tt::datum Class Reference

#include <ttauri/datum.hpp>

Data Structures
struct	break_type
struct	continue_type

Public Types
using	vector_type = std::vector<datum>
using	map_type = std::map<datum, datum>

Public Member Functions
constexpr	datum (datum const &other) noexcept
constexpr	datum (datum &&other) noexcept
constexpr	datum (std::monostate) noexcept
constexpr	datum (nullptr_t) noexcept
constexpr	datum (continue_type) noexcept
constexpr	datum (break_type) noexcept
constexpr	datum (bool value) noexcept
constexpr	datum (std::floating_point auto value) noexcept
constexpr	datum (numeric_integral auto value) noexcept
constexpr	datum (decimal value) noexcept
constexpr	datum (std::chrono::year_month_day value) noexcept
	datum (std::string value) noexcept
	datum (std::string_view value) noexcept
	datum (char const *value) noexcept
	datum (vector_type value) noexcept
	datum (map_type value) noexcept
	datum (URL value) noexcept
	datum (bstring value) noexcept
constexpr datum &	operator= (datum const &other) noexcept
constexpr datum &	operator= (datum &&other) noexcept
constexpr datum &	operator= (std::floating_point auto value) noexcept(sizeof(value)<=4)
constexpr datum &	operator= (numeric_integral auto value) noexcept(sizeof(value)<=4)
constexpr datum &	operator= (decimal value)
constexpr datum &	operator= (bool value) noexcept
constexpr datum &	operator= (std::chrono::year_month_day value) noexcept
constexpr datum &	operator= (std::monostate) noexcept
constexpr datum &	operator= (nullptr_t) noexcept
datum &	operator= (std::string value) noexcept
datum &	operator= (char const *value) noexcept
datum &	operator= (std::string_view value) noexcept
datum &	operator= (vector_type value) noexcept
datum &	operator= (map_type value) noexcept
datum &	operator= (URL value) noexcept
datum &	operator= (bstring value) noexcept
constexpr	operator bool () const noexcept
template<std::floating_point T>
constexpr	operator T () const
constexpr	operator decimal () const
template<numeric_integral T>
constexpr	operator T () const
constexpr	operator std::chrono::year_month_day () const
	operator std::string () const noexcept
	operator std::string_view () const
	operator vector_type () const
	operator map_type () const
	operator URL () const
	operator bstring () const
constexpr char const *	type_name () const noexcept
constexpr bool	is_undefined () const noexcept
	Check if the datum has an undefined value.
constexpr bool	is_break () const noexcept
	Check if the result of a expression was a break flow control statement.
constexpr bool	is_continue () const noexcept
	Check if the result of a expression was a continue flow control statement.
constexpr size_t	hash () const noexcept
constexpr size_t	size () const
constexpr datum const &	back () const
constexpr datum &	back ()
constexpr datum const &	front () const
constexpr datum &	front ()
constexpr auto	cbegin () const
constexpr auto	begin () const
constexpr auto	begin ()
constexpr auto	cend () const
constexpr auto	end () const
constexpr auto	end ()
constexpr vector_type	keys () const
	Get the sorted list of keys of a map.
constexpr vector_type	values () const
	Get the list of values of a map.
constexpr vector_type	items () const
	Get key value pairs of items of a map sorted by the key.
constexpr void	push_back (datum const &rhs)
constexpr void	push_back (datum &&rhs)
template<typename Arg >
constexpr void	push_back (Arg &&arg)
constexpr void	pop_back ()
constexpr bool	contains (datum const &rhs) const
template<typename Arg >
constexpr bool	contains (Arg const &arg) const
std::vector< datum * >	find (jsonpath const &path) noexcept
std::vector< datum const * >	find (jsonpath const &path) const noexcept
bool	remove (jsonpath const &path) noexcept
	Remove the object by path.
datum *	find_one (jsonpath const &path) noexcept
	Find a object by path.
datum *	find_one_or_create (jsonpath const &path) noexcept
	Find a object by path potentially creating intermediate objects.
datum const *	find_one (jsonpath const &path) const noexcept
	Find a object by path.
constexpr datum const &	operator[] (datum const &rhs) const
constexpr datum &	operator[] (datum const &rhs)
constexpr datum const &	operator[] (auto const &rhs) const
constexpr datum &	operator[] (auto const &rhs)
constexpr datum &	operator++ ()
constexpr datum &	operator-- ()
constexpr datum	operator++ (int)
constexpr datum	operator-- (int)
constexpr datum &	operator+= (auto const &rhs)
	X (-=, -) X(*
*	X (/=,/) X(%
X(&	X (|=,|) X(^=, ^) X(<<=,<<) X(> >=, > >) friend constexpr bool operator==(datum const &lhs, datum const &rhs) noexcept { if(ttlet doubles=promote_if< double >(lhs, rhs)) { return doubles.lhs()==doubles.rhs();} else if(ttlet decimals=promote_if< decimal >(lhs, rhs)) { return decimals.lhs()==decimals.rhs();} else if(ttlet long_longs=promote_if< long long >(lhs, rhs)) { return long_longs.lhs()==long_longs.rhs();} else if(ttlet bools=promote_if< bool >(lhs, rhs)) { return bools.lhs()==bools.rhs();} else if(ttlet ymds=promote_if< std::chrono::year_month_day >(lhs, rhs)) { return ymds.lhs()==ymds.rhs();} else if(ttlet urls=promote_if< URL >(lhs, rhs)) { return urls.lhs()==urls.rhs();} else if(ttlet strings=promote_if< std::string >(lhs, rhs)) { return strings.lhs()==strings.rhs();} else if(ttlet vectors=promote_if< vector_type >(lhs, rhs)) { return vectors.lhs()==vectors.rhs();} else if(ttlet maps=promote_if< map_type >(lhs, rhs)) { return maps.lhs()==maps.rhs();} else { return lhs._tag==rhs._tag;} } friend constexpr std::partial_ordering operator<=>(datum const &lhs, datum const &rhs) noexcept { if(ttlet doubles=promote_if< double >(lhs, rhs)) { return doubles.lhs()<=> doubles.rhs();} else if(ttlet decimals=promote_if< decimal >(lhs, rhs)) { return decimals.lhs()<=> decimals.rhs();} else if(ttlet long_longs=promote_if< long long >(lhs, rhs)) { return long_longs.lhs()<=> long_longs.rhs();} else if(ttlet bools=promote_if< bool >(lhs, rhs)) { return bools.lhs()<=> bools.rhs();} else if(ttlet year_month_days=promote_if< std::chrono::year_month_day >(lhs, rhs)) { return year_month_days.lhs()<=> year_month_days.rhs();} else if(ttlet urls=promote_if< URL >(lhs, rhs)) { return urls.lhs()<=> urls.rhs();} else if(ttlet strings=promote_if< std::string >(lhs, rhs)) { return strings.lhs()<=> strings.rhs();} else if(ttlet vectors=promote_if< vector_type >(lhs, rhs)) { return vectors.lhs()<=> vectors.rhs();} else if(ttlet maps=promote_if< map_type >(lhs, rhs)) { return maps.lhs()<=> maps.rhs();} else if(ttlet bstrings=promote_if< bstring >(lhs, rhs)) { return bstrings.lhs()<=> bstrings.rhs();} else { return lhs._tag<=> rhs._tag;} } friend constexpr datum operator-(datum const &rhs) { if(ttlet rhs_double=get_if< double >(rhs)) { return datum{- *rhs_double};} else if(ttlet rhs_decimal=get_if< decimal >(rhs)) { return datum{- *rhs_decimal};} else if(ttlet rhs_long_long=get_if< long long >(rhs)) { return datum{- *rhs_long_long};} else { throw std::domain_error(std::format("Can not evaluate -{}", repr(rhs)));} } friend constexpr datum operator~(datum const &rhs) { if(ttlet rhs_long_long=get_if< long long >(rhs)) { return datum{~ *rhs_long_long};} else { throw std::domain_error(std::format("Can not evaluate ~{}", repr(rhs)));} } friend constexpr datum operator+(datum const &lhs, datum const &rhs) { if(ttlet doubles=promote_if< double >(lhs, rhs)) { return datum{doubles.lhs()+doubles.rhs()};} else if(ttlet decimals=promote_if< decimal >(lhs, rhs)) { return datum{decimals.lhs()+decimals.rhs()};} else if(ttlet long_longs=promote_if< long long >(lhs, rhs)) { return datum{long_longs.lhs()+long_longs.rhs()};} else if(ttlet strings=promote_if< std::string >(lhs, rhs)) { return datum{strings.lhs()+strings.rhs()};} else if(ttlet vectors=promote_if< vector_type >(lhs, rhs)) { auto r=vectors.lhs();r.insert(r.end(), vectors.rhs().begin(), vectors.rhs().end());return datum{std::move(r)};} else { throw std::domain_error(std::format("Can not evaluate {} '+' {}", repr(lhs), repr(rhs)));} } friend constexpr datum operator-(datum const &lhs, datum const &rhs) { if(ttlet doubles=promote_if< double >(lhs, rhs)) { return datum{doubles.lhs() - doubles.rhs()};} else if(ttlet decimals=promote_if< decimal >(lhs, rhs)) { return datum{decimals.lhs() - decimals.rhs()};} else if(ttlet long_longs=promote_if< long long >(lhs, rhs)) { return datum{long_longs.lhs() - long_longs.rhs()};} else { throw std::domain_error(std::format("Can not evaluate {} '-' {}", repr(lhs), repr(rhs)));} } friend constexpr datum operator*(datum const &lhs, datum const &rhs) { if(ttlet doubles=promote_if< double >(lhs, rhs)) { return datum{doubles.lhs() *doubles.rhs()};} else if(ttlet decimals=promote_if< decimal >(lhs, rhs)) { return datum{decimals.lhs() *decimals.rhs()};} else if(ttlet long_longs=promote_if< long long >(lhs, rhs)) { return datum{long_longs.lhs() *long_longs.rhs()};} else { throw std::domain_error(std::format("Can not evaluate {} '*' {}", repr(lhs), repr(rhs)));} } friend constexpr datum operator/(datum const &lhs, datum const &rhs) { if(ttlet doubles=promote_if< double >(lhs, rhs)) { if(doubles.rhs()==0) { throw std::domain_error(std::format("Divide by zero {} '/' {}", repr(lhs), repr(rhs)));} return datum{doubles.lhs()/doubles.rhs()};} else if(ttlet decimals=promote_if< decimal >(lhs, rhs)) { if(decimals.rhs()==0) { throw std::domain_error(std::format("Divide by zero {} '/' {}", repr(lhs), repr(rhs)));} return datum{decimals.lhs()/decimals.rhs()};} else if(ttlet long_longs=promote_if< long long >(lhs, rhs)) { if(long_longs.rhs()==0) { throw std::domain_error(std::format("Divide by zero {} '/' {}", repr(lhs), repr(rhs)));} return datum{long_longs.lhs()/long_longs.rhs()};} else if(ttlet urls=promote_if< URL >(lhs, rhs)) { return datum{urls.lhs()/urls.rhs()};} else { throw std::domain_error(std::format("Can not evaluate {} '/' {}", repr(lhs), repr(rhs)));} } friend constexpr datum operator%(datum const &lhs, datum const &rhs) { if(ttlet long_longs=promote_if< long long >(lhs, rhs)) { if(long_longs.rhs()==0) { throw std::domain_error(std::format("Divide by zero {} '%' {}", repr(lhs), repr(rhs)));} return datum{long_longs.lhs() % long_longs.rhs()};} else { throw std::domain_error(std::format("Can not evaluate {} '%' {}", repr(lhs), repr(rhs)));} } friend constexpr datum pow(datum const &lhs, datum const &rhs) { if(ttlet doubles=promote_if< double >(lhs, rhs)) { return datum{pow(doubles.lhs(), doubles.rhs())};} else if(ttlet long_longs=promote_if< long long >(lhs, rhs)) { return datum{pow(long_longs.lhs(), long_longs.rhs())};} else { throw std::domain_error(std::format("Can not evaluate pow({}, {})", repr(lhs), repr(rhs)));} } friend constexpr datum operator&(datum const &lhs, datum const &rhs) { if(ttlet long_longs=promote_if< long long >(lhs, rhs)) { return datum{long_longs.lhs() &long_longs.rhs()};} else if(ttlet bools=promote_if< bool >(lhs, rhs)) { return datum{bools.lhs() and bools.rhs()};} else { throw std::domain_error(std::format("Can not evaluate {} '&' {}", repr(lhs), repr(rhs)));} } friend constexpr datum operator|(datum const &lhs, datum const &rhs) { if(ttlet long_longs=promote_if< long long >(lhs, rhs)) { return datum{long_longs.lhs()|long_longs.rhs()};} else if(ttlet bools=promote_if< bool >(lhs, rhs)) { return datum{bools.lhs() or bools.rhs()};} else { throw std::domain_error(std::format("Can not evaluate {} '|' {}", repr(lhs), repr(rhs)));} } friend constexpr datum operator^(datum const &lhs, datum const &rhs) { if(ttlet long_longs=promote_if< long long >(lhs, rhs)) { return datum{long_longs.lhs() ^ long_longs.rhs()};} else if(ttlet bools=promote_if< bool >(lhs, rhs)) { return datum{bools.lhs() !=bools.rhs()};} else { throw std::domain_error(std::format("Can not evaluate {} '^' {}", repr(lhs), repr(rhs)));} } friend constexpr datum operator<<(datum const &lhs, datum const &rhs) { if(ttlet long_longs=promote_if< long long >(lhs, rhs)) { if(long_longs.rhs()< 0 or long_longs.rhs() >(sizeof(long long) *CHAR_BIT - 1)) { throw std::domain_error(std::format("Invalid shift count {} '<<' {}", repr(lhs), repr(rhs)));} return datum{long_longs.lhs()<< long_longs.rhs()};} else { throw std::domain_error(std::format("Can not evaluate {} '<<' {}", repr(lhs), repr(rhs)));} } friend constexpr datum operator>>(datum const &lhs, datum const &rhs) { if(ttlet long_longs=promote_if< long long >(lhs, rhs)) { if(long_longs.rhs()< 0 or long_longs.rhs() >(sizeof(long long) *CHAR_BIT - 1)) { throw std::domain_error(std::format("Invalid shift count {} '>>' {}", repr(lhs), repr(rhs)));} return datum{long_longs.lhs() > > long_longs.rhs()};} else { throw std::domain_error(std::format("Can not evaluate {} '>>' {}", repr(lhs), repr(rhs)));} } friend std::ostream &operator<<(std::ostream &lhs, datum const &rhs) { return lhs<< to_string(rhs);}#define X(op) \ \ \ \ \ \ \ \ X(==) X(<=>) X(+) X(-) X(*) X(/) X(%) X(&) X(|) X(^) X(<<) X(> >) friend std::string repr(datum const &rhs) noexcept { switch(rhs._tag) { case tag_type::monostate:return "undefined";case tag_type::floating_point:return std::format("{:.1f}", rhs._value._double);case tag_type::decimal:return to_string(rhs._value._decimal);case tag_type::integral:return std::format("{}", rhs._value._long_long);case tag_type::boolean:return rhs._value._bool ? "true" :"false";case tag_type::year_month_day:return std::format("{:%Y-%m-%d}", rhs._value._year_month_day);case tag_type::null:return "null";case tag_type::flow_break:return "break";case tag_type::flow_continue:return "continue";case tag_type::string:return std::format("\"{}\"", *rhs._value._string);case tag_type::url:return to_string(*rhs._value._url);case tag_type::vector:{ auto r=std::string{"["};for(ttlet &item :*rhs._value._vector) { r+=repr(item);r+=',';} r+=']
	for (ttlet &item :*rhs._value._map)

Static Public Member Functions
template<typename... Args>
static datum	make_vector (Args const &...args) noexcept
template<typename Key , typename Value , typename... Args>
static void	populate_map (map_type &r, Key const &key, Value const &value, Args const &...args) noexcept
template<typename... Args>
static datum	make_map (Args const &...args) noexcept
static datum	make_break () noexcept
static datum	make_continue () noexcept

Data Fields
return	r
	r = '}'
default	: tt_no_default()

Friends
std::string	to_string (datum const &rhs) noexcept
	Get the string representation of the value.
template<typename T >
constexpr bool	holds_alternative (datum const &rhs) noexcept
	Check if the stored value is of a specific type.
template<typename To >
constexpr bool	promotable_to (datum const &rhs) noexcept
	Check if the type held by the datum can be promoted.
template<typename T >
constexpr T const &	get (datum const &rhs) noexcept
	Get the value of a datum.
template<typename T >
constexpr T &	get (datum &rhs) noexcept
	Get the value of a datum.
template<typename T >
constexpr T *	get_if (datum &rhs) noexcept
	Get the value of a datum.
template<typename T >
constexpr T const *	get_if (datum const &rhs) noexcept
	Get the value of a datum.
template<typename T >
T *	get_if (datum &rhs, jsonpath const &path) noexcept
	Get the value of a datum.
template<typename T >
T const *	get_if (datum const &rhs, jsonpath const &path) noexcept
	Get the value of a datum.
template<typename To >
constexpr auto	promote_if (datum const &lhs, datum const &rhs) noexcept
	Promote two datum-arguments to a common type.

Detailed Description

A dynamic data type.

This class holds data of different types, useful as the data-type used for variables of scripting languages, or for serializing and deserializing JSON and other object storage formats.

Not only does this datum handle the storage of data, but can also different operations which are dynamically executed.

Member Function Documentation

find_one() [1/2]

datum const * tt::datum::find_one ( jsonpath const & path ) const

inlinenoexcept

Find a object by path.

Parameters

path	The json path to use to find an object. Path must be singular.

Returns

A pointer to the object found, or nullptr.

find_one() [2/2]

datum * tt::datum::find_one ( jsonpath const & path )

inlinenoexcept

Find a object by path.

Parameters

path	The json path to use to find an object. Path must be singular.

Returns

A pointer to the object found, or nullptr.

find_one_or_create()

datum * tt::datum::find_one_or_create ( jsonpath const & path )

inlinenoexcept

Find a object by path potentially creating intermediate objects.

Parameters

path	The json path to use to find an object. Path must be singular.

Returns

A pointer to the object found, or nullptr.

is_break()

constexpr bool tt::datum::is_break ( ) const

inlineconstexprnoexcept

Check if the result of a expression was a break flow control statement.

See also

skeleton_node

is_continue()

constexpr bool tt::datum::is_continue ( ) const

inlineconstexprnoexcept

Check if the result of a expression was a continue flow control statement.

See also

skeleton_node

is_undefined()

constexpr bool tt::datum::is_undefined ( ) const

inlineconstexprnoexcept

Check if the datum has an undefined value.

items()

constexpr vector_type tt::datum::items ( ) const

inlineconstexpr

Get key value pairs of items of a map sorted by the key.

keys()

constexpr vector_type tt::datum::keys ( ) const

inlineconstexpr

Get the sorted list of keys of a map.

remove()

bool tt::datum::remove ( jsonpath const & path )

inlinenoexcept

Remove the object by path.

This function will remove the object pointed to with path. Any resulting empty maps and arrays will also be removed.

Parameters

path	A json path to remove.

Returns

true if one or more objects where removed.

values()

constexpr vector_type tt::datum::values ( ) const

inlineconstexpr

Get the list of values of a map.

Friends And Related Symbol Documentation

get [1/2]

template<typename T >

constexpr T & get ( datum & rhs )

friend

Get the value of a datum.

It is undefined behavior if the type does not match the stored value.

Template Parameters

T	Type to check, must be one of: bool, double, long long, decimal, std::chrono::year_month_day

Parameters

rhs	The datum to get the value from.

Returns

A copy of the value in the datum.

get [2/2]

template<typename T >

constexpr T const & get ( datum const & rhs )

friend

Get the value of a datum.

It is monostate behavior if the type does not match the stored value.

Template Parameters

T	Type to check, must be one of: bool, double, long long, decimal, std::chrono::year_month_day

Parameters

rhs	The datum to get the value from.

Returns

A copy of the value in the datum.

get_if [1/4]

template<typename T >

constexpr T * get_if ( datum & rhs )

friend

Get the value of a datum.

If the type does not matched the stored value this function will return a nullptr.

Template Parameters

T	Type to check.

Parameters

rhs	The datum to get the value from.

Returns

A pointer to the value, or nullptr.

get_if [2/4]

template<typename T >

T * get_if ( datum & rhs, jsonpath const & path )

friend

Get the value of a datum.

If the type does not matched the stored value this function will return a nullptr.

Template Parameters

T	Type to check.

Parameters

rhs	The datum to get the value from.
path	The json-path to the value to extract.

Returns

A pointer to the value, or nullptr.

get_if [3/4]

template<typename T >

constexpr T const * get_if ( datum const & rhs )

friend

Get the value of a datum.

If the type does not matched the stored value this function will return a nullptr.

Template Parameters

T	Type to check.

Parameters

rhs	The datum to get the value from.

Returns

A pointer to the value, or nullptr.

get_if [4/4]

template<typename T >

T const * get_if ( datum const & rhs, jsonpath const & path )

friend

Get the value of a datum.

If the type does not matched the stored value this function will return a nullptr.

Template Parameters

T	Type to check.

Parameters

rhs	The datum to get the value from.
path	The json-path to the value to extract.

Returns

A pointer to the value, or nullptr.

holds_alternative

template<typename T >

constexpr bool holds_alternative ( datum const & rhs )

friend

Check if the stored value is of a specific type.

Template Parameters

T	Type to check.

Parameters

rhs	The datum to check the value-type of.

Returns

True if the value-type matches the template parameter T

promotable_to

template<typename To >

constexpr bool promotable_to ( datum const & rhs )

friend

Check if the type held by the datum can be promoted.

A value can always be promoted to its own type. The following promotions also exist:

• decimal -> ‘double’
• long long -> ‘decimal’
• bool -> ‘long long’
• std::string -> ‘URL’
• URL -> ‘std::string’

Template Parameters

To	Type to promote the value to.

Parameters

rhs	The value to promote.

promote_if

template<typename To >

constexpr auto promote_if ( datum const & lhs, datum const & rhs )

friend

Promote two datum-arguments to a common type.

Template Parameters

To	Type to promote to.

Parameters

lhs	The left hand side.
rhs	The right hand side.

to_string

std::string to_string ( datum const & rhs )

friend

Get the string representation of the value.

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The documentation for this class was generated from the following file:

• hikogui/src/ttauri/datum.hpp