MutationMessage Struct Reference

#include "lib/diff/mutation-message.hpp"

Description

Opaque message to effect a structural change on a target, which is likewise only known in an abstract way, as being specifically structured.

Sending such messages typically allows some implementation defined part within the Session to communicate structure and content to some other implementation defined part within the UI-Layer, without the necessity of both partners to be tightly coupled on implementation level or even know much about the other's implementation details. As motivation, contrast this to a naive UI implementation, which directly accesses some backend data structure; any change to the backend implementation typically affects the UI implementation on a detail level.

Warning

be sure to understand the fundamental problem of diff generation and application: the production context of diff messages need to be conserved beyond the producer's thread context, because it will be pulled asynchronous from within the UI event thread!

Definition at line 124 of file mutation-message.hpp.

Public Types
using	_FrontEnd = DiffSource::iterator
Public Types inherited from IterSource< TY >::iterator
using	_I = IterAdapter< Pos, DataHandle >
Public Types inherited from IterAdapter< Pos, DataHandle >
using	pointer = typename _ValTrait::pointer
using	reference = typename _ValTrait::reference
using	value_type = typename _ValTrait::value_type

Public Member Functions
	MutationMessage (MutationMessage &&)=default
	MutationMessage (MutationMessage const &)=default
	MutationMessage (MutationMessage &o)
	MutationMessage (DiffSource *diffGenerationContext)
	MutationMessage builder: take ownership of an opaque heap allocated context from which the concrete diff can be pulled on demand.
	MutationMessage (std::initializer_list< DiffStep > const &&ili)
	Convenience builder for consuming an brace enclosed initializer_list. More...
template<typename... ARGS>
	MutationMessage (ARGS &&...args)
	Convenience builder to take an arbitrary number of DiffStep arguments. More...
template<class IT >
	MutationMessage (IT &&ii, enable_if< can_IterForEach< IT >, void *>=nullptr)
	Convenience builder to piggyback any Lumiera Forward Iterator. More...
template<class CON >
	MutationMessage (CON &container, enable_if< __and_< can_STL_ForEach< CON >, __not_< can_IterForEach< CON >>>, void *>=nullptr)
	Convenience builder to use elements form any STL-like container. More...
MutationMessage &	operator= (MutationMessage const &)=default
MutationMessage &	operator= (MutationMessage &&)=default
MutationMessage &	updateDiagnostics ()
	enable support to show content of the message. More...
Public Member Functions inherited from IterSource< TY >::iterator
	operator string () const
Public Member Functions inherited from IterAdapter< Pos, DataHandle >
	IterAdapter (DataHandle src, Pos const &startpos)
bool	empty () const
	ENABLE_USE_IN_STD_RANGE_FOR_LOOPS (IterAdapter)
bool	isValid () const
	operator bool () const
reference	operator* () const
IterAdapter &	operator++ ()
pointer	operator-> () const

Additional Inherited Members
Protected Types inherited from IterAdapter< Pos, DataHandle >
using	ConRef = typename meta::RefTraits< DataHandle >::Reference
Protected Member Functions inherited from IterAdapter< Pos, DataHandle >
bool	check () const
	ask the controlling container if this position is valid. More...
void	iterate ()
	ask the controlling container to yield the next position. More...
void	resetPos (Pos otherPos)
ConRef	source ()
	allow derived classes to access backing container
const ConRef	source () const

Constructor & Destructor Documentation

MutationMessage() [1/4]

MutationMessage ( std::initializer_list< DiffStep > const &&  ili )

inline

Convenience builder for consuming an brace enclosed initializer_list.

Note

initialiser elements will be copied into a heap allocated snapshot (vector), which is then managed by shared_ptr

Definition at line 152 of file mutation-message.hpp.

MutationMessage() [2/4]

MutationMessage ( ARGS &&...  args )

inline

Convenience builder to take an arbitrary number of DiffStep arguments.

Note

like for the initializer_list, arguments will be copied into a heap allocated snapshot

Definition at line 162 of file mutation-message.hpp.

MutationMessage() [3/4]

MutationMessage ( IT &&  ii, enable_if< can_IterForEach< IT >, void *>  = nullptr  )

inline

Convenience builder to piggyback any Lumiera Forward Iterator.

Note

source iterator is copied into a heap allocated IterSource

Definition at line 171 of file mutation-message.hpp.

MutationMessage() [4/4]

MutationMessage ( CON &  container, enable_if< __and_< can_STL_ForEach< CON >, __not_< can_IterForEach< CON >>>, void *>  = nullptr  )

inline

Convenience builder to use elements form any STL-like container.

Note

creating heap allocated IterSource, which refers to the original container

Warning

like with any classical iterators, the container must stay alive and accessible

Definition at line 181 of file mutation-message.hpp.

References MutationMessage::updateDiagnostics().

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Member Function Documentation

updateDiagnostics()

MutationMessage & updateDiagnostics ( )

inline

enable support to show content of the message.

After calling this function, operator string() renders all DiffSteps

Warning

since by design a MutationMessage can only be ``pulled'' once, this operation needs to impose a side effect: it materialises the complete diff sequence at once into a heap allocated buffer.

operational semantics

Since the underlying generator of the DiffStep sequence is an iterator, the "materialised view" can only capture what's left at the point when updateDiagnostics() is invoked. The captured rest sequence seamlessly becomes the new generator and the old generator object is released, since the assignment of the new backend typically removes the last reference in the smart-ptr managing the generation backend. This process can be repeated and then the diagnostics will show the remainder of the sequence left at that point.

Definition at line 254 of file mutation-message.hpp.

Referenced by MutationMessage::MutationMessage().

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Inheritance diagram for MutationMessage:

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

• mutation-message.hpp