org.lsmp.djep.xjep
Class XOperator

java.lang.Object
  org.nfunk.jep.Operator
      org.lsmp.djep.xjep.XOperator

public class XOperator
extends Operator

An Operator with additional information about its commutativity etc.

Operators have a number of properties:

• A symbol or name of the operator "+".
• The number of arguments NO_ARGS 0, UNARY 1 (eg UMINUS -x), BINARY 2 (eq x+y), and NARY either 3 ( a>b ? a : b) or unspecified like a list [x,y,z,w].
• The binging of the operator, LEFT 1+2+3 -> (1+2)+3 or RIGHT 1=2=3 -> 1=(2=3).
• Whether the operator is ASSOCIATIVE or COMMUTATIVE.
• The precedence of the operators + has a higher precedence than *.
• For unary opperators they can either be PREFIX like -x or SUFIX like x%.
• Comparative operators can be REFLEXIVE, SYMMETRIC, TRANSITIVE or EQUIVILENCE which has all three properties.
• A reference to a PostfixtMathCommandI object which is used to evaluate an equation containing the operator.

various is... and get... methods are provided to query the properties of the opperator.

Author:

Rich Morris Created on 19-Oct-2003

Field Summary

static int	ASSOCIATIVE Associative operators x*(y*z) == (x*y)*z .
static int	BINARY Binary operators, such as x+y, x>y
static int	COMMUTATIVE Commutative operators x*y = y*x.
static int	COMPOSITE composite operators, like a-b which is a+(-b)
static int	EQUIVILENCE Equivilence relations = reflexive, transative and symetric.
static int	LEFT Left binding like +: 1+2+3 -> (1+2)+3
static int	NARY Trinary ops such as ?
static int	NO_ARGS No arguments to operator
static int	PREFIX prefix operators -x
static int	REFLEXIVE Reflecive relations x=x for all x.
static int	RIGHT Right binding like =: 1=2=3 -> 1=(2=3)
static int	SELF_INVERSE self inverse operators like -(-x) !
static int	SUFIX postfix operators x%, if neiter prefix and postif then infix, if both trifix like x?
static int	SYMMETRIC Symmetric relation x=y implies y=x.
static int	TRANSITIVE Transative relations x=y and y=z implies x=z
static int	UNARY Unary operators, such as -x !
static int	USE_BINDING_FOR_PRINT For non commutative operators printing can be determined by the left or right binding.

Constructor Summary

XOperator(Operator op, int flags)

XOperator(Operator op, int flags, int precedence)

XOperator(java.lang.String name, PostfixMathCommandI pfmc, int flags)
construct a new operator.

XOperator(java.lang.String name, PostfixMathCommandI pfmc, int flags, int precedence)
Allows a given precedent to be set.

XOperator(java.lang.String name, java.lang.String symbol, PostfixMathCommandI pfmc, int flags)
construct a new operator, with a different name and symbol

XOperator(java.lang.String name, java.lang.String symbol, PostfixMathCommandI pfmc, int flags, int precedence)
Allows a given precedent to be set.

Method Summary

Operator	getBinaryInverseOp()
int	getBinding() When parsing how is x+y+z interpreted.
Operator	getInverseOp()
int	getPrecedence()
Operator	getRootOp()
boolean	isAssociative()
boolean	isBinary()
boolean	isCommutative()
boolean	isComposite()
boolean	isDistributiveOver(Operator op)
boolean	isEquivilence()
boolean	isNary()
boolean	isPrefix()
boolean	isReflexive()
boolean	isSelfInverse()
boolean	isSufix()
boolean	isSymmetric()
boolean	isTransitive()
boolean	isUnary()
int	numArgs()
protected void	setBinaryInverseOp(Operator inv)
protected void	setDistributiveOver(Operator op)
protected void	setInverseOp(Operator inv)
protected void	setPrecedence(int i)
protected void	setRootOp(Operator root)
java.lang.String	toFullString() returns a verbose representation of the operator and all its properties.
boolean	useBindingForPrint()

Methods inherited from class org.nfunk.jep.Operator

getName, getPFMC, getSymbol, setPFMC, toString

Methods inherited from class java.lang.Object

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

Field Detail

NO_ARGS

public static final int NO_ARGS

No arguments to operator

See Also:

Constant Field Values

UNARY

public static final int UNARY

Unary operators, such as -x !x ~x

See Also:

Constant Field Values

BINARY

public static final int BINARY

Binary operators, such as x+y, x>y

See Also:

Constant Field Values

NARY

public static final int NARY

Trinary ops such as ?: and or higher like [x,y,z,w]

See Also:

Constant Field Values

LEFT

public static final int LEFT

Left binding like +: 1+2+3 -> (1+2)+3

See Also:

Constant Field Values

RIGHT

public static final int RIGHT

Right binding like =: 1=2=3 -> 1=(2=3)

See Also:

Constant Field Values

ASSOCIATIVE

public static final int ASSOCIATIVE

Associative operators x*(y*z) == (x*y)*z .

See Also:

Constant Field Values

COMMUTATIVE

public static final int COMMUTATIVE

Commutative operators x*y = y*x.

See Also:

Constant Field Values

REFLEXIVE

public static final int REFLEXIVE

Reflecive relations x=x for all x.

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Constant Field Values

SYMMETRIC

public static final int SYMMETRIC

Symmetric relation x=y implies y=x.

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Constant Field Values

TRANSITIVE

public static final int TRANSITIVE

Transative relations x=y and y=z implies x=z

See Also:

Constant Field Values

EQUIVILENCE

public static final int EQUIVILENCE

Equivilence relations = reflexive, transative and symetric.

See Also:

Constant Field Values

PREFIX

public static final int PREFIX

prefix operators -x

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Constant Field Values

SUFIX

public static final int SUFIX

postfix operators x%, if neiter prefix and postif then infix, if both trifix like x?y:z

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Constant Field Values

SELF_INVERSE

public static final int SELF_INVERSE

self inverse operators like -(-x) !(!x)

See Also:

Constant Field Values

COMPOSITE

public static final int COMPOSITE

composite operators, like a-b which is a+(-b)

See Also:

Constant Field Values

USE_BINDING_FOR_PRINT

public static final int USE_BINDING_FOR_PRINT

For non commutative operators printing can be determined by the left or right binding. For example (a-b)-c is printed as a-b-c. But a/b/c could be ambiguous so (a/b)/c is printed with brackets.

See Also:

Constant Field Values

Constructor Detail

XOperator

public XOperator(java.lang.String name,
                 PostfixMathCommandI pfmc,
                 int flags)

construct a new operator.

Parameters:

name - printable name of operator

pfmc - postfix math command for opperator

flags - set of flags defining the porperties of the operator.

XOperator

public XOperator(java.lang.String name,
                 PostfixMathCommandI pfmc,
                 int flags,
                 int precedence)

Allows a given precedent to be set.

Parameters:

name -

pfmc -

flags -

precedence -

XOperator

public XOperator(java.lang.String name,
                 java.lang.String symbol,
                 PostfixMathCommandI pfmc,
                 int flags)

construct a new operator, with a different name and symbol

Parameters:

name - name of operator, must be unique, used when describing operator

symbol - printable name of operator, used for printing equations

pfmc - postfix math command for opperator

flags - set of flags defining the porperties of the operator.

XOperator

public XOperator(java.lang.String name,
                 java.lang.String symbol,
                 PostfixMathCommandI pfmc,
                 int flags,
                 int precedence)

Allows a given precedent to be set.

Parameters:

name -

pfmc -

flags -

precedence -

XOperator

public XOperator(Operator op,
                 int flags,
                 int precedence)

XOperator

public XOperator(Operator op,
                 int flags)

Method Detail

getPrecedence

public final int getPrecedence()

setPrecedence

protected final void setPrecedence(int i)

setDistributiveOver

protected final void setDistributiveOver(Operator op)

isDistributiveOver

public boolean isDistributiveOver(Operator op)

setRootOp

protected void setRootOp(Operator root)

setInverseOp

protected void setInverseOp(Operator inv)

setBinaryInverseOp

protected void setBinaryInverseOp(Operator inv)

getRootOp

public Operator getRootOp()

getInverseOp

public Operator getInverseOp()

getBinaryInverseOp

public Operator getBinaryInverseOp()

getBinding

public final int getBinding()

When parsing how is x+y+z interpreted. Can be Operator.LEFT x+y+z -> (x+y)+z or Operator.RIGHT x=y=z -> x=(y=z).

isAssociative

public final boolean isAssociative()

isCommutative

public final boolean isCommutative()

isBinary

public final boolean isBinary()

isUnary

public final boolean isUnary()

isNary

public final boolean isNary()

numArgs

public final int numArgs()

isTransitive

public final boolean isTransitive()

isSymmetric

public final boolean isSymmetric()

isReflexive

public final boolean isReflexive()

isEquivilence

public final boolean isEquivilence()

isPrefix

public final boolean isPrefix()

isSufix

public final boolean isSufix()

isComposite

public final boolean isComposite()

isSelfInverse

public final boolean isSelfInverse()

useBindingForPrint

public final boolean useBindingForPrint()

toFullString

public java.lang.String toFullString()

returns a verbose representation of the operator and all its properties.