njin_json.h

#pragma once
#include "_types.h"
#include <string>
#include <string_view>
#include <utility>
#include <vector>
 
namespace njin {

struct json_value {
  enum kind_t {
    null,    
    boolean, 
    number,  
    string,  
    array,   
    object,  
  };
  kind_t kind = null; 
  bool b = false;     
  f64 num = 0.0;      
  std::string str;    
  std::vector<json_value> items; 
  std::vector<std::pair<std::string, json_value>> members; 
 
  json_value() = default;
  json_value(bool v) : kind(boolean), b(v) {}
  json_value(i32 v) : kind(number), num(v) {}
  json_value(i64 v) : kind(number), num((f64)v) {}
  json_value(u32 v) : kind(number), num(v) {}
  json_value(f32 v) : kind(number), num(v) {}
  json_value(f64 v) : kind(number), num(v) {}
  json_value(const char *v) : kind(v != nullptr ? string : null), str(v != nullptr ? v : "") {}
  json_value(std::string v) : kind(string), str(std::move(v)) {}

  static json_value make_object() {
    json_value v;
    v.kind = kind_t::object;
    return v;
  }

  static json_value make_array() {
    json_value v;
    v.kind = kind_t::array;
    return v;
  }

  bool is(kind_t k) const { return kind == k; }

  const json_value &operator[](std::string_view key) const;

  const json_value &operator[](usize index) const;

  json_value *find(std::string_view key);

  bool has(std::string_view key) const;

  usize size() const;

  json_value &set(std::string_view key, json_value value);

  json_value &push(json_value value);

  f64 number_or(f64 fallback) const { return kind == number ? num : fallback; }
  f32 f32_or(f32 fallback) const { return kind == number ? (f32)num : fallback; }
  i32 int_or(i32 fallback) const { return kind == number ? (i32)num : fallback; }
  bool bool_or(bool fallback) const { return kind == boolean ? b : fallback; }
  const char *string_or(const char *fallback) const {
    return kind == string ? str.c_str() : fallback;
  }
};

bool json_parse(std::string_view text, json_value &out, std::string *error = nullptr);

std::string json_dump(const json_value &value, bool pretty = true);

bool json_load(const char *path, json_value &out);

bool json_save(const char *path, const json_value &value, bool pretty = true);
} // namespace njin