119 lines
2.8 KiB
Java
119 lines
2.8 KiB
Java
package expression;
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import java.math.BigDecimal;
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import java.math.BigInteger;
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import java.util.List;
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/**
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* @author Doschennikov Nikita (me@fymio.us)
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*/
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public class Variable extends AbstractExpression {
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private final String name;
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private final int index;
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public Variable(String name) {
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this.name = name;
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this.index = -1;
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}
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public Variable(int index) {
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this.index = index;
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this.name = "$" + index;
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}
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public Variable(int index, String name) {
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this.index = index;
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this.name = name;
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}
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@Override
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public int evaluate(int x) {
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if (index >= 0) {
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if (index == 0) return x;
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throw new IllegalStateException(
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"Positional variable $" +
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index +
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" cannot be evaluated with a single value"
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);
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}
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if ("x".equals(name)) return x;
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throw new IllegalStateException(
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"Variable '" + name + "' is not 'x'; use evaluate(x, y, z) instead"
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);
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}
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@Override
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public int evaluate(int x, int y, int z) {
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if (index >= 0) {
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return switch (index) {
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case 0 -> x;
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case 1 -> y;
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case 2 -> z;
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default -> throw new IndexOutOfBoundsException(
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"Variable index " +
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index +
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" out of range for triple evaluate"
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);
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};
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}
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return switch (name) {
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case "x" -> x;
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case "y" -> y;
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case "z" -> z;
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default -> throw new IllegalStateException(
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"Unknown variable: " + name
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);
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};
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}
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@Override
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public int evaluate(List<Integer> vars) {
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return vars.get(resolvedIndex());
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}
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@Override
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public BigInteger evaluateBi(List<BigInteger> vars) {
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return vars.get(resolvedIndex());
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}
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@Override
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public BigDecimal evaluateBd(List<BigDecimal> vars) {
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return vars.get(resolvedIndex());
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}
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private int resolvedIndex() {
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if (index >= 0) return index;
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return switch (name) {
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case "x" -> 0;
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case "y" -> 1;
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case "z" -> 2;
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default -> throw new IllegalStateException(
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"Unknown variable: " + name
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);
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};
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}
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@Override
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public String toString() {
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return name;
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}
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@Override
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public String toMiniString() {
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return name;
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}
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@Override
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public boolean equals(Object obj) {
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if (this == obj) return true;
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if (!(obj instanceof Variable)) return false;
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return name.equals(((Variable) obj).name);
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}
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@Override
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public int hashCode() {
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return name.hashCode();
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}
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}
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