Abstract base for entity components. More...

#include <entitygen.hpp>

Inheritance diagram for dasmig::component:

Public Member Functions
	component ()=default
	Default constructor.

	component (const component &)=default
	Copyable.

component &	operator= (const component &)=default
	Copyable.

	component (component &&) noexcept=default
	Movable.

component &	operator= (component &&) noexcept=default
	Movable.

virtual	~component ()=default
	Virtual destructor for proper cleanup of derived classes.

virtual std::wstring	key () const =0
	Unique key identifying this component (e.g. `"name"`, `"age"`).

virtual std::any	generate (const generation_context &ctx) const =0
	Generate a random value for this component.

virtual std::wstring	to_string (const std::any &value) const =0
	Convert a generated value to a displayable string.

virtual json_value	to_json (const std::any &value) const
	Convert a generated value to JSON, for entity::to_json().

virtual std::wstring	label () const
	Display name of this component, used by entity::to_string().

virtual std::vector< std::wstring >	depends_on () const
	Keys of the components this one reads from the context.

virtual std::uint64_t	data_hash () const
	Hash of the data this component draws from, for replay.

virtual double	weight () const
	Inclusion weight for this component (0.0 to 1.0).

virtual bool	validate (const std::any &value) const
	Validate a generated value.

virtual bool	should_generate (const generation_context &ctx) const
	Decide whether this component should be generated.

Static Protected Member Functions
static std::wstring	default_to_string (const std::any &value)
	Default conversion covering common standard types.

static json_value	default_to_json (const std::any &value, const std::wstring &display)
	Default JSON conversion used by to_json().

Detailed Description

Abstract base for entity components.

Implement this interface to define custom components that the entity generator can produce. Each component has a unique key, generates typed random values, and converts them to display strings.

See also: generation_context, eg::add()

Definition at line 293 of file entitygen.hpp.

Member Function Documentation

◆ data_hash()

virtual std::uint64_t dasmig::component::data_hash ( ) const

inlinevirtual

Hash of the data this component draws from, for replay.

A component that calls a generator with data returns that generator's data_hash(). entity::signature() combines the hashes of the components that ran, so a replay shows whether the data changed.

Returns: The hash; 0 (no data) by default.

Reimplemented in dasmig::field_component< T >.

Definition at line 359 of file entitygen.hpp.

◆ default_to_json()

static json_value dasmig::component::default_to_json	(	const std::any &	value,
		const std::wstring &	display
	)

inlinestaticprotected

Default JSON conversion used by to_json().

Parameters

value	The value to convert.
display	Its to_string() form, used for unrecognized types.

Returns: The JSON value.

Definition at line 453 of file entitygen.hpp.

◆ default_to_string()

static std::wstring dasmig::component::default_to_string ( const std::any & value )

inlinestaticprotected

Default conversion covering common standard types.

Handles std::wstring, std::string (UTF-8), bool, float, double and the integer types int, long, long long and their unsigned forms. Returns "[?]" for unrecognized types.

Parameters

value The value to convert.

Returns: A wide-string representation.

Definition at line 399 of file entitygen.hpp.

◆ depends_on()

virtual std::vector< std::wstring > dasmig::component::depends_on ( ) const

inlinevirtual

Keys of the components this one reads from the context.

A request that selects this component also generates its dependencies (transitively) and orders them before it, whatever the registration order. If a dependency is skipped (weight roll or should_generate()), this component is skipped too. A dependency that is not registered, or a cycle, makes generation throw.

Returns: The dependency keys; empty by default.

Reimplemented in dasmig::field_component< T >.

Definition at line 351 of file entitygen.hpp.

◆ generate()

virtual std::any dasmig::component::generate ( const generation_context & ctx ) const

pure virtual

Generate a random value for this component.

Parameters

ctx	Context providing access to previously generated values and a seeded random engine.

Returns: The generated value wrapped in std::any.

Implemented in dasmig::constant_component< T, Formatter >, dasmig::choice_component< T, Formatter >, dasmig::range_component< T, Formatter >, dasmig::callback_component< T, GenFn, Formatter >, dasmig::field_component< T >, and dasmig::weighted_choice_component< T, Formatter >.

◆ key()

virtual std::wstring dasmig::component::key ( ) const

pure virtual

Unique key identifying this component (e.g. "name", "age").

Returns: The component key as a wide string.

Implemented in dasmig::constant_component< T, Formatter >, dasmig::choice_component< T, Formatter >, dasmig::range_component< T, Formatter >, dasmig::callback_component< T, GenFn, Formatter >, dasmig::field_component< T >, and dasmig::weighted_choice_component< T, Formatter >.

◆ label()

virtual std::wstring dasmig::component::label ( ) const

inlinevirtual

Display name of this component, used by entity::to_string().

The key stays the identifier (lookups, seeds, JSON). A key with dots is a path: L"identity.age" is written as {"identity":{"age":..}}.

Returns: The label; defaults to the key.

Reimplemented in dasmig::field_component< T >.

Definition at line 341 of file entitygen.hpp.

◆ should_generate()

virtual bool dasmig::component::should_generate ( const generation_context & ctx ) const

inlinevirtual

Decide whether this component should be generated.

Unlike weight() (probabilistic), this is logic-driven. Return false to skip generation entirely based on the current context.

Parameters

ctx	Context with previously generated component values.

Returns: true to generate, false to skip.

Reimplemented in dasmig::field_component< T >.

Definition at line 385 of file entitygen.hpp.

◆ to_json()

virtual json_value dasmig::component::to_json ( const std::any & value ) const

inlinevirtual

Convert a generated value to JSON, for entity::to_json().

The default writes bool as a boolean, integers as integers, double and float as numbers (non-finite ones as null), std::wstring and std::string as strings, and anything else as the string from to_string(). Override it to write a richer value: a json_value can hold arrays and objects.

Parameters

value The value previously returned by generate().

Returns: The JSON value.

Reimplemented in dasmig::field_component< T >.

Definition at line 331 of file entitygen.hpp.

◆ to_string()

virtual std::wstring dasmig::component::to_string ( const std::any & value ) const

pure virtual

Convert a generated value to a displayable string.

Parameters

value The value previously returned by generate().

Returns: A human-readable wide-string representation.

See also: default_to_string()

Implemented in dasmig::constant_component< T, Formatter >, dasmig::choice_component< T, Formatter >, dasmig::range_component< T, Formatter >, dasmig::callback_component< T, GenFn, Formatter >, dasmig::field_component< T >, and dasmig::weighted_choice_component< T, Formatter >.

◆ validate()

virtual bool dasmig::component::validate ( const std::any & value ) const

inlinevirtual

Validate a generated value.

Parameters

value The value to validate.

Returns: true to accept, false to retry generation.

See also: eg::max_retries()

Reimplemented in dasmig::field_component< T >.

Definition at line 374 of file entitygen.hpp.

◆ weight()

virtual double dasmig::component::weight ( ) const

inlinevirtual

Inclusion weight for this component (0.0 to 1.0).

A value of 1.0 means always included; 0.5 means included roughly half the time. The generator may override this per-component at registration time via eg::add(comp, weight) or eg::weight().

Returns: The inclusion probability.

See also: eg::weight()

Reimplemented in dasmig::field_component< T >.

Definition at line 368 of file entitygen.hpp.

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

dasmig/entitygen.hpp

Public Member Functions

Static Protected Member Functions

Detailed Description

Member Function Documentation

◆ data_hash()

◆ default_to_json()

◆ default_to_string()

◆ depends_on()

◆ generate()

◆ key()

◆ label()

◆ should_generate()

◆ to_json()

◆ to_string()

◆ validate()

◆ weight()