base_parser.hpp

#pragma once
 
#include <userver/formats/json/parser/exception.hpp>
#include <userver/formats/json/parser/parser_state.hpp>
 
USERVER_NAMESPACE_BEGIN
 
namespace formats::json::parser {
 
/// @brief Base class for SAX parser.
///
class BaseParser {
public:
    virtual ~BaseParser() = default;
 
    BaseParser() = default;
    BaseParser(BaseParser&&) = delete;
    BaseParser(const BaseParser&) = delete;
    BaseParser& operator=(const BaseParser&) = delete;
    BaseParser& operator=(BaseParser&&) = delete;
 
    virtual void Null() { Throw("null"); }
    virtual void Bool(bool) { Throw("bool"); }
    virtual void Int64(int64_t) { Throw("integer"); }
    virtual void Uint64(uint64_t) { Throw("integer"); }
    virtual void Double(double) { Throw("double"); }
    virtual void String(std::string_view) { Throw("string"); }
    virtual void StartObject() { Throw("object"); }
    virtual void Key(std::string_view key) { Throw("field '" + std::string(key) + "'"); }
    virtual void EndObject() { Throw("'}'"); }
    virtual void StartArray() { Throw("array"); }
    virtual void EndArray() { Throw("']'"); }
 
    // Low-level variants of EndObject/EndArray
    virtual void EndObject(size_t /* members */) { EndObject(); }
    virtual void EndArray(size_t /* members */) { EndArray(); }
 
    void SetState(ParserState& state) { parser_state_ = &state; }
 
    virtual std::string GetPathItem() const = 0;
 
    std::string GetCurrentPath() const { return parser_state_->GetCurrentPath(); }
 
protected:
    [[noreturn]] void Throw(const std::string& found) {
        throw InternalParseError(Expected() + " was expected, but " + found + " found");
    }
 
    virtual std::string Expected() const = 0;
 
    // NOLINTNEXTLINE(misc-non-private-member-variables-in-classes)
    ParserState* parser_state_{nullptr};
};
 
}  // namespace formats::json::parser
 
USERVER_NAMESPACE_END