package node.exprNode;
import node.*;
import env.*;
import type.*;
import type.basicType.*;
import runEnv.*;
import runEnv.basicValue.*;
import text.*;

public class CastNode extends ExprNode {

	private Type type;
	private ExprNode expr;

	 public CastNode( Type type, ExprNode expr ) {
		this.type = type;
		this.expr = expr;
		precedence = PREC_PREFIX;
		}

	public String toString() {
		return "( " + type + " ) " + expr.toString( precedence );
		}
		
	public void genEnv( Env env ) {
		super.genEnv( env );
		error( "Should never invoke genEnv() for a CastNode()" );
		}

	public Type checkType() {
		error( "Should never invoke checkType() for a CastNode()" );
		return ErrorType.type;
		}
	
	public RunValue eval( RunEnv runEnv ) {
		RunValue exprValue = expr.eval( runEnv );
		if ( type instanceof RealType )
			return new RealValue( ( double ) exprValue.intValue() );
		else if ( type.equals( StringType.type ) )
			if ( exprValue == null )
				return NullValue.value;
			else
				return new StringValue( exprValue.stringValue() );
		else if ( type instanceof VoidType )
			return new VoidValue();
		else
			return exprValue;
		}

	}