School Commit Init

Anul 2/Semestrul 1/Metode avansate de programare/Interpretor/Models/Expressions/ReadHeap.java

@@ -0,0 +1,41 @@
+package Models.Expressions;
+
+import Exceptions.BaseException;
+import Models.Program.IDictionary;
+import Models.Program.IHeap;
+import Models.Types.IType;
+import Models.Types.ReferenceType;
+import Models.Values.IValue;
+import Models.Values.ReferenceValue;
+
+public class ReadHeap implements IExpression {
+    private IExpression expression;
+
+    public ReadHeap(IExpression expression) {
+        this.expression = expression;
+    }
+
+    public IValue evaluate(IDictionary<String, IValue> table, IHeap heap) throws BaseException {
+        IValue value = this.expression.evaluate(table, heap);
+        if(!(value instanceof ReferenceValue)) {
+            throw new BaseException("Expression is not a reference value");
+        }
+        int address = ((ReferenceValue)value).getAddress();
+        if(!heap.contains(address)) {
+            throw new BaseException("Address " + address + " is not in the heap");
+        }
+        return heap.get(address);
+    }
+
+    public IExpression copy() {
+        return new ReadHeap(this.expression.copy());
+    }
+
+    public IType typeCheck(IDictionary<String, IType> typeTable) throws BaseException {
+        IType type = this.expression.typeCheck(typeTable);
+        if(!(type instanceof ReferenceType)) {
+            throw new BaseException("Expression is not a reference value");
+        }
+        return ((ReferenceType)type).getInnerType();
+    }
+}