Lambda Support

beanshell · Net-0 · Sep 5, 2000 · Sep 5, 2000 · Sep 5, 2000 · Jul 7, 2024
commit f7fc761b01886c5dce60f4798400dee78d817dd8
diff --git a/pom.xml b/pom.xml
@@ -319,6 +319,12 @@
       <version>1.3</version>
       <scope>test</scope>
     </dependency>
+    <dependency>
+      <groupId>org.mockito</groupId>
+      <artifactId>mockito-inline</artifactId>
+      <version>4.0.0</version>
+      <scope>test</scope>
+    </dependency>
 
     <dependency>
       <groupId>javax.servlet</groupId>

diff --git a/src/main/java/bsh/BSHFormalParameters.java b/src/main/java/bsh/BSHFormalParameters.java
@@ -98,7 +98,7 @@ void insureParsed()
         Evaluate the types.
         Note that type resolution does not require the interpreter instance.
     */
-    public Object eval( CallStack callstack, Interpreter interpreter )
+    public Class<?>[] eval( CallStack callstack, Interpreter interpreter )
         throws EvalError
     {
         if ( paramTypes != null )

diff --git a/src/main/java/bsh/BSHLambdaExpression.java b/src/main/java/bsh/BSHLambdaExpression.java
@@ -0,0 +1,40 @@
+package bsh;
+
+class BSHLambdaExpression extends SimpleNode {
+
+    String singleParamName;
+
+    private boolean initializedValues = false;
+    private Modifiers[] paramsModifiers;
+    private Class<?>[] paramsTypes;
+    private String[] paramsNames;
+    private Node body;
+
+    public BSHLambdaExpression(int i) {
+        super(i);
+    }
+
+    private void initValues(CallStack callstack, Interpreter interpreter) throws EvalError {
+        if (this.initializedValues) return;
+        if (this.jjtGetNumChildren() == 2) {
+            BSHFormalParameters parameters = (BSHFormalParameters) this.jjtGetChild(0);
+            this.paramsTypes = parameters.eval(callstack, interpreter);
+            this.paramsModifiers = parameters.getParamModifiers();
+            this.paramsNames = parameters.getParamNames();
+            this.body = this.jjtGetChild(1);
+        } else {
+            this.paramsTypes = new Class[] { null };
+            this.paramsModifiers = new Modifiers[] { null };
+            this.paramsNames = new String[] { this.singleParamName };
+            this.body = this.jjtGetChild(0);
+        }
+        this.initializedValues = true;
+    }
+
+    @Override
+    public Object eval(CallStack callstack, Interpreter interpreter) throws EvalError {
+        this.initValues(callstack, interpreter);
+        return BshLambda.fromLambdaExpression(this, callstack.top(), this.paramsModifiers, this.paramsTypes, this.paramsNames, this.body);
+    }
+
+}
diff --git a/src/main/java/bsh/BSHPrimaryExpression.java b/src/main/java/bsh/BSHPrimaryExpression.java
@@ -96,11 +96,15 @@ private Object eval( boolean toLHS,
         if ( isArrayExpression && null != cached )
             return cached;
 
-        Object obj = jjtGetChild(0);
-
-        for( int i=1; i < jjtGetNumChildren(); i++ )
-            obj = ((BSHPrimarySuffix) jjtGetChild(i)).doSuffix(
-                obj, toLHS, callstack, interpreter);
+        Node[] children = this.jjtGetChildren();
+        Object obj = children[0];
+        for (int i = 1; i < children.length; i++) {
+            BSHPrimarySuffix primarySuffix = (BSHPrimarySuffix) jjtGetChild(i);
+            if (primarySuffix.operation == BSHPrimarySuffix.METHODREF && i != (children.length-1))
+                throw new EvalError("Method Reference must be the last suffix!", primarySuffix, callstack);
+
+            obj = primarySuffix.doSuffix(obj, toLHS, callstack, interpreter);
+        }
 
         /*
             If the result is a Node eval() it to an object or LHS

diff --git a/src/main/java/bsh/BSHPrimarySuffix.java b/src/main/java/bsh/BSHPrimarySuffix.java
@@ -36,7 +36,8 @@ class BSHPrimarySuffix extends SimpleNode
         INDEX = 1,
         NAME = 2,
         PROPERTY = 3,
-        NEW = 4;
+        NEW = 4,
+        METHODREF = 5;
 
     public int operation;
     Object index;
@@ -117,6 +118,10 @@ make a static method nodeToObject() or something.  The point is
 
                 case NEW:
                     return doNewInner(obj, toLHS, callstack, interpreter);
+
+                case METHODREF:
+                    return doMethodRef ( obj );
+
                 default:
                     throw new InterpreterError( "Unknown suffix type" );
             }
@@ -375,6 +380,10 @@ private Object doProperty( boolean toLHS,
         }
     }
 
+    private BshLambda doMethodRef(Object obj) {
+        return BshLambda.fromMethodReference(this, obj, field);
+    }
+
     @Override
     public String toString() {
         if (operation == INDEX)