Yes. The second one does seem to be a bug.
Here’s a corrected patch to reproduce that:
diff --git
a/frameworks/projects/Collections/src/main/royale/org/apache/royale/collections/ISort.as
b/frameworks/projects/Collections/src/main/royale/org/apache/royale/collections/ISort.as
index 14073e1da9..d39c9a3b46 100644
---
a/frameworks/projects/Collections/src/main/royale/org/apache/royale/collections/ISort.as
+++
b/frameworks/projects/Collections/src/main/royale/org/apache/royale/collections/ISort.as
@@ -123,13 +123,13 @@ public interface ISort {
* @playerversion AIR 2.6
* @productversion Flex 4.5
*/
- function get compareFunction():Function;
+ function get compareFunction():(a:Object, b:Object, fields?:Array)=>int;
/**
* @deprecated A future release of Apache Flex SDK will remove this
function. Please use the constructor
* argument instead.
*/
- function set compareFunction(value:Function):void;
+ function set compareFunction(value:(a:Object, b:Object,
fields?:Array)=>int):void;
/**
* An <code>Array</code> of <code>ISortField</code> objects that
@@ -280,7 +280,7 @@ public interface ISort {
values:Object,
mode:String,
returnInsertionIndex:Boolean = false,
- compareFunction:Function = null):int;
+ compareFunction:(a:Object, b:Object, fields?:Array)=>int =
null):int;
/**
* Return whether the specified property is used to control the sort.
diff --git
a/frameworks/projects/Collections/src/main/royale/org/apache/royale/collections/Sort.as
b/frameworks/projects/Collections/src/main/royale/org/apache/royale/collections/Sort.as
index d16869fa1f..caf80b6559 100644
---
a/frameworks/projects/Collections/src/main/royale/org/apache/royale/collections/Sort.as
+++
b/frameworks/projects/Collections/src/main/royale/org/apache/royale/collections/Sort.as
@@ -186,7 +186,7 @@ public class Sort extends EventDispatcher implements ISort
* @playerversion AIR 2.6
* @productversion Royale 0.0
*/
- public function Sort(fields:Array = null, customCompareFunction:Function =
null, unique:Boolean = false)
+ public function Sort(fields:Array = null, customCompareFunction:(a:Object,
b:Object, fields?:Array)=>int = null, unique:Boolean = false)
{
super();
@@ -236,7 +236,7 @@ public class Sort extends EventDispatcher implements ISort
* @private
* Storage for the compareFunction property.
*/
- private var _compareFunction:Function;
+ private var _compareFunction:(a:Object, b:Object, fields?:Array)=>int;
/**
* @private
@@ -253,7 +253,7 @@ public class Sort extends EventDispatcher implements ISort
* @playerversion AIR 2.6
* @productversion Royale 0.0
*/
- public function get compareFunction():Function
+ public function get compareFunction():(a:Object, b:Object,
fields?:Array)=>int
{
return usingCustomCompareFunction ? _compareFunction : internalCompare;
}
@@ -261,7 +261,7 @@ public class Sort extends EventDispatcher implements ISort
/**
* @private
*/
- public function set compareFunction(value:Function):void
+ public function set compareFunction(value:(a:Object, b:Object,
fields?:Array)=>int):void
{
_compareFunction = value;
usingCustomCompareFunction = _compareFunction != null;
@@ -376,9 +376,9 @@ public class Sort extends EventDispatcher implements ISort
values:Object,
mode:String,
returnInsertionIndex:Boolean = false,
- compareFunction:Function = null):int
+ compareFunction:(a:Object, b:Object,
fields?:Array)=>int = null):int
{
- var compareForFind:Function;
+ var compareForFind:(a:Object, b:Object, fields?:Array)=>int;
var fieldsForCompare:Array;
var message:String;
@@ -615,7 +615,7 @@ public class Sort extends EventDispatcher implements ISort
// the Sort.internalCompare function knows to use Sort._fields;
that same logic
// needs to be part of calling a custom compareFunction. Of
course, a user shouldn't
// be doing this -- so I wrap calls to compareFunction with
_fields as the last parameter
- const fixedCompareFunction:Function =
+ const fixedCompareFunction:(a:Object, b:Object)=>int =
function (a:Object, b:Object):int
{
// append our fields to the call, since items.sort()
won't
@@ -760,7 +760,7 @@ public class Sort extends EventDispatcher implements ISort
var len:int = fields ? fields.length : _fields.length;
while (result == 0 && (i < len))
{
- var sf:ISortField = ISortField(_fields[i]);
+ var sf:ISortField = (_fields[i] as ISortField);
result = sf.compareFunction(a, b);
if (sf.descending)
result *= -1;
> On Jan 30, 2026, at 5:17 PM, Josh Tynjala <[email protected]> wrote:
>
>> Error: Implicit coercion of a value of type (a:Object,b:Object)=>int to
> an unrelated type (values:Object,obj:Object,fieldsForCompare?:Array)=>int.
>
> This error appears to be correct because you have omitted the third
> parameter. The argument may be omitted only when calling the function. It
> can’t be omitted when defining the function. You’d have a similar error if
> an interface had an optional parameter, and you tried to define a method on
> an implementing class that didn’t include the optional parameter.
>
>> Error: Implicit coercion of a value of type Function to an unrelated type
> (values:Object,obj:Object,fieldsForCompare?:Array)=>int.
>
> This one seems like it might be a bug, though. The compiler may be ignoring
> the function type expression somewhere.
>
>
> --
> Josh Tynjala
> Bowler Hat LLC
> https://bowlerhat.dev/
>
>
> On Fri, Jan 30, 2026 at 5:10 AM Harbs <[email protected]> wrote:
>
>> I tried to use them in the Sort classes, and I got the following error.
>>
>> Is this user error or a bug?
>>
>>
>> [java]
>> /Users/harbs/Apache/royale-asjs/frameworks/projects/Collections/src/main/royale/org/apache/royale/collections/Sort.as(397):
>> col: 30 Error: Implicit coercion of a value of type Function to an
>> unrelated type (values:Object,obj:Object,fieldsForCompare?:Array)=>int.
>> [java]
>> [java] compareForFind = this.compareFunction;
>> [java] ^
>> [java]
>> [java]
>> /Users/harbs/Apache/royale-asjs/frameworks/projects/Collections/src/main/royale/org/apache/royale/collections/Sort.as(619):
>> col: 21 Error: Implicit coercion of a value of type
>> (a:Object,b:Object)=>int to an unrelated type
>> (values:Object,obj:Object,fieldsForCompare?:Array)=>int.
>> [java]
>> [java] function (a:Object, b:Object):int
>> [java] ^
>> [java]
>> [java]
>> /Users/harbs/Apache/royale-asjs/frameworks/projects/Collections/src/main/royale/org/apache/royale/collections/Sort.as(397):
>> col: 30 Implicit coercion of a value of type Function to an unrelated type
>> (values:Object,obj:Object,fieldsForCompare?:Array)=>int.
>> [java]
>> [java] compareForFind = this.compareFunction;
>> [java] ^
>> [java]
>> [java]
>> /Users/harbs/Apache/royale-asjs/frameworks/projects/Collections/src/main/royale/org/apache/royale/collections/Sort.as(619):
>> col: 21 Implicit coercion of a value of type (a:Object,b:Object)=>int to an
>> unrelated type (values:Object,obj:Object,fieldsForCompare?:Array)=>int.
>> [java]
>> [java] function (a:Object, b:Object):int
>> [java] ^
>>
>>
>> Changes:
>>
>> diff --git
>> a/frameworks/projects/Collections/src/main/royale/org/apache/royale/collections/ISort.as
>> b/frameworks/projects/Collections/src/main/royale/org/apache/royale/collections/ISort.as
>> index 14073e1da9..02a7bcc86d 100644
>> ---
>> a/frameworks/projects/Collections/src/main/royale/org/apache/royale/collections/ISort.as
>> +++
>> b/frameworks/projects/Collections/src/main/royale/org/apache/royale/collections/ISort.as
>> @@ -123,13 +123,13 @@ public interface ISort {
>> * @playerversion AIR 2.6
>> * @productversion Flex 4.5
>> */
>> - function get compareFunction():Function;
>> + function get compareFunction():(values:Object, obj:Object,
>> fieldsForCompare?:Array) => int;
>>
>> /**
>> * @deprecated A future release of Apache Flex SDK will remove this
>> function. Please use the constructor
>> * argument instead.
>> */
>> - function set compareFunction(value:Function):void;
>> + function set compareFunction(value:(values:Object, obj:Object,
>> fieldsForCompare?:Array) => int):void;
>>
>> /**
>> * An <code>Array</code> of <code>ISortField</code> objects that
>>
>>
>> diff --git
>> a/frameworks/projects/Collections/src/main/royale/org/apache/royale/collections/Sort.as
>> b/frameworks/projects/Collections/src/main/royale/org/apache/royale/collections/Sort.as
>> index d16869fa1f..abec999093 100644
>> ---
>> a/frameworks/projects/Collections/src/main/royale/org/apache/royale/collections/Sort.as
>> +++
>> b/frameworks/projects/Collections/src/main/royale/org/apache/royale/collections/Sort.as
>> @@ -186,7 +186,7 @@ public class Sort extends EventDispatcher implements
>> ISort
>> * @playerversion AIR 2.6
>> * @productversion Royale 0.0
>> */
>> - public function Sort(fields:Array = null,
>> customCompareFunction:Function = null, unique:Boolean = false)
>> + public function Sort(fields:Array = null,
>> customCompareFunction:(values:Object, obj:Object, fieldsForCompare?:Array)
>> => int = null, unique:Boolean = false)
>> {
>> super();
>>
>> @@ -236,7 +236,7 @@ public class Sort extends EventDispatcher implements
>> ISort
>> * @private
>> * Storage for the compareFunction property.
>> */
>> - private var _compareFunction:Function;
>> + private var _compareFunction:(values:Object, obj:Object,
>> fieldsForCompare?:Array) => int;
>>
>> /**
>> * @private
>> @@ -253,7 +253,7 @@ public class Sort extends EventDispatcher implements
>> ISort
>> * @playerversion AIR 2.6
>> * @productversion Royale 0.0
>> */
>> - public function get compareFunction():Function
>> + public function get compareFunction():(values:Object, obj:Object,
>> fieldsForCompare?:Array) => int
>> {
>> return usingCustomCompareFunction ? _compareFunction :
>> internalCompare;
>> }
>> @@ -261,7 +261,7 @@ public class Sort extends EventDispatcher implements
>> ISort
>> /**
>> * @private
>> */
>> - public function set compareFunction(value:Function):void
>> + public function set compareFunction(value:(values:Object, obj:Object,
>> fieldsForCompare?:Array) => int):void
>> {
>> _compareFunction = value;
>> usingCustomCompareFunction = _compareFunction != null;
>> @@ -376,9 +376,9 @@ public class Sort extends EventDispatcher implements
>> ISort
>> values:Object,
>> mode:String,
>> returnInsertionIndex:Boolean = false,
>> - compareFunction:Function = null):int
>> + compareFunction:(values:Object, obj:Object,
>> fieldsForCompare?:Array) => int = null):int
>> {
>> - var compareForFind:Function;
>> + var compareForFind:(values:Object, obj:Object,
>> fieldsForCompare?:Array) => int;
>> var fieldsForCompare:Array;
>> var message:String;
>>
>> @@ -615,7 +615,7 @@ public class Sort extends EventDispatcher implements
>> ISort
>> // the Sort.internalCompare function knows to use
>> Sort._fields; that same logic
>> // needs to be part of calling a custom compareFunction. Of
>> course, a user shouldn't
>> // be doing this -- so I wrap calls to compareFunction with
>> _fields as the last parameter
>> - const fixedCompareFunction:Function =
>> + const fixedCompareFunction:(values:Object, obj:Object,
>> fieldsForCompare?:Array) => int =
>> function (a:Object, b:Object):int
>> {
>> // append our fields to the call, since
>> items.sort() won't
>>
>>
