src/model/model_base.nit

   1 # This file is part of NIT ( http://www.nitlanguage.org ).
   2 #
   3 # Copyright 2012 Jean Privat <jean@pryen.org>
   4 #
   5 # Licensed under the Apache License, Version 2.0 (the "License");
   6 # you may not use this file except in compliance with the License.
   7 # You may obtain a copy of the License at
   8 #
   9 #     http://www.apache.org/licenses/LICENSE-2.0
  10 #
  11 # Unless required by applicable law or agreed to in writing, software
  12 # distributed under the License is distributed on an "AS IS" BASIS,
  13 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  14 # See the License for the specific language governing permissions and
  15 # limitations under the License.
  16
  17 # The abstract concept of model and related common things
  18 module model_base
  19
  20 # The container class of a Nit object-oriented model.
  21 # A model knows modules, classes and properties and can retrieve them.
  22 class Model
  23 end
  24
  25 # A named and possibly documented entity in the model.
  26 # This class is useful to generalize presentation of entities to the human.
  27 abstract class MEntity
  28         # The short (unqualified) name of this model entity.
  29         #
  30         # The short-name is based from the identifiers used to declare or denote the entity.
  31         # It is usually globally ambiguous but is often enough in a precise local context.
  32         #
  33         # It is suitable to use the short-name in message to the user.
  34         # However, special care must be used in case of potential ambiguities or name conflict.
  35         fun name: String is abstract
  36
  37         # A fully-qualified name of this model entity.
  38         #
  39         # The full-name is based on the short name and is usually prefixed by the name of an outer entity.
  40         # Usually the quad (`::`) is used to separate the different names.
  41         #
  42         # The full-name is expected to be unique and unambiguous in lawful Nit models for the same kind of entity.
  43         #
  44         # It is often suitable to use it in message to the user.
  45         # However, some full-name could be long and verbose,
  46         #
  47         # See the specific implementation in subclasses for details.
  48         fun full_name: String is abstract
  49
  50         # A Model Entity has a direct link to its model
  51         fun model: Model is abstract
  52 end
  53
  54 # Something that represents a concern
  55 abstract class MConcern
  56         super MEntity
  57         # The concern that contains `self` or null if `self` is the root of the concern hierarchy
  58         fun parent_concern: nullable MConcern is abstract
  59 end
  60
  61 # A visibility (for modules, class and properties)
  62 # Valid visibility are:
  63 #
  64 #  * `intrude_visibility`
  65 #  * `public_visibility`
  66 #  * `protected_visibility`
  67 #  * `none_visibility`
  68 #  * `private_visiblity`
  69 #
  70 # Note this class is basically an enum.
  71 # FIXME: use a real enum once user-defined enums are available
  72 class MVisibility
  73         super Comparable
  74         redef type OTHER: MVisibility
  75
  76         redef var to_s: String
  77
  78         private var level: Int
  79
  80         # TODO: private init because enumeration.
  81
  82         # Is self give less visibility than other
  83         # none < private < protected < public < intrude
  84         redef fun <(other)
  85         do
  86                 return self.level < other.level
  87         end
  88 end
  89
  90 # The visibility level `intrude`
  91 fun intrude_visibility: MVisibility do return once new MVisibility("intrude", 5)
  92 # The visibility level `public`
  93 fun public_visibility: MVisibility do return once new MVisibility("public", 4)
  94 # The visibility level `protected`
  95 fun protected_visibility: MVisibility do return once new MVisibility("protected", 3)
  96 # The visibility level `private`
  97 fun private_visibility: MVisibility do return once new MVisibility("private", 2)
  98 # The visibility level `none` (no visibility)
  99 fun none_visibility: MVisibility do return once new MVisibility("none", 1)