refactor: Symbol as record

Makes the intent of the code clearer by explicitly overriding equals and
hashCode for by-reference comparison. Also fixes Sonar warning.

1 files changed, 8 insertions, 28 deletions

diff --git a/subprojects/store/src/main/java/tools/refinery/store/representation/Symbol.java b/subprojects/store/src/main/java/tools/refinery/store/representation/Symbol.java
index 77fae5f4..85ea15f4 100644
--- a/subprojects/store/src/main/java/tools/refinery/store/representation/Symbol.java
+++ b/subprojects/store/src/main/java/tools/refinery/store/representation/Symbol.java
@@ -2,40 +2,20 @@ package tools.refinery.store.representation;
 
 import java.util.Objects;
 
-public final class Symbol<T> implements AnySymbol {
-        private final String name;
-        private final int arity;
-        private final Class<T> valueType;
-        private final T defaultValue;
-
-        public Symbol(String name, int arity, Class<T> valueType, T defaultValue) {
-                this.name = name;
-                this.arity = arity;
-                this.valueType = valueType;
-                this.defaultValue = defaultValue;
-        }
-
-        @Override
-        public String name() {
-                return name;
+public record Symbol<T>(String name, int arity, Class<T> valueType, T defaultValue) implements AnySymbol {
+        public boolean isDefaultValue(T value) {
+                return Objects.equals(defaultValue, value);
         }
 
         @Override
-        public int arity() {
-                return arity;
+        public boolean equals(Object o) {
+                return this == o;
         }
 
         @Override
-        public Class<T> valueType() {
-                return valueType;
-        }
-
-        public T defaultValue() {
-                return defaultValue;
-        }
-
-        public boolean isDefaultValue(T value) {
-                return Objects.equals(defaultValue, value);
+        public int hashCode() {
+                // Compare by identity to make hash table lookups more efficient.
+                return System.identityHashCode(this);
         }
 
         @Override