [ Error ErrorCode.InvalidConstructorExpression ]
+        "new Qubit => Unit : Adj[0]",
+        true,
+        toExpr InvalidExpr,
+        [
+            Error ErrorCode.InvalidConstructorExpression
+            Warning WarningCode.DeprecatedNewArray
+        ]
+        "new (Qubit => Unit) : Adj[0]",
+        true,
+        toExpr InvalidExpr,
+        [
+            Error ErrorCode.InvalidConstructorExpression
+            Warning WarningCode.DeprecatedNewArray
+        ]
 
         "new (Qubit => Unit is Adj + Ctl)[0]",
         true,
         toNewArray (toTupleType [ toOpType qubitType unitType adjCtlSet ]) (toInt 0),
-        []
+        [ Warning WarningCode.DeprecatedNewArray ]
 
         "new Qubit => Unit is Adj + Ctl[0]",
         true,
         toNewArray (toOpType qubitType unitType adjCtlSet) (toInt 0),
-        [ Error ErrorCode.MissingLTupleBracket; Error ErrorCode.MissingRTupleBracket ]
+        [
+            Error ErrorCode.MissingLTupleBracket
+            Error ErrorCode.MissingRTupleBracket
+            Warning WarningCode.DeprecatedNewArray
+        ]
 
         "new (Qubit => Unit) is Adj + Ctl[0]",
         true,
         toExpr InvalidExpr,
-        [ Error ErrorCode.InvalidConstructorExpression ]
+        [
+            Error ErrorCode.InvalidConstructorExpression
+            Warning WarningCode.DeprecatedNewArray
+        ]
 
         "new (Qubit => Unit : Adjoint, Controlled)[0]",
         true,
@@ -1032,25 +1077,47 @@ let ``Operation type tests`` () =
             (toTupleType [ toOpType qubitType unitType emptySet
                            toType InvalidType ])
             (toInt 0),
-        [ Error ErrorCode.ExcessContinuation; Error ErrorCode.InvalidType ]
+        [
+            Error ErrorCode.ExcessContinuation
+            Error ErrorCode.InvalidType
+            Warning WarningCode.DeprecatedNewArray
+        ]
 
         "new Qubit => Unit : Adjoint, Controlled[0]",
         true,
         toExpr InvalidExpr,
-        [ Error ErrorCode.InvalidConstructorExpression ]
+        [
+            Error ErrorCode.InvalidConstructorExpression
+            Warning WarningCode.DeprecatedNewArray
+        ]
 
         "new (Qubit => Unit) : Adjoint, Controlled[0]",
         true,
         toExpr InvalidExpr,
-        [ Error ErrorCode.InvalidConstructorExpression ]
+        [
+            Error ErrorCode.InvalidConstructorExpression
+            Warning WarningCode.DeprecatedNewArray
+        ]
 
         "new (Qubit => Unit : Adj + Ctl)[0]",
         true,
         toNewArray (toTupleType [ toOpType qubitType unitType emptySet ]) (toInt 0),
-        [ Error ErrorCode.ExcessContinuation ]
+        [ Error ErrorCode.ExcessContinuation; Warning WarningCode.DeprecatedNewArray ]
 
-        "new Qubit => Unit : Adj + Ctl[0]", true, toExpr InvalidExpr, [ Error ErrorCode.InvalidConstructorExpression ]
-        "new (Qubit => Unit) : Adj + Ctl[0]", true, toExpr InvalidExpr, [ Error ErrorCode.InvalidConstructorExpression ]
+        "new Qubit => Unit : Adj + Ctl[0]",
+        true,
+        toExpr InvalidExpr,
+        [
+            Error ErrorCode.InvalidConstructorExpression
+            Warning WarningCode.DeprecatedNewArray
+        ]
+        "new (Qubit => Unit) : Adj + Ctl[0]",
+        true,
+        toExpr InvalidExpr,
+        [
+            Error ErrorCode.InvalidConstructorExpression
+            Warning WarningCode.DeprecatedNewArray
+        ]
 
         "new (Qubit => Unit : Adj, Ctl)[0]",
         true,
@@ -1058,10 +1125,26 @@ let ``Operation type tests`` () =
             (toTupleType [ toOpType qubitType unitType emptySet
                            toType InvalidType ])
             (toInt 0),
-        [ Error ErrorCode.ExcessContinuation; Error ErrorCode.InvalidType ]
+        [
+            Error ErrorCode.ExcessContinuation
+            Error ErrorCode.InvalidType
+            Warning WarningCode.DeprecatedNewArray
+        ]
 
-        "new Qubit => Unit : Adj, Ctl[0]", true, toExpr InvalidExpr, [ Error ErrorCode.InvalidConstructorExpression ]
-        "new (Qubit => Unit) : Adj, Ctl[0]", true, toExpr InvalidExpr, [ Error ErrorCode.InvalidConstructorExpression ]
+        "new Qubit => Unit : Adj, Ctl[0]",
+        true,
+        toExpr InvalidExpr,
+        [
+            Error ErrorCode.InvalidConstructorExpression
+            Warning WarningCode.DeprecatedNewArray
+        ]
+        "new (Qubit => Unit) : Adj, Ctl[0]",
+        true,
+        toExpr InvalidExpr,
+        [
+            Error ErrorCode.InvalidConstructorExpression
+            Warning WarningCode.DeprecatedNewArray
+        ]
 
         "new (Qubit => Unit is Adj, Ctl)[0]",
         true,
@@ -1069,50 +1152,68 @@ let ``Operation type tests`` () =
             (toTupleType [ toOpType qubitType unitType adjSet
                            toType InvalidType ])
             (toInt 0),
-        [ Error ErrorCode.InvalidType ]
+        [ Error ErrorCode.InvalidType; Warning WarningCode.DeprecatedNewArray ]
 
-        "new Qubit => Unit is Adj, Ctl[0]", true, toExpr InvalidExpr, [ Error ErrorCode.InvalidConstructorExpression ]
-        "new (Qubit => Unit) is Adj, Ctl[0]", true, toExpr InvalidExpr, [ Error ErrorCode.InvalidConstructorExpression ]
+        "new Qubit => Unit is Adj, Ctl[0]",
+        true,
+        toExpr InvalidExpr,
+        [
+            Error ErrorCode.InvalidConstructorExpression
+            Warning WarningCode.DeprecatedNewArray
+        ]
+        "new (Qubit => Unit) is Adj, Ctl[0]",
+        true,
+        toExpr InvalidExpr,
+        [
+            Error ErrorCode.InvalidConstructorExpression
+            Warning WarningCode.DeprecatedNewArray
+        ]
 
         "new (Qubit => Unit is (Adj + Ctl))[0]",
         true,
         toNewArray (toTupleType [ toOpType qubitType unitType adjCtlSet ]) (toInt 0),
-        []
+        [ Warning WarningCode.DeprecatedNewArray ]
 
         "new (Qubit => Unit is ((Adj) + (Ctl)))[0]",
         true,
         toNewArray (toTupleType [ toOpType qubitType unitType adjCtlSet ]) (toInt 0),
-        []
+        [ Warning WarningCode.DeprecatedNewArray ]
 
         "new (Qubit => Unit is (Adj + Ctl _))[0]",
         true,
         toNewArray (toTupleType [ toOpType qubitType unitType adjCtlSet ]) (toInt 0),
-        [ Error ErrorCode.ExcessContinuation ]
+        [ Error ErrorCode.ExcessContinuation; Warning WarningCode.DeprecatedNewArray ]
 
         "new (Qubit => Unit is ())[0]",
         true,
         toNewArray (toTupleType [ toOpType qubitType unitType (toCharacteristicsExpr InvalidSetExpr) ]) (toInt 0),
-        [ Error ErrorCode.MissingOperationCharacteristics ]
+        [
+            Error ErrorCode.MissingOperationCharacteristics
+            Warning WarningCode.DeprecatedNewArray
+        ]
 
         "new (Qubit => Unit is (Adj + (Ctl + )))[0]",
         true,
         toNewArray (toTupleType [ toOpType qubitType unitType (toCharacteristicsExpr InvalidSetExpr) ]) (toInt 0),
-        [ Error ErrorCode.InvalidOperationCharacteristics ]
+        [
+            Error ErrorCode.InvalidOperationCharacteristics
+            Warning WarningCode.DeprecatedNewArray
+        ]
 
         "new (Qubit => Unit is MySet)[0]",
         true,
         toNewArray (toTupleType [ toOpType qubitType unitType (toCharacteristicsExpr InvalidSetExpr) ]) (toInt 0),
-        [ Error ErrorCode.UnknownSetName ]
+        [ Error ErrorCode.UnknownSetName; Warning WarningCode.DeprecatedNewArray ]
 
         "new (Qubit => Unit is Adj + MySet)[0]",
         true,
         toNewArray (toTupleType [ toOpType qubitType unitType (toCharacteristicsExpr InvalidSetExpr) ]) (toInt 0),
-        [ Error ErrorCode.UnknownSetName ]
+        [ Error ErrorCode.UnknownSetName; Warning WarningCode.DeprecatedNewArray ]
 
         "new (Qubit => Unit is (Adj + MySet))[0]",
         true,
         toNewArray (toTupleType [ toOpType qubitType unitType (toCharacteristicsExpr InvalidSetExpr) ]) (toInt 0),
-        [ Error ErrorCode.UnknownSetName ]
+        [ Error ErrorCode.UnknownSetName; Warning WarningCode.DeprecatedNewArray ]
     ]
     |> List.iter testExpr
 
diff --git a/src/QsCompiler/Tests.Compiler/TestCases/ExecutionTests/LoggingBasedTests.qs b/src/QsCompiler/Tests.Compiler/TestCases/ExecutionTests/LoggingBasedTests.qs
index d07ed13cb6..8404ec6fc9 100644
--- a/src/QsCompiler/Tests.Compiler/TestCases/ExecutionTests/LoggingBasedTests.qs
+++ b/src/QsCompiler/Tests.Compiler/TestCases/ExecutionTests/LoggingBasedTests.qs
@@ -25,7 +25,7 @@ namespace Microsoft.Quantum.Testing.ExecutionTests {
 
     // tests related to auto-generation of functor specializations for operations involving conjugations
 
-    operation SpecGenForConjugations () : Unit 
+    operation SpecGenForConjugations () : Unit
     is Adj + Ctl {
 
         within {
@@ -64,11 +64,11 @@ namespace Microsoft.Quantum.Testing.ExecutionTests {
     }
 
     operation ConjugationsInControlled () : Unit {
-        Controlled SpecGenForConjugations(new Qubit[0], ());
+        Controlled SpecGenForConjugations([], ());
     }
 
     operation ConjugationsInControlledAdjoint () : Unit {
-        Controlled Adjoint SpecGenForConjugations(new Qubit[0], ());
+        Controlled Adjoint SpecGenForConjugations([], ());
     }
 
 
diff --git a/src/QsCompiler/Tests.Compiler/TestCases/ExecutionTests/Packaging.qs b/src/QsCompiler/Tests.Compiler/TestCases/ExecutionTests/Packaging.qs
index f7c979ad95..6451b1673a 100644
--- a/src/QsCompiler/Tests.Compiler/TestCases/ExecutionTests/Packaging.qs
+++ b/src/QsCompiler/Tests.Compiler/TestCases/ExecutionTests/Packaging.qs
@@ -1,20 +1,17 @@
 // Copyright (c) Microsoft Corporation. All rights reserved.
 // Licensed under the MIT License.
 
-namespace Microsoft.Quantum.Testing.ExecutionTests
-{
+namespace Microsoft.Quantum.Testing.ExecutionTests {
     open Microsoft.Quantum.Intrinsic;
     open Microsoft.Quantum.Testing;
 
-
     operation PackageAndProjectReference () : Unit {
         Message("Welcome to Q#!");
         Log(1, "Go check out https://docs.microsoft.com/azure/quantum.");
     }
 
     operation TypeInReferencedProject () : Unit {
-        mutable arr = new Complex[1];
-        set arr w/= 0 <- Complex(1.,0.);
+        let arr = [Complex(1., 0.)];
         Message($"{arr}");
     }
 }
diff --git a/src/QsCompiler/Tests.Compiler/TestCases/FunctorGeneration.qs b/src/QsCompiler/Tests.Compiler/TestCases/FunctorGeneration.qs
index ea5f174b11..f2966fca7f 100644
--- a/src/QsCompiler/Tests.Compiler/TestCases/FunctorGeneration.qs
+++ b/src/QsCompiler/Tests.Compiler/TestCases/FunctorGeneration.qs
@@ -156,14 +156,14 @@ namespace Microsoft.Quantum.Testing.FunctorGeneration {
     operation ControlledAdjointGenDirective10 (q : Qubit) : Unit {
         body (...) { }
         adjoint (...) { }
-        controlled adjoint self; 
+        controlled adjoint self;
         controlled auto;
     }
 
     operation ControlledAdjointGenDirective11 (q : Qubit) : Unit {
         body (...) { }
         adjoint invert;
-        controlled adjoint self; 
+        controlled adjoint self;
         controlled auto;
     }
 
@@ -291,30 +291,30 @@ namespace Microsoft.Quantum.Testing.FunctorGeneration {
     // checking that functor support is verified for local variables and partial application as well
 
     operation VariableNeedsFunctorSupport1 (q : Qubit) : Unit {
-        body (...) { 
+        body (...) {
             let op = Controllable;
-            op(q); 
+            op(q);
         }
         adjoint auto;
     }
 
     operation VariableNeedsFunctorSupport2 (q : Qubit) : Unit {
-        body (...) { 
+        body (...) {
             let op = Adjointable;
-            op(q); 
+            op(q);
         }
         controlled auto;
     }
 
     operation VariableNeedsFunctorSupport3 (q : Qubit) : Unit {
-        body (...) { 
+        body (...) {
             (Controllable(_))(q);
         }
         adjoint auto;
     }
 
     operation VariableNeedsFunctorSupport4 (q : Qubit) : Unit {
-        body (...) { 
+        body (...) {
             (Adjointable(_))(q);
         }
         controlled auto;
@@ -322,30 +322,30 @@ namespace Microsoft.Quantum.Testing.FunctorGeneration {
 
 
     operation VariableWithFunctorSupport1 (q : Qubit) : Unit {
-        body (...) { 
+        body (...) {
             let op = Controllable;
-            op(q); 
+            op(q);
         }
         controlled auto;
     }
 
     operation VariableWithFunctorSupport2 (q : Qubit) : Unit {
-        body (...) { 
+        body (...) {
             let op = Adjointable;
-            op(q); 
+            op(q);
         }
         adjoint auto;
     }
 
     operation VariableWithFunctorSupport3 (q : Qubit) : Unit {
-        body (...) { 
+        body (...) {
             (Controllable(_))(q);
         }
         controlled auto;
     }
 
     operation VariableWithFunctorSupport4 (q : Qubit) : Unit {
-        body (...) { 
+        body (...) {
             (Adjointable(_))(q);
         }
         adjoint auto;
@@ -401,7 +401,7 @@ namespace Microsoft.Quantum.Testing.FunctorGeneration {
     }
 
     operation NeedsFunctorSupport10 (q : Qubit) : Unit {
-        body (...) { 
+        body (...) {
             within { Controllable(q); }
             apply {}
         }
@@ -409,7 +409,7 @@ namespace Microsoft.Quantum.Testing.FunctorGeneration {
     }
 
     operation NeedsFunctorSupport11 (q : Qubit) : Unit {
-        body (...) { 
+        body (...) {
             within { }
             apply { Operation(q); }
         }
@@ -417,7 +417,7 @@ namespace Microsoft.Quantum.Testing.FunctorGeneration {
     }
 
     operation NeedsFunctorSupport12 (q : Qubit) : Unit {
-        body (...) { 
+        body (...) {
             within { }
             apply { Operation(q); }
         }
@@ -425,7 +425,7 @@ namespace Microsoft.Quantum.Testing.FunctorGeneration {
     }
 
     operation NeedsFunctorSupport13 (q : Qubit) : Unit {
-        body (...) { 
+        body (...) {
             within { }
             apply { Controllable(q); }
         }
@@ -445,7 +445,7 @@ namespace Microsoft.Quantum.Testing.FunctorGeneration {
     operation NeedsFunctorSupport16(q : Qubit) : Unit {
         body (...) {
             within { Operation(q); }
-            apply { }        
+            apply { }
         }
         adjoint self;
     }
@@ -453,7 +453,7 @@ namespace Microsoft.Quantum.Testing.FunctorGeneration {
     operation NeedsFunctorSupport17(q : Qubit) : Unit
     is Adj {
         within { Controllable(q); }
-        apply { }        
+        apply { }
     }
 
 
@@ -520,7 +520,7 @@ namespace Microsoft.Quantum.Testing.FunctorGeneration {
     }
 
     operation FunctorSupport13 (q : Qubit) : Unit {
-        body (...) { 
+        body (...) {
             within { Adjointable(q); }
             apply {}
         }
@@ -528,7 +528,7 @@ namespace Microsoft.Quantum.Testing.FunctorGeneration {
     }
 
     operation FunctorSupport14 (q : Qubit) : Unit {
-        body (...) { 
+        body (...) {
             within { Adjointable(q); }
             apply {}
         }
@@ -536,7 +536,7 @@ namespace Microsoft.Quantum.Testing.FunctorGeneration {
     }
 
     operation FunctorSupport15 (q : Qubit) : Unit {
-        body (...) { 
+        body (...) {
             within {}
             apply { Operation(q); }
         }
@@ -614,9 +614,9 @@ namespace Microsoft.Quantum.Testing.FunctorGeneration {
 
     operation InvalidAutoInversion1(q : Qubit) : Unit {
         body (...) {
-            return ();            
+            return ();
         }
-        adjoint auto;    
+        adjoint auto;
     }
 
     operation InvalidAutoInversion2(q : Qubit) : Unit {
@@ -625,21 +625,21 @@ namespace Microsoft.Quantum.Testing.FunctorGeneration {
             until (true)
             fixup {}
         }
-        adjoint auto;    
+        adjoint auto;
     }
 
     operation InvalidAutoInversion3(q : Qubit) : Unit {
         body (...) {
             set _ = 1;
         }
-        adjoint auto;    
+        adjoint auto;
     }
 
     operation InvalidAutoInversion4(q : Qubit) : Unit {
         body (...) {
             if (true) { return (); }
         }
-        adjoint auto;    
+        adjoint auto;
     }
 
     operation InvalidAutoInversion5(q : Qubit) : Unit {
@@ -650,21 +650,21 @@ namespace Microsoft.Quantum.Testing.FunctorGeneration {
                 fixup {}
             }
         }
-        adjoint auto;    
+        adjoint auto;
     }
 
     operation InvalidAutoInversion6(q : Qubit) : Unit {
         body (...) {
             if (true) { set _ = 1; }
         }
-        adjoint auto;    
+        adjoint auto;
     }
 
     operation InvalidAutoInversion7(q : Qubit) : Unit {
         body (...) {
             for i in 1..10 { return (); }
         }
-        adjoint auto;    
+        adjoint auto;
     }
 
     operation InvalidAutoInversion8(q : Qubit) : Unit {
@@ -675,21 +675,21 @@ namespace Microsoft.Quantum.Testing.FunctorGeneration {
                 fixup {}
             }
         }
-        adjoint auto;    
+        adjoint auto;
     }
 
     operation InvalidAutoInversion9(q : Qubit) : Unit {
         body (...) {
             for i in 1..10 { set _ = 1; }
         }
-        adjoint auto;    
+        adjoint auto;
     }
 
     operation InvalidAutoInversion10(q : Qubit) : Unit {
         body (...) {
             use c = Qubit() { return (); }
         }
-        adjoint auto;    
+        adjoint auto;
     }
 
     operation InvalidAutoInversion11(q : Qubit) : Unit {
@@ -700,21 +700,21 @@ namespace Microsoft.Quantum.Testing.FunctorGeneration {
                 fixup {}
             }
         }
-        adjoint auto;    
+        adjoint auto;
     }
 
     operation InvalidAutoInversion12(q : Qubit) : Unit {
         body (...) {
             use c = Qubit() { set _ = 1; }
         }
-        adjoint auto;    
+        adjoint auto;
     }
 
     operation InvalidAutoInversion13(q : Qubit) : Unit {
         body (...) {
             borrow c = Qubit() { return (); }
         }
-        adjoint auto;    
+        adjoint auto;
     }
 
     operation InvalidAutoInversion14(q : Qubit) : Unit {
@@ -725,14 +725,14 @@ namespace Microsoft.Quantum.Testing.FunctorGeneration {
                 fixup {}
             }
         }
-        adjoint auto;    
+        adjoint auto;
     }
 
     operation InvalidAutoInversion15(q : Qubit) : Unit {
         body (...) {
             borrow c = Qubit() { set _ = 1; }
         }
-        adjoint auto;    
+        adjoint auto;
     }
 
     operation InvalidAutoInversion16(q : Qubit) : Unit {
@@ -756,7 +756,7 @@ namespace Microsoft.Quantum.Testing.FunctorGeneration {
 
     operation ValidInversion1(q : Qubit) : Unit {
         body (...) {
-            return ();            
+            return ();
         }
         adjoint self;
     }
@@ -767,7 +767,7 @@ namespace Microsoft.Quantum.Testing.FunctorGeneration {
             until (true)
             fixup {}
         }
-        adjoint self;    
+        adjoint self;
     }
 
     operation ValidInversion3(q : Qubit) : Unit {
@@ -775,15 +775,15 @@ namespace Microsoft.Quantum.Testing.FunctorGeneration {
             mutable foo = 0;
             set foo = 1;
         }
-        adjoint self;    
+        adjoint self;
     }
 
     operation ValidInversion4(q : Qubit) : Unit {
         body (...) {
-            // NOTE: this is ok because, opposed to a return-statement, 
+            // NOTE: this is ok because, opposed to a return-statement,
             // there is no way modify control flow in a meaningful way using a fail
             // (the computation fails either way albeit potentially a bit earlier rather than later)
-            fail "not yet implemented";  
+            fail "not yet implemented";
         }
         adjoint auto;
     }
@@ -848,7 +848,7 @@ namespace Microsoft.Quantum.Testing.FunctorGeneration {
 
     operation WithInvalidQuantumDependency5 (q : Qubit) : Unit {
         body (...) {
-            for i in CoinFlip() ? new Int[0] | new Int[1] {}
+            for i in CoinFlip() ? [] | [0] {}
         }
         adjoint auto;
     }
@@ -929,7 +929,7 @@ namespace Microsoft.Quantum.Testing.FunctorGeneration {
 
     operation InvalidControlled2 (q : Qubit) : Unit {
         body (...) {
-            for i in CoinFlip() ? new Int[0] | new Int[1] {}
+            for i in CoinFlip() ? [] | [0] {}
         }
         controlled auto;
     }
@@ -951,42 +951,42 @@ namespace Microsoft.Quantum.Testing.FunctorGeneration {
 
     operation ValidControlled1 (q : Qubit) : Unit {
         body (...) {
-            let _ = Controllable (q);        
+            let _ = Controllable (q);
         }
         controlled auto;
     }
 
     operation ValidControlled2 (q : Qubit) : Unit {
         body (...) {
-            mutable _ = Controllable (q);        
+            mutable _ = Controllable (q);
         }
         controlled auto;
     }
 
     operation ValidControlled3 (q : Qubit) : Unit {
         body (...) {
-            set _ = Controllable (q);        
+            set _ = Controllable (q);
         }
         controlled auto;
     }
 
     operation ValidControlled4 (q : Qubit) : Unit {
         body (...) {
-            return Controllable(q);        
+            return Controllable(q);
         }
         controlled auto;
     }
 
     operation ValidControlled5 (q : Qubit) : Unit {
         body (...) {
-            fail $"{Controllable (q)}";        
+            fail $"{Controllable (q)}";
         }
         controlled auto;
     }
 
     operation ValidControlled6 (q : Qubit) : Unit {
         body (...) {
-            if (true) { Controllable(q); }        
+            if (true) { Controllable(q); }
         }
         controlled auto;
     }
@@ -1063,7 +1063,7 @@ namespace Microsoft.Quantum.Testing.FunctorGeneration {
         controlled auto;
         controlled adjoint invert;
     }
-    
+
 
     operation ValidControlledAdjointGeneration1 (q : Qubit) : Unit {
         body (...) { Operation (q); }
@@ -1194,51 +1194,51 @@ namespace Microsoft.Quantum.Testing.FunctorGeneration {
 
 
     operation AutoAdjSpec () : Unit {
-        adjoint auto; 
+        adjoint auto;
     }
 
     operation InvertAdjSpec () : Unit {
-        adjoint invert; 
+        adjoint invert;
     }
 
     operation SelfAdjSpec () : Unit {
-        adjoint self; 
+        adjoint self;
     }
 
     operation AutoCtlSpec () : Unit {
         controlled auto;
-    } 
+    }
 
     operation DistrCtlSpec () : Unit {
-        controlled distribute; 
+        controlled distribute;
     }
 
     operation CtlAffAutoAdjSpec () : Unit is Ctl {
-        adjoint auto; 
+        adjoint auto;
     }
 
     operation CtlAffInvertAdjSpec () : Unit is Ctl {
-        adjoint invert; 
+        adjoint invert;
     }
 
     operation CtlAffSelfAdjSpec () : Unit is Ctl {
-        adjoint self; 
+        adjoint self;
     }
 
     operation AdjAffAutoCtlSpec () : Unit is Adj {
         controlled auto;
-    } 
+    }
 
     operation AdjAffDistrCtlSpec () : Unit is Adj {
-        controlled distribute; 
+        controlled distribute;
     }
 
 
     // operation characteristics expressions
 
     operation OperationCharacteristics1 (qs : Qubit[]) : Unit {
-        NoAffiliation(); 
-        AdjAffiliation(); 
+        NoAffiliation();
+        AdjAffiliation();
         CtlAffiliation();
         CtlAdjAffiliation();
         AdjCtlAffiliation();
@@ -1251,96 +1251,96 @@ namespace Microsoft.Quantum.Testing.FunctorGeneration {
         Adjoint AdjCtlAffiliation();
         Adjoint AdjViaIntersection();
         Controlled CtlAffiliation(qs, ());
-        Controlled CtlAdjAffiliation(qs, ()); 
-        Controlled AdjCtlAffiliation(qs, ()); 
-        Controlled CtlViaIntersection(qs, ()); 
+        Controlled CtlAdjAffiliation(qs, ());
+        Controlled AdjCtlAffiliation(qs, ());
+        Controlled CtlViaIntersection(qs, ());
     }
 
     operation OperationCharacteristics2 (qs : Qubit[]) : Unit {
-        Adjoint NoAffiliation(); 
+        Adjoint NoAffiliation();
     }
 
     operation OperationCharacteristics3 (qs : Qubit[]) : Unit {
-        Controlled NoAffiliation((), qs); 
+        Controlled NoAffiliation((), qs);
     }
 
     operation OperationCharacteristics4 (qs : Qubit[]) : Unit {
-        Controlled AdjAffiliation((), qs);        
+        Controlled AdjAffiliation((), qs);
     }
 
     operation OperationCharacteristics5 (qs : Qubit[]) : Unit {
-        Adjoint CtlAffiliation();        
+        Adjoint CtlAffiliation();
     }
 
     operation OperationCharacteristics6 (qs : Qubit[]) : Unit {
-        Adjoint AdjCtlIntersection();        
+        Adjoint AdjCtlIntersection();
     }
 
     operation OperationCharacteristics7 (qs : Qubit[]) : Unit {
-        Adjoint CtlAdjIntersection();        
+        Adjoint CtlAdjIntersection();
     }
 
     operation OperationCharacteristics8 (qs : Qubit[]) : Unit {
-        Adjoint CtlViaIntersection();        
+        Adjoint CtlViaIntersection();
     }
 
     operation OperationCharacteristics9 (qs : Qubit[]) : Unit {
-        Controlled AdjCtlIntersection(qs, ());        
+        Controlled AdjCtlIntersection(qs, ());
     }
 
     operation OperationCharacteristics10 (qs : Qubit[]) : Unit {
-        Controlled CtlAdjIntersection(qs, ());        
+        Controlled CtlAdjIntersection(qs, ());
     }
 
     operation OperationCharacteristics11 (qs : Qubit[]) : Unit {
-        Controlled AdjViaIntersection(qs, ());        
+        Controlled AdjViaIntersection(qs, ());
     }
 
     operation OperationCharacteristics12 (qs : Qubit[]) : Unit {
-        Adjoint EmptyIntersection1();        
+        Adjoint EmptyIntersection1();
     }
 
     operation OperationCharacteristics13 (qs : Qubit[]) : Unit {
-        Adjoint EmptyIntersection2();        
+        Adjoint EmptyIntersection2();
     }
 
     operation OperationCharacteristics14 (qs : Qubit[]) : Unit {
-        Controlled EmptyIntersection1(qs, ());        
+        Controlled EmptyIntersection1(qs, ());
     }
 
     operation OperationCharacteristics15 (qs : Qubit[]) : Unit {
-        Controlled EmptyIntersection2(qs, ());        
+        Controlled EmptyIntersection2(qs, ());
     }
 
     operation OperationCharacteristics16 (qs : Qubit[]) : Unit {
-        CtlAffAutoAdjSpec(); 
-        CtlAffInvertAdjSpec(); 
+        CtlAffAutoAdjSpec();
+        CtlAffInvertAdjSpec();
         CtlAffSelfAdjSpec();
         Adjoint CtlAffAutoAdjSpec();
         Adjoint CtlAffInvertAdjSpec();
         Adjoint CtlAffSelfAdjSpec();
-        Controlled CtlAffAutoAdjSpec(qs, ()); 
-        Controlled CtlAffInvertAdjSpec(qs, ()); 
-        Controlled CtlAffSelfAdjSpec(qs, ()); 
+        Controlled CtlAffAutoAdjSpec(qs, ());
+        Controlled CtlAffInvertAdjSpec(qs, ());
+        Controlled CtlAffSelfAdjSpec(qs, ());
     }
 
     operation OperationCharacteristics17 (qs : Qubit[]) : Unit {
-        AdjAffAutoCtlSpec(); 
+        AdjAffAutoCtlSpec();
         AdjAffDistrCtlSpec();
         Adjoint AdjAffAutoCtlSpec();
         Adjoint AdjAffDistrCtlSpec();
-        Controlled AdjAffAutoCtlSpec(qs, ()); 
-        Controlled AdjAffDistrCtlSpec(qs, ()); 
+        Controlled AdjAffAutoCtlSpec(qs, ());
+        Controlled AdjAffDistrCtlSpec(qs, ());
     }
 
     operation OperationCharacteristics18 (qs : Qubit[]) : Unit {
-        AutoCtlSpec(); 
+        AutoCtlSpec();
         DistrCtlSpec();
-        AutoAdjSpec(); 
-        InvertAdjSpec(); 
+        AutoAdjSpec();
+        InvertAdjSpec();
         SelfAdjSpec();
-        Controlled AutoCtlSpec(qs, ()); 
-        Controlled DistrCtlSpec(qs, ()); 
+        Controlled AutoCtlSpec(qs, ());
+        Controlled DistrCtlSpec(qs, ());
         Adjoint AutoAdjSpec();
         Adjoint InvertAdjSpec();
         Adjoint SelfAdjSpec();
@@ -1355,15 +1355,15 @@ namespace Microsoft.Quantum.Testing.FunctorGeneration {
     }
 
     operation OperationCharacteristics21 (qs : Qubit[]) : Unit {
-        Controlled AutoAdjSpec(qs, ()); 
+        Controlled AutoAdjSpec(qs, ());
     }
 
     operation OperationCharacteristics22 (qs : Qubit[]) : Unit {
-        Controlled InvertAdjSpec(qs, ()); 
+        Controlled InvertAdjSpec(qs, ());
     }
 
     operation OperationCharacteristics23 (qs : Qubit[]) : Unit {
-        Controlled SelfAdjSpec(qs, ()); 
+        Controlled SelfAdjSpec(qs, ());
     }
 
 }
diff --git a/src/QsCompiler/Tests.Compiler/TestCases/LocalVerification.qs b/src/QsCompiler/Tests.Compiler/TestCases/LocalVerification.qs
index ae83d16960..d0f34986e2 100644
--- a/src/QsCompiler/Tests.Compiler/TestCases/LocalVerification.qs
+++ b/src/QsCompiler/Tests.Compiler/TestCases/LocalVerification.qs
@@ -43,13 +43,13 @@ namespace Microsoft.Quantum.Testing.LocalVerification {
     }
 
     operation TypeArgumentsInference6<'T>(cnt: Int, arg : 'T) : Unit {
-        mutable arr = new ('T => Unit)[0];
+        mutable arr = [];
         set arr = [TypeArgumentsInference6(1, _)];
         arr[0](arg);
     }
 
     operation TypeArgumentsInference7<'T>(cnt: Int, arg : 'T) : Unit {
-        mutable arr = new ('T => Unit)[0];
+        mutable arr = [];
         set arr += [TypeArgumentsInference7(1, _)];
         arr[0](arg);
     }
@@ -69,7 +69,7 @@ namespace Microsoft.Quantum.Testing.LocalVerification {
     }
 
     operation TypeArgumentsInference10<'T>(cnt: Int, arg : 'T) : Unit {
-        mutable arr = new (Int => Unit)[0];
+        mutable arr = [];
         set arr += [TypeArgumentsInference12(_, arg), TypeArgumentsInference12(_, "")];
         arr[0](cnt - 1);
     }
@@ -94,14 +94,14 @@ namespace Microsoft.Quantum.Testing.LocalVerification {
     }
 
     operation TypeArgumentsInference14<'T>(cnt: Int, arg : 'T) : Unit {
-        mutable arr = new (Int => Unit)[0];
+        mutable arr = [];
         set arr = [TypeArgumentsInference14(_, PauliX)];
         set arr = [TypeArgumentsInference14(_, arg)];
         arr[0](cnt - 1);
     }
 
     operation TypeArgumentsInference15<'T>(cnt: Int, arg : 'T) : Unit {
-        mutable arr = new (Int => Unit)[0];
+        mutable arr = [];
         set arr += [TypeArgumentsInference15(_, PauliX)];
         set arr += [TypeArgumentsInference15(_, arg)];
         arr[1](cnt - 1);
@@ -300,7 +300,7 @@ namespace Microsoft.Quantum.Testing.LocalVerification {
     }
 
     operation VariableDeclaration13<'T>(cnt: Int, arg : 'T) : Unit {
-        mutable arr = new ((Int, 'T) => Unit)[0];
+        mutable arr = [];
         set arr += [VariableDeclaration12];
         arr[0](cnt - 1, arg);
     }
@@ -312,13 +312,13 @@ namespace Microsoft.Quantum.Testing.LocalVerification {
     }
 
     operation VariableDeclaration15<'T>(cnt: Int, arg : 'T) : Unit {
-        mutable arr = new ((Int, 'T) => Unit)[0];
+        mutable arr = [];
         set arr = [VariableDeclaration15];
         arr[0](cnt - 1, arg);
     }
 
     operation VariableDeclaration16<'T>(cnt: Int, arg : 'T) : Unit {
-        mutable arr = new ((Int, 'T) => Unit)[0];
+        mutable arr = [];
         set arr += [VariableDeclaration16];
         arr[0](cnt - 1, arg);
     }
@@ -351,7 +351,7 @@ namespace Microsoft.Quantum.Testing.LocalVerification {
         let tuple = (1, (VariableDeclaration21, ""));
         let a1 = [VariableDeclaration21];
         mutable a2 = [VariableDeclaration21];
-        mutable arr = new ((Int, Double) => Unit)[0];
+        mutable arr = [];
         set arr = [VariableDeclaration21];
         set arr += [VariableDeclaration21];
         set arr w/= 0 <- VariableDeclaration21;
@@ -442,7 +442,7 @@ namespace Microsoft.Quantum.Testing.LocalVerification {
     }
 
     function CopyAndUpdateArray3 (arr : Int[][]) : Int[][] {
-        return arr w/ 0 <- new Int[10];
+        return arr w/ 0 <- [0, size = 10];
     }
 
     function CopyAndUpdateArray4<'T> (arr : 'T[]) : 'T[] {
@@ -527,27 +527,27 @@ namespace Microsoft.Quantum.Testing.LocalVerification {
     // update-and-reassign array
 
     function UpdateAndReassign1 () : Unit {
-        mutable arr = new Int[10];
+        mutable arr = [0, size = 10];
         set arr w/= 1 <- 0;
     }
 
     function UpdateAndReassign2 () : Unit {
-        mutable arr = new Int[10];
+        mutable arr = [0, size = 10];
         set arr w/= 0 .. 2 <- [0,0,0];
     }
 
     function UpdateAndReassign3 () : Unit {
-        mutable arr = new Int[10];
+        mutable arr = [0, size = 10];
         set arr w/= 0 .. Length(arr)-1 <- arr w/ 0 <- 1;
     }
 
     function UpdateAndReassign4 () : Unit {
-        mutable arr = new Int[10];
+        mutable arr = [0, size = 10];
         set arr w/= 1 <- 0.;
     }
 
     function UpdateAndReassign5 () : Unit {
-        mutable arr = new Int[10];
+        mutable arr = [0, size = 10];
         set arr w/= 0 .. Length(arr) <- 1 .. Length(arr);
     }
 
@@ -634,12 +634,12 @@ namespace Microsoft.Quantum.Testing.LocalVerification {
     }
 
     function ApplyAndReassign9 () : Unit {
-        mutable a = new Int[10];
+        mutable a = [0, size = 10];
         set a[0] = 1;
     }
 
     function ApplyAndReassign10 () : Unit {
-        mutable a = new Int[10];
+        mutable a = [0, size = 10];
         set a[0] += 1;
     }
 
@@ -691,7 +691,7 @@ namespace Microsoft.Quantum.Testing.LocalVerification {
             fail "length mismatch";
         }
 
-        mutable res = new (Int,Int,Int)[0];
+        mutable res = [];
         for (i1, i2) in arg2::Name {
             set res += [(i1, i2, arg1::Name[Length(res)])];
         }
@@ -814,8 +814,8 @@ namespace Microsoft.Quantum.Testing.LocalVerification {
     function ItemUpdate9 () : Unit {
         mutable arr = new ArrayType10[5];
         for i in 0..4 {
-            mutable item = arr[i] w/ Phase <- new Int[10];
-            set item w/= Const <- new Double[10];
+            mutable item = arr[i] w/ Phase <- [0, size = 10];
+            set item w/= Const <- [0.0, size = 10];
             set arr w/= i <- item;
         }
     }
@@ -823,7 +823,7 @@ namespace Microsoft.Quantum.Testing.LocalVerification {
     function ItemUpdate10 () : Unit {
         mutable arr = new ArrayType10[5];
         for i in 0..4 {
-            mutable item = arr[i] w/ Phase <- new Int[10];
+            mutable item = arr[i] w/ Phase <- [0, size = 10];
             set item::Phase w/= 0 <- 1;
         }
     }
@@ -831,7 +831,7 @@ namespace Microsoft.Quantum.Testing.LocalVerification {
     function ItemUpdate11 () : Unit {
         mutable arr = new ArrayType10[5];
         for i in 0..4 {
-            set arr[i] w/= Phase <- new Int[10];
+            set arr[i] w/= Phase <- [0, size = 10];
         }
     }
 
diff --git a/src/QsCompiler/Tests.Compiler/TypeCheckingTests.fs b/src/QsCompiler/Tests.Compiler/TypeCheckingTests.fs
index 742fc83817..b4433e13dc 100644
--- a/src/QsCompiler/Tests.Compiler/TypeCheckingTests.fs
+++ b/src/QsCompiler/Tests.Compiler/TypeCheckingTests.fs
@@ -91,12 +91,12 @@ type TypeCheckingTests() =
 
     [<Fact>]
     member this.Variance() =
-        this.Expect "Variance1" []
-        this.Expect "Variance2" [ Error ErrorCode.TypeMismatch ]
-        this.Expect "Variance3" [ Error ErrorCode.TypeMismatch ]
-        this.Expect "Variance4" [ Error ErrorCode.TypeMismatch ]
-        this.Expect "Variance5" [ Error ErrorCode.TypeMismatch ]
-        this.Expect "Variance6" [ Error ErrorCode.TypeMismatch ]
+        this.Expect "Variance1" (Warning WarningCode.DeprecatedNewArray |> List.replicate 5)
+        this.Expect "Variance2" [ Error ErrorCode.TypeMismatch; Warning WarningCode.DeprecatedNewArray ]
+        this.Expect "Variance3" [ Error ErrorCode.TypeMismatch; Warning WarningCode.DeprecatedNewArray ]
+        this.Expect "Variance4" [ Error ErrorCode.TypeMismatch; Warning WarningCode.DeprecatedNewArray ]
+        this.Expect "Variance5" [ Error ErrorCode.TypeMismatch; Warning WarningCode.DeprecatedNewArray ]
+        this.Expect "Variance6" [ Error ErrorCode.TypeMismatch; Warning WarningCode.DeprecatedNewArray ]
 
         this.Expect
             "Variance7"
@@ -137,10 +137,32 @@ type TypeCheckingTests() =
 
     [<Fact>]
     member this.``Common base type``() =
-        this.Expect "CommonBaseType1" []
-        this.Expect "CommonBaseType2" [ Error ErrorCode.TypeIntersectionMismatch ]
-        this.Expect "CommonBaseType3" [ Error ErrorCode.TypeIntersectionMismatch ]
-        this.Expect "CommonBaseType4" [ Error ErrorCode.TypeMismatchInReturn ]
+        this.Expect "CommonBaseType1" (Warning WarningCode.DeprecatedNewArray |> List.replicate 2)
+
+        this.Expect
+            "CommonBaseType2"
+            [
+                Error ErrorCode.TypeIntersectionMismatch
+                Warning WarningCode.DeprecatedNewArray
+                Warning WarningCode.DeprecatedNewArray
+            ]
+
+        this.Expect
+            "CommonBaseType3"
+            [
+                Error ErrorCode.TypeIntersectionMismatch
+                Warning WarningCode.DeprecatedNewArray
+                Warning WarningCode.DeprecatedNewArray
+            ]
+
+        this.Expect
+            "CommonBaseType4"
+            [
+                Error ErrorCode.TypeMismatchInReturn
+                Warning WarningCode.DeprecatedNewArray
+                Warning WarningCode.DeprecatedNewArray
+            ]
+
         this.Expect "CommonBaseType5" []
         this.Expect "CommonBaseType6" []
         this.Expect "CommonBaseType7" []
@@ -155,9 +177,30 @@ type TypeCheckingTests() =
         this.Expect "CommonBaseType16" [ Error ErrorCode.TypeIntersectionMismatch ]
         this.Expect "CommonBaseType17" []
         this.Expect "CommonBaseType18" []
-        this.Expect "CommonBaseType19" [ Warning WarningCode.UnusedTypeParam ]
-        this.Expect "CommonBaseType20" [ Error ErrorCode.TypeIntersectionMismatch ]
-        this.Expect "CommonBaseType21" []
+
+        this.Expect
+            "CommonBaseType19"
+            [
+                Warning WarningCode.UnusedTypeParam
+                Warning WarningCode.DeprecatedNewArray
+                Warning WarningCode.DeprecatedNewArray
+            ]
+
+        this.Expect
+            "CommonBaseType20"
+            [
+                Error ErrorCode.TypeIntersectionMismatch
+                Warning WarningCode.DeprecatedNewArray
+                Warning WarningCode.DeprecatedNewArray
+            ]
+
+        this.Expect
+            "CommonBaseType21"
+            [
+                Warning WarningCode.DeprecatedNewArray
+                Warning WarningCode.DeprecatedNewArray
+            ]
+
         this.Expect "CommonBaseType22" []
         this.Expect "CommonBaseType23" []
         this.Expect "CommonBaseType24" []
@@ -221,7 +264,7 @@ type TypeCheckingTests() =
     member this.``Argument matching``() =
         this.Expect "MatchArgument1" []
         this.Expect "MatchArgument2" []
-        this.Expect "MatchArgument3" []
+        this.Expect "MatchArgument3" (Warning WarningCode.DeprecatedNewArray |> List.replicate 2)
         this.Expect "MatchArgument4" []
         this.Expect "MatchArgument5" []
         this.Expect "MatchArgument6" []
diff --git a/src/QsCompiler/TextProcessor/QsExpressionParsing.fs b/src/QsCompiler/TextProcessor/QsExpressionParsing.fs
index b9c0eace8e..b5f1157736 100644
--- a/src/QsCompiler/TextProcessor/QsExpressionParsing.fs
+++ b/src/QsCompiler/TextProcessor/QsExpressionParsing.fs
@@ -515,19 +515,28 @@ let private valueArray =
     <|> bracketDefinedCommaSepExpr (lArray, rArray)
 
 /// Parses a Q# array declaration as QsExpression.
-/// Raises an InvalidContructorExpression if the array declaration keyword is not followed by a valid array constructor,
+/// Adds an InvalidConstructorExpression if the array declaration keyword is not followed by a valid array constructor,
 /// and advances to the next whitespace character or QsFragmentHeader.
 let private newArray =
     let itemType = expectedQsType (lArray >>% ()) >>= fun itemType -> validateTypeSyntax true itemType >>% itemType
     let body = itemType .>>. (arrayBrackets (expectedExpr eof) |>> fst) |>> NewArray
 
+    let toExpr headRange (kind, bodyRange) =
+        QsExpression.New(kind, Range.Span headRange bodyRange)
+
     let invalid =
         checkForInvalid
             (qsFragmentHeader >>% "" <|> (nextCharSatisfies Text.IsWhitespace >>. emptySpace))
             ErrorCode.InvalidConstructorExpression
         >>% unknownExpr
 
-    arrayDecl.parse >>. (term body |>> QsExpression.New <|> (term invalid |>> fst))
+    let withWarning (expr: QsExpression) =
+        let range = expr.Range |> QsNullable.defaultValue Range.Zero
+        QsCompilerDiagnostic.Warning(WarningCode.DeprecatedNewArray, []) range |> pushDiagnostic >>% expr
+
+    arrayDecl.parse
+    >>= fun headRange -> term body |>> toExpr headRange <|> (term invalid |>> fst)
+    >>= withWarning
 
 /// used to temporarily store item accessors for both array item and named item access expressions
 type private ItemAccessor =