An immutable value, following the JSON type schema. More...

Inheritance diagram for hocon::config_value:

Classes
class	modifier

class	no_exceptions_modifier

Public Types
enum	type { OBJECT, LIST, NUMBER, BOOLEAN, CONFIG_NULL, STRING, UNSPECIFIED }
	The type of a configuration value (following the JSON type schema). More...

Public Member Functions
virtual shared_origin const &	origin () const
	The origin of the value (file, line number, etc.), for debugging and error messages. More...

virtual type	value_type () const =0
	The type of the value; matches the JSON type schema. More...

char const *	value_type_name () const
	The printable name of the value type. More...

virtual unwrapped_value	unwrapped () const =0

virtual std::string	render () const
	Renders the config value as a HOCON string. More...

virtual std::string	render (config_render_options options) const
	Renders the config value to a string, using the provided options. More...

shared_config	at_key (std::string const &key) const
	Places the value inside a config at the given key. More...

shared_config	at_path (std::string const &path_expression) const
	Places the value inside a config at the given path. More...

virtual shared_value	with_origin (shared_origin origin) const
	Returns a. More...

virtual shared_value	relativized (std::string prefix) const
	This is used when including one file in another; the included file is relativized to the path it's included into in the parent file. More...

virtual resolve_status	get_resolve_status () const

std::shared_ptr< const config_mergeable >	with_fallback (std::shared_ptr< const config_mergeable > other) const override
	Returns a new value computed by merging this value with another, with keys in this value "winning" over the other one. More...

virtual bool	operator== (config_value const &other) const =0

virtual std::string	transform_to_string () const

Static Public Member Functions
static char const *	type_name (type t)

Protected Member Functions
	config_value (shared_origin origin)

virtual void	render (std::string &result, int indent, bool at_root, std::string const &at_key, config_render_options options) const

virtual void	render (std::string &result, int indent, bool at_root, config_render_options options) const

shared_config	at_key (shared_origin origin, std::string const &key) const

shared_config	at_path (shared_origin origin, path raw_path) const

virtual shared_value	new_copy (shared_origin origin) const =0

virtual resolve_result< shared_value >	resolve_substitutions (resolve_context const &context, resolve_source const &source) const

void	require_not_ignoring_fallbacks () const

virtual bool	ignores_fallbacks () const

virtual shared_value	with_fallbacks_ignored () const

shared_value	merged_with_the_unmergeable (std::vector< shared_value > stack, std::shared_ptr< const unmergeable > fallback) const

shared_value	merged_with_the_unmergeable (std::shared_ptr< const unmergeable > fallback) const

shared_value	merged_with_object (std::vector< shared_value > stack, shared_object fallback) const

virtual shared_value	merged_with_object (shared_object fallback) const

shared_value	merged_with_non_object (std::vector< shared_value > stack, shared_value fallback) const

shared_value	merged_with_non_object (shared_value fallback) const

virtual shared_value	construct_delayed_merge (shared_origin origin, std::vector< shared_value > stack) const

shared_value	to_fallback_value () const override
	Converts a config to its root object and a config_value to itself. More...

Static Protected Member Functions
static void	indent (std::string &result, int indent, config_render_options const &options)

static std::vector< shared_value >	replace_child_in_list (std::vector< shared_value > const &values, shared_value const &child, shared_value replacement)

static bool	has_descendant_in_list (std::vector< shared_value > const &values, shared_value const &descendant)

template<typename T >
static bool	equals (config_value const &other, std::function< bool(T const &)> checker)

Friends
class	token

class	value

class	default_transformer

class	config

class	config_object

class	simple_config_object

class	simple_config_list

class	config_concatenation

class	resolve_context

class	config_delayed_merge

class	config_delayed_merge_object

resolve_status	resolve_status_from_values (std::vector< shared_value > const &v)

Detailed Description

An immutable value, following the JSON type schema.

Because this object is immutable, it is safe to use from multiple threads and there's no need for "defensive copies."

Do not implement interface

config_value

; it should only be implemented by the config library. Arbitrary implementations will not work because the library internals assume a specific concrete implementation. Also, this interface is likely to grow new methods over time, so third-party implementations will break.

Definition at line 39 of file config_value.hpp.

Member Enumeration Documentation

◆ type

enum hocon::config_value::type

strong

The type of a configuration value (following the JSON type schema).

Definition at line 56 of file config_value.hpp.

Member Function Documentation

◆ at_key()

shared_config hocon::config_value::at_key ( std::string const & key ) const

Places the value inside a config at the given key.

◆ at_path()

shared_config hocon::config_value::at_path ( std::string const & path_expression ) const

Places the value inside a config at the given path.

◆ origin()

virtual shared_origin const& hocon::config_value::origin ( ) const

virtual

The origin of the value (file, line number, etc.), for debugging and error messages.

Returns: where the value came from

◆ relativized()

virtual shared_value hocon::config_value::relativized ( std::string prefix ) const

inlinevirtual

This is used when including one file in another; the included file is relativized to the path it's included into in the parent file.

The point is that if you include a file at foo.bar in the parent, and the included file as a substitution ${a.b.c}, the included substitution now needs to be ${foo.bar.a.b.c} because we resolve substitutions globally only after parsing everything.

Parameters

prefix

Returns: value relativized to the given path or the same value if nothing to do

Reimplemented in hocon::config_concatenation, and hocon::simple_config_list.

Definition at line 181 of file config_value.hpp.

◆ render() [1/2]

virtual std::string hocon::config_value::render ( ) const

virtual

Renders the config value as a HOCON string.

This method is primarily intended for debugging, so it tries to add helpful comments and whitespace.

If the config value has not been resolved (see config#resolve), it's possible that it can't be rendered as valid HOCON. In that case the rendering should still be useful for debugging but you might not be able to parse it. If the value has been resolved, it will always be parseable.

This method is equivalent to

render(config_render_options())

.

Returns: the rendered value

◆ render() [2/2]

virtual std::string hocon::config_value::render ( config_render_options options ) const

virtual

Renders the config value to a string, using the provided options.

If the config value has not been resolved (see config#resolve), it's possible that it can't be rendered as valid HOCON. In that case the rendering should still be useful for debugging but you might not be able to parse it. If the value has been resolved, it will always be parseable.

If the config value has been resolved and the options disable all HOCON-specific features (such as comments), the rendering will be valid JSON. If you enable HOCON-only features such as comments, the rendering will not be valid JSON.

Parameters

options the rendering options

Returns: the rendered value

◆ to_fallback_value()

shared_value hocon::config_value::to_fallback_value ( ) const

overrideprotectedvirtual

Converts a config to its root object and a config_value to itself.

Originally in the MergeableValue interface, squashing to ease C++ public API separation

Implements hocon::config_mergeable.

◆ value_type()

virtual type hocon::config_value::value_type ( ) const

pure virtual

The type of the value; matches the JSON type schema.

Returns: value's type

Implemented in hocon::config_object, hocon::config_concatenation, hocon::config_null, hocon::simple_config_list, hocon::config_reference, hocon::config_number, hocon::config_delayed_merge, hocon::config_string, and hocon::config_boolean.

◆ value_type_name()

char const* hocon::config_value::value_type_name ( ) const

inline

The printable name of the value type.

Returns: value's type's name

Definition at line 92 of file config_value.hpp.

◆ with_fallback()

std::shared_ptr<const config_mergeable> hocon::config_value::with_fallback ( std::shared_ptr< const config_mergeable > other ) const

overridevirtual

Returns a new value computed by merging this value with another, with keys in this value "winning" over the other one.

This associative operation may be used to combine configurations from multiple sources (such as multiple configuration files).

The semantics of merging are described in the spec for HOCON. Merging typically occurs when either the same object is created twice in the same file, or two config files are both loaded. For example:

 foo = { a: 42 }
 foo = { b: 43 }

Here, the two objects are merged as if you had written:

 foo = { a: 42, b: 43 }

Only config_object and config instances do anything in this method (they need to merge the fallback keys into themselves). All other values just return the original value, since they automatically override any fallback. This means that objects do not merge "across" non-objects; if you write object.withFallback(nonObject).withFallback(otherObject), then otherObject will simply be ignored. This is an intentional part of how merging works, because non-objects such as strings and integers replace (rather than merging with) any prior value:

foo = { a: 42 }
foo = 10

Here, the number 10 "wins" and the value of foo would be simply 10. Again, for details see the spec.

Parameters

other an object whose keys should be used as fallbacks, if the keys are not present in this one

Returns: a new object (or the original one, if the fallback doesn't get used)

Implements hocon::config_mergeable.

◆ with_origin()

virtual shared_value hocon::config_value::with_origin ( shared_origin origin ) const

virtual

Returns a.

config_value

based on this one, but with the given origin. This is useful when you are parsing a new format of file or setting comments for a single config_value.

Parameters

origin the origin set on the returned value

Returns: the new config_value with the given origin

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

hocon/config_value.hpp

Classes

Public Types

Public Member Functions

Static Public Member Functions

Protected Member Functions

Static Protected Member Functions

Friends

Detailed Description

Member Enumeration Documentation

◆ type

Member Function Documentation

◆ at_key()

◆ at_path()

◆ origin()

◆ relativized()

◆ render() [1/2]

◆ render() [2/2]

◆ to_fallback_value()

◆ value_type()

◆ value_type_name()

◆ with_fallback()

◆ with_origin()