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[lsnes.git] / include / library / json.hpp

#ifndef _library__json__hpp__included__
#define _library__json__hpp__included__

#include <cstdint>
#include <string>
#include <list>
#include <vector>
#include <stdexcept>
#include <map>
#include "utf8.hpp"

namespace JSON
{
class node;

struct number_tag
{
        const static int id = 2;
        node operator()(double v) const;
        node operator()(uint64_t v) const;
        node operator()(int64_t v) const;
        bool operator==(const int& n) const { return n == id; }
        bool operator!=(const int& n) const { return !(*this == n); }
        operator int() { return id; }
};

struct string_tag
{
        const static int id = 3;
        node operator()(const std::string& s) const;
        node operator()(const std::u32string& s) const;
        bool operator==(const int& n) const { return n == id; }
        bool operator!=(const int& n) const { return !(*this == n); }
        operator int() { return id; }
};

struct boolean_tag
{
        const static int id = 1;
        node operator()(bool v);
        bool operator==(const int& n) const { return n == id; }
        bool operator!=(const int& n) const { return !(*this == n); }
        operator int() { return id; }
};

struct array_tag
{
        const static int id = 4;
        node operator()() const;
        bool operator==(const int& n) const { return n == id; }
        bool operator!=(const int& n) const { return !(*this == n); }
        operator int() { return id; }
};

struct object_tag {
        const static int id = 5;
        node operator()() const;
        bool operator==(const int& n) const { return n == id; }
        bool operator!=(const int& n) const { return !(*this == n); }
        operator int() { return id; }
};

struct null_tag
{
        const static int id = 0;
        node operator()() const;
        bool operator==(const int& n) const { return n == id; }
        bool operator!=(const int& n) const { return !(*this == n); }
        operator int() { return id; }
};

struct none_tag
{
        const static int id = -1;
        bool operator==(const int& n) const { return n == id; }
        bool operator!=(const int& n) const { return !(*this == n); }
        operator int() { return id; }
};

extern number_tag number;
extern string_tag string;
extern boolean_tag boolean;
extern array_tag array;
extern object_tag object;
extern null_tag null;
extern none_tag none;

node i(int64_t n);
node u(uint64_t n);
node f(double n);
node b(bool bl);
node s(const std::string& st);
node s(const std::u32string& st);
node n();

enum errorcode
{
        ERR_OK = 0,                     //All OK.
        ERR_NOT_A_NUMBER,               //Not a number in operation expecting one.
        ERR_NOT_A_STRING,               //Not a string in operation expecting one.
        ERR_NOT_A_BOOLEAN,              //Not a boolean in operation expecting one.
        ERR_NOT_AN_ARRAY,               //Not an array in operation expecting one.
        ERR_NOT_AN_OBJECT,              //Not an object in operation expecting one.
        ERR_NOT_ARRAY_NOR_OBJECT,       //Not array nor object in operation expecting either.
        ERR_INDEX_INVALID,              //Non-existent index accessed.
        ERR_KEY_INVALID,                //Non-existent key accessed.
        ERR_INSTANCE_INVALID,           //Non-existent instance (of key) accessed.
        ERR_POINTER_TRAILING_ESCAPE,    //JSON pointer has trailing escape.
        ERR_POINTER_INVALID_ESCAPE,     //JSON pointer has invalid escape.
        ERR_BAD_HEX,                    //Bad hexadecimal character.
        ERR_INVALID_SURROGATE,          //Invalid surrogate escape sequence.
        ERR_INVALID_ESCAPE,             //Invalid escape sequence.
        ERR_TRUNCATED_STRING,           //Truncated string.
        ERR_UNKNOWN_TYPE,               //Unknown value type.
        ERR_GARBAGE_AFTER_END,          //Garbage after end of JSON.
        ERR_TRUNCATED_JSON,             //JSON truncated.
        ERR_UNEXPECTED_COMMA,           //Unexpected ','.
        ERR_UNEXPECTED_COLON,           //Unexpected ':'.
        ERR_UNEXPECTED_RIGHT_BRACE,     //Unexpected '}'.
        ERR_UNEXPECTED_RIGHT_BRACKET,   //Unexpected ']'.
        ERR_INVALID_NUMBER,             //Bad number syntax.
        ERR_EXPECTED_STRING_KEY,        //Object key is not a string.
        ERR_EXPECTED_COLON,             //Expected ':' here.
        ERR_EXPECTED_COMMA,             //Expected ',' here.
        ERR_UNKNOWN_CHARACTER,          //Unknown token type.
        ERR_POINTER_BAD_APPEND,         //Bad JSON pointer append.
        ERR_POINTER_BAD_INDEX,          //Bad JSON pointer index.
        ERR_ITERATOR_END,               //Iterator already at end.
        ERR_ITERATOR_DELETED,           //Iterator points to deleted object.
        ERR_WRONG_OBJECT,               //Iterator points to wrong object.
        ERR_ILLEGAL_CHARACTER,          //Illegal character generated by escape.
        ERR_CONTROL_CHARACTER,          //Control character in string.
        ERR_UNKNOWN_SUBTYPE,            //Unknown value subtype.
        ERR_PATCH_BAD,                  //Bad JSON patch.
        ERR_PATCH_TEST_FAILED,          //TEST operation in patch failed.
        ERR_PATCH_ILLEGAL_MOVE,         //MOVE operation in patch illegal.
};

enum parsestate
{
        PARSE_NOT_PARSING = 0,          //Not parsing.
        PARSE_ARRAY_AFTER_VALUE,        //After value in array
        PARSE_END_OF_DOCUMENT,          //At end of document
        PARSE_OBJECT_AFTER_VALUE,       //After value in object
        PARSE_OBJECT_COLON,             //Expecting for colon in object
        PARSE_OBJECT_NAME,              //Expecting name in object
        PARSE_STRING_BODY,              //Parsing string body
        PARSE_STRING_ESCAPE,            //Parsing escape in string body
        PARSE_VALUE_START,              //Parsing start of value
        PARSE_NUMBER,                   //Parsing number.
};

extern const char* error_desc[];
extern const char* state_desc[];

struct error : public std::runtime_error
{
        error(errorcode _code) : runtime_error(error_desc[_code]), code(_code), state(PARSE_NOT_PARSING),
                position(std::string::npos) {}
        error(errorcode _code, parsestate _state, size_t pos) : runtime_error(error_desc[_code]), code(_code), 
                state(_state), position(pos) {}
        errorcode get_code() { return code; }
        parsestate get_state() { return state; }
        size_t get_position() { return position; }
        std::pair<size_t, size_t> get_position_lc(const std::string& doc) { return get_position_lc(doc, position); }
        std::pair<size_t, size_t> get_position_lc(const std::string& doc, size_t pos);
        const char* what() const throw();
        std::string extended_error(const std::string& doc);
private:
        errorcode code;
        parsestate state;
        size_t position;
        mutable char buffer[512];
};

class node;

/**
 * A JSON pointer
 */
class pointer
{
public:
        pointer();
        pointer(const std::string& ptr) throw(std::bad_alloc);
        pointer(const std::u32string& ptr) throw(std::bad_alloc);
        pointer pastend() const throw(std::bad_alloc) { return field(U"-"); }
        pointer& pastend_inplace() throw(std::bad_alloc) { return field_inplace(U"-"); }
        pointer index(uint64_t idx) const throw(std::bad_alloc);
        pointer& index_inplace(uint64_t idx) throw(std::bad_alloc);
        pointer field(const std::string& fld) const throw(std::bad_alloc) { return field(to_u32string(fld)); }
        pointer& field_inplace(const std::string& fld) throw(std::bad_alloc)
        {
                return field_inplace(to_u32string(fld));
        }
        pointer field(const std::u32string& fld) const throw(std::bad_alloc);
        pointer& field_inplace(const std::u32string& fld) throw(std::bad_alloc);
        pointer remove() const throw(std::bad_alloc);
        pointer& remove_inplace() throw(std::bad_alloc);
        std::string as_string8() const { return to_u8string(_pointer); }
        std::u32string as_string() const { return _pointer; }
        friend std::ostream& operator<<(std::ostream& s, const pointer& p);
        friend std::basic_ostream<char32_t>& operator<<(std::basic_ostream<char32_t>& s, const pointer& p);
private:
        friend class node;
        std::u32string _pointer;
};

/**
 * A JSON node.
 */
class node
{
public:
/**
 * Type of node.
 */
/**
 * Construct null object.
 */
        node() throw();
/**
 * Construct object of specified type.
 */
        node(null_tag) throw();
        node(boolean_tag, bool b) throw();
        node(string_tag, const std::u32string& str) throw(std::bad_alloc);
        node(string_tag, const std::string& str) throw(std::bad_alloc);
        node(number_tag, double n) throw();
        node(number_tag, int64_t n) throw();
        node(number_tag, uint64_t n) throw();
        node(array_tag) throw();
        node(object_tag) throw();
/**
 * Compare nodes.
 */
        bool operator==(const node& n) const;
        bool operator!=(const node& n) const { return !(*this == n); }
/**
 * Copy Constructor.
 */
        node(const node& _node) throw(std::bad_alloc);
/**
 * Construct object from description.
 */
        node(const std::string& doc) throw(std::bad_alloc, error);
/**
 * Serialize document.
 */
        std::string serialize() const throw(std::bad_alloc, error);
/**
 * Get type of node.
 */
        int type() const throw();
/**
 * Get type of node by pointer.
 */
        int type_of(const std::u32string& pointer) const throw(std::bad_alloc);
        int type_of(const std::string& pointer) const throw(std::bad_alloc)
        {
                return type_of(to_u32string(pointer));
        }
        int type_of(const pointer& ptr) const throw(std::bad_alloc)
        {
                return type_of(ptr._pointer);
        }
/**
 * Get type of node by pointer (indirect).
 */
        int type_of_indirect(const std::u32string& pointer) const throw(std::bad_alloc);
        int type_of_indirect(const std::string& pointer) const throw(std::bad_alloc)
        {
                return type_of_indirect(to_u32string(pointer));
        }
        int type_of_indirect(const pointer& ptr) const throw(std::bad_alloc)
        {
                return type_of_indirect(ptr._pointer);
        }
/**
 * Resolve an indirect pointer
 */
        std::u32string resolve_indirect(const std::u32string& pointer) const throw(std::bad_alloc);
        std::string resolve_indirect(const std::string& pointer) const throw(std::bad_alloc)
        {
                return to_u8string(resolve_indirect(to_u32string(pointer)));
        }
        pointer resolve_indirect(const pointer& ptr) const throw(std::bad_alloc)
        {
                return pointer(resolve_indirect(ptr._pointer));
        }
/**
 * Get double numeric value (NT_NUMBER).
 */
        double as_double() const throw(error);
/**
 * Get int64_t value (NT_NUMBER).
 */
        int64_t as_int() const throw(error);
/**
 * Get uint64_t value (NT_NUMBER).
 */
        uint64_t as_uint() const throw(error);
/**
 * Read the string as UTF-8 (NT_STRING).
 */
        const std::u32string& as_string() const throw(std::bad_alloc, error);
        std::string as_string8() const throw(std::bad_alloc, error) { return to_u8string(as_string()); }
/**
 * Get boolean value (NT_BOOLEAN).
 */
        bool as_bool() const throw(error);
/**
 * Read number of indices in array (NT_ARRAY).
 */
        size_t index_count() const throw(error);
/**
 * Read specified index from array (NT_ARRAY).
 */
        const node& index(size_t idx) const throw(error)
        {
                const node* n;
                auto e = index_soft(idx, n);
                if(e != ERR_OK) throw error(e);
                return *n;
        }
/**
 * Read number of indices in object key (NT_OBJECT).
 */
        size_t field_count(const std::u32string& key) const throw(error);
        size_t field_count(const std::string& key) const throw(std::bad_alloc, error)
        {
                return field_count(to_u32string(key));
        }
/**
 * Specified field exists (NT_OBJECT)
 */
        bool field_exists(const std::u32string& key) const throw(error);
        bool field_exists(const std::string& key) const throw(std::bad_alloc, error)
        {
                return field_exists(to_u32string(key));
        }
/**
 * Read specified key from object (NT_OBJECT).
 */
        const node& field(const std::u32string& key, size_t subindex = 0) const throw(error)
        {
                const node* n;
                auto e = field_soft(key, subindex, n);
                if(e != ERR_OK) throw error(e);
                return *n;
        }
        const node& field(const std::string& key, size_t subindex = 0) const throw(std::bad_alloc, error)
        {
                return field(to_u32string(key), subindex);
        }

/**
 * Apply JSON pointer (RFC 6901).
 */
        const node& follow(const std::u32string& pointer) const throw(std::bad_alloc, error)
        {
                const node* n;
                auto e = follow_soft(pointer, n);
                if(e != ERR_OK) throw error(e);
                return *n;
        }
        const node& follow(const std::string& pointer) const throw(std::bad_alloc, error)
        {
                return follow(to_u32string(pointer));
        }
        const node& follow(const pointer& ptr) const throw(std::bad_alloc, error)
        {
                return follow(ptr._pointer);
        }
/**
 * Apply JSON pointer (RFC 6901) following strings as indirect references.
 */
        const node& follow_indirect(const std::u32string& pointer) const throw(std::bad_alloc, error)
        {
                return follow(resolve_indirect(pointer));
        }
        const node& follow_indirect(const std::string& pointer) const throw(std::bad_alloc, error)
        {
                return follow_indirect(to_u32string(pointer));
        }
        const node& follow_indirect(const pointer& ptr) const throw(std::bad_alloc, error)
        {
                return follow_indirect(ptr._pointer);
        }
/**
 * Set value of node (any).
 */
        node& operator=(const node& node) throw(std::bad_alloc);
/**
 * Set value of node.
 */
        node& set(null_tag) throw();
        node& set(boolean_tag, bool number) throw();
        node& set(number_tag, double number) throw();
        node& set(number_tag, int64_t number) throw();
        node& set(number_tag, uint64_t number) throw();
        node& set(string_tag, const std::u32string& key) throw(std::bad_alloc);
        node& set(string_tag tag, const std::string& key) throw(std::bad_alloc)
        {
                return set(tag, to_u32string(key));
        }
/**
 * Read/Write specified index from array (NT_ARRAY).
 */
        node& index(size_t idx) throw(error)
        {
                node* n;
                auto e = index_soft(idx, n);
                if(e != ERR_OK) throw error(e);
                return *n;
        }
/**
 * Append new element to array (NT_ARRAY).
 */
        node& append(const node& node) throw(std::bad_alloc, error);
/**
 * Read/Write specified key from object (NT_OBJECT).
 */
        node& field(const std::u32string& key, size_t subindex = 0) throw(error)
        {
                node* n;
                auto e = field_soft(key, subindex, n);
                if(e != ERR_OK) throw error(e);
                return *n;
        }
        node& field(const std::string& key, size_t subindex = 0) throw(std::bad_alloc, error)
        {
                return field(to_u32string(key), subindex);
        }
/**
 * Insert new element to object (NT_OBJECT).
 */
        node& insert(const std::u32string& key, const node& node) throw(std::bad_alloc, error);
        node& insert(const std::string& key, const node& node) throw(std::bad_alloc, error)
        {
                return insert(to_u32string(key), node);
        }
/**
 * Apply JSON pointer (RFC 6901).
 */
        node& follow(const std::u32string& pointer) throw(std::bad_alloc, error)
        {
                node* n;
                auto e = follow_soft(pointer, n);
                if(e != ERR_OK) throw error(e);
                return *n;
        }
        node& follow(const std::string& pointer) throw(std::bad_alloc, error)
        {
                return follow(to_u32string(pointer));
        }
        node& follow(const pointer& ptr) throw(std::bad_alloc, error)
        {
                return follow(ptr._pointer);
        }
/**
 * Apply JSON pointer (RFC 6901) following strings as indirect references.
 */
        node& follow_indirect(const std::u32string& pointer) throw(std::bad_alloc, error)
        {
                return follow(resolve_indirect(pointer));
        }
        node& follow_indirect(const std::string& pointer) throw(std::bad_alloc, error)
        {
                return follow_indirect(to_u32string(pointer));
        }
        node& follow_indirect(const pointer& ptr) throw(std::bad_alloc, error)
        {
                return follow_indirect(ptr._pointer);
        }
/**
 * Return node specified by JSON pointer (RFC 6901). If the last component doesn't exist, it is created as NULL.
 */
        node& operator[](const std::u32string& pointer) throw(std::bad_alloc, error);
        node& operator[](const std::string& pointer) throw(std::bad_alloc, error)
        {
                return (*this)[to_u32string(pointer)];
        }
        node& operator[](const pointer& ptr) throw(std::bad_alloc, error)
        {
                return (*this)[ptr._pointer];
        }
/**
 * Create node at specified pointer and return it.
 */
        node& insert_node(const std::u32string& pointer, const node& nwn) throw(std::bad_alloc, error);
        node& insert_node(const std::string& pointer, const node& nwn) throw(std::bad_alloc, error)
        {
                return insert_node(to_u32string(pointer), nwn);
        }
        node& insert_node(const pointer& ptr, const node& nwn) throw(std::bad_alloc, error)
        {
                return insert_node(ptr._pointer, nwn);
        }
/**
 * Delete a node by pointer and return what was deleted.
 */
        node delete_node(const std::u32string& pointer) throw(std::bad_alloc, error);
        node delete_node(const std::string& pointer) throw(std::bad_alloc, error)
        {
                return delete_node(to_u32string(pointer));
        }
        node delete_node(const pointer& ptr) throw(std::bad_alloc, error)
        {
                return delete_node(ptr._pointer);
        }
/**
 * Synonym for follow().
 */
        const node& operator[](const std::u32string& pointer) const throw(std::bad_alloc, error)
        {
                return follow(pointer);
        }
        const node& operator[](const std::string& pointer) const throw(std::bad_alloc, error)
        {
                return follow(pointer);
        }
        const node& operator[](const pointer& ptr) const throw(std::bad_alloc, error)
        {
                return follow(ptr._pointer);
        }
/**
 * Delete an array index. The rest are shifted.
 */
        void erase_index(size_t idx) throw(error);
/**
 * Delete an array field. The rest are shifted.
 */
        void erase_field(const std::u32string& fld, size_t idx = 0) throw(error);
        void erase_field(const std::string& fld, size_t idx = 0) throw(std::bad_alloc, error)
        {
                erase_field(to_u32string(fld), idx);
        }
/**
 * Delete an entiere array field.
 */
        void erase_field_all(const std::u32string& fld) throw(error);
        void erase_field_all(const std::string& fld) throw(std::bad_alloc, error)
        {
                erase_field_all(to_u32string(fld));
        }
/**
 * Apply a JSON patch.
 */
        node patch(const node& patch) const throw(std::bad_alloc, error);
/**
 * Clear entiere array or object.
 */
        void clear() throw(error);
/**
 * Iterator.
 */
        class iterator
        {
        public:
                typedef std::forward_iterator_tag iterator_category;
                typedef node value_type;
                typedef int difference_type;
                typedef node& reference;
                typedef node* pointer;
                iterator() throw();
                iterator(node& n) throw(error);
                std::u32string key() throw(std::bad_alloc, error);
                std::string key8() throw(std::bad_alloc, error) { return to_u8string(key()); }
                size_t index() throw(error);
                node& operator*() throw(error);
                node* operator->() throw(error);
                iterator operator++(int) throw(error);
                iterator& operator++() throw(error);
                bool operator==(const iterator& i) throw();
                bool operator!=(const iterator& i) throw();
        private:
                friend class node;
                node* n;
                size_t idx;
                std::u32string _key;
        };
/**
 * Constant iterator.
 */
        class const_iterator
        {
        public:
                typedef std::forward_iterator_tag iterator_category;
                typedef node value_type;
                typedef int difference_type;
                typedef const node& reference;
                typedef const node* pointer;
                const_iterator() throw();
                const_iterator(const node& n) throw(error);
                std::u32string key() throw(std::bad_alloc, error);
                std::string key8() throw(std::bad_alloc, error) { return to_u8string(key()); }
                size_t index() throw(error);
                const node& operator*() throw(error);
                const node* operator->() throw(error);
                const_iterator operator++(int) throw(error);
                const_iterator& operator++() throw(error);
                bool operator==(const const_iterator& i) throw();
                bool operator!=(const const_iterator& i) throw();
        private:
                const node* n;
                size_t idx;
                std::u32string _key;
        };
/**
 * Iterators
 */
        const_iterator begin() const throw(error) { return const_iterator(*this); }
        const_iterator end() const throw() { return const_iterator(); }
        iterator begin() throw(error) { return iterator(*this); }
        iterator end() throw() { return iterator(); }
/**
 * Delete item pointed by iterator. The rest are shifted and new iterator is returned.
 */
        iterator erase(iterator itr) throw(error);
private:
        class number_holder
        {
        public:
                number_holder() { sub = 0; n.n0 = 0; }
                number_holder(const std::string& expr, size_t& ptr, size_t len);
                template<typename T> T to() const
                {
                        switch(sub) {
                        case 0: return n.n0;
                        case 1: return n.n1;
                        case 2: return n.n2;
                        }
                        return 0;
                }
                template<typename T> void from(T val);
                void write(std::ostream& s) const;
                bool operator==(const number_holder& h) const;
        private:
                template<typename T> bool cmp(const T& num) const;
                unsigned sub;
                union {
                        double n0;
                        uint64_t n1;
                        int64_t n2;
                } n;
        };
        friend class iterator;
        friend class const_iterator;
        void fixup_nodes(const node& _node);
        void ctor(const std::string& doc, size_t& ptr, size_t len) throw(std::bad_alloc, error);
        node(const std::string& doc, size_t& ptr, size_t len) throw(std::bad_alloc, error);
        template<typename T> void set_helper(T v)
        {
                std::u32string tmp;
                vtype = number;
                _number.from<T>(v);
                std::swap(_string, tmp);
                xarray.clear();
                xobject.clear();
        }
        template<typename T> T get_number_helper() const
        {
                if(vtype != number)
                        throw error(ERR_NOT_A_NUMBER);
                return _number.to<T>();
        }

        int vtype;
        number_holder _number;
        bool _boolean;
        std::u32string _string;
        std::list<node> xarray;
        std::vector<node*> xarray_index;
        std::map<std::u32string, std::list<node>> xobject;
        errorcode follow_soft(const std::u32string& pointer, const node*& out) const throw(std::bad_alloc);
        errorcode follow_soft(const std::u32string& pointer, node*& out) throw(std::bad_alloc);
        errorcode field_soft(const std::u32string& key, size_t subindex, node*& out) throw();
        errorcode field_soft(const std::u32string& key, size_t subindex, const node*& out) const throw();
        errorcode index_soft(size_t index, node*& out) throw();
        errorcode index_soft(size_t index, const node*& out) const throw();
};
}

bool operator==(const int& n, const JSON::number_tag& v);
bool operator==(const int& n, const JSON::string_tag& v);
bool operator==(const int& n, const JSON::boolean_tag& v);
bool operator==(const int& n, const JSON::array_tag& v);
bool operator==(const int& n, const JSON::object_tag& v);
bool operator==(const int& n, const JSON::null_tag& v);
bool operator!=(const int& n, const JSON::number_tag& v);
bool operator!=(const int& n, const JSON::string_tag& v);
bool operator!=(const int& n, const JSON::boolean_tag& v);
bool operator!=(const int& n, const JSON::array_tag& v);
bool operator!=(const int& n, const JSON::object_tag& v);
bool operator!=(const int& n, const JSON::null_tag& v);


#endif