bkietz commented on a change in pull request #8894: URL: https://github.com/apache/arrow/pull/8894#discussion_r545410376
########## File path: cpp/src/arrow/dataset/expression_internal.h ########## @@ -0,0 +1,465 @@ +// Licensed to the Apache Software Foundation (ASF) under one +// or more contributor license agreements. See the NOTICE file +// distributed with this work for additional information +// regarding copyright ownership. The ASF licenses this file +// to you under the Apache License, Version 2.0 (the +// "License"); you may not use this file except in compliance +// with the License. You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, +// software distributed under the License is distributed on an +// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY +// KIND, either express or implied. See the License for the +// specific language governing permissions and limitations +// under the License. + +#include "arrow/dataset/expression.h" + +#include <unordered_map> +#include <unordered_set> +#include <vector> + +#include "arrow/compute/api_vector.h" +#include "arrow/compute/registry.h" +#include "arrow/record_batch.h" +#include "arrow/table.h" +#include "arrow/util/logging.h" + +namespace arrow { + +using internal::checked_cast; + +namespace dataset { + +bool Identical(const Expression& l, const Expression& r) { return l.impl_ == r.impl_; } + +const Expression::Call* CallNotNull(const Expression& expr) { + auto call = expr.call(); + DCHECK_NE(call, nullptr); + return call; +} + +inline void GetAllFieldRefs(const Expression& expr, + std::unordered_set<FieldRef, FieldRef::Hash>* refs) { + if (auto lit = expr.literal()) return; + + if (auto ref = expr.field_ref()) { + refs->emplace(*ref); + return; + } + + for (const Expression& arg : CallNotNull(expr)->arguments) { + GetAllFieldRefs(arg, refs); + } +} + +inline std::vector<ValueDescr> GetDescriptors(const std::vector<Expression>& exprs) { + std::vector<ValueDescr> descrs(exprs.size()); + for (size_t i = 0; i < exprs.size(); ++i) { + DCHECK(exprs[i].IsBound()); + descrs[i] = exprs[i].descr(); + } + return descrs; +} + +inline std::vector<ValueDescr> GetDescriptors(const std::vector<Datum>& values) { + std::vector<ValueDescr> descrs(values.size()); + for (size_t i = 0; i < values.size(); ++i) { + descrs[i] = values[i].descr(); + } + return descrs; +} + +struct FieldPathGetDatumImpl { + template <typename T, typename = decltype(FieldPath{}.Get(std::declval<const T&>()))> + Result<Datum> operator()(const std::shared_ptr<T>& ptr) { + return path_.Get(*ptr).template As<Datum>(); + } + + template <typename T> + Result<Datum> operator()(const T&) { + return Status::NotImplemented("FieldPath::Get() into Datum ", datum_.ToString()); + } + + const Datum& datum_; + const FieldPath& path_; +}; + +inline Result<Datum> GetDatumField(const FieldRef& ref, const Datum& input) { + Datum field; + + FieldPath path; + if (auto type = input.type()) { + ARROW_ASSIGN_OR_RAISE(path, ref.FindOneOrNone(*input.type())); + } else if (input.kind() == Datum::RECORD_BATCH) { + ARROW_ASSIGN_OR_RAISE(path, ref.FindOneOrNone(*input.record_batch()->schema())); + } else if (input.kind() == Datum::TABLE) { + ARROW_ASSIGN_OR_RAISE(path, ref.FindOneOrNone(*input.table()->schema())); + } + + if (path) { + ARROW_ASSIGN_OR_RAISE(field, + util::visit(FieldPathGetDatumImpl{input, path}, input.value)); + } + + if (field == Datum{}) { + field = Datum(std::make_shared<NullScalar>()); + } + + return field; +} + +struct Comparison { + enum type { + NA = 0, + EQUAL = 1, + LESS = 2, + GREATER = 4, + NOT_EQUAL = LESS | GREATER, + LESS_EQUAL = LESS | EQUAL, + GREATER_EQUAL = GREATER | EQUAL, + }; + + static const type* Get(const std::string& function) { + static std::unordered_map<std::string, type> flipped_comparisons{ + {"equal", EQUAL}, {"not_equal", NOT_EQUAL}, + {"less", LESS}, {"less_equal", LESS_EQUAL}, + {"greater", GREATER}, {"greater_equal", GREATER_EQUAL}, + }; + + auto it = flipped_comparisons.find(function); + return it != flipped_comparisons.end() ? &it->second : nullptr; + } + + static const type* Get(const Expression& expr) { + if (auto call = expr.call()) { + return Comparison::Get(call->function_name); + } + return nullptr; + } + + // Execute a simple Comparison between scalars, casting the RHS if types disagree + static Result<type> Execute(Datum l, Datum r) { + if (!l.is_scalar() || !r.is_scalar()) { + return Status::Invalid("Cannot Execute Comparison on non-scalars"); + } + + if (!l.type()->Equals(r.type())) { + ARROW_ASSIGN_OR_RAISE(r, compute::Cast(r, l.type())); Review comment: Proper argument promotion will be handled in: https://issues.apache.org/jira/browse/ARROW-8919 For now, I'm maintaining the old behavior ---------------------------------------------------------------- This is an automated message from the Apache Git Service. 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