pattern.h

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/*
 * Copyright 2026 The A11 Authors
 *
 * 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.
 */
 
#ifndef A11_FLOW_PATTERN_H_
#define A11_FLOW_PATTERN_H_
 
#include <cstddef>
#include <optional>
#include <string>
#include <string_view>
#include <vector>
 
namespace a11::flow::pattern {
 
enum class HoleType {
  kString,
  kInt,
  kNumber,
  kBool,
  kWord,
  kLine,
  kRest,
  kDuration,
  kTime,
  kJson,
};
 
std::string_view HoleTypeName(HoleType type);
 
std::optional<HoleType> HoleTypeFromName(std::string_view name);
 
struct Hole {
  std::string name;
  HoleType type = HoleType::kString;
  size_t position = 0;
};
 
struct Pattern {
  struct Piece {
    bool is_hole = false;
    std::string literal;
    Hole hole;
  };
 
  std::vector<Piece> pieces;
  std::vector<Hole> holes;
 
  [[nodiscard]] bool AllNamed() const;
};
 
struct Compiled {
  Pattern pattern;
  std::string error;
  size_t column = 0;
 
  [[nodiscard]] bool ok() const { return error.empty(); }
};
 
Compiled Compile(std::string_view text);
 
struct Capture {
  std::string_view text;
};
 
std::optional<std::vector<Capture>> Match(const Pattern& pattern,
                                          std::string_view subject);
 
}  // namespace a11::flow::pattern
 
#endif  // A11_FLOW_PATTERN_H_