ppsspp/json/json_writer.h

// Minimal-state JSON writer. Consumes almost no memory
// apart from the string being built-up, which could easily be replaced
// with a file stream (although I've chosen not to do that just yet).
//
// Writes nicely 2-space indented output with correct comma-placement
// in arrays and dictionaries.
//
// Does not deal with encodings in any way.
//
// Zero dependencies apart from stdlib.
// See json_writer_test.cpp for usage.

#include <string>
#include <vector>
#include <sstream>

#include "base/basictypes.h"

class JsonWriter {
public:
  JsonWriter();
  ~JsonWriter();
  void begin();
  void end();
  void pushDict(const char *name);
  void pushArray(const char *name);
  void pop();
  void writeBool(bool value);
  void writeBool(const char *name, bool value);
  void writeInt(int value);
  void writeInt(const char *name, int value);
  void writeFloat(double value);
  void writeFloat(const char *name, double value);
  void writeString(const char *value);
  void writeString(const char *name, const char *value);

  std::string str() const {
    return str_.str();
  }

private:
  const char *indent(int n) const;
  const char *comma() const;
  const char *arrayComma() const;
  const char *indent() const;
  const char *arrayIndent() const;
  enum BlockType {
    ARRAY,
    DICT,
  };
  struct StackEntry {
    StackEntry(BlockType t) : type(t), first(true) {}
    BlockType type;
    bool first;
  };
  std::vector<StackEntry> stack_;
  std::ostringstream str_;

  DISALLOW_COPY_AND_ASSIGN(JsonWriter);
};