public class KiviFieldExpression extends Object implements KiviPredExpression
Constructor and Description |
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KiviFieldExpression(String field) |
Modifier and Type | Method and Description |
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Object |
evaluateExpression(Tuple tuple) |
void |
generatePred(kv.NP pred,
TableModel model,
Reg dest) |
Type |
getType(TableModel tableModel)
Returns the result type of the expression, evaluated against a given TableModel
|
boolean |
isConstant()
Returns whether the expression result has a constant value, it means, does not depend on any tuple field
values.
|
boolean |
isNullable()
Returns whether the result of the expression can be null.
|
String |
toString()
This method should be used for debug purposes, and it should show the complete nesting
of the expressions
|
public KiviFieldExpression(String field)
public void generatePred(kv.NP pred, TableModel model, Reg dest)
generatePred
in interface KiviPredExpression
public Object evaluateExpression(Tuple tuple)
evaluateExpression
in interface KiviPredExpression
public Type getType(TableModel tableModel)
Expression
getType
in interface Expression
tableModel
- TableModel to be evaluatedpublic boolean isConstant()
Expression
isConstant
in interface Expression
public boolean isNullable()
Expression
isNullable
in interface Expression
public String toString()
Expression
toString
in interface Expression
toString
in class Object
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