Changes between Version 3 and Version 4 of C++Features

Timestamp:

Aug 12, 2025, 2:39:27 PM (2 months ago)

Author:

pett

Comment:

--

C++Features

@@ -32 +32 @@
 
 [https://www.stroustrup.com/C++11FAQ.html#raw-strings More discussion]
+
+== Humongous Lambdas ==
+
+It just didn't occur to me that lambdas could be more than short anonymous functions handled off as arguments to other functions, ''e.g.'':
+
+{{{
+    // as_term
+    spec_parser["as_term"] = [](const SemanticValues &vs) {
+        auto objects_inst = std::any_cast<PyObject*>(vs[0]);
+        if (vs.choice() == 1) {
+            // tilde
+            auto ret = PyObject_CallMethodObjArgs(objects_inst, invert_arg, session, models, nullptr);
+            if (ret == nullptr)
+                throw std::logic_error(use_python_error);
+            Py_DECREF(ret);
+            outermost_inversion = true;
+        } else
+            outermost_inversion = false;
+        if (vs.size() == 1)
+            return objects_inst;
+
+        // there's a zone selector
+        return process_zone(std::any_cast<PyObject*>(vs[0]), vs[1]);
+    };
+}}}