Changes between Version 3 and Version 4 of API/Part1

Author:

JarrettBillingsley (IP: 65.117.184.122)

Timestamp:

08/02/07 13:35:47 (17 years ago)

Comment:

--

API/Part1

@@ -226 +226 @@
-
-Here we define a "calculate" function which takes an operation function and two operands.  It calls the operation with the two operands, expects one result, and returns that result.  easyCall makes this very straightforward.  The parameters to it are, in order: the object to call, the number of return values we want, the context pointer to call it with, and then a variadic list of arguments.  We expect exactly one result, and since it's already on the stack when easyCall returns, we can just return 1 and that value will become the return value of calculate.  This program will output "9" and "20" when run.
+
+The last thing I should show you is how to call methods.  Method lookup is a bit tricky, so it's usually not something that you want to do on your own.  So MDState provides the callMethod function which takes an object and a method name to call.
+
+{{{
+#!d
+void main()
+{
+        MDContext ctx = NewContext();
+        ctx.globals["callSomething"d] = ctx.newClosure(&callSomething, "callSomething");
+        loadStatementString(ctx.mainThread,
+                `class A
+                {
+                        function foo(x, y)
+                        {
+                                writefln("A.foo ", x, ", ", y);
+                        }
+                }
+                
+                local a = A();
+                callSomething(a, "foo");
+                `
+        );
+}
+
+int callSomething(MDState s, uint numParams)
+{
+        auto context = s.getParam(0u);
+        auto cl = s.getParam!(MDString)(1);
+
+        s.callMethod(context, cl, 0, 5, 10);
+        return 0;
+}
+}}}
+
+callMethod is very straightforward.  It takes the object to call the method on (which will also be used as the 'this' pointer of course), the name of the method to call, the number of returns, and then a list of parameters.  This code will display "A.foo 5, 10" when run.