Package uk.ac.starlink.ttools.jel
Interface Constant<T>
- All Known Implementing Classes:
FixedConstant
public interface Constant<T>
Defines a typed value. Not necessarily constant in that the value will
not change, but in the context of the jel package it is not dependent
on the column index.
- Since:
- 10 Dec 2007
- Author:
- Mark Taylor
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Method Summary
Modifier and TypeMethodDescriptionReturns a class of which this object's value will be an instance.getValue()
Returns this object's value.boolean
Indicates whether evaluation of this constant needs to know the row index.
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Method Details
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getContentClass
Returns a class of which this object's value will be an instance.- Returns:
- content class
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getValue
T getValue()Returns this object's value. Not necessarily always the same.- Returns:
- value
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requiresRowIndex
boolean requiresRowIndex()Indicates whether evaluation of this constant needs to know the row index. If executinggetValue()
may result in a call toStarTableJELRowReader.getCurrentRow()
, this method must return true.- Returns:
- true if evaluating this constant needs or may need to know the current row index
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