#include <computed.hpp>

Inheritance diagram for aria::reactive::Computed< T >:

Public Types
using	value_type = T

Public Member Functions
template<std::invocable<> Fn> requires std::convertible_to<std::invoke_result_t<Fn>, T>
	Computed (Fn fn)
	Construct and perform the initial compute eagerly, so get() immediately returns the correct value without any flush.
	Computed (const Computed &)=delete
Computed &	operator= (const Computed &)=delete
	Computed (Computed &&)=delete
Computed &	operator= (Computed &&)=delete
	~Computed () noexcept override
	Explicit destructor: detach every upstream edge before the edge pool releases the storage backing them.
T	get () const
	Return the cached value, ensuring it is up to date.
const T &	get_ref () const
	Read by const reference.
T	peek () const noexcept(std::is_nothrow_copy_constructible_v< T >)
	Non-tracking snapshot read.
const T &	peek_ref () const noexcept
	Non-tracking snapshot read by const reference.
	operator T () const
::aria::Subscription	on_changed (std::function< void(const T &)> fn)
::aria::Subscription	bind (std::function< void(const T &)> fn)
::aria::Subscription	observe (std::function< void(const T &, const T &)> fn)
bool	recompute () override
	Called by the Graph when an upstream has changed.
std::size_t	dependency_count () const noexcept
	Number of upstreams currently in use.
Public Member Functions inherited from aria::reactive::Node
	Node (NodeKind kind) noexcept
virtual	~Node () noexcept
	Node (const Node &)=delete
Node &	operator= (const Node &)=delete
	Node (Node &&)=delete
Node &	operator= (Node &&)=delete
NodeKind	kind () const noexcept
NodeState	state () const noexcept
std::uint64_t	version () const noexcept
const std::string &	debug_name () const noexcept
void	set_debug_name (std::string name)
const std::string &	effective_debug_name () const
	A non-empty debug label for diagnostic output.
void	notify_changed ()
	Called by a Source after its value has actually changed: bumps the version and colors all downstream nodes MaybeDirty.
void	mark_downstream_maybe_dirty ()
	Mark self and all reachable descendants as MaybeDirty.
void	mark_dirty () noexcept
	Escalate state to Dirty (used by Graph::pull after confirming an upstream has truly moved).
std::uint32_t	depth () const noexcept
	Topological depth used by flush ordering.
void	set_depth (std::uint32_t d) noexcept
virtual std::shared_ptr< Node >	retain_for_recompute () noexcept
	Reactions are shared-owned and may cancel themselves while running.
void	attach_as_observer_of (Node &source, Edge &edge) noexcept
void	detach_edge (Edge &edge) noexcept
void	clear_sources () noexcept
	Drop every upstream edge.
template<class F>
void	for_each_observer (F &&f)
	Iterate the observer list (used by Graph to color downstream nodes).
template<class F>
void	for_each_source (F &&f) const
	Iterate the source list (used by a Derivation in pull() to compare each upstream's current version against observed_version).
bool	has_observers () const noexcept
bool	has_sources () const noexcept

Additional Inherited Members
Static Public Member Functions inherited from aria::reactive::Node
static Graph &	graph () noexcept
	Returns the process-wide singleton Graph this node belongs to.
Protected Member Functions inherited from aria::reactive::Node
void	retire_ () noexcept
	Retire before derived members (including user captures) are destroyed.
void	bump_version_ () noexcept
void	set_state_ (NodeState s) noexcept

Member Typedef Documentation

◆ value_type

template<PropertyValue T>

using aria::reactive::Computed< T >::value_type = T

Constructor & Destructor Documentation

◆ Computed() [1/3]

template<PropertyValue T>

template<std::invocable<> Fn>
requires std::convertible_to<std::invoke_result_t<Fn>, T>

aria::reactive::Computed< T >::Computed ( Fn fn )

inlineexplicit

Construct and perform the initial compute eagerly, so get() immediately returns the correct value without any flush.

A deliberate choice: eager first-run keeps observer semantics simple (observers never see "empty" / default-constructed state).

◆ Computed() [2/3]

template<PropertyValue T>

aria::reactive::Computed< T >::Computed ( const Computed< T > & )

delete

◆ Computed() [3/3]

template<PropertyValue T>

aria::reactive::Computed< T >::Computed ( Computed< T > && )

delete

◆ ~Computed()

template<PropertyValue T>

aria::reactive::Computed< T >::~Computed ( )

inlineoverridenoexcept

Explicit destructor: detach every upstream edge before the edge pool releases the storage backing them.

If we rely on the default destruction sequence, edge_pool_ (a derived-class member) runs first and frees every Edge object; then ~Node() would call clear_sources() and dereference the already-freed list head -> classic use-after-free SIGSEGV.

Member Function Documentation

◆ operator=() [1/2]

template<PropertyValue T>

Computed & aria::reactive::Computed< T >::operator= ( const Computed< T > & )

delete

◆ operator=() [2/2]

template<PropertyValue T>

Computed & aria::reactive::Computed< T >::operator= ( Computed< T > && )

delete

◆ get()

template<PropertyValue T>

T aria::reactive::Computed< T >::get ( ) const

inlinenodiscard

Return the cached value, ensuring it is up to date.

If the graph has pending changes that could affect us, we pull ourselves first so the caller always sees a glitch-free value.

◆ get_ref()

template<PropertyValue T>

const T & aria::reactive::Computed< T >::get_ref ( ) const

inlinenodiscard

Read by const reference.

Same semantics as get() (auto-tracking

lazy pull) but avoids the copy on hot paths.

◆ peek()

template<PropertyValue T>

T aria::reactive::Computed< T >::peek ( ) const

inlinenodiscardnoexcept

Non-tracking snapshot read.

noexcept is conditional on T's copy ctor; if T may throw we still don't want to terminate.

◆ peek_ref()

template<PropertyValue T>

const T & aria::reactive::Computed< T >::peek_ref ( ) const

inlinenodiscardnoexcept

Non-tracking snapshot read by const reference.

◆ operator T()

template<PropertyValue T>

aria::reactive::Computed< T >::operator T ( ) const

inline

◆ on_changed()

template<PropertyValue T>

aria::Subscription aria::reactive::Computed< T >::on_changed ( std::function< void(const T &)> fn )

nodiscard

◆ bind()

template<PropertyValue T>

aria::Subscription aria::reactive::Computed< T >::bind ( std::function< void(const T &)> fn )

nodiscard

◆ observe()

template<PropertyValue T>

aria::Subscription aria::reactive::Computed< T >::observe ( std::function< void(const T &, const T &)> fn )

nodiscard

◆ recompute()

template<PropertyValue T>

bool aria::reactive::Computed< T >::recompute ( )

inlineoverridevirtual

Called by the Graph when an upstream has changed.

Re-establishes edges from scratch using a fresh TrackingContext and commits the new value, returning true iff the cached value actually moved.

Exception safety: if the user-supplied compute_() throws, we MUST keep the previous edge set intact — otherwise this Computed becomes orphaned in the graph and never recomputes again, even after the upstream stabilises. We achieve this by computing the new value FIRST under a temporary tracker (without touching our existing edges), and only swapping edges in once the user code has succeeded.

Reimplemented from aria::reactive::Node.

◆ dependency_count()

template<PropertyValue T>

std::size_t aria::reactive::Computed< T >::dependency_count ( ) const

inlinenodiscardnoexcept

Number of upstreams currently in use.

Exposed for diagnostics / tests; not part of the user-facing API surface.

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

modules/core/include/aria/reactive/computed.hpp
modules/core/include/aria/reactive/effect.hpp

Public Types

Public Member Functions

Additional Inherited Members

Member Typedef Documentation

◆ value_type

Constructor & Destructor Documentation

◆ Computed() [1/3]

◆ Computed() [2/3]

◆ Computed() [3/3]

◆ ~Computed()

Member Function Documentation

◆ operator=() [1/2]

◆ operator=() [2/2]

◆ get()

◆ get_ref()

◆ peek()

◆ peek_ref()

◆ operator T()

◆ on_changed()

◆ bind()

◆ observe()

◆ recompute()

◆ dependency_count()