[C++] Cast function bind failed after add a alias name through AddAlias #40183
Description
Describe the bug, including details regarding any error messages, version, and platform.
How to reproduce
auto fm = arrow::compute::GetFunctionRegistry();
ASSERT_OK(fm->AddAlias("alias_cast", "cast"));
auto s1 = arrow::schema({arrow::field("f1", arrow::decimal128(30, 3))});
auto b = arrow::RecordBatchFromJSON(s1, R"([
["1.000"],
["-4567.890"]
])");
auto expr = arrow::compute::call("alias_cast", {arrow::compute::field_ref("f1")},
arrow::compute::CastOptions::Unsafe(arrow::int32()));
ASSERT_OK_AND_ASSIGN(expr, expr.Bind(*s1)); // Bind failed
ASSERT_OK_AND_ASSIGN(auto input, arrow::compute::MakeExecBatch(*s1, b));
ASSERT_OK_AND_ASSIGN(auto res_dat,
arrow::compute::ExecuteScalarExpression(expr, input));Bind failed with NotImplemented: Dispatch for a MetaFunction's Kernels.
Reason
BindNonRecursive will call arrow::compute::GetFunction, the function handle the cast with specific name and
return an original function object rather than CastFunction which override the DispatchExact.
inline Result<std::shared_ptr<compute::Function>> GetFunction(
const Expression::Call& call, compute::ExecContext* exec_context) {
if (call.function_name != "cast") {
return exec_context->func_registry()->GetFunction(call.function_name);
}
// XXX this special case is strange; why not make "cast" a ScalarFunction?
const TypeHolder& to_type =
::arrow::internal::checked_cast<const compute::CastOptions&>(*call.options).to_type;
return GetCastFunction(*to_type);
}It's a huge project for us to unify the CastFunction schedule path to standard ScalarFunction, so i think maybe we should ban AddAlias for cast?
Component(s)
C++