# A named and possibly documented entity in the model.
# This class is useful to generalize presentation of entities to the human.
abstract class MEntity
	# The short (unqualified) name of this model entity.
	#
	# The short-name is based from the identifiers used to declare or denote the entity.
	# It is usually globally ambiguous but is often enough in a precise local context.
	#
	# It is suitable to use the short-name in message to the user.
	# However, special care must be used in case of potential ambiguities or name conflict.
	fun name: String is abstract

	# A fully-qualified name of this model entity.
	#
	# The full-name is based on the short name and is usually prefixed by the name of an outer entity.
	# Usually the quad (`::`) is used to separate the different names.
	#
	# The full-name is expected to be unique and unambiguous in lawful Nit models for the same kind of entity.
	#
	# It is often suitable to use it in message to the user.
	# However, some full-name could be long and verbose,
	#
	# See the specific implementation in subclasses for details.
	fun full_name: String is abstract

	# A fully-qualified C-like identifier of this model entity.
	#
	# The C-name is a name that respects the rule of identifiers in the C language:
	# it is only made of alphanumeric characters and starts with a letter (or a underscore).
	#
	# The C-name can be seen as a mangled version of the `full_name`.
	# Therefore, it is expected to be unique and unambiguous in lawful Nit models for the same kind of entity.
	#
	# The C-name is used by tools that need some identifiers in generated files to designate the
	# entity.
	#
	# Is is not suitable to use it directly with the user (e.g. in message) and
	# indirect use should be restricted (e.g. to name a web-page)
	fun c_name: String is abstract

	# The origin of the definition.
	#
	# Most model entities are defined in a specific place in the source base.
	#
	# Because most model entities have one,
	# it is simpler for the client to have a non-nullable return value.
	# For entities that lack a location, mock-up special locations are used instead.
	# By default it is `model.no_location`.
	fun location: Location do return model.no_location

	# A Model Entity has a direct link to its model
	fun model: Model is abstract

	# The indication that the entity did not pass some semantic verifications.
	#
	# This simple flag is set by a given analysis to say that the entity is broken and unusable in
	# an execution.
	# When an entity status is set to broken, it is usually associated with a error message.
	#
	# If it is safe to do so, clients of the model SHOULD just skip broken entities in their processing.
	# Clients that do not care about the executability (e.g. metrics) MAY still process the entity or
	# perform specific checks to determinate the validity of the entity.
	#
	# Note that the broken status is not propagated to enclosing and enclosed entities.
	# e.g. a broken method does not make the whole module broken.
	var is_broken = false is writable

	# Is `self` created for internal purpose?
	#
	# Fictive entities are used internally but they should not be
	# exposed to the final user.
	var is_fictive: Bool = false is writable

	# Is `self` created for unit testing purpose?
	#
	# See `nitunit`.
	var is_test: Bool = false is writable
end