com.sh.compile.express

类 MathExpParser

java.lang.Object

com.sh.compile.express.MathExpParser

public class MathExpParser
extends java.lang.Object

Description:

Title:首亨软件 - TSS/CRM等

从以下版本开始:

2014年12月11日

版本:

3.0

作者:

江兴春

构造器概要

构造器

构造器和说明
MathExpParser()

方法概要

限定符和类型	方法和说明
void	addFunction(java.lang.String functionName, java.lang.Object function)
void	addStandardConstants() Adds the constants pi and e to the parser.
void	addStandardFunctions() Adds the standard functions to the parser.
java.lang.Double	addVariable(java.lang.String name, double value) Adds a new variable to the parser, or updates the value of an existing variable.
void	addVariableCallback(MathExpVariable_I mevCallback)
java.lang.String	getErrorInfo() Reports information on the error in the expression
SimpleNode	getTopNode()
double	getValue()
double	getValue(DoubleStack evalStack)
ASTVarNode	getVarNode(java.lang.String var)
boolean	hasError() Reports whether there is an error in the expression
void	initFunTab() Initializes the function table
void	initSymTab() Initializes the symbol table
void	parseExpression(java.lang.String expression_in) Parses the expression
void	setVarNode(java.lang.String var, ASTVarNode node)

从类继承的方法 java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

构造器详细资料

MathExpParser

public MathExpParser()

方法详细资料

addVariableCallback

public void addVariableCallback(MathExpVariable_I mevCallback)

initSymTab

public void initSymTab()

Initializes the symbol table

initFunTab

public void initFunTab()

Initializes the function table

addStandardFunctions

public void addStandardFunctions()

Adds the standard functions to the parser. If this function is not called before parsing an expression, functions such as sin() or cos() would produce an "Unrecognized function..." error. In most cases, this method should be called immediately after the JEP object is created.

addStandardConstants

public void addStandardConstants()

Adds the constants pi and e to the parser. As addStandardFunctions(), this method should be called immediatly after the JEP object is created.

addFunction

public void addFunction(java.lang.String functionName,
                        java.lang.Object function)

addVariable

public java.lang.Double addVariable(java.lang.String name,
                                    double value)

Adds a new variable to the parser, or updates the value of an existing variable. This must be done before parsing an expression so the parser is aware that the new variable may be contained in the expression.

参数:

name - Name of the variable to be added

value - Initial value or new value for the variable

返回:

Double object of the variable

getVarNode

public ASTVarNode getVarNode(java.lang.String var)

setVarNode

public void setVarNode(java.lang.String var,
                       ASTVarNode node)

parseExpression

public void parseExpression(java.lang.String expression_in)

Parses the expression

参数:

expression_in - The input expression string

getValue

public double getValue()
                throws ParseException

抛出:

ParseException

getTopNode

public SimpleNode getTopNode()

getValue

public double getValue(DoubleStack evalStack)
                throws ParseException

抛出:

ParseException

hasError

public boolean hasError()

Reports whether there is an error in the expression

返回:

Returns true if the expression has an error

getErrorInfo

public java.lang.String getErrorInfo()

Reports information on the error in the expression

返回:

Returns a string containing information on the error; null if no error has occured