Implement getValues() method on ListArray proxy C++ class

mathworks · Oct 11, 2023 · 528168f · 528168f
1 parent f07977e
commit 528168f
Showing 1 changed file with 20 additions and 2 deletions.
diff --git a/matlab/src/cpp/arrow/matlab/array/proxy/list_array.cc b/matlab/src/cpp/arrow/matlab/array/proxy/list_array.cc
@@ -18,7 +18,7 @@
 
 #include "arrow/matlab/array/proxy/list_array.h"
 #include "arrow/matlab/array/proxy/wrap.h"
-
+#include "arrow/matlab/error/error.h"
 #include "libmexclass/proxy/ProxyManager.h"
 
 namespace arrow::matlab::array::proxy {
@@ -31,7 +31,25 @@ namespace arrow::matlab::array::proxy {
 
     void ListArray::getValues(libmexclass::proxy::method::Context& context) {
         namespace mda = ::matlab::data;
-        // STUB METHOD
+
+        auto list_array = std::static_pointer_cast<arrow::ListArray>(array);
+        auto value_array = list_array->values();
+
+        // Wrap the array within a proxy object if possible.
+        MATLAB_ASSIGN_OR_ERROR_WITH_CONTEXT(auto value_array_proxy,
+                                            proxy::wrap(value_array),
+                                            context, error::UNKNOWN_PROXY_FOR_ARRAY_TYPE);
+        const auto value_array_proxy_id = ProxyManager::manageProxy(value_array_proxy);
+        const auto type_id = value_array->type_id();
+
+        // Return a struct with two fields: ProxyID and TypeID. The MATLAB
+        // layer will use these values to construct the appropriate MATLAB
+        // arrow.array.Array subclass.
+        mda::ArrayFactory factory;
+        mda::StructArray output = factory.createStructArray({1, 1}, {"ProxyID", "TypeID"});
+        output[0]["ProxyID"] = factory.createScalar(field_array_proxy_id);
+        output[0]["TypeID"] = factory.createScalar(static_cast<int32_t>(type_id));
+        context.outputs[0] = output;
     }
 
     void ListArray::getOffsets(libmexclass::proxy::method::Context& context) {