morph::reactive::Effect Class Reference

A side effect: runs once on construction, then in a flush after any source it read changed. More...

#include <signal.hpp>

Inheritance diagram for morph::reactive::Effect:

Public Member Functions
template<typename F> requires std::invocable<F&> && std::move_constructible<F>
	Effect (Runtime &runtime, F fn, std::size_t depth=0)
	Constructs the Effect and runs it once. Off the owner this is reported (detail::site::kOffOwner) and the Effect never runs.
	Effect (Effect const &)=delete
Effect &	operator= (Effect const &)=delete
	Effect (Effect &&)=delete
Effect &	operator= (Effect &&)=delete
Public Member Functions inherited from morph::reactive::detail::Node
	Node (std::shared_ptr< RuntimeCore > core, std::size_t depth=0)
	Constructs a node. Off the owner this is reported (site::kOffOwner) and the node is not counted towards the core's live nodes, whose counter belongs to the owner.
virtual	~Node ()
	Unlinks this node from its sources and observers, drops every reference the core holds to it, and tells a pull running on it that it is gone.
	Node (Node const &)=delete
Node &	operator= (Node const &)=delete
	Node (Node &&)=delete
Node &	operator= (Node &&)=delete
void	markStale (Colour colour)
	Push phase: raises this node to colour and marks its observers Check.
bool	updateIfNecessary ()
	Pull phase: brings this node up to date, recomputing only if a source really changed.
std::size_t	countRun (std::uint64_t epoch) noexcept
	Counts one run of this Effect in the flush numbered epoch.
std::size_t	depth () const noexcept
	How deeply the scope owning this node is nested; the flush runs shallower Effects first.
bool	runsAfter (Node const &other) const noexcept
	Whether this node runs after other when both are queued: it is deeper, or as deep and newer.
std::uint64_t	creationOrder () const noexcept
	Where this node stands in its runtime's creation order; among Effects of one depth, the flush runs older ones first.
void	settle () noexcept
	Marks this node Clean without running it (a dropped queue entry).

Additional Inherited Members
Protected Member Functions inherited from morph::reactive::detail::Node
RuntimeCore &	core () const noexcept
	The runtime core.
bool	bornOnOwner () const noexcept
	Whether this node was constructed on the owner; one that was not is refused its work.
void	trackRead () const
	Registers this node as a source of the innermost tracked run, if any.
void	forceDirty () noexcept
	Marks this node Dirty, so the next pull recomputes it.
bool	isPulling () const noexcept
	Whether a pull is bringing this node up to date right now. A read of the node from inside that pull can only come from its own run or from a source's run that reads it: a cycle.
void	markObserversStale (Colour colour)
	Marks every observer of this node colour.
void	adoptSources (std::vector< Node * > fresh)
	Replaces this node's sources with fresh, unlinking the ones no longer read.
void	mergeSources (std::vector< Node * > fresh)
	Adds fresh to this node's sources without dropping any: what a failed run keeps.

Detailed Description

A side effect: runs once on construction, then in a flush after any source it read changed.

Queued Effects run shallowest scope first: an Effect a Scope makes carries that scope's depth, so an owner's Effects run before those of the scopes it owns. Among Effects of one depth, older ones run first.

An exception escaping it is a defect: reported (detail::site::kEffectThrew), and the flush stops. A run that throws keeps every source it has read, before and during that run, so a later change to any of them runs it again. A body may destroy its own Effect (a remount); the body's callable stays alive until the body returns, and the Effect is not touched afterwards.

Definition at line 350 of file signal.hpp.

Constructor & Destructor Documentation

Effect()

template<typename F>
requires std::invocable<F&> && std::move_constructible<F>

morph::reactive::Effect::Effect ( Runtime & runtime, F fn, std::size_t depth = 0 )

inline

Constructs the Effect and runs it once. Off the owner this is reported (detail::site::kOffOwner) and the Effect never runs.

Template Parameters

F	A callable taking no arguments; it may be move-only.

Parameters

runtime	The runtime this effect belongs to.
fn	The body; every signal it reads becomes a dependency.
depth	The depth of the Scope that owns this Effect (Scope::depth()); zero for an Effect no scope owns.

Definition at line 361 of file signal.hpp.

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

• morph/reactive/signal.hpp