1 files changed, 58 insertions, 0 deletions
diff --git a/icing/scoring/advanced_scoring/advanced-scorer.cc b/icing/scoring/advanced_scoring/advanced-scorer.cc
new file mode 100644
index 0000000..9d52fde
--- /dev/null
+++ b/icing/scoring/advanced_scoring/advanced-scorer.cc
@@ -0,0 +1,58 @@
+// Copyright (C) 2022 Google LLC
+//
+// Licensed 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 "icing/scoring/advanced_scoring/advanced-scorer.h"
+
+#include <memory>
+
+#include "icing/query/advanced_query_parser/lexer.h"
+#include "icing/query/advanced_query_parser/parser.h"
+#include "icing/scoring/advanced_scoring/score-expression.h"
+#include "icing/scoring/advanced_scoring/scoring-visitor.h"
+
+namespace icing {
+namespace lib {
+
+libtextclassifier3::StatusOr<std::unique_ptr<AdvancedScorer>>
+AdvancedScorer::Create(const ScoringSpecProto& scoring_spec,
+                       double default_score,
+                       const DocumentStore* document_store,
+                       const SchemaStore* schema_store) {
+  ICING_RETURN_ERROR_IF_NULL(document_store);
+  ICING_RETURN_ERROR_IF_NULL(schema_store);
+
+  Lexer lexer(scoring_spec.advanced_scoring_expression(),
+              Lexer::Language::SCORING);
+  ICING_ASSIGN_OR_RETURN(std::vector<Lexer::LexerToken> lexer_tokens,
+                         lexer.ExtractTokens());
+  Parser parser = Parser::Create(std::move(lexer_tokens));
+  ICING_ASSIGN_OR_RETURN(std::unique_ptr<Node> tree_root,
+                         parser.ConsumeScoring());
+
+  ScoringVisitor visitor(default_score);
+  tree_root->Accept(&visitor);
+
+  ICING_ASSIGN_OR_RETURN(std::unique_ptr<ScoreExpression> expression,
+                         std::move(visitor).Expression());
+  if (expression->is_document_type()) {
+    return absl_ports::InvalidArgumentError(
+        "The root scoring expression will always be evaluated to a document, "
+        "but a number is expected.");
+  }
+  return std::unique_ptr<AdvancedScorer>(
+      new AdvancedScorer(std::move(expression), default_score));
+}
+
+}  // namespace lib
+}  // namespace icing