1package io.protobase.f7.formulas.math;
 2
 3import io.protobase.f7.formulas.AbstractFormula;
 4import io.protobase.f7.formulas.FormulaName;
 5import io.protobase.f7.models.GridColumnRowKey;
 6import io.protobase.f7.utils.Converters;
 7
 8import java.util.function.BiFunction;
 9import java.util.function.Function;
10
11public class EVEN extends AbstractFormula {
12  public static FormulaName NAME = FormulaName.EVEN;
13  public static EVEN SELF = new EVEN();
14
15  public EVEN() {
16    super();
17  }
18
19  public EVEN(Function<Object, Object> lookup, BiFunction<GridColumnRowKey, Object, Object> collateralLookup) {
20    super(lookup, collateralLookup);
21  }
22
23  @Override
24  public Object internal(GridColumnRowKey origin, Object... values) {
25    checkLength(values.length, 1, NAME);
26    double value = Converters.toDouble(Converters.first(collateralLookup.apply(origin, values[0])));
27    double rounded;
28    if (value < 0) {
29      rounded = Math.floor(value);
30      if (rounded % 2 != 0 || rounded % 2 != -0) {
31        return rounded - 1.0;
32      }
33    } else {
34      rounded = Math.ceil(value);
35      if (rounded % 2 != 0 || rounded % 2 != -0) {
36        return rounded + 1.0;
37      }
38    }
39    return rounded;
40  }
41}