The script engine is given a better binding mechanism and reflexive access

Better binding mecanism : formerly done through the default SimpleBindings
shipped with the API, it now goes through a custom IBindings class
which uses the bind method of the interpreter instead of simply
making the bindings available as a Map.

Reflexive access : the script engine is made available to itself
through a bound variable "engine" of type javax.script.ScriptEngine.
This will allow "variable injection" i.e. programmatic redefinition
of variables, among others.

2 files changed, 61 insertions, 4 deletions

diff --git a/src/repl/scala/tools/nsc/interpreter/IBindings.java b/src/repl/scala/tools/nsc/interpreter/IBindings.java
new file mode 100644
index 0000000000..b4cee4b957
--- /dev/null
+++ b/src/repl/scala/tools/nsc/interpreter/IBindings.java
@@ -0,0 +1,45 @@
+/* NSC -- new Scala compiler
+ * Copyright 2005-2013 LAMP/EPFL
+ * @author Raphael Jolly
+ */
+
+package scala.tools.nsc.interpreter;
+
+import java.util.Map;
+import java.util.AbstractMap;
+import java.util.Set;
+import java.util.AbstractSet;
+import java.util.Iterator;
+import java.util.NoSuchElementException;
+import javax.script.Bindings;
+
+abstract class IBindings extends AbstractMap<String, Object> implements Bindings {
+    public Set<Map.Entry<String, Object>> entrySet() {
+        return new AbstractSet<Map.Entry<String, Object>>() {
+            public int size() {
+                return 0;
+            }
+
+            public Iterator<Map.Entry<String, Object>> iterator() {
+                return new Iterator<Map.Entry<String, Object>>() {
+                    public boolean hasNext() {
+                        return false;
+                    }
+
+                    public Map.Entry<String, Object> next() {
+                        throw new NoSuchElementException();
+                    }
+
+                    public void remove() {
+                        throw new UnsupportedOperationException();
+                    }
+                };
+            }
+
+            public boolean add(Map.Entry<String, Object> e) {
+                IBindings.this.put(e.getKey(), e.getValue());
+                return true;
+            }
+        };
+    }
+}
diff --git a/src/repl/scala/tools/nsc/interpreter/IMain.scala b/src/repl/scala/tools/nsc/interpreter/IMain.scala
index c92777c13e..d2b6cdd7f0 100644
--- a/src/repl/scala/tools/nsc/interpreter/IMain.scala
+++ b/src/repl/scala/tools/nsc/interpreter/IMain.scala
@@ -21,7 +21,7 @@ import scala.tools.nsc.util.Exceptional.unwrap
 import scala.collection.{ mutable, immutable }
 import scala.reflect.BeanProperty
 import scala.util.Properties.versionString
-import javax.script.{AbstractScriptEngine, Bindings, ScriptContext, ScriptEngine, ScriptEngineFactory, ScriptException, SimpleBindings, CompiledScript, Compilable}
+import javax.script.{AbstractScriptEngine, Bindings, ScriptContext, ScriptEngine, ScriptEngineFactory, ScriptException, CompiledScript, Compilable}
 import java.io.{ StringWriter, Reader }
 import java.util.Arrays
 import IMain._
@@ -62,9 +62,10 @@ import StdReplTags._
  *  @author Moez A. Abdel-Gawad
  *  @author Lex Spoon
  */
-class IMain(@BeanProperty val factory: ScriptEngineFactory, initialSettings: Settings, protected val out: JPrintWriter) extends AbstractScriptEngine(new SimpleBindings) with Compilable with Imports {
+class IMain(@BeanProperty val factory: ScriptEngineFactory, initialSettings: Settings, protected val out: JPrintWriter) extends AbstractScriptEngine with Compilable with Imports {
   imain =>
 
+  setBindings(createBindings, ScriptContext.ENGINE_SCOPE)
   object replOutput extends ReplOutput(settings.Yreploutdir) { }
 
   @deprecated("Use replOutput.dir instead", "2.11.0")
@@ -554,7 +555,7 @@ class IMain(@BeanProperty val factory: ScriptEngineFactory, initialSettings: Set
   @throws(classOf[ScriptException])
   def compile(script: String): CompiledScript = {
     if (!bound) {
-      quietBind("bindings", getBindings(ScriptContext.ENGINE_SCOPE))
+      quietBind("engine", this.asInstanceOf[ScriptEngine])
       bound = true
     }
     val cat = code + script
@@ -969,7 +970,18 @@ class IMain(@BeanProperty val factory: ScriptEngineFactory, initialSettings: Set
     override def toString = "Request(line=%s, %s trees)".format(line, trees.size)
   }
 
-  def createBindings: Bindings = new SimpleBindings
+  def createBindings: Bindings = new IBindings {
+    override def put(name: String, value: Object): Object = {
+      val n = name.indexOf(":")
+      val p: NamedParam = if (n < 0) (name, value) else {
+        val nme = name.substring(0, n).trim
+        val tpe = name.substring(n + 1).trim
+        NamedParamClass(nme, tpe, value)
+      }
+      if (!p.name.startsWith("javax.script")) bind(p)
+      null
+    }
+  }
 
   @throws(classOf[ScriptException])
   def eval(script: String, context: ScriptContext): Object = compile(script).eval(context)