paleolimbot commented on code in PR #13397:
URL: https://github.com/apache/arrow/pull/13397#discussion_r916744966
##########
r/src/compute.cpp:
##########
@@ -574,3 +576,186 @@ SEXP compute__CallFunction(std::string func_name,
cpp11::list args, cpp11::list
std::vector<std::string> compute__GetFunctionNames() {
return arrow::compute::GetFunctionRegistry()->GetFunctionNames();
}
+
+class RScalarUDFKernelState : public arrow::compute::KernelState {
+ public:
+ RScalarUDFKernelState(cpp11::sexp exec_func, cpp11::sexp resolver)
+ : exec_func_(exec_func), resolver_(resolver) {}
+
+ cpp11::function exec_func_;
+ cpp11::function resolver_;
+};
+
+class RScalarUDFOutputTypeResolver : public
arrow::compute::OutputType::Resolver {
+ public:
+ arrow::Result<arrow::ValueDescr> operator()(
+ arrow::compute::KernelContext* context,
+ const std::vector<arrow::ValueDescr>& descr) {
+ return SafeCallIntoR<arrow::ValueDescr>(
+ [&]() -> arrow::ValueDescr {
+ auto kernel =
+ reinterpret_cast<const
arrow::compute::ScalarKernel*>(context->kernel());
+ auto state =
std::dynamic_pointer_cast<RScalarUDFKernelState>(kernel->data);
+
+ cpp11::writable::list input_types_sexp(descr.size());
+ for (size_t i = 0; i < descr.size(); i++) {
+ input_types_sexp[i] = cpp11::to_r6<arrow::DataType>(descr[i].type);
+ }
+
+ cpp11::sexp output_type_sexp = state->resolver_(input_types_sexp);
+ if (!Rf_inherits(output_type_sexp, "DataType")) {
+ cpp11::stop("arrow_scalar_function resolver must return a
DataType");
+ }
+
+ return arrow::ValueDescr(
+
cpp11::as_cpp<std::shared_ptr<arrow::DataType>>(output_type_sexp));
+ },
+ "resolve scalar user-defined function output data type");
+ }
+};
+
+class RScalarUDFCallable : public arrow::compute::ArrayKernelExec {
+ public:
+ arrow::Status operator()(arrow::compute::KernelContext* context,
Review Comment:
The signature of `ArrayKernelExec` doesn't seem to have `const` (and I also
get an error because the `memory_pool()` method isn't marked `const`).
--
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
To unsubscribe, e-mail: github-unsubscr...@arrow.apache.org
For queries about this service, please contact Infrastructure at:
us...@infra.apache.org
