####################################
# First example:
####################################

var intstring : list<int|string> = {};

intstring.append( 123 );
intstring.append( "abc" );

#intstring.append( {} ); # typing error

io.writeln( intstring, intstring[0], intstring[1] );



####################################
# Second example:
####################################

interface HasSizeMethod
{
	routine Size()=>int;
}
class AA
{
	routine Size()=>int{ return 10 }
}
class BB
{
	routine Size()=>int{ return 20 }
}

routine Test( object: AA | BB | HasSizeMethod )
{
# casting to an interface will invoke automatic binding:
	var object2 = (HasSizeMethod) object;
	io.writeln( object2.Size() )
}

io.writeln( std.about( Test ) );

Test( AA() )
Test( BB() )

routine Test2( data: int|float|string )
{
	switch( data ) type {
	case int    : io.writeln( "handling int", std.about( data ) );
	case float  : io.writeln( "handling float", std.about( data ) );
	case string : io.writeln( "handling string", std.about( data ) );
	}
}

Test2( 1 );
Test2( 1.0 );
Test2( "abc" );



####################################
# Third example:
####################################

class FakeImage
{
	var image = [1,2,3,4;5,6,7,8;11,12,13,14;15,16,17,18];

# instead of writing routine methods with all the combinations
# such as tuple<int,int>, tuple<int,none>, ...
# one can use disjoint union to simplify this.
	routine[]( i: int, js: none|tuple<int|none,int|none> )=>array<int>
	{
# one can simply return image[i,js], but the following is for demonstration purpose:
		var j1 = 0;
		var j2 = image.dim(1) - 1;
		if( js == none ) return image[i,:];
		if( js[0] != none ) j1 = js[0];
		if( js[1] != none ) j2 = js[1];
		return image[i,j1:j2];
	}
}

var image = FakeImage();
io.writeln( image[1,1:] );
io.writeln( image[2,:1] );



####################################
# Fourth example:
####################################

routine Sum( alist : list<@T<int|string>> ) => @T
{
#	reflect.trace();
	return alist.sum();
}

var s = Sum( { 1, 2, 3 } );
#s += "a"; # typing error
io.writeln( s );

var s2 = Sum( { "a", "b", "c" } );
io.writeln( s2 );