first commit

2026-04-08 21:25:17 +03:00
parent 3681b8eccd
commit 371b14c5e3
173 changed files with 14126 additions and 0 deletions
--- a/java/expression/Variable.java
+++ b/java/expression/Variable.java
@@ -0,0 +1,118 @@
+package expression;
+
+import java.math.BigDecimal;
+import java.math.BigInteger;
+import java.util.List;
+
+/**
+ * @author Doschennikov Nikita (me@fymio.us)
+ */
+public class Variable extends AbstractExpression {
+
+    private final String name;
+    private final int index;
+
+    public Variable(String name) {
+        this.name = name;
+        this.index = -1;
+    }
+
+    public Variable(int index) {
+        this.index = index;
+        this.name = "$" + index;
+    }
+
+    public Variable(int index, String name) {
+        this.index = index;
+        this.name = name;
+    }
+
+    @Override
+    public int evaluate(int x) {
+        if (index >= 0) {
+            if (index == 0) return x;
+            throw new IllegalStateException(
+                "Positional variable $" +
+                    index +
+                    " cannot be evaluated with a single value"
+            );
+        }
+        if ("x".equals(name)) return x;
+        throw new IllegalStateException(
+            "Variable '" + name + "' is not 'x'; use evaluate(x, y, z) instead"
+        );
+    }
+
+    @Override
+    public int evaluate(int x, int y, int z) {
+        if (index >= 0) {
+            return switch (index) {
+                case 0 -> x;
+                case 1 -> y;
+                case 2 -> z;
+                default -> throw new IndexOutOfBoundsException(
+                    "Variable index " +
+                        index +
+                        " out of range for triple evaluate"
+                );
+            };
+        }
+        return switch (name) {
+            case "x" -> x;
+            case "y" -> y;
+            case "z" -> z;
+            default -> throw new IllegalStateException(
+                "Unknown variable: " + name
+            );
+        };
+    }
+
+    @Override
+    public int evaluate(List<Integer> vars) {
+        return vars.get(resolvedIndex());
+    }
+
+    @Override
+    public BigInteger evaluateBi(List<BigInteger> vars) {
+        return vars.get(resolvedIndex());
+    }
+
+    @Override
+    public BigDecimal evaluateBd(List<BigDecimal> vars) {
+        return vars.get(resolvedIndex());
+    }
+
+    private int resolvedIndex() {
+        if (index >= 0) return index;
+        return switch (name) {
+            case "x" -> 0;
+            case "y" -> 1;
+            case "z" -> 2;
+            default -> throw new IllegalStateException(
+                "Unknown variable: " + name
+            );
+        };
+    }
+
+    @Override
+    public String toString() {
+        return name;
+    }
+
+    @Override
+    public String toMiniString() {
+        return name;
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (this == obj) return true;
+        if (!(obj instanceof Variable)) return false;
+        return name.equals(((Variable) obj).name);
+    }
+
+    @Override
+    public int hashCode() {
+        return name.hashCode();
+    }
+}