org.matheclipse.core.expression

Class Symbol

java.lang.Object

org.matheclipse.core.expression.ExprImpl

org.matheclipse.core.expression.Symbol

All Implemented Interfaces:

AbelianGroupElem<IExpr>, Element<IExpr>, MonoidElem<IExpr>, RingElem<IExpr>, java.io.Serializable, java.lang.Comparable<IExpr>, IExpr, ISymbol

Direct Known Subclasses:

MethodSymbol

public class Symbol
extends ExprImpl
implements ISymbol

Implements Symbols for function, constant and variable names

See Also:

Serialized Form

Field Summary

Fields inherited from interface org.matheclipse.core.interfaces.ISymbol

CONSOLE_OUTPUT, CONSTANT, DEFAULT_RULE_PRIORITY, FLAT, FLATORDERLESS, HOLDALL, HOLDFIRST, HOLDREST, LISTABLE, NHOLDALL, NHOLDFIRST, NHOLDREST, NOATTRIBUTE, NUMERICFUNCTION, ONEIDENTITY, ORDERLESS, PACKAGE_LOADED

Fields inherited from interface org.matheclipse.core.interfaces.IExpr

ASTID, COMPLEXID, DOUBLECOMPLEXID, DOUBLEID, FRACTIONID, INTEGERID, METHODSYMBOLID, PATTERNID, STRINGID, SYMBOLID

Constructor Summary

Constructors

Constructor and Description
Symbol(java.lang.String symbolName)
Symbol(java.lang.String symbolName, IEvaluator evaluator)

Method Summary

Modifier and Type	Method and Description
<T> T	accept(IVisitor<T> visitor) Accept a visitor with return type T
boolean	accept(IVisitorBoolean visitor) Accept a visitor with return type boolean
int	accept(IVisitorInt visitor) Accept a visitor with return type int
IExpr	apply(IExpr... expressions)
void	clear(EvalEngine engine) Clear the associated rules for this symbol
void	clearAll(EvalEngine engine) Clear all associated rules and attributes for this symbol
int	compareTo(IExpr obj) Compares this expression with the specified expression for order.
java.util.List<IAST>	definition() Return a list of the rules associated to this symbol
java.lang.String	definitionToString() Return the rules associated to this symbol in String representation
boolean	equals(java.lang.Object obj) Test if this is equal to b.
IExpr	evalDownRule(IEvaluationEngine ee, IExpr expression) Evaluate the given expression for the "down value" rules associated with this symbol
IExpr	evaluate(EvalEngine engine) Evaluate an expression
IExpr	evalUpRule(IEvaluationEngine ee, IExpr expression) Evaluate the given expression for the "up value" rules associated with this symbol
java.lang.String	fullFormString() Return the FullForm of this expression
IExpr	get() Get the topmost value from the local variable stack
IExpr	getAssignedValue() Get the value which is assigned to the symbol or null, if no value is assigned.
int	getAttributes() Get the Attributes of this symbol (i.e.
IExpr	getDefaultValue() Get the general default value for this symbol (i.e.
IExpr	getDefaultValue(int pos) Get the default value at the arguments position for this symbol (i.e.
IEvaluator	getEvaluator() Get the current evaluator for this symbol
java.lang.String	getSymbol()
int	hashCode() Hashcode of this Element.
boolean	hasLocalVariableStack() Is a local variable stack created for this symbol ?
ISymbol	head() If this object is an instance of IAST get the first element (offset 0) of the IAST list (i.e.
int	hierarchy() A unique integer ID for the implementation of this expression
java.lang.String	internalFormString(boolean symbolsAsFactoryMethod, int depth) Return the internal Java form of this expression.
boolean	isAtom() Test if this expression is an atomic expression (i.e.
boolean	isConstant() Test if this expression is a symbol with attribute Constant.
boolean	isFalse() Test if this expression equals the symbol "False"
boolean	isNegative() Test if this object is a negative signed number.
boolean	isPositive() Test if this object is a positive signed number.
boolean	isString(java.lang.String str) Tests if this symbols name equals the given string
boolean	isSymbolName(java.lang.String name) Returns true, if this symbol has the given name.
boolean	isTrue() Test if this expression equals the symbol "True"
boolean	isValue() Returns true, if this symbol or ast expression is bound to a value (i.e.
IExpr	mapConstantDouble(INumericFunction<IExpr> function) If this symbol has attribute ISymbol.CONSTANT and the symbol's evaluator is of instance INumericConstant, then apply the constants double value to the given function and return the result, otherwise return null.
IExpr	negate() Negate this.
void	popLocalVariable() Delete the topmost placeholder from the local variable stack
void	pushLocalVariable() Create a new variable placeholder on the symbols variable stack
void	pushLocalVariable(IExpr expression) Create a new variable placeholder on the symbols variable stack and set the local value
IPatternMatcher	putDownRule(ISymbol symbol, boolean equalRule, IExpr leftHandSide, IExpr rightHandSide, boolean packageMode) Associate a new "down value" rule with default priority to this symbol.
IPatternMatcher	putDownRule(ISymbol setSymbol, boolean equalRule, IExpr leftHandSide, IExpr rightHandSide, int priority, boolean packageMode) Associate a new rule with the given priority to this symbol. Rules with lower numbers have higher priorities.
PatternMatcher	putDownRule(PatternMatcherAndInvoker pmEvaluator) Associate a new rule, which invokes a method, to this symbol.
IPatternMatcher	putUpRule(ISymbol symbol, boolean equalRule, IAST leftHandSide, IExpr rightHandSide) Associate a new "up value" rule with default priority to this symbol.
IPatternMatcher	putUpRule(ISymbol setSymbol, boolean equalRule, IAST leftHandSide, IExpr rightHandSide, int priority) Associate a new "up value" rule with the given priority to this symbol. Rules with lower numbers have higher priorities.
void	readSymbol(java.io.ObjectInputStream stream) Deserialize the rules associated to this object
IExpr[]	reassignSymbolValue(Function<IExpr,IExpr> function, ISymbol functionSymbol) Apply the function to the currently assigned value of the symbol and reassign the result value to the symbol.
void	set(IExpr value) Set the value of the local variable on top of the local variable stack
void	setAttributes(int attributes) Set the Attributes of this symbol (i.e.
void	setDefaultValue(IExpr expr) Set the general default value for this symbol (i.e.
void	setDefaultValue(int pos, IExpr expr) Set the default value at the arguments position for this symbol (i.e.
void	setEvaluator(IEvaluator evaluator) Set the current evaluator which is associated to this symbol
java.lang.String	toString()
IExpr	variables2Slots(java.util.Map<IExpr,IExpr> map, java.util.List<IExpr> variableList) Convert the variables (i.e.
void	writeSymbol(java.io.ObjectOutputStream stream) Serialize the rules associated to this object

Methods inherited from class org.matheclipse.core.expression.ExprImpl

abs, and, apply, asType, copy, divide, egcd, factory, gcd, getAt, inverse, isAnd, isArcCos, isArcCosh, isArcSin, isArcSinh, isArcTan, isArcTanh, isAST, isAST, isAST, isAST, isAST, isAST, isASTSizeGE, isComplex, isComplexInfinity, isComplexNumeric, isCondition, isCos, isCosh, isDirectedInfinity, isFlatAST, isFraction, isFree, isFree, isFunction, isGEOrdered, isGTOrdered, isInfinity, isInteger, isLEOrdered, isList, isListOfLists, isLog, isLTOrdered, isMatrix, isMember, isMember, isMinusOne, isModule, isNegativeInfinity, isNot, isNumber, isNumEqualInteger, isNumeric, isNumericFunction, isNumIntValue, isOne, isONE, isOr, isOrderlessAST, isPattern, isPatternExpr, isPatternSequence, isPlus, isPower, isRational, isRealFunction, isRuleAST, isSame, isSame, isSequence, isSignedNumber, isSin, isSinh, isSlot, isSlotSequence, isSymbol, isTan, isTanh, isTimes, isUnit, isVector, isZero, isZERO, leaves, minus, mod, multiply, negative, opposite, or, plus, power, power, remainder, replaceAll, replaceAll, replacePart, replaceRepeated, replaceRepeated, replaceRepeated, replaceSlots, signum, subtract, sum, times, topHead, toScript, toScriptFactory

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface org.matheclipse.core.interfaces.IExpr

and, apply, asType, getAt, inverse, isAnd, isArcCos, isArcCosh, isArcSin, isArcSinh, isArcTan, isArcTanh, isAST, isAST, isAST, isAST, isAST, isAST, isASTSizeGE, isComplex, isComplexInfinity, isComplexNumeric, isCondition, isCos, isCosh, isDirectedInfinity, isFlatAST, isFraction, isFree, isFree, isFunction, isGEOrdered, isGTOrdered, isInfinity, isInteger, isLEOrdered, isList, isListOfLists, isLog, isLTOrdered, isMatrix, isMember, isMember, isMinusOne, isModule, isNegativeInfinity, isNot, isNumber, isNumEqualInteger, isNumeric, isNumericFunction, isNumIntValue, isOne, isOr, isOrderlessAST, isPattern, isPatternExpr, isPatternSequence, isPlus, isPower, isRational, isRealFunction, isRuleAST, isSame, isSame, isSequence, isSignedNumber, isSin, isSinh, isSlot, isSlotSequence, isSymbol, isTan, isTanh, isTimes, isVector, isZero, leaves, minus, mod, multiply, negative, or, plus, power, power, replaceAll, replaceAll, replacePart, replaceRepeated, replaceRepeated, replaceSlots, signum, times, topHead

Methods inherited from interface edu.jas.structure.RingElem

egcd, gcd

Methods inherited from interface edu.jas.structure.AbelianGroupElem

abs, isZERO, subtract, sum

Methods inherited from interface edu.jas.structure.MonoidElem

divide, isONE, isUnit, remainder

Methods inherited from interface edu.jas.structure.Element

copy, factory, toScript, toScriptFactory

Constructor Detail

Symbol

public Symbol(java.lang.String symbolName)

Symbol

public Symbol(java.lang.String symbolName,
              IEvaluator evaluator)

Method Detail

reassignSymbolValue

public IExpr[] reassignSymbolValue(Function<IExpr,IExpr> function,
                                   ISymbol functionSymbol)

Apply the function to the currently assigned value of the symbol and reassign the result value to the symbol.

Specified by:

reassignSymbolValue in interface ISymbol

Parameters:

function - the function which should be applied

functionSymbol - TODO

Returns:

an array with the currently assigned value of the symbol and the new calculated value of the symbol or null if the reassignment isn't possible.

getAssignedValue

public IExpr getAssignedValue()

Get the value which is assigned to the symbol or null, if no value is assigned.

Specified by:

getAssignedValue in interface ISymbol

Returns:

null, if no value is assigned.

apply

public IExpr apply(IExpr... expressions)

Specified by:

apply in interface IExpr

Overrides:

apply in class ExprImpl

Returns:

an IExpr instance with the current expression as head(), and leaves as leaves().

pushLocalVariable

public void pushLocalVariable()

Create a new variable placeholder on the symbols variable stack

Specified by:

pushLocalVariable in interface ISymbol

pushLocalVariable

public void pushLocalVariable(IExpr expression)

Create a new variable placeholder on the symbols variable stack and set the local value

Specified by:

pushLocalVariable in interface ISymbol

popLocalVariable

public void popLocalVariable()

Delete the topmost placeholder from the local variable stack

Specified by:

popLocalVariable in interface ISymbol

clear

public void clear(EvalEngine engine)

Clear the associated rules for this symbol

Specified by:

clear in interface ISymbol

clearAll

public void clearAll(EvalEngine engine)

Clear all associated rules and attributes for this symbol

Specified by:

clearAll in interface ISymbol

equals

public boolean equals(java.lang.Object obj)

Test if this is equal to b.

Specified by:

equals in interface Element<IExpr>

Overrides:

equals in class java.lang.Object

Returns:

true if this is equal to b, else false.

isSymbolName

public boolean isSymbolName(java.lang.String name)

Description copied from interface: ISymbol

Returns true, if this symbol has the given name. The comparison of the symbols name with the given name is done according to the Config.PARSER_USE_LOWERCASE_SYMBOLS setting.

Specified by:

isSymbolName in interface ISymbol

evaluate

public IExpr evaluate(EvalEngine engine)

Evaluate an expression

Specified by:

evaluate in interface IExpr

Overrides:

evaluate in class ExprImpl

Parameters:

engine - the evaluation engine

Returns:

the evaluated Object or null if the evaluation is not possible (i.e. the evaluation doesn't change the object).

evalDownRule

public IExpr evalDownRule(IEvaluationEngine ee,
                          IExpr expression)

Evaluate the given expression for the "down value" rules associated with this symbol

Specified by:

evalDownRule in interface ISymbol

Returns:

evalUpRule

public IExpr evalUpRule(IEvaluationEngine ee,
                        IExpr expression)

Evaluate the given expression for the "up value" rules associated with this symbol

Specified by:

evalUpRule in interface ISymbol

Returns:

getAttributes

public final int getAttributes()

Get the Attributes of this symbol (i.e. LISTABLE, FLAT, ORDERLESS,...)

Specified by:

getAttributes in interface ISymbol

Returns:

See Also:

ISymbol.FLAT

getEvaluator

public IEvaluator getEvaluator()

Get the current evaluator for this symbol

Specified by:

getEvaluator in interface ISymbol

Returns:

the evaluator which is associated to this symbol or null if no evaluator is associated

hasLocalVariableStack

public boolean hasLocalVariableStack()

Is a local variable stack created for this symbol ?

Specified by:

hasLocalVariableStack in interface ISymbol

Returns:

true if this symbol has a local variable stack

get

public IExpr get()

Get the topmost value from the local variable stack

Specified by:

get in interface ISymbol

Returns:

null if no local variable is defined

set

public void set(IExpr value)

Set the value of the local variable on top of the local variable stack

Specified by:

set in interface ISymbol

hashCode

public int hashCode()

Hashcode of this Element.

Specified by:

hashCode in interface Element<IExpr>

Overrides:

hashCode in class java.lang.Object

Returns:

the hashCode.

hierarchy

public int hierarchy()

A unique integer ID for the implementation of this expression

Specified by:

hierarchy in interface IExpr

Returns:

a unique integer id for the implementation of this expression

isString

public final boolean isString(java.lang.String str)

Tests if this symbols name equals the given string

Specified by:

isString in interface ISymbol

Returns:

putDownRule

public IPatternMatcher putDownRule(ISymbol symbol,
                                   boolean equalRule,
                                   IExpr leftHandSide,
                                   IExpr rightHandSide,
                                   boolean packageMode)

Associate a new "down value" rule with default priority to this symbol.

Specified by:

putDownRule in interface ISymbol

equalRule - true if the leftHandSide could be matched with equality

packageMode - TODO

Returns:

See Also:

ISymbol.DEFAULT_RULE_PRIORITY

putDownRule

public IPatternMatcher putDownRule(ISymbol setSymbol,
                                   boolean equalRule,
                                   IExpr leftHandSide,
                                   IExpr rightHandSide,
                                   int priority,
                                   boolean packageMode)

Associate a new rule with the given priority to this symbol.
Rules with lower numbers have higher priorities.

Specified by:

putDownRule in interface ISymbol

equalRule - true if the leftHandSide could be matched with equality

priority - the priority of the rule

packageMode - TODO

Returns:

See Also:

ISymbol.DEFAULT_RULE_PRIORITY

putDownRule

public PatternMatcher putDownRule(PatternMatcherAndInvoker pmEvaluator)

Associate a new rule, which invokes a method, to this symbol.

Specified by:

putDownRule in interface ISymbol

putUpRule

public IPatternMatcher putUpRule(ISymbol symbol,
                                 boolean equalRule,
                                 IAST leftHandSide,
                                 IExpr rightHandSide)

Associate a new "up value" rule with default priority to this symbol.

Specified by:

putUpRule in interface ISymbol

equalRule - true if the leftHandSide could be matched with equality

Returns:

See Also:

ISymbol.DEFAULT_RULE_PRIORITY

putUpRule

public IPatternMatcher putUpRule(ISymbol setSymbol,
                                 boolean equalRule,
                                 IAST leftHandSide,
                                 IExpr rightHandSide,
                                 int priority)

Associate a new "up value" rule with the given priority to this symbol.
Rules with lower numbers have higher priorities.

Specified by:

putUpRule in interface ISymbol

equalRule - true if the leftHandSide could be matched with equality

priority - the priority of the rule

Returns:

See Also:

ISymbol.DEFAULT_RULE_PRIORITY

setAttributes

public void setAttributes(int attributes)

Set the Attributes of this symbol (i.e. LISTABLE, FLAT, ORDERLESS,...)

Specified by:

setAttributes in interface ISymbol

Parameters:

attributes - the Attributes of this symbol

setEvaluator

public final void setEvaluator(IEvaluator evaluator)

Set the current evaluator which is associated to this symbol

Specified by:

setEvaluator in interface ISymbol

compareTo

public int compareTo(IExpr obj)

Compares this expression with the specified expression for order. Returns a negative integer, zero, or a positive integer as this expression is canonical less than, equal to, or greater than the specified expression.

Specified by:

compareTo in interface Element<IExpr>

Specified by:

compareTo in interface java.lang.Comparable<IExpr>

Specified by:

compareTo in interface IExpr

Returns:

0 if this is equal to b, -1 if this is less then b, else +1.

isAtom

public final boolean isAtom()

Test if this expression is an atomic expression (i.e. no AST expression)

Specified by:

isAtom in interface IExpr

Overrides:

isAtom in class ExprImpl

isConstant

public boolean isConstant()

Test if this expression is a symbol with attribute Constant. Therefore numbers return false for this method!

Specified by:

isConstant in interface IExpr

Overrides:

isConstant in class ExprImpl

See Also:

IExpr.isRealFunction(), IExpr.isNumericFunction()

isTrue

public boolean isTrue()

Test if this expression equals the symbol "True"

Specified by:

isTrue in interface IExpr

Overrides:

isTrue in class ExprImpl

isValue

public final boolean isValue()

Returns true, if this symbol or ast expression is bound to a value (i.e. the evaluation returns an assigned value).

Specified by:

isValue in interface IExpr

Overrides:

isValue in class ExprImpl

isFalse

public boolean isFalse()

Test if this expression equals the symbol "False"

Specified by:

isFalse in interface IExpr

Overrides:

isFalse in class ExprImpl

isNegative

public boolean isNegative()

Test if this object is a negative signed number.

Specified by:

isNegative in interface IExpr

Overrides:

isNegative in class ExprImpl

Returns:

true, if this < 0; false in all other case.

isPositive

public boolean isPositive()

Test if this object is a positive signed number.

Specified by:

isPositive in interface IExpr

Overrides:

isPositive in class ExprImpl

Returns:

true, if this > 0; false in all other case.

head

public ISymbol head()

If this object is an instance of IAST get the first element (offset 0) of the IAST list (i.e. get(0) ).

Specified by:

head in interface IExpr

Specified by:

head in class ExprImpl

Returns:

the head of the expression, which must not be null.

getSymbol

public final java.lang.String getSymbol()

variables2Slots

public IExpr variables2Slots(java.util.Map<IExpr,IExpr> map,
                             java.util.List<IExpr> variableList)

Description copied from interface: IExpr

Convert the variables (i.e. ISymbol's with lower case character in the 0-th position of their name) in this expression into Slot[] s.

Specified by:

variables2Slots in interface IExpr

Overrides:

variables2Slots in class ExprImpl

Returns:

null if the expression contains a variable with a '$' character in the 0-th position of its name and the math engine runs in server mode.

internalFormString

public java.lang.String internalFormString(boolean symbolsAsFactoryMethod,
                                           int depth)

Description copied from interface: IExpr

Return the internal Java form of this expression.

Specified by:

internalFormString in interface IExpr

Overrides:

internalFormString in class ExprImpl

Parameters:

symbolsAsFactoryMethod - if true use the F.symbol() method, otherwise print the symbol name.

depth - the recursion depth of this call. 0 indicates "recurse without a limit".

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

fullFormString

public java.lang.String fullFormString()

Return the FullForm of this expression

Specified by:

fullFormString in interface IExpr

Overrides:

fullFormString in class ExprImpl

definition

public java.util.List<IAST> definition()

Return a list of the rules associated to this symbol

Specified by:

definition in interface ISymbol

Returns:

getDefaultValue

public IExpr getDefaultValue()

Get the general default value for this symbol (i.e. 1 is the default value for Times, 0 is the default value for Plus). The general default value is used in pattern-matching for expressions like a_. * b_. + c_

Specified by:

getDefaultValue in interface ISymbol

Returns:

the default value or null if undefined.

getDefaultValue

public IExpr getDefaultValue(int pos)

Get the default value at the arguments position for this symbol (i.e. 1 is the default value for Power at position 2). The default value is used in pattern-matching for expressions like a ^ b_.

Specified by:

getDefaultValue in interface ISymbol

Parameters:

pos - the position for the default value

Returns:

the default value or null if undefined.

setDefaultValue

public void setDefaultValue(IExpr expr)

Set the general default value for this symbol (i.e. 1 is the default value for Times, 0 is the default value for Plus). The general default value is used in pattern-matching for expressions like a_. * b_. + c_

Specified by:

setDefaultValue in interface ISymbol

Parameters:

expr - the general default value

See Also:

ISymbol.getDefaultValue()

setDefaultValue

public void setDefaultValue(int pos,
                            IExpr expr)

Set the default value at the arguments position for this symbol (i.e. 1 is the default value for Power at position 2). The default value is used in pattern-matching for expressions like a ^ b_.

Specified by:

setDefaultValue in interface ISymbol

Parameters:

pos - the position for the default value

expr - the default value for the given position

See Also:

ISymbol.getDefaultValue(int)

definitionToString

public java.lang.String definitionToString()
                                    throws java.io.IOException

Return the rules associated to this symbol in String representation

Specified by:

definitionToString in interface ISymbol

Returns:

Throws:

java.io.IOException

readSymbol

public void readSymbol(java.io.ObjectInputStream stream)
                throws java.io.IOException

Deserialize the rules associated to this object

Specified by:

readSymbol in interface ISymbol

Throws:

java.io.IOException

writeSymbol

public void writeSymbol(java.io.ObjectOutputStream stream)
                 throws java.io.IOException

Serialize the rules associated to this object

Specified by:

writeSymbol in interface ISymbol

Throws:

java.io.IOException

accept

public <T> T accept(IVisitor<T> visitor)

Accept a visitor with return type T

Specified by:

accept in interface IExpr

accept

public boolean accept(IVisitorBoolean visitor)

Accept a visitor with return type boolean

Specified by:

accept in interface IExpr

accept

public int accept(IVisitorInt visitor)

Accept a visitor with return type int

Specified by:

accept in interface IExpr

Returns:

mapConstantDouble

public IExpr mapConstantDouble(INumericFunction<IExpr> function)

If this symbol has attribute ISymbol.CONSTANT and the symbol's evaluator is of instance INumericConstant, then apply the constants double value to the given function and return the result, otherwise return null.

Specified by:

mapConstantDouble in interface ISymbol

Parameters:

function - applys the function to a double value, resulting in an object of type IExpr.

Returns:

the resulting expression from the function or null.

See Also:

Abs, Ceiling, Floor

negate

public IExpr negate()

Description copied from interface: AbelianGroupElem

Negate this.

Specified by:

negate in interface AbelianGroupElem<IExpr>

Overrides:

negate in class ExprImpl

Returns:

- this.