koobas.hobune.stream
Internal compiler error
This code throws an internal compiler error.
public delegate IEnumerator SimpleRoutine ();
public void FUNC (SimpleRoutine onStarted = null) {
onStarted = onStarted ?? delegate { yield break; };
}
Looking at the console log, Mono throws this:
Unhandled Exception: Mono.CSharp.InternalErrorException: myscriptatsomepath.cs (174,42): ---> System.NotSupportedException: Operation is not supported.
at Mono.CSharp.YieldBreak.CloneTo (Mono.CSharp.CloneContext clonectx, Mono.CSharp.Statement target) [0x00000] in <filename unknown>:0
at Mono.CSharp.Statement.Clone (Mono.CSharp.CloneContext clonectx) [0x00000] in <filename unknown>:0
at Mono.CSharp.Block.CloneTo (Mono.CSharp.CloneContext clonectx, Mono.CSharp.Statement t) [0x00000] in <filename unknown>:0
at Mono.CSharp.ExplicitBlock.CloneTo (Mono.CSharp.CloneContext clonectx, Mono.CSharp.Statement t) [0x00000] in <filename unknown>:0
at Mono.CSharp.ToplevelBlock.CloneTo (Mono.CSharp.CloneContext clonectx, Mono.CSharp.Statement t) [0x00000] in <filename unknown>:0
at Mono.CSharp.Statement.Clone (Mono.CSharp.CloneContext clonectx) [0x00000] in <filename unknown>:0
at Mono.CSharp.Statement.PerformClone () [0x00000] in <filename unknown>:0
at Mono.CSharp.AnonymousMethodExpression.CompatibleMethod (Mono.CSharp.ResolveContext ec, Mono.CSharp.TypeInferenceContext tic, System.Type return_type, System.Type delegate_type) [0x00000] in <filename unknown>:0
at Mono.CSharp.AnonymousMethodExpression.Compatible (Mono.CSharp.ResolveContext ec, System.Type type) [0x00000] in <filename unknown>:0
--- End of inner exception stack trace ---
at Mono.CSharp.AnonymousMethodExpression.Compatible (Mono.CSharp.ResolveContext ec, System.Type type) [0x00000] in <filename unknown>:0
at Mono.CSharp.AnonymousMethodExpression.ImplicitStandardConversionExists (Mono.CSharp.ResolveContext ec, System.Type delegate_type) [0x00000] in <filename unknown>:0
at Mono.CSharp.Convert.ImplicitConversionExists (Mono.CSharp.ResolveContext ec, Mono.CSharp.Expression expr, System.Type target_type) [0x00000] in <filename unknown>:0
at Mono.CSharp.Nullable.NullCoalescingOperator.ConvertExpression (Mono.CSharp.ResolveContext ec) [0x00000] in <filename unknown>:0
at Mono.CSharp.Nullable.NullCoalescingOperator.DoResolve (Mono.CSharp.ResolveContext ec) [0x00000] in <filename unknown>:0
at Mono.CSharp.Expression.Resolve (Mono.CSharp.ResolveContext ec, ResolveFlags flags) [0x00000] in <filename unknown>:0
at Mono.CSharp.Expression.Resolve (Mono.CSharp.ResolveContext ec) [0x00000] in <filename unknown>:0
at Mono.CSharp.Assign.DoResolve (Mono.CSharp.ResolveContext ec) [0x00000] in <filename unknown>:0
at Mono.CSharp.SimpleAssign.DoResolve (Mono.CSharp.ResolveContext ec) [0x00000] in <filename unknown>:0
at Mono.CSharp.Expression.Resolve (Mono.CSharp.ResolveContext ec, ResolveFlags flags) [0x00000] in <filename unknown>:0
at Mono.CSharp.Expression.Resolve (Mono.CSharp.ResolveContext ec) [0x00000] in <filename unknown>:0
at Mono.CSharp.ExpressionStatement.ResolveStatement (Mono.CSharp.BlockContext ec) [0x00000] in <filename unknown>:0
at Mono.CSharp.StatementExpression.Resolve (Mono.CSharp.BlockContext ec) [0x00000] in <filename unknown>:0
at Mono.CSharp.Block.Resolve (Mono.CSharp.BlockContext ec) [0x00000] in <filename unknown>:0
at Mono.CSharp.ToplevelBlock.Resolve (Mono.CSharp.FlowBranching parent, Mono.CSharp.BlockContext rc, Mono.CSharp.ParametersCompiled ip, IMethodData md) [0x00000] in <filename unknown>:0
(Filename: Line: 0)
Is this a known issue? Any workaround? Thanks!
You can't use yield inside anonymous delegate. You can read the details here: http://blogs.msdn.com/b/ericlippert/archive/2009/08/24/iterator-blocks-part-seven-why-no-anonymous-iterators.aspx
Instead of using anonymous delegate, you can simply declare a standard method:
public delegate IEnumerator SimpleRoutine();
public static void FUNC(ref SimpleRoutine onStarted)
{
onStarted = onStarted ?? SimpleRoutineExample;
}
public static IEnumerator SimpleRoutineExample()
{
yield break;
}
I've changed the signature of FUNC method as well, because by default delegates aren't passed by reference.
Good to know. Thanks! Anyway, shouldn't Unity/$$anonymous$$ono handle the error in other way than internal error which may be not very helpful?
It's hard to say why there is no exact error message in Unity. If you compile this code in Visual Studio or $$anonymous$$onoDevelop, then the proper compilation error is displayed.
As a side note: when compiling your code, my version of $$anonymous$$onoDevelop complains about 'SimpleRoutine onStarted = null', stating that 'Default parameter specifiers are not permitted'. But in Unity it compiles without any problems :)
