Code to support invoke-dynamic for structural t...

Code to support invoke-dynamic for structural types. Not yet complete,
built around the JSR 292 spec of December 2008.

1 files changed, 42 insertions, 0 deletions

diff --git a/src/library/scala/runtime/DynamicDispatch.java b/src/library/scala/runtime/DynamicDispatch.java
new file mode 100644
index 0000000000..2868298211
--- /dev/null
+++ b/src/library/scala/runtime/DynamicDispatch.java
@@ -0,0 +1,42 @@
+package scala.runtime;
+
+import java.dyn.CallSite;
+import java.dyn.MethodHandle;
+
+/**
+ * This class resolves calls through refinement types. The
+ * bootstrap method is called when an invokedynamic is found
+ * by the Java VM.
+ *
+ * Note: Requires Java 7 with invoke dynamic support (see JSR 292)
+ *
+ * @author Iulian Dragos
+ * @see JSR292
+ */
+public class DynamicDispatch {
+
+    /**
+     * Resolve an invoke dynamic in Scala code. invokedynamic calls appear
+     * when a method defined by a refinement type is called. It is resolved
+     * by looking up a method with the same name and types in the receiver
+     * object. It is guaranteed by the type checker that such a method
+     * exists.
+     *
+     * The current implementation is not correct, a call site being
+     * always bootstrapped to a method handle. A bound call site should be
+     * guarded by a test on the receiver type. Such code should either
+     * be generated by the compiler, or by this bootstrap method using
+     * one of the code combinators provided in java.dyn.*.
+     *
+     * ATM, they are not yet available in the JVM.
+     */
+    public static bootstrapInvokeDynamic(CallSite cs, Object... args) {
+        println(cs);
+
+        MethodHandle mh = MethodHandles.findVirtual(cs.callerClass(),
+                                                    cs.name(),
+                                                    cs.type());
+        cs.setTarget(mh);
+        return mh(args)
+    }
+}