@[test(code_00)]
routine @Decorator( func(args) : routine )
{
    io.writeln( "@Decorator()" );
    return func( args, ... );
}

@Decorator
routine Function(){ io.writeln( "Function()" ); }

@Decorator
routine Function( a : int ){ io.writeln( "Function(int)", a ); }

Function();
Function(123);
@[test(code_00)]
@[test(code_00)]
@Decorator()
Function()
@Decorator()
Function(int) 123
@[test(code_00)]




@[test(code_00)]
routine @TestDecorator( func(args) : routine<index:int=>string>, expected = "" )
{
    res = func( args, ... );
    io.writeln( res );
    io.writeln( "Test result:", res == expected ? "passed" : "failed" );
    return res;
}

@TestDecorator( "Hello" )
routine Hello( index = 0 )
{
    io.writeln( "Calling Hello(int)" );
    return "Hello";
}

Hello();
@[test(code_00)]
@[test(code_00)]
Calling Hello(int)
Hello
Test result: passed
@[test(code_00)]




@[test(code_00)]
routine @Decorator( func(args) : routine )
{
    io.writeln( "@Decorator()" );
    return func( args, ... ); # ... for parameter expanding;
}
routine @TestDecorator( func(args) : routine<index:int=>string>, expected = "" )
{
    res = func( args, ... );
    io.writeln( res );
    io.writeln( "Test result:", res == expected ? "passed" : "failed" );
    return res;
}
routine @TestDecorator( func(args) : routine<name:string=>int>, expected = 0 )
{
    res = func( args, ... );
    io.writeln( res );
    io.writeln( "Test result:", res == expected ? "passed" : "failed" );
    return res;
}

@Decorator
@TestDecorator( 123 )
routine Hello( name : string )
{
    io.writeln( "Calling Hello(string)", name );
    return 123;
}

io.writeln( Hello( "abc" ), "\n" );

const Hello3 = @Decorator( Hello )
Hello3( "def" )

@[test(code_00)]
@[test(code_00)]
@Decorator()
Calling Hello(string) abc
123
Test result: passed
123 

@Decorator()
@Decorator()
Calling Hello(string) def
123
Test result: passed
@[test(code_00)]




@[test(code_00)]
routine @Decorator( func(args) : routine )
{
    io.writeln( "@Decorator()" );
    return func( args, ... ); # ... for parameter expanding;
}
routine @TestDecorator( func(args) : routine<index:int=>string>, expected = "" )
{
    res = func( args, ... );
    io.writeln( "Test result:", res == expected ? "passed" : "failed" );
    return res;
}
routine Hello2( index = 123 )
{
    io.writeln( "Calling Hello2(int)", index );
    return "Hello";
}

# Running time decoration:
func = @TestDecorator( Hello2, "Hello" );
func(123)

func = @TestDecorator( func );
func(123)
@[test(code_00)]
@[test(code_00)]
Calling Hello2(int) 123
Test result: passed
Calling Hello2(int) 123
Test result: passed
Test result: failed
@[test(code_00)]




@[test(code_00)]
routine @Decorator( func(args) : routine )
{
    io.writeln( "@Decorator()" );
    return func( args, ... ); # ... for parameter expanding;
}
routine Hello2( index = 123 )
{
    io.writeln( "Calling Hello2(int)", index );
    return "Hello";
}

deco : any = @Decorator;
func = deco( Hello2 );

func(789);
@[test(code_00)]
@[test(code_00)]
@Decorator()
Calling Hello2(int) 789
@[test(code_00)]




@[test(code_00)]
routine @StaticDecorator( meth(args) :routine<id:int=>int>, value = 123 )
{
    io.writeln( args, value );
    args.id = value;
    return meth( args, ... );
}
routine @MethodDecorator( meth(args) :routine<self:@T,id:int=>int>, value = 123 )
{
    args.id = value;
    return meth( args, ... );
}
class Klass
{
    static routine @ClassDecorator( meth(args) :routine<id:string=>@X>, value = "abc" ){
        io.writeln( args, value );
        args.id = value;
        return meth( args, ... );
    }

    @StaticDecorator( 456 )
    static routine StaticMeth( id :int ){ io.writeln( id ); return id }

    @ClassDecorator
    static routine StaticMeth( id :string ){ io.writeln( id ) }

    @MethodDecorator( 789 )
    routine Meth( id :int ){ io.writeln( id ); return id }
}

Klass::StaticMeth( 0 );
Klass::StaticMeth( "a" );

k = Klass();
k.Meth(1);
@[test(code_00)]
@[test(code_00)]
( 0 ) 456
456
( "a" ) abc
abc
789
@[test(code_00)]




@[test(code_00)]
routine @Decorator( func(args) : routine[...] )
{
    io.writeln( "Calling @Decorator()" );
    return func( args, ... ){ [X] 
        io.writeln( "Yielding", X );
        yield( X )
    }   
}

@Decorator
routine Function()[int]
{
    io.writeln( "Function()" );
    for( i = 1 : 3 ) yield(i)
}

Function{ [X] io.writeln(X) }
@[test(code_00)]
@[test(code_00)]
Calling @Decorator()
Function()
Yielding 1
1
Yielding 2
2
Yielding 3
3
@[test(code_00)]




@[test(code_00)]
routine @Decorator( func(args) : routine[...] )
{
    io.writeln( "Calling @Decorator()" );
    return func( args, ... ){ [... as csargs] 
        io.writeln( "Yielding", csargs );
        yield( csargs, ... )
    }   
}

@Decorator
routine Function()[int]
{
    io.writeln( "Function()" );
    for( i = 1 : 3 ) yield(i)
}

Function{ [X] io.writeln(X) }
@[test(code_00)]
@[test(code_00)]
Calling @Decorator()
Function()
Yielding ( 1 )
1
Yielding ( 2 )
2
Yielding ( 3 )
3
@[test(code_00)]