com.mpobjects.bdparsii.eval

Class BinaryOperation

java.lang.Object

com.mpobjects.bdparsii.eval.AbstractExpression

com.mpobjects.bdparsii.eval.BinaryOperation

All Implemented Interfaces:

Expression

public final class BinaryOperation
extends AbstractExpression

Represents a binary operation.

A binary operation has two sub-expressions. A set of supported operations is also defined. If both arguments are constant, simplifying this expression will again lead to a constant expression.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	BinaryOperation.Op Enumerates the operations supported by this expression.

Constructor Summary

Constructors

Constructor and Description
BinaryOperation(MathContext mathContext, BinaryOperation.Op op, Expression left, Expression right) Creates a new binary operator for the given operator and operands.

Method Summary

Modifier and Type	Method and Description
BigDecimal	evaluate(MathContext mathContext) Evaluates the expression to a BigDecimal number.
Expression	getLeft() Returns the left operand
BinaryOperation.Op	getOp() Returns the operation performed by this binary operation.
Expression	getRight() Returns the right operand
boolean	isSealed() Determines if the operation is sealed and operands must not be re-ordered.
static BigDecimal	pow(BigDecimal x, BigDecimal y, MathContext mathContext) power function which uses the JRE's BigDecimal.pow(int, MathContext) when y is an integer within range.
void	seal() Marks an operation as sealed, meaning that re-ordering or operations on the same level must not be re-ordered.
void	setLeft(Expression left) Replaces the left operand of the operation with the given expression.
Expression	simplify(MathContext mathContext) Returns a simplified version of this expression.
String	toString()

Methods inherited from class com.mpobjects.bdparsii.eval.AbstractExpression

getMathContext

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Methods inherited from interface com.mpobjects.bdparsii.eval.Expression

evaluate, isConstant

Constructor Detail

BinaryOperation

public BinaryOperation(MathContext mathContext,
                       BinaryOperation.Op op,
                       Expression left,
                       Expression right)

Creates a new binary operator for the given operator and operands.

Parameters:

mathContext - the math context

op - the operator of the operation

left - the left operand

right - the right operand

Method Detail

pow

public static BigDecimal pow(BigDecimal x,
                             BigDecimal y,
                             MathContext mathContext)

power function which uses the JRE's BigDecimal.pow(int, MathContext) when y is an integer within range. Otherwise use BigDecimalMath.pow(BigDecimal, BigDecimal, MathContext).

Parameters:

x - the BigDecimal value to take to the power

y - the BigDecimal value to serve as exponent

mathContext - the MathContext used for the result

Returns:

the calculated x to the power of y with the precision specified in the mathContext

getOp

public BinaryOperation.Op getOp()

Returns the operation performed by this binary operation.

Returns:

the operation performed

getLeft

public Expression getLeft()

Returns the left operand

Returns:

the left operand of this operation

setLeft

public void setLeft(Expression left)

Replaces the left operand of the operation with the given expression.

Parameters:

left - the new expression to be used as left operand

getRight

public Expression getRight()

Returns the right operand

Returns:

the right operand of this operation

seal

public void seal()

Marks an operation as sealed, meaning that re-ordering or operations on the same level must not be re-ordered.

Binary operations are sealed if they're e.g. surrounded by braces.

isSealed

public boolean isSealed()

Determines if the operation is sealed and operands must not be re-ordered.

Returns:

true if the operation is protected by braces and operands might not be exchanged with operations nearby.

evaluate

public BigDecimal evaluate(MathContext mathContext)

Description copied from interface: Expression

Evaluates the expression to a BigDecimal number.

Parameters:

mathContext - Use this math context during calculation instead of the one provided during parsing. Does not affect already simplified subexpressions.

Returns:

the double value as a result of evaluating this expression.

simplify

public Expression simplify(MathContext mathContext)

Description copied from interface: Expression

Returns a simplified version of this expression.

Parameters:

mathContext - Match context used during simplification.

Returns:

a simplified version of this expression or this if the expression cannot be simplified

toString

public String toString()

Overrides:

toString in class Object