Package com.singularsys.jep.functions
Class LazyLogical
- java.lang.Object
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- com.singularsys.jep.functions.PostfixMathCommand
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- com.singularsys.jep.functions.LazyLogical
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- All Implemented Interfaces:
CallbackEvaluationI
,PostfixMathCommandI
,java.io.Serializable
public class LazyLogical extends PostfixMathCommand implements CallbackEvaluationI
A version of the logical operators which use lazy evaluation. The first argument is always evaluated but the second argument is only evaluated if needed. Hence0 || arg2
arg2 is evaluated1 || arg2
arg2 is not evaluated and true is returned0 && arg2
arg2 is not evaluated and false is returned1 && arg2
arg2 is evaluated
- Since:
- 3.1
- See Also:
- Serialized Form
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Field Summary
Fields Modifier and Type Field Description protected boolean
allowNumbers
static int
AND
protected int
id
Represents which logical operator this is.static int
OR
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Fields inherited from class com.singularsys.jep.functions.PostfixMathCommand
curNumberOfParameters, name, NaN, numberOfParameters
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Constructor Summary
Constructors Constructor Description LazyLogical(int id_in)
Standard constructor, non zero Numbers will be treated as true and zero Numbers as false.LazyLogical(int id_in, boolean disallowNumbers)
Constructor which restricts type of arguments.
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description java.lang.Object
evaluate(Node node, Evaluator pv)
Performs some special evaluation on the node.int
getId()
Return a code indicating the type of this operatorboolean
isAllowNumbers()
Returns whether numbers are treated as booleans-
Methods inherited from class com.singularsys.jep.functions.PostfixMathCommand
asArray, asBool, asDouble, asInt, asLong, asStrictInt, asString, checkNumberOfParameters, getName, getNumberOfParameters, run, setCurNumberOfParameters, setName, toString, toString
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Field Detail
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id
protected int id
Represents which logical operator this is.
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AND
public static final int AND
- See Also:
- Constant Field Values
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OR
public static final int OR
- See Also:
- Constant Field Values
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allowNumbers
protected boolean allowNumbers
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Constructor Detail
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LazyLogical
public LazyLogical(int id_in)
Standard constructor, non zero Numbers will be treated as true and zero Numbers as false.- Parameters:
id_in
- either of the constants AND or OR
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LazyLogical
public LazyLogical(int id_in, boolean disallowNumbers)
Constructor which restricts type of arguments.- Parameters:
id_in
- Either AND or ORdisallowNumbers
- if true Number arguments will raise exceptions, otherwise as the Standard constructor.
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Method Detail
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evaluate
public java.lang.Object evaluate(Node node, Evaluator pv) throws EvaluationException
Description copied from interface:CallbackEvaluationI
Performs some special evaluation on the node. This method has the responsibility for evaluating the children of the node and it should generally callpv.eval(node.jjtGetChild(i))
for each child. The SymbolTable is not passed as an argument. This is because it is better practice to get and set variable values by using node.getVar().setValue() rather that through the SymbolTable with requires a hashtable lookup.- Specified by:
evaluate
in interfaceCallbackEvaluationI
- Parameters:
node
- The current nodepv
- The visitor, can be used evaluate the children- Returns:
- the value after evaluation. This value will be passed to other functions higher up the node tree. The value can be any type including Double or Vector<Object>
- Throws:
EvaluationException
- if the calculation cannot be performed- See Also:
Evaluator
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getId
public int getId()
Return a code indicating the type of this operator- Returns:
- the id
- Since:
- 3.4.0
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isAllowNumbers
public boolean isAllowNumbers()
Returns whether numbers are treated as booleans- Returns:
- true if numbers can be used
- Since:
- 3.4.0
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