MultiplicativeExpression.java

/*
 * Copyright 2013 Guidewire Software, Inc.
 */

package gw.internal.gosu.parser.expressions;

import gw.config.CommonServices;
import gw.internal.gosu.parser.ParserBase;
import gw.lang.IDimension;
import gw.lang.parser.expressions.IMultiplicativeExpression;
import gw.lang.reflect.IPlaceholder;
import gw.lang.reflect.IType;
import gw.lang.reflect.TypeSystem;
import gw.lang.reflect.java.JavaTypes;

import java.math.BigDecimal;
import java.math.MathContext;


/**
 * Represents a multiplicative expression in the Gosu grammar:
 * <pre>
 * <i>multiplicative-expression</i>
 *   <unary-expression>
 *   <multiplicative-expression> <b>*</b> <unary-expression>
 *   <multiplicative-expression> <b>/</b> <unary-expression>
 *   <multiplicative-expression> <b>%</b> <unary-expression>
 * </pre>
 * <p/>
 *
 * @see gw.lang.parser.IGosuParser
 */
public final class MultiplicativeExpression extends ArithmeticExpression implements IMultiplicativeExpression
{
  /**
   * Evaluate the expression.
   */
  public Object evaluate()
  {
    if( !isCompileTimeConstant() )
    {
      return super.evaluate();
    }

    return evaluate( getType(), getLHS().evaluate(), getRHS().evaluate(), getLHS().getType(), getRHS().getType(), getOperator().charAt( 0 ), false );
  }

  public static Object evaluate( IType type, Object lhsValue, Object rhsValue, IType lhsType, IType rhsType, int iOperator, boolean bNullSafe, Object ctx, int startLhs, int endLhs, int startRhs, int endRhs )
  {
    AdditiveExpression.maybeThrowRichNPE( lhsValue, rhsValue, bNullSafe, ctx, startLhs, endLhs, startRhs, endRhs );
    return evaluate( type, lhsValue, rhsValue, lhsType, rhsType, iOperator, bNullSafe );
  }


  // Potentially called from generated bytecode
  @SuppressWarnings({"ConstantConditions"})
  public static Object evaluate( IType type, Object lhsValue, Object rhsValue, IType lhsType, IType rhsType, int iOperator, boolean bNullSafe )
  {
    if( lhsType instanceof IPlaceholder && ((IPlaceholder)lhsType).isPlaceholder() )
    {
      lhsType = TypeSystem.getFromObject( lhsValue );
      type = ParserBase.resolveRuntimeType( lhsType, iOperator, rhsType );
    }
    if( rhsType instanceof IPlaceholder && ((IPlaceholder)rhsType).isPlaceholder() )
    {
      rhsType = TypeSystem.getFromObject( rhsValue );
      type = ParserBase.resolveRuntimeType( lhsType, iOperator, rhsType );
    }

    if( lhsValue == null )
    {
      if( bNullSafe )
      {
        return null;
      }
      throw new NullPointerException("left-hand operand was null");
    }
    if( rhsValue == null )
    {
      if( bNullSafe )
      {
        return null;
      }
      throw new NullPointerException("right-hand operand was null");
    }

    DimensionOperandResolver customNumberResolver =
      DimensionOperandResolver.resolve( type, (char)iOperator, lhsType, lhsValue, rhsType, rhsValue );
    type = customNumberResolver.getRawNumberType();
    lhsValue = customNumberResolver.getLhsValue();
    rhsValue = customNumberResolver.getRhsValue();
    IDimension customNumberBase = customNumberResolver.getBase();

    Object retValue;
    switch( iOperator )
    {
      case '*':
      {
        if( type == JavaTypes.BIG_DECIMAL() )
        {
          BigDecimal lhsBD = CommonServices.getCoercionManager().makeBigDecimalFrom( lhsValue );
          BigDecimal rhsBD = CommonServices.getCoercionManager().makeBigDecimalFrom( rhsValue );
          retValue = lhsBD.multiply( rhsBD );
        }
        else if( type == JavaTypes.BIG_INTEGER() )
        {
          retValue = CommonServices.getCoercionManager().makeBigIntegerFrom( lhsValue ).multiply( CommonServices.getCoercionManager().makeBigIntegerFrom( rhsValue ) );
        }
        else if( type == JavaTypes.INTEGER() || type == JavaTypes.pINT() )
        {
          retValue = CommonServices.getCoercionManager().makeIntegerFrom( lhsValue ) * CommonServices.getCoercionManager().makeIntegerFrom( rhsValue );
        }
        else if( type == JavaTypes.LONG() || type == JavaTypes.pLONG() )
        {
          retValue = makeLong( CommonServices.getCoercionManager().makeLongFrom( lhsValue ) * CommonServices.getCoercionManager().makeLongFrom( rhsValue ) );
        }
        else if( type == JavaTypes.DOUBLE() || type == JavaTypes.pDOUBLE() )
        {
          retValue =  makeDoubleValue( makeDoubleValue( lhsValue ) * makeDoubleValue( rhsValue ) );
        }
        else if( type == JavaTypes.FLOAT() || type == JavaTypes.pFLOAT() )
        {
          retValue = makeFloatValue( makeFloatValue( lhsValue ) * makeFloatValue( rhsValue ) );
        }
        else if( type == JavaTypes.SHORT() || type == JavaTypes.pSHORT() )
        {
          retValue = Integer.valueOf( CommonServices.getCoercionManager().makeIntegerFrom( lhsValue ) * CommonServices.getCoercionManager().makeIntegerFrom( rhsValue ) ).shortValue();
        }
        else if( type == JavaTypes.BYTE() || type == JavaTypes.pBYTE() )
        {
          retValue = (byte)(CommonServices.getCoercionManager().makeIntegerFrom( lhsValue ) * CommonServices.getCoercionManager().makeIntegerFrom( rhsValue ));
        }
        else
        {
          throw new UnsupportedNumberTypeException(type);
        }
        break;
      }

      case '/':
      {
        if( type == JavaTypes.BIG_DECIMAL() )
        {
          BigDecimal lhsBD = CommonServices.getCoercionManager().makeBigDecimalFrom( lhsValue );
          BigDecimal rhsBD = CommonServices.getCoercionManager().makeBigDecimalFrom( rhsValue );
          retValue = lhsBD.divide( rhsBD, MathContext.DECIMAL128 );
        }
        else if( type == JavaTypes.BIG_INTEGER() )
        {
          retValue = CommonServices.getCoercionManager().makeBigIntegerFrom( lhsValue ).divide( CommonServices.getCoercionManager().makeBigIntegerFrom( rhsValue ) );
        }
        else if( type == JavaTypes.INTEGER() || type == JavaTypes.pINT() )
        {
          retValue = CommonServices.getCoercionManager().makeIntegerFrom( lhsValue ) / CommonServices.getCoercionManager().makeIntegerFrom( rhsValue );
        }
        else if( type == JavaTypes.LONG() || type == JavaTypes.pLONG() )
        {
          retValue = makeLong( CommonServices.getCoercionManager().makeLongFrom( lhsValue ) / CommonServices.getCoercionManager().makeLongFrom( rhsValue ) );
        }
        else if( type == JavaTypes.DOUBLE() || type == JavaTypes.pDOUBLE() )
        {
          retValue = makeDoubleValue( makeDoubleValue( lhsValue ) / makeDoubleValue( rhsValue ) );
        }
        else if( type == JavaTypes.FLOAT() || type == JavaTypes.pFLOAT() )
        {
          retValue = makeFloatValue( makeFloatValue( lhsValue ) / makeFloatValue( rhsValue ) );
        }
        else if( type == JavaTypes.SHORT() || type == JavaTypes.pSHORT() )
        {
          retValue = Integer.valueOf( CommonServices.getCoercionManager().makeIntegerFrom( lhsValue ) / CommonServices.getCoercionManager().makeIntegerFrom( rhsValue ) ).shortValue();
        }
        else if( type == JavaTypes.BYTE() || type == JavaTypes.pBYTE() )
        {
          retValue = (byte)(CommonServices.getCoercionManager().makeIntegerFrom( lhsValue ) / CommonServices.getCoercionManager().makeIntegerFrom( rhsValue ));
        }
        else
        {
          throw new UnsupportedNumberTypeException(type);
        }
        break;
      }

      case '%':
      {
        if( type == JavaTypes.BIG_DECIMAL() )
        {
          BigDecimal lhsBD = CommonServices.getCoercionManager().makeBigDecimalFrom( lhsValue );
          BigDecimal rhsBD = CommonServices.getCoercionManager().makeBigDecimalFrom( rhsValue );
          BigDecimal result = lhsBD.remainder( rhsBD, MathContext.DECIMAL128 );
          retValue = result.abs();
        }
        else if( type == JavaTypes.BIG_INTEGER() )
        {
          retValue = CommonServices.getCoercionManager().makeBigIntegerFrom( lhsValue ).mod( CommonServices.getCoercionManager().makeBigIntegerFrom( rhsValue ) );
        }
        else if( type == JavaTypes.INTEGER() || type == JavaTypes.pINT() )
        {
          retValue = CommonServices.getCoercionManager().makeIntegerFrom( lhsValue ) % CommonServices.getCoercionManager().makeIntegerFrom( rhsValue );
        }
        else if( type == JavaTypes.LONG() || type == JavaTypes.pLONG() )
        {
          retValue = makeLong( CommonServices.getCoercionManager().makeLongFrom( lhsValue ) % CommonServices.getCoercionManager().makeLongFrom( rhsValue ) );
        }
        else if( type == JavaTypes.DOUBLE() || type == JavaTypes.pDOUBLE() )
        {
          retValue = makeDoubleValue( makeDoubleValue( lhsValue ) % makeDoubleValue( rhsValue ) );
        }
        else if( type == JavaTypes.FLOAT() || type == JavaTypes.pFLOAT() )
        {
          retValue = makeFloatValue( makeFloatValue( lhsValue ) % makeFloatValue( rhsValue ) );
        }
        else if( type == JavaTypes.SHORT() || type == JavaTypes.pSHORT() )
        {
          retValue = Integer.valueOf( CommonServices.getCoercionManager().makeIntegerFrom( lhsValue ) % CommonServices.getCoercionManager().makeIntegerFrom( rhsValue ) ).shortValue();
        }
        else if( type == JavaTypes.BYTE() || type == JavaTypes.pBYTE() )
        {
          retValue = (byte)(CommonServices.getCoercionManager().makeIntegerFrom( lhsValue ) % CommonServices.getCoercionManager().makeIntegerFrom( rhsValue ));
        }
        else
        {
          throw new UnsupportedNumberTypeException(type);
        }
        break;
      }

      default:
        retValue = null;
    }

    if( retValue != null )
    {
      if( customNumberBase != null )
      {
        //noinspection unchecked
        retValue = customNumberBase.fromNumber( (Number)retValue );
      }
    }
    return retValue;
  }

}