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21 
22 
23 package com.sun.star.report;
24 
25 /**
26  * Expressions are simple computation components.
27  *
28  * Expressions are always assumed to be immutable. They are not allowed to
29  * change their state and it is not guaranteed, in which order they get called.
30  * If the expression has been called before, the last computed value will be
31  * available from the datarow.
32  *
33  * This construct allows us to write expressions in the form
34  * "Sum := Sum + Column".
35  *
36  * Multiple calls to getValue on the same expression instance must return the
37  * same value (assuming that the datarow passed in is the same).
38  */
39 public interface ReportExpression
40 {
41 
setParameters(Object[] parameters)42     void setParameters(Object[] parameters);
43 
getParameters()44     Object getParameters();
45 
getValue(DataRow row)46     Object getValue(DataRow row);
47 }
48