sub circumfix:<[ ]>( *@a ) 
{
    Range.new( @a[0], @a[1] );
};

sub circumfix:<( )>( *@a ) 
{
    Range.new( @a[0]+1, @a[1]-1 );
};

sub circumfix:<( ]>( *@a ) 
{
    Range.new( @a[0]+1, @a[1] );
};

sub circumfix:<[ )>( *@a ) 
{
    Range.new( @a[0], @a[1]-1 );
};

say [ 1, 10 ];
say ( 1, 10 );
say ( 1, 10 ];
say [ 1, 10 );