public override void run( State state )
{
// We execute by running the "lhs" and "rhs", and then applying the operator to them,
// producing another value. If the result of either is an LValue, we have to dereference it.
state.pushAction(
new Step( this, st =>
{
object right = LValue.Deref( st );
if( this.op == "+=" )
{
object left = st.popResult();
// This one is a bit trickier since we do different things based on different
// types, and the left side needs to be an LValue.
if( !(left is LValue) )
throw CoralException.GetArg( "Left-hand side of += must be LValue" );
// We need to write the LValue back, but keep the result value on
// the result stack since this can be used as a normal expression too.
LValue lv = (LValue)left;
object val = lv.read( st );
val = Plus( val, right );
lv.write( st, val );
st.pushResult( val );
}
else
{
if( this.left != null )
{
object left = LValue.Deref( st );
st.pushResult( s_operations[this.op]( left, right ) );
}
else if( this.op == "-" )
{
st.pushResult( s_operations[this.op]( null, right ) );
}
else if( this.op == "!" )
{
st.pushResult( !((bool)Util.CoerceBool( right ) ) );
}
else
throw CoralException.GetInvProg( "Unary operator not supported" );
}
} )
);
this.right.run( state );
if( this.left != null )
this.left.run( state );
else
state.pushResult( null );
}
/// <summary>
/// Implements the string.join method.
/// </summary>
static void MethodJoin( State state, object[] args )
{
// Args should be a separator string and an array of stuff to join.
if( args.Length != 2 )
throw CoralException.GetArg( "string.join must be called with a separator string and an array of strings" );
string sep = Util.CoerceString( args[0] );
string[] arr = Util.CoerceStringArray( args[1] );
state.pushResult( String.Join( sep, arr ) );
}