Implemented Interpreter for compare functions

Author: Fynn Henck

src/main/java/com/compiler/ast/ASTCompareExprNode.java

@@ -1,7 +1,9 @@
 package com.compiler.ast;
 
+import com.compiler.InstrIntf;
 import com.compiler.TokenIntf;
 
+import com.compiler.instr.InstrCompare;
 import java.io.OutputStreamWriter;
 
 public class ASTCompareExprNode extends ASTExprNode{
@@ -37,4 +39,14 @@ public void print(OutputStreamWriter outStream, String indent) throws Exception
         m_operand0.print(outStream, indent + "  ");
         m_operand1.print(outStream, indent + "  ");
     }
+
+    @Override
+    public com.compiler.InstrIntf codegen(com.compiler.CompileEnvIntf env) {
+        final InstrIntf operand0 = m_operand0.codegen(env);
+        final InstrIntf operand1 = m_operand1.codegen(env);
+        final InstrIntf compareExp = new InstrCompare(m_operator, operand0, operand1);
+
+        env.addInstr(compareExp);
+        return compareExp;
+    }
 }

src/main/java/com/compiler/instr/InstrCompare.java

@@ -0,0 +1,58 @@
+package com.compiler.instr;
+
+import com.compiler.ExecutionEnvIntf;
+import com.compiler.InstrIntf;
+import com.compiler.TokenIntf;
+import com.compiler.TokenIntf.Type;
+import java.io.OutputStreamWriter;
+
+public class InstrCompare extends InstrIntf {
+
+    protected TokenIntf.Type m_operator;
+    protected InstrIntf m_operand0;
+    protected InstrIntf m_operand1;
+
+    public InstrCompare(final Type m_operator, final InstrIntf m_operand0, final InstrIntf m_operand1) {
+        this.m_operator = m_operator;
+        this.m_operand0 = m_operand0;
+        this.m_operand1 = m_operand1;
+    }
+
+    @Override
+    public void execute(ExecutionEnvIntf env) throws Exception {
+        //ergebnis : m_value
+
+        switch (m_operator) {
+            case GREATER:
+                if(m_operand0.getValue() > m_operand1.getValue()) {
+                    m_value = 1;
+                    break;
+                }
+                m_value = 0;
+                break;
+            case LESS:
+                if(m_operand0.getValue() < m_operand1.getValue()) {
+                    m_value = 1;
+                    break;
+                }
+                m_value = 0;
+                break;
+            case EQUAL:
+                if(m_operand0.getValue() == m_operand1.getValue()) {
+                    m_value = 1;
+                    break;
+                }
+                m_value = 0;
+                break;
+        }
+
+    }
+
+    @Override
+    public void trace(OutputStreamWriter os) throws Exception {
+        os.write(
+            String.format("%%%d = %s %%%d, %%%d\n",
+                m_id, m_operator.toString(), m_operand0.getId(), m_operand1.getId()
+            ));
+    }
+}

src/test/java/com/compiler/InterpreterCompareTest.java

@@ -0,0 +1,32 @@
+package com.compiler;
+
+import org.junit.Test;
+
+public class InterpreterCompareTest extends InterpreterTestBase{
+
+    @Test
+    public void compare() throws Exception {
+        final String program = """
+                {
+                  PRINT 1 > 2;
+                }
+                """;
+
+        testInterpreter(program, "0\n");
+    }
+
+    @Test
+    public void compareAgain() throws Exception {
+        final String program = """
+                {
+                  PRINT 4 > 1 == 1 > 0;
+                }
+                """;
+
+        testInterpreter(program, "1\n");
+    }
+
+
+
+
+}