1 # This file is part of NIT ( http://www.nitlanguage.org ).
3 # Copyright 2012 Jean Privat <jean@pryen.org>
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
9 # http://www.apache.org/licenses/LICENSE-2.0
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.
17 # Classes, types and properties
19 # All three concepts are defined in this same module because these are strongly connected:
20 # * types are based on classes
21 # * classes contains properties
22 # * some properties are types (virtual types)
24 # TODO: liearization, extern stuff
25 # FIXME: better handling of the types
31 private import more_collections
35 var mclasses
= new Array[MClass]
37 # All known properties
38 var mproperties
= new Array[MProperty]
40 # Hierarchy of class definition.
42 # Each classdef is associated with its super-classdefs in regard to
43 # its module of definition.
44 var mclassdef_hierarchy
= new POSet[MClassDef]
46 # Class-type hierarchy restricted to the introduction.
48 # The idea is that what is true on introduction is always true whatever
49 # the module considered.
50 # Therefore, this hierarchy is used for a fast positive subtype check.
52 # This poset will evolve in a monotonous way:
53 # * Two non connected nodes will remain unconnected
54 # * New nodes can appear with new edges
55 private var intro_mtype_specialization_hierarchy
= new POSet[MClassType]
57 # Global overlapped class-type hierarchy.
58 # The hierarchy when all modules are combined.
59 # Therefore, this hierarchy is used for a fast negative subtype check.
61 # This poset will evolve in an anarchic way. Loops can even be created.
63 # FIXME decide what to do on loops
64 private var full_mtype_specialization_hierarchy
= new POSet[MClassType]
66 # Collections of classes grouped by their short name
67 private var mclasses_by_name
= new MultiHashMap[String, MClass]
69 # Return all class named `name`.
71 # If such a class does not exist, null is returned
72 # (instead of an empty array)
74 # Visibility or modules are not considered
75 fun get_mclasses_by_name
(name
: String): nullable Array[MClass]
77 return mclasses_by_name
.get_or_null
(name
)
80 # Collections of properties grouped by their short name
81 private var mproperties_by_name
= new MultiHashMap[String, MProperty]
83 # Return all properties named `name`.
85 # If such a property does not exist, null is returned
86 # (instead of an empty array)
88 # Visibility or modules are not considered
89 fun get_mproperties_by_name
(name
: String): nullable Array[MProperty]
91 return mproperties_by_name
.get_or_null
(name
)
95 var null_type
= new MNullType(self)
97 # Build an ordered tree with from `concerns`
98 fun concerns_tree
(mconcerns
: Collection[MConcern]): ConcernsTree do
99 var seen
= new HashSet[MConcern]
100 var res
= new ConcernsTree
102 var todo
= new Array[MConcern]
103 todo
.add_all mconcerns
105 while not todo
.is_empty
do
107 if seen
.has
(c
) then continue
108 var pc
= c
.parent_concern
122 # An OrderedTree that can be easily refined for display purposes
124 super OrderedTree[MConcern]
128 # All the classes introduced in the module
129 var intro_mclasses
= new Array[MClass]
131 # All the class definitions of the module
132 # (introduction and refinement)
133 var mclassdefs
= new Array[MClassDef]
135 # Does the current module has a given class `mclass`?
136 # Return true if the mmodule introduces, refines or imports a class.
137 # Visibility is not considered.
138 fun has_mclass
(mclass
: MClass): Bool
140 return self.in_importation
<= mclass
.intro_mmodule
143 # Full hierarchy of introduced ans imported classes.
145 # Create a new hierarchy got by flattening the classes for the module
146 # and its imported modules.
147 # Visibility is not considered.
149 # Note: this function is expensive and is usually used for the main
150 # module of a program only. Do not use it to do you own subtype
152 fun flatten_mclass_hierarchy
: POSet[MClass]
154 var res
= self.flatten_mclass_hierarchy_cache
155 if res
!= null then return res
156 res
= new POSet[MClass]
157 for m
in self.in_importation
.greaters
do
158 for cd
in m
.mclassdefs
do
161 for s
in cd
.supertypes
do
162 res
.add_edge
(c
, s
.mclass
)
166 self.flatten_mclass_hierarchy_cache
= res
170 # Sort a given array of classes using the linearization order of the module
171 # The most general is first, the most specific is last
172 fun linearize_mclasses
(mclasses
: Array[MClass])
174 self.flatten_mclass_hierarchy
.sort
(mclasses
)
177 # Sort a given array of class definitions using the linearization order of the module
178 # the refinement link is stronger than the specialisation link
179 # The most general is first, the most specific is last
180 fun linearize_mclassdefs
(mclassdefs
: Array[MClassDef])
182 var sorter
= new MClassDefSorter(self)
183 sorter
.sort
(mclassdefs
)
186 # Sort a given array of property definitions using the linearization order of the module
187 # the refinement link is stronger than the specialisation link
188 # The most general is first, the most specific is last
189 fun linearize_mpropdefs
(mpropdefs
: Array[MPropDef])
191 var sorter
= new MPropDefSorter(self)
192 sorter
.sort
(mpropdefs
)
195 private var flatten_mclass_hierarchy_cache
: nullable POSet[MClass] = null
197 # The primitive type `Object`, the root of the class hierarchy
198 var object_type
: MClassType = self.get_primitive_class
("Object").mclass_type
is lazy
200 # The type `Pointer`, super class to all extern classes
201 var pointer_type
: MClassType = self.get_primitive_class
("Pointer").mclass_type
is lazy
203 # The primitive type `Bool`
204 var bool_type
: MClassType = self.get_primitive_class
("Bool").mclass_type
is lazy
206 # The primitive type `Int`
207 var int_type
: MClassType = self.get_primitive_class
("Int").mclass_type
is lazy
209 # The primitive type `Byte`
210 var byte_type
: MClassType = self.get_primitive_class
("Byte").mclass_type
is lazy
212 # The primitive type `Char`
213 var char_type
: MClassType = self.get_primitive_class
("Char").mclass_type
is lazy
215 # The primitive type `Float`
216 var float_type
: MClassType = self.get_primitive_class
("Float").mclass_type
is lazy
218 # The primitive type `String`
219 var string_type
: MClassType = self.get_primitive_class
("String").mclass_type
is lazy
221 # The primitive type `NativeString`
222 var native_string_type
: MClassType = self.get_primitive_class
("NativeString").mclass_type
is lazy
224 # A primitive type of `Array`
225 fun array_type
(elt_type
: MType): MClassType do return array_class
.get_mtype
([elt_type
])
227 # The primitive class `Array`
228 var array_class
: MClass = self.get_primitive_class
("Array") is lazy
230 # A primitive type of `NativeArray`
231 fun native_array_type
(elt_type
: MType): MClassType do return native_array_class
.get_mtype
([elt_type
])
233 # The primitive class `NativeArray`
234 var native_array_class
: MClass = self.get_primitive_class
("NativeArray") is lazy
236 # The primitive type `Sys`, the main type of the program, if any
237 fun sys_type
: nullable MClassType
239 var clas
= self.model
.get_mclasses_by_name
("Sys")
240 if clas
== null then return null
241 return get_primitive_class
("Sys").mclass_type
244 # The primitive type `Finalizable`
245 # Used to tag classes that need to be finalized.
246 fun finalizable_type
: nullable MClassType
248 var clas
= self.model
.get_mclasses_by_name
("Finalizable")
249 if clas
== null then return null
250 return get_primitive_class
("Finalizable").mclass_type
253 # Force to get the primitive class named `name` or abort
254 fun get_primitive_class
(name
: String): MClass
256 var cla
= self.model
.get_mclasses_by_name
(name
)
257 # Filter classes by introducing module
258 if cla
!= null then cla
= [for c
in cla
do if self.in_importation
<= c
.intro_mmodule
then c
]
259 if cla
== null or cla
.is_empty
then
260 if name
== "Bool" and self.model
.get_mclasses_by_name
("Object") != null then
261 # Bool is injected because it is needed by engine to code the result
262 # of the implicit casts.
263 var c
= new MClass(self, name
, null, enum_kind
, public_visibility
)
264 var cladef
= new MClassDef(self, c
.mclass_type
, new Location(null, 0,0,0,0))
265 cladef
.set_supertypes
([object_type
])
266 cladef
.add_in_hierarchy
269 print
("Fatal Error: no primitive class {name} in {self}")
272 if cla
.length
!= 1 then
273 var msg
= "Fatal Error: more than one primitive class {name} in {self}:"
274 for c
in cla
do msg
+= " {c.full_name}"
281 # Try to get the primitive method named `name` on the type `recv`
282 fun try_get_primitive_method
(name
: String, recv
: MClass): nullable MMethod
284 var props
= self.model
.get_mproperties_by_name
(name
)
285 if props
== null then return null
286 var res
: nullable MMethod = null
287 for mprop
in props
do
288 assert mprop
isa MMethod
289 var intro
= mprop
.intro_mclassdef
290 for mclassdef
in recv
.mclassdefs
do
291 if not self.in_importation
.greaters
.has
(mclassdef
.mmodule
) then continue
292 if not mclassdef
.in_hierarchy
.greaters
.has
(intro
) then continue
295 else if res
!= mprop
then
296 print
("Fatal Error: ambigous property name '{name}'; conflict between {mprop.full_name} and {res.full_name}")
305 private class MClassDefSorter
307 redef type COMPARED: MClassDef
309 redef fun compare
(a
, b
)
313 if ca
!= cb
then return mmodule
.flatten_mclass_hierarchy
.compare
(ca
, cb
)
314 return mmodule
.model
.mclassdef_hierarchy
.compare
(a
, b
)
318 private class MPropDefSorter
320 redef type COMPARED: MPropDef
322 redef fun compare
(pa
, pb
)
328 if ca
!= cb
then return mmodule
.flatten_mclass_hierarchy
.compare
(ca
, cb
)
329 return mmodule
.model
.mclassdef_hierarchy
.compare
(a
, b
)
335 # `MClass` are global to the model; it means that a `MClass` is not bound to a
336 # specific `MModule`.
338 # This characteristic helps the reasoning about classes in a program since a
339 # single `MClass` object always denote the same class.
341 # The drawback is that classes (`MClass`) contain almost nothing by themselves.
342 # These do not really have properties nor belong to a hierarchy since the property and the
343 # hierarchy of a class depends of the refinement in the modules.
345 # Most services on classes require the precision of a module, and no one can asks what are
346 # the super-classes of a class nor what are properties of a class without precising what is
347 # the module considered.
349 # For instance, during the typing of a source-file, the module considered is the module of the file.
350 # eg. the question *is the method `foo` exists in the class `Bar`?* must be reformulated into
351 # *is the method `foo` exists in the class `Bar` in the current module?*
353 # During some global analysis, the module considered may be the main module of the program.
357 # The module that introduce the class
358 # While classes are not bound to a specific module,
359 # the introducing module is used for naming an visibility
360 var intro_mmodule
: MModule
362 # The short name of the class
363 # In Nit, the name of a class cannot evolve in refinements
364 redef var name
: String
366 # The canonical name of the class
368 # It is the name of the class prefixed by the full_name of the `intro_mmodule`
369 # Example: `"owner::module::MyClass"`
370 redef var full_name
is lazy
do
371 return "{self.intro_mmodule.namespace_for(visibility)}::{name}"
374 redef var c_name
is lazy
do
375 return "{intro_mmodule.c_namespace_for(visibility)}__{name.to_cmangle}"
378 # The number of generic formal parameters
379 # 0 if the class is not generic
380 var arity
: Int is noinit
382 # Each generic formal parameters in order.
383 # is empty if the class is not generic
384 var mparameters
= new Array[MParameterType]
386 # A string version of the signature a generic class.
388 # eg. `Map[K: nullable Object, V: nullable Object]`
390 # If the class in non generic the name is just given.
393 fun signature_to_s
: String
395 if arity
== 0 then return name
396 var res
= new FlatBuffer
399 for i
in [0..arity
[ do
400 if i
> 0 then res
.append
", "
401 res
.append mparameters
[i
].name
403 res
.append intro
.bound_mtype
.arguments
[i
].to_s
409 # Initialize `mparameters` from their names.
410 protected fun setup_parameter_names
(parameter_names
: nullable Array[String]) is
413 if parameter_names
== null then
416 self.arity
= parameter_names
.length
419 # Create the formal parameter types
421 assert parameter_names
!= null
422 var mparametertypes
= new Array[MParameterType]
423 for i
in [0..arity
[ do
424 var mparametertype
= new MParameterType(self, i
, parameter_names
[i
])
425 mparametertypes
.add
(mparametertype
)
427 self.mparameters
= mparametertypes
428 var mclass_type
= new MGenericType(self, mparametertypes
)
429 self.mclass_type
= mclass_type
430 self.get_mtype_cache
[mparametertypes
] = mclass_type
432 self.mclass_type
= new MClassType(self)
436 # The kind of the class (interface, abstract class, etc.)
437 # In Nit, the kind of a class cannot evolve in refinements
440 # The visibility of the class
441 # In Nit, the visibility of a class cannot evolve in refinements
442 var visibility
: MVisibility
446 intro_mmodule
.intro_mclasses
.add
(self)
447 var model
= intro_mmodule
.model
448 model
.mclasses_by_name
.add_one
(name
, self)
449 model
.mclasses
.add
(self)
452 redef fun model
do return intro_mmodule
.model
454 # All class definitions (introduction and refinements)
455 var mclassdefs
= new Array[MClassDef]
458 redef fun to_s
do return self.name
460 # The definition that introduces the class.
462 # Warning: such a definition may not exist in the early life of the object.
463 # In this case, the method will abort.
465 # Use `try_intro` instead
466 var intro
: MClassDef is noinit
468 # The definition that introduces the class or null if not yet known.
471 fun try_intro
: nullable MClassDef do
472 if isset _intro
then return _intro
else return null
475 # Return the class `self` in the class hierarchy of the module `mmodule`.
477 # SEE: `MModule::flatten_mclass_hierarchy`
478 # REQUIRE: `mmodule.has_mclass(self)`
479 fun in_hierarchy
(mmodule
: MModule): POSetElement[MClass]
481 return mmodule
.flatten_mclass_hierarchy
[self]
484 # The principal static type of the class.
486 # For non-generic class, mclass_type is the only `MClassType` based
489 # For a generic class, the arguments are the formal parameters.
490 # i.e.: for the class Array[E:Object], the `mclass_type` is Array[E].
491 # If you want Array[Object] the see `MClassDef::bound_mtype`
493 # For generic classes, the mclass_type is also the way to get a formal
494 # generic parameter type.
496 # To get other types based on a generic class, see `get_mtype`.
498 # ENSURE: `mclass_type.mclass == self`
499 var mclass_type
: MClassType is noinit
501 # Return a generic type based on the class
502 # Is the class is not generic, then the result is `mclass_type`
504 # REQUIRE: `mtype_arguments.length == self.arity`
505 fun get_mtype
(mtype_arguments
: Array[MType]): MClassType
507 assert mtype_arguments
.length
== self.arity
508 if self.arity
== 0 then return self.mclass_type
509 var res
= get_mtype_cache
.get_or_null
(mtype_arguments
)
510 if res
!= null then return res
511 res
= new MGenericType(self, mtype_arguments
)
512 self.get_mtype_cache
[mtype_arguments
.to_a
] = res
516 private var get_mtype_cache
= new HashMap[Array[MType], MGenericType]
518 # Is there a `new` factory to allow the pseudo instantiation?
519 var has_new_factory
= false is writable
521 # Is `self` a standard or abstract class kind?
522 var is_class
: Bool is lazy
do return kind
== concrete_kind
or kind
== abstract_kind
524 # Is `self` an interface kind?
525 var is_interface
: Bool is lazy
do return kind
== interface_kind
527 # Is `self` an enum kind?
528 var is_enum
: Bool is lazy
do return kind
== enum_kind
530 # Is `self` and abstract class?
531 var is_abstract
: Bool is lazy
do return kind
== abstract_kind
535 # A definition (an introduction or a refinement) of a class in a module
537 # A `MClassDef` is associated with an explicit (or almost) definition of a
538 # class. Unlike `MClass`, a `MClassDef` is a local definition that belong to
539 # a specific class and a specific module, and contains declarations like super-classes
542 # It is the class definitions that are the backbone of most things in the model:
543 # ClassDefs are defined with regard with other classdefs.
544 # Refinement and specialization are combined to produce a big poset called the `Model::mclassdef_hierarchy`.
546 # Moreover, the extension and the intention of types is defined by looking at the MClassDefs.
550 # The module where the definition is
553 # The associated `MClass`
554 var mclass
: MClass is noinit
556 # The bounded type associated to the mclassdef
558 # For a non-generic class, `bound_mtype` and `mclass.mclass_type`
562 # For the classdef Array[E: Object], the bound_mtype is Array[Object].
563 # If you want Array[E], then see `mclass.mclass_type`
565 # ENSURE: `bound_mtype.mclass == self.mclass`
566 var bound_mtype
: MClassType
568 # The origin of the definition
569 var location
: Location
571 # Internal name combining the module and the class
572 # Example: "mymodule#MyClass"
573 redef var to_s
: String is noinit
577 self.mclass
= bound_mtype
.mclass
578 mmodule
.mclassdefs
.add
(self)
579 mclass
.mclassdefs
.add
(self)
580 if mclass
.intro_mmodule
== mmodule
then
581 assert not isset mclass
._intro
584 self.to_s
= "{mmodule}#{mclass}"
587 # Actually the name of the `mclass`
588 redef fun name
do return mclass
.name
590 # The module and class name separated by a '#'.
592 # The short-name of the class is used for introduction.
593 # Example: "my_module#MyClass"
595 # The full-name of the class is used for refinement.
596 # Example: "my_module#intro_module::MyClass"
597 redef var full_name
is lazy
do
600 # private gives 'p::m#A'
601 return "{mmodule.namespace_for(mclass.visibility)}#{mclass.name}"
602 else if mclass
.intro_mmodule
.mproject
!= mmodule
.mproject
then
603 # public gives 'q::n#p::A'
604 # private gives 'q::n#p::m::A'
605 return "{mmodule.full_name}#{mclass.full_name}"
606 else if mclass
.visibility
> private_visibility
then
607 # public gives 'p::n#A'
608 return "{mmodule.full_name}#{mclass.name}"
610 # private gives 'p::n#::m::A' (redundant p is omitted)
611 return "{mmodule.full_name}#::{mclass.intro_mmodule.name}::{mclass.name}"
615 redef var c_name
is lazy
do
617 return "{mmodule.c_namespace_for(mclass.visibility)}___{mclass.c_name}"
618 else if mclass
.intro_mmodule
.mproject
== mmodule
.mproject
and mclass
.visibility
> private_visibility
then
619 return "{mmodule.c_name}___{mclass.name.to_cmangle}"
621 return "{mmodule.c_name}___{mclass.c_name}"
625 redef fun model
do return mmodule
.model
627 # All declared super-types
628 # FIXME: quite ugly but not better idea yet
629 var supertypes
= new Array[MClassType]
631 # Register some super-types for the class (ie "super SomeType")
633 # The hierarchy must not already be set
634 # REQUIRE: `self.in_hierarchy == null`
635 fun set_supertypes
(supertypes
: Array[MClassType])
637 assert unique_invocation
: self.in_hierarchy
== null
638 var mmodule
= self.mmodule
639 var model
= mmodule
.model
640 var mtype
= self.bound_mtype
642 for supertype
in supertypes
do
643 self.supertypes
.add
(supertype
)
645 # Register in full_type_specialization_hierarchy
646 model
.full_mtype_specialization_hierarchy
.add_edge
(mtype
, supertype
)
647 # Register in intro_type_specialization_hierarchy
648 if mclass
.intro_mmodule
== mmodule
and supertype
.mclass
.intro_mmodule
== mmodule
then
649 model
.intro_mtype_specialization_hierarchy
.add_edge
(mtype
, supertype
)
655 # Collect the super-types (set by set_supertypes) to build the hierarchy
657 # This function can only invoked once by class
658 # REQUIRE: `self.in_hierarchy == null`
659 # ENSURE: `self.in_hierarchy != null`
662 assert unique_invocation
: self.in_hierarchy
== null
663 var model
= mmodule
.model
664 var res
= model
.mclassdef_hierarchy
.add_node
(self)
665 self.in_hierarchy
= res
666 var mtype
= self.bound_mtype
668 # Here we need to connect the mclassdef to its pairs in the mclassdef_hierarchy
669 # The simpliest way is to attach it to collect_mclassdefs
670 for mclassdef
in mtype
.collect_mclassdefs
(mmodule
) do
671 res
.poset
.add_edge
(self, mclassdef
)
675 # The view of the class definition in `mclassdef_hierarchy`
676 var in_hierarchy
: nullable POSetElement[MClassDef] = null
678 # Is the definition the one that introduced `mclass`?
679 fun is_intro
: Bool do return isset mclass
._intro
and mclass
.intro
== self
681 # All properties introduced by the classdef
682 var intro_mproperties
= new Array[MProperty]
684 # All property definitions in the class (introductions and redefinitions)
685 var mpropdefs
= new Array[MPropDef]
688 # A global static type
690 # MType are global to the model; it means that a `MType` is not bound to a
691 # specific `MModule`.
692 # This characteristic helps the reasoning about static types in a program
693 # since a single `MType` object always denote the same type.
695 # However, because a `MType` is global, it does not really have properties
696 # nor have subtypes to a hierarchy since the property and the class hierarchy
697 # depends of a module.
698 # Moreover, virtual types an formal generic parameter types also depends on
699 # a receiver to have sense.
701 # Therefore, most method of the types require a module and an anchor.
702 # The module is used to know what are the classes and the specialization
704 # The anchor is used to know what is the bound of the virtual types and formal
705 # generic parameter types.
707 # MType are not directly usable to get properties. See the `anchor_to` method
708 # and the `MClassType` class.
710 # FIXME: the order of the parameters is not the best. We mus pick on from:
711 # * foo(mmodule, anchor, othertype)
712 # * foo(othertype, anchor, mmodule)
713 # * foo(anchor, mmodule, othertype)
714 # * foo(othertype, mmodule, anchor)
718 redef fun name
do return to_s
720 # Return true if `self` is an subtype of `sup`.
721 # The typing is done using the standard typing policy of Nit.
723 # REQUIRE: `anchor == null implies not self.need_anchor and not sup.need_anchor`
724 # REQUIRE: `anchor != null implies self.can_resolve_for(anchor, null, mmodule) and sup.can_resolve_for(anchor, null, mmodule)`
725 fun is_subtype
(mmodule
: MModule, anchor
: nullable MClassType, sup
: MType): Bool
728 if sub
== sup
then return true
730 #print "1.is {sub} a {sup}? ===="
732 if anchor
== null then
733 assert not sub
.need_anchor
734 assert not sup
.need_anchor
736 # First, resolve the formal types to the simplest equivalent forms in the receiver
737 assert sub
.can_resolve_for
(anchor
, null, mmodule
)
738 sub
= sub
.lookup_fixed
(mmodule
, anchor
)
739 assert sup
.can_resolve_for
(anchor
, null, mmodule
)
740 sup
= sup
.lookup_fixed
(mmodule
, anchor
)
743 # Does `sup` accept null or not?
744 # Discard the nullable marker if it exists
745 var sup_accept_null
= false
746 if sup
isa MNullableType then
747 sup_accept_null
= true
749 else if sup
isa MNotNullType then
751 else if sup
isa MNullType then
752 sup_accept_null
= true
755 # Can `sub` provide null or not?
756 # Thus we can match with `sup_accept_null`
757 # Also discard the nullable marker if it exists
758 var sub_reject_null
= false
759 if sub
isa MNullableType then
760 if not sup_accept_null
then return false
762 else if sub
isa MNotNullType then
763 sub_reject_null
= true
765 else if sub
isa MNullType then
766 return sup_accept_null
768 # Now the case of direct null and nullable is over.
770 # If `sub` is a formal type, then it is accepted if its bound is accepted
771 while sub
isa MFormalType do
772 #print "3.is {sub} a {sup}?"
774 # A unfixed formal type can only accept itself
775 if sub
== sup
then return true
777 assert anchor
!= null
778 sub
= sub
.lookup_bound
(mmodule
, anchor
)
779 if sub_reject_null
then sub
= sub
.as_notnull
781 #print "3.is {sub} a {sup}?"
783 # Manage the second layer of null/nullable
784 if sub
isa MNullableType then
785 if not sup_accept_null
and not sub_reject_null
then return false
787 else if sub
isa MNotNullType then
788 sub_reject_null
= true
790 else if sub
isa MNullType then
791 return sup_accept_null
794 #print "4.is {sub} a {sup}? <- no more resolution"
796 assert sub
isa MClassType else print
"{sub} <? {sub}" # It is the only remaining type
798 # A unfixed formal type can only accept itself
799 if sup
isa MFormalType then
803 if sup
isa MNullType then
804 # `sup` accepts only null
808 assert sup
isa MClassType # It is the only remaining type
810 # Now both are MClassType, we need to dig
812 if sub
== sup
then return true
814 if anchor
== null then anchor
= sub
# UGLY: any anchor will work
815 var resolved_sub
= sub
.anchor_to
(mmodule
, anchor
)
816 var res
= resolved_sub
.collect_mclasses
(mmodule
).has
(sup
.mclass
)
817 if res
== false then return false
818 if not sup
isa MGenericType then return true
819 var sub2
= sub
.supertype_to
(mmodule
, anchor
, sup
.mclass
)
820 assert sub2
.mclass
== sup
.mclass
821 for i
in [0..sup
.mclass
.arity
[ do
822 var sub_arg
= sub2
.arguments
[i
]
823 var sup_arg
= sup
.arguments
[i
]
824 res
= sub_arg
.is_subtype
(mmodule
, anchor
, sup_arg
)
825 if res
== false then return false
830 # The base class type on which self is based
832 # This base type is used to get property (an internally to perform
833 # unsafe type comparison).
835 # Beware: some types (like null) are not based on a class thus this
838 # Basically, this function transform the virtual types and parameter
839 # types to their bounds.
844 # class B super A end
846 # class Y super X end
855 # Map[T,U] anchor_to H #-> Map[B,Y]
857 # Explanation of the example:
858 # In H, T is set to B, because "H super G[B]", and U is bound to Y,
859 # because "redef type U: Y". Therefore, Map[T, U] is bound to
862 # ENSURE: `not self.need_anchor implies result == self`
863 # ENSURE: `not result.need_anchor`
864 fun anchor_to
(mmodule
: MModule, anchor
: MClassType): MType
866 if not need_anchor
then return self
867 assert not anchor
.need_anchor
868 # Just resolve to the anchor and clear all the virtual types
869 var res
= self.resolve_for
(anchor
, null, mmodule
, true)
870 assert not res
.need_anchor
874 # Does `self` contain a virtual type or a formal generic parameter type?
875 # In order to remove those types, you usually want to use `anchor_to`.
876 fun need_anchor
: Bool do return true
878 # Return the supertype when adapted to a class.
880 # In Nit, for each super-class of a type, there is a equivalent super-type.
886 # class H[V] super G[V, Bool] end
888 # H[Int] supertype_to G #-> G[Int, Bool]
891 # REQUIRE: `super_mclass` is a super-class of `self`
892 # REQUIRE: `self.need_anchor implies anchor != null and self.can_resolve_for(anchor, null, mmodule)`
893 # ENSURE: `result.mclass = super_mclass`
894 fun supertype_to
(mmodule
: MModule, anchor
: nullable MClassType, super_mclass
: MClass): MClassType
896 if super_mclass
.arity
== 0 then return super_mclass
.mclass_type
897 if self isa MClassType and self.mclass
== super_mclass
then return self
899 if self.need_anchor
then
900 assert anchor
!= null
901 resolved_self
= self.anchor_to
(mmodule
, anchor
)
905 var supertypes
= resolved_self
.collect_mtypes
(mmodule
)
906 for supertype
in supertypes
do
907 if supertype
.mclass
== super_mclass
then
908 # FIXME: Here, we stop on the first goal. Should we check others and detect inconsistencies?
909 return supertype
.resolve_for
(self, anchor
, mmodule
, false)
915 # Replace formals generic types in self with resolved values in `mtype`
916 # If `cleanup_virtual` is true, then virtual types are also replaced
919 # This function returns self if `need_anchor` is false.
925 # class H[F] super G[F] end
929 # * Array[E].resolve_for(H[Int]) #-> Array[Int]
930 # * Array[E].resolve_for(G[Z], X[Int]) #-> Array[Z]
932 # Explanation of the example:
933 # * Array[E].need_anchor is true because there is a formal generic parameter type E
934 # * E makes sense for H[Int] because E is a formal parameter of G and H specialize G
935 # * Since "H[F] super G[F]", E is in fact F for H
936 # * More specifically, in H[Int], E is Int
937 # * So, in H[Int], Array[E] is Array[Int]
939 # This function is mainly used to inherit a signature.
940 # Because, unlike `anchor_to`, we do not want a full resolution of
941 # a type but only an adapted version of it.
947 # fun foo(e:E):E is abstract
949 # class B super A[Int] end
952 # The signature on foo is (e: E): E
953 # If we resolve the signature for B, we get (e:Int):Int
959 # fun foo(e:E):E is abstract
963 # fun bar do a.foo(x) # <- x is here
967 # The first question is: is foo available on `a`?
969 # The static type of a is `A[Array[F]]`, that is an open type.
970 # in order to find a method `foo`, whe must look at a resolved type.
972 # A[Array[F]].anchor_to(C[nullable Object]) #-> A[Array[nullable Object]]
974 # the method `foo` exists in `A[Array[nullable Object]]`, therefore `foo` exists for `a`.
976 # The next question is: what is the accepted types for `x`?
978 # the signature of `foo` is `foo(e:E)`, thus we must resolve the type E
980 # E.resolve_for(A[Array[F]],C[nullable Object]) #-> Array[F]
982 # The resolution can be done because `E` make sense for the class A (see `can_resolve_for`)
984 # FIXME: the parameter `cleanup_virtual` is just a bad idea, but having
985 # two function instead of one seems also to be a bad idea.
987 # REQUIRE: `can_resolve_for(mtype, anchor, mmodule)`
988 # ENSURE: `not self.need_anchor implies result == self`
989 fun resolve_for
(mtype
: MType, anchor
: nullable MClassType, mmodule
: MModule, cleanup_virtual
: Bool): MType is abstract
991 # Resolve formal type to its verbatim bound.
992 # If the type is not formal, just return self
994 # The result is returned exactly as declared in the "type" property (verbatim).
995 # So it could be another formal type.
997 # In case of conflict, the method aborts.
998 fun lookup_bound
(mmodule
: MModule, resolved_receiver
: MType): MType do return self
1000 # Resolve the formal type to its simplest equivalent form.
1002 # Formal types are either free or fixed.
1003 # When it is fixed, it means that it is equivalent with a simpler type.
1004 # When a formal type is free, it means that it is only equivalent with itself.
1005 # This method return the most simple equivalent type of `self`.
1007 # This method is mainly used for subtype test in order to sanely compare fixed.
1009 # By default, return self.
1010 # See the redefinitions for specific behavior in each kind of type.
1011 fun lookup_fixed
(mmodule
: MModule, resolved_receiver
: MType): MType do return self
1013 # Can the type be resolved?
1015 # In order to resolve open types, the formal types must make sence.
1025 # E.can_resolve_for(A[Int]) #-> true, E make sense in A
1027 # E.can_resolve_for(B[Int]) #-> false, E does not make sense in B
1029 # B[E].can_resolve_for(A[F], B[Object]) #-> true,
1030 # # B[E] is a red hearing only the E is important,
1031 # # E make sense in A
1034 # REQUIRE: `anchor != null implies not anchor.need_anchor`
1035 # REQUIRE: `mtype.need_anchor implies anchor != null and mtype.can_resolve_for(anchor, null, mmodule)`
1036 # ENSURE: `not self.need_anchor implies result == true`
1037 fun can_resolve_for
(mtype
: MType, anchor
: nullable MClassType, mmodule
: MModule): Bool is abstract
1039 # Return the nullable version of the type
1040 # If the type is already nullable then self is returned
1041 fun as_nullable
: MType
1043 var res
= self.as_nullable_cache
1044 if res
!= null then return res
1045 res
= new MNullableType(self)
1046 self.as_nullable_cache
= res
1050 # Remove the base type of a decorated (proxy) type.
1051 # Is the type is not decorated, then self is returned.
1053 # Most of the time it is used to return the not nullable version of a nullable type.
1054 # In this case, this just remove the `nullable` notation, but the result can still contains null.
1055 # For instance if `self isa MNullType` or self is a formal type bounded by a nullable type.
1056 # If you really want to exclude the `null` value, then use `as_notnull`
1057 fun undecorate
: MType
1062 # Returns the not null version of the type.
1063 # That is `self` minus the `null` value.
1065 # For most types, this return `self`.
1066 # For formal types, this returns a special `MNotNullType`
1067 fun as_notnull
: MType do return self
1069 private var as_nullable_cache
: nullable MType = null
1072 # The depth of the type seen as a tree.
1079 # Formal types have a depth of 1.
1085 # The length of the type seen as a tree.
1092 # Formal types have a length of 1.
1098 # Compute all the classdefs inherited/imported.
1099 # The returned set contains:
1100 # * the class definitions from `mmodule` and its imported modules
1101 # * the class definitions of this type and its super-types
1103 # This function is used mainly internally.
1105 # REQUIRE: `not self.need_anchor`
1106 fun collect_mclassdefs
(mmodule
: MModule): Set[MClassDef] is abstract
1108 # Compute all the super-classes.
1109 # This function is used mainly internally.
1111 # REQUIRE: `not self.need_anchor`
1112 fun collect_mclasses
(mmodule
: MModule): Set[MClass] is abstract
1114 # Compute all the declared super-types.
1115 # Super-types are returned as declared in the classdefs (verbatim).
1116 # This function is used mainly internally.
1118 # REQUIRE: `not self.need_anchor`
1119 fun collect_mtypes
(mmodule
: MModule): Set[MClassType] is abstract
1121 # Is the property in self for a given module
1122 # This method does not filter visibility or whatever
1124 # REQUIRE: `not self.need_anchor`
1125 fun has_mproperty
(mmodule
: MModule, mproperty
: MProperty): Bool
1127 assert not self.need_anchor
1128 return self.collect_mclassdefs
(mmodule
).has
(mproperty
.intro_mclassdef
)
1132 # A type based on a class.
1134 # `MClassType` have properties (see `has_mproperty`).
1138 # The associated class
1141 redef fun model
do return self.mclass
.intro_mmodule
.model
1143 # TODO: private init because strongly bounded to its mclass. see `mclass.mclass_type`
1145 # The formal arguments of the type
1146 # ENSURE: `result.length == self.mclass.arity`
1147 var arguments
= new Array[MType]
1149 redef fun to_s
do return mclass
.to_s
1151 redef fun full_name
do return mclass
.full_name
1153 redef fun c_name
do return mclass
.c_name
1155 redef fun need_anchor
do return false
1157 redef fun anchor_to
(mmodule
: MModule, anchor
: MClassType): MClassType
1159 return super.as(MClassType)
1162 redef fun resolve_for
(mtype
: MType, anchor
: nullable MClassType, mmodule
: MModule, cleanup_virtual
: Bool): MClassType do return self
1164 redef fun can_resolve_for
(mtype
, anchor
, mmodule
) do return true
1166 redef fun collect_mclassdefs
(mmodule
)
1168 assert not self.need_anchor
1169 var cache
= self.collect_mclassdefs_cache
1170 if not cache
.has_key
(mmodule
) then
1171 self.collect_things
(mmodule
)
1173 return cache
[mmodule
]
1176 redef fun collect_mclasses
(mmodule
)
1178 if collect_mclasses_last_module
== mmodule
then return collect_mclasses_last_module_cache
1179 assert not self.need_anchor
1180 var cache
= self.collect_mclasses_cache
1181 if not cache
.has_key
(mmodule
) then
1182 self.collect_things
(mmodule
)
1184 var res
= cache
[mmodule
]
1185 collect_mclasses_last_module
= mmodule
1186 collect_mclasses_last_module_cache
= res
1190 private var collect_mclasses_last_module
: nullable MModule = null
1191 private var collect_mclasses_last_module_cache
: Set[MClass] is noinit
1193 redef fun collect_mtypes
(mmodule
)
1195 assert not self.need_anchor
1196 var cache
= self.collect_mtypes_cache
1197 if not cache
.has_key
(mmodule
) then
1198 self.collect_things
(mmodule
)
1200 return cache
[mmodule
]
1203 # common implementation for `collect_mclassdefs`, `collect_mclasses`, and `collect_mtypes`.
1204 private fun collect_things
(mmodule
: MModule)
1206 var res
= new HashSet[MClassDef]
1207 var seen
= new HashSet[MClass]
1208 var types
= new HashSet[MClassType]
1209 seen
.add
(self.mclass
)
1210 var todo
= [self.mclass
]
1211 while not todo
.is_empty
do
1212 var mclass
= todo
.pop
1213 #print "process {mclass}"
1214 for mclassdef
in mclass
.mclassdefs
do
1215 if not mmodule
.in_importation
<= mclassdef
.mmodule
then continue
1216 #print " process {mclassdef}"
1218 for supertype
in mclassdef
.supertypes
do
1219 types
.add
(supertype
)
1220 var superclass
= supertype
.mclass
1221 if seen
.has
(superclass
) then continue
1222 #print " add {superclass}"
1223 seen
.add
(superclass
)
1224 todo
.add
(superclass
)
1228 collect_mclassdefs_cache
[mmodule
] = res
1229 collect_mclasses_cache
[mmodule
] = seen
1230 collect_mtypes_cache
[mmodule
] = types
1233 private var collect_mclassdefs_cache
= new HashMap[MModule, Set[MClassDef]]
1234 private var collect_mclasses_cache
= new HashMap[MModule, Set[MClass]]
1235 private var collect_mtypes_cache
= new HashMap[MModule, Set[MClassType]]
1239 # A type based on a generic class.
1240 # A generic type a just a class with additional formal generic arguments.
1246 # TODO: private init because strongly bounded to its mclass. see `mclass.get_mtype`
1250 assert self.mclass
.arity
== arguments
.length
1252 self.need_anchor
= false
1253 for t
in arguments
do
1254 if t
.need_anchor
then
1255 self.need_anchor
= true
1260 self.to_s
= "{mclass}[{arguments.join(", ")}]"
1263 # The short-name of the class, then the full-name of each type arguments within brackets.
1264 # Example: `"Map[String, List[Int]]"`
1265 redef var to_s
: String is noinit
1267 # The full-name of the class, then the full-name of each type arguments within brackets.
1268 # Example: `"standard::Map[standard::String, standard::List[standard::Int]]"`
1269 redef var full_name
is lazy
do
1270 var args
= new Array[String]
1271 for t
in arguments
do
1272 args
.add t
.full_name
1274 return "{mclass.full_name}[{args.join(", ")}]"
1277 redef var c_name
is lazy
do
1278 var res
= mclass
.c_name
1279 # Note: because the arity is known, a prefix notation is enough
1280 for t
in arguments
do
1287 redef var need_anchor
: Bool is noinit
1289 redef fun resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1291 if not need_anchor
then return self
1292 assert can_resolve_for
(mtype
, anchor
, mmodule
)
1293 var types
= new Array[MType]
1294 for t
in arguments
do
1295 types
.add
(t
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
))
1297 return mclass
.get_mtype
(types
)
1300 redef fun can_resolve_for
(mtype
, anchor
, mmodule
)
1302 if not need_anchor
then return true
1303 for t
in arguments
do
1304 if not t
.can_resolve_for
(mtype
, anchor
, mmodule
) then return false
1313 for a
in self.arguments
do
1315 if d
> dmax
then dmax
= d
1323 for a
in self.arguments
do
1330 # A formal type (either virtual of parametric).
1332 # The main issue with formal types is that they offer very little information on their own
1333 # and need a context (anchor and mmodule) to be useful.
1334 abstract class MFormalType
1337 redef var as_notnull
= new MNotNullType(self) is lazy
1340 # A virtual formal type.
1344 # The property associated with the type.
1345 # Its the definitions of this property that determine the bound or the virtual type.
1346 var mproperty
: MVirtualTypeProp
1348 redef fun model
do return self.mproperty
.intro_mclassdef
.mmodule
.model
1350 redef fun lookup_bound
(mmodule
: MModule, resolved_receiver
: MType): MType
1352 return lookup_single_definition
(mmodule
, resolved_receiver
).bound
.as(not null)
1355 private fun lookup_single_definition
(mmodule
: MModule, resolved_receiver
: MType): MVirtualTypeDef
1357 assert not resolved_receiver
.need_anchor
1358 var props
= self.mproperty
.lookup_definitions
(mmodule
, resolved_receiver
)
1359 if props
.is_empty
then
1361 else if props
.length
== 1 then
1364 var types
= new ArraySet[MType]
1365 var res
= props
.first
1367 types
.add
(p
.bound
.as(not null))
1368 if not res
.is_fixed
then res
= p
1370 if types
.length
== 1 then
1376 # A VT is fixed when:
1377 # * the VT is (re-)defined with the annotation `is fixed`
1378 # * the VT is (indirectly) bound to an enum class (see `enum_kind`) since there is no subtype possible
1379 # * the receiver is an enum class since there is no subtype possible
1380 redef fun lookup_fixed
(mmodule
: MModule, resolved_receiver
: MType): MType
1382 assert not resolved_receiver
.need_anchor
1383 resolved_receiver
= resolved_receiver
.undecorate
1384 assert resolved_receiver
isa MClassType # It is the only remaining type
1386 var prop
= lookup_single_definition
(mmodule
, resolved_receiver
)
1387 var res
= prop
.bound
.as(not null)
1389 # Recursively lookup the fixed result
1390 res
= res
.lookup_fixed
(mmodule
, resolved_receiver
)
1392 # 1. For a fixed VT, return the resolved bound
1393 if prop
.is_fixed
then return res
1395 # 2. For a enum boud, return the bound
1396 if res
isa MClassType and res
.mclass
.kind
== enum_kind
then return res
1398 # 3. for a enum receiver return the bound
1399 if resolved_receiver
.mclass
.kind
== enum_kind
then return res
1404 redef fun resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1406 if not cleanup_virtual
then return self
1407 assert can_resolve_for
(mtype
, anchor
, mmodule
)
1408 # self is a virtual type declared (or inherited) in mtype
1409 # The point of the function it to get the bound of the virtual type that make sense for mtype
1410 # But because mtype is maybe a virtual/formal type, we need to get a real receiver first
1411 #print "{class_name}: {self}/{mtype}/{anchor}?"
1412 var resolved_receiver
1413 if mtype
.need_anchor
then
1414 assert anchor
!= null
1415 resolved_receiver
= mtype
.resolve_for
(anchor
, null, mmodule
, true)
1417 resolved_receiver
= mtype
1419 # Now, we can get the bound
1420 var verbatim_bound
= lookup_bound
(mmodule
, resolved_receiver
)
1421 # The bound is exactly as declared in the "type" property, so we must resolve it again
1422 var res
= verbatim_bound
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1427 redef fun can_resolve_for
(mtype
, anchor
, mmodule
)
1429 if mtype
.need_anchor
then
1430 assert anchor
!= null
1431 mtype
= mtype
.anchor_to
(mmodule
, anchor
)
1433 return mtype
.has_mproperty
(mmodule
, mproperty
)
1436 redef fun to_s
do return self.mproperty
.to_s
1438 redef fun full_name
do return self.mproperty
.full_name
1440 redef fun c_name
do return self.mproperty
.c_name
1443 # The type associated to a formal parameter generic type of a class
1445 # Each parameter type is associated to a specific class.
1446 # It means that all refinements of a same class "share" the parameter type,
1447 # but that a generic subclass has its own parameter types.
1449 # However, in the sense of the meta-model, a parameter type of a class is
1450 # a valid type in a subclass. The "in the sense of the meta-model" is
1451 # important because, in the Nit language, the programmer cannot refers
1452 # directly to the parameter types of the super-classes.
1457 # fun e: E is abstract
1463 # In the class definition B[F], `F` is a valid type but `E` is not.
1464 # However, `self.e` is a valid method call, and the signature of `e` is
1467 # Note that parameter types are shared among class refinements.
1468 # Therefore parameter only have an internal name (see `to_s` for details).
1469 class MParameterType
1472 # The generic class where the parameter belong
1475 redef fun model
do return self.mclass
.intro_mmodule
.model
1477 # The position of the parameter (0 for the first parameter)
1478 # FIXME: is `position` a better name?
1483 redef fun to_s
do return name
1485 redef var full_name
is lazy
do return "{mclass.full_name}::{name}"
1487 redef var c_name
is lazy
do return mclass
.c_name
+ "__" + "#{name}".to_cmangle
1489 redef fun lookup_bound
(mmodule
: MModule, resolved_receiver
: MType): MType
1491 assert not resolved_receiver
.need_anchor
1492 resolved_receiver
= resolved_receiver
.undecorate
1493 assert resolved_receiver
isa MClassType # It is the only remaining type
1494 var goalclass
= self.mclass
1495 if resolved_receiver
.mclass
== goalclass
then
1496 return resolved_receiver
.arguments
[self.rank
]
1498 var supertypes
= resolved_receiver
.collect_mtypes
(mmodule
)
1499 for t
in supertypes
do
1500 if t
.mclass
== goalclass
then
1501 # Yeah! c specialize goalclass with a "super `t'". So the question is what is the argument of f
1502 # FIXME: Here, we stop on the first goal. Should we check others and detect inconsistencies?
1503 var res
= t
.arguments
[self.rank
]
1510 # A PT is fixed when:
1511 # * Its bound is a enum class (see `enum_kind`).
1512 # The PT is just useless, but it is still a case.
1513 # * More usually, the `resolved_receiver` is a subclass of `self.mclass`,
1514 # so it is necessarily fixed in a `super` clause, either with a normal type
1515 # or with another PT.
1516 # See `resolve_for` for examples about related issues.
1517 redef fun lookup_fixed
(mmodule
: MModule, resolved_receiver
: MType): MType
1519 assert not resolved_receiver
.need_anchor
1520 resolved_receiver
= resolved_receiver
.undecorate
1521 assert resolved_receiver
isa MClassType # It is the only remaining type
1522 var res
= self.resolve_for
(resolved_receiver
.mclass
.mclass_type
, resolved_receiver
, mmodule
, false)
1526 redef fun resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1528 assert can_resolve_for
(mtype
, anchor
, mmodule
)
1529 #print "{class_name}: {self}/{mtype}/{anchor}?"
1531 if mtype
isa MGenericType and mtype
.mclass
== self.mclass
then
1532 var res
= mtype
.arguments
[self.rank
]
1533 if anchor
!= null and res
.need_anchor
then
1534 # Maybe the result can be resolved more if are bound to a final class
1535 var r2
= res
.anchor_to
(mmodule
, anchor
)
1536 if r2
isa MClassType and r2
.mclass
.kind
== enum_kind
then return r2
1541 # self is a parameter type of mtype (or of a super-class of mtype)
1542 # The point of the function it to get the bound of the virtual type that make sense for mtype
1543 # But because mtype is maybe a virtual/formal type, we need to get a real receiver first
1544 # FIXME: What happens here is far from clear. Thus this part must be validated and clarified
1545 var resolved_receiver
1546 if mtype
.need_anchor
then
1547 assert anchor
!= null
1548 resolved_receiver
= mtype
.resolve_for
(anchor
.mclass
.mclass_type
, anchor
, mmodule
, true)
1550 resolved_receiver
= mtype
1552 if resolved_receiver
isa MNullableType then resolved_receiver
= resolved_receiver
.mtype
1553 if resolved_receiver
isa MParameterType then
1554 assert resolved_receiver
.mclass
== anchor
.mclass
1555 resolved_receiver
= anchor
.arguments
[resolved_receiver
.rank
]
1556 if resolved_receiver
isa MNullableType then resolved_receiver
= resolved_receiver
.mtype
1558 assert resolved_receiver
isa MClassType # It is the only remaining type
1560 # Eh! The parameter is in the current class.
1561 # So we return the corresponding argument, no mater what!
1562 if resolved_receiver
.mclass
== self.mclass
then
1563 var res
= resolved_receiver
.arguments
[self.rank
]
1564 #print "{class_name}: {self}/{mtype}/{anchor} -> direct {res}"
1568 if resolved_receiver
.need_anchor
then
1569 assert anchor
!= null
1570 resolved_receiver
= resolved_receiver
.resolve_for
(anchor
, null, mmodule
, false)
1572 # Now, we can get the bound
1573 var verbatim_bound
= lookup_bound
(mmodule
, resolved_receiver
)
1574 # The bound is exactly as declared in the "type" property, so we must resolve it again
1575 var res
= verbatim_bound
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1577 #print "{class_name}: {self}/{mtype}/{anchor} -> indirect {res}"
1582 redef fun can_resolve_for
(mtype
, anchor
, mmodule
)
1584 if mtype
.need_anchor
then
1585 assert anchor
!= null
1586 mtype
= mtype
.anchor_to
(mmodule
, anchor
)
1588 return mtype
.collect_mclassdefs
(mmodule
).has
(mclass
.intro
)
1592 # A type that decorates another type.
1594 # The point of this class is to provide a common implementation of sevices that just forward to the original type.
1595 # Specific decorator are expected to redefine (or to extend) the default implementation as this suit them.
1596 abstract class MProxyType
1601 redef fun model
do return self.mtype
.model
1602 redef fun need_anchor
do return mtype
.need_anchor
1603 redef fun as_nullable
do return mtype
.as_nullable
1604 redef fun as_notnull
do return mtype
.as_notnull
1605 redef fun undecorate
do return mtype
.undecorate
1606 redef fun resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1608 var res
= self.mtype
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1612 redef fun can_resolve_for
(mtype
, anchor
, mmodule
)
1614 return self.mtype
.can_resolve_for
(mtype
, anchor
, mmodule
)
1617 redef fun lookup_fixed
(mmodule
, resolved_receiver
)
1619 var t
= mtype
.lookup_fixed
(mmodule
, resolved_receiver
)
1623 redef fun depth
do return self.mtype
.depth
1625 redef fun length
do return self.mtype
.length
1627 redef fun collect_mclassdefs
(mmodule
)
1629 assert not self.need_anchor
1630 return self.mtype
.collect_mclassdefs
(mmodule
)
1633 redef fun collect_mclasses
(mmodule
)
1635 assert not self.need_anchor
1636 return self.mtype
.collect_mclasses
(mmodule
)
1639 redef fun collect_mtypes
(mmodule
)
1641 assert not self.need_anchor
1642 return self.mtype
.collect_mtypes
(mmodule
)
1646 # A type prefixed with "nullable"
1652 self.to_s
= "nullable {mtype}"
1655 redef var to_s
: String is noinit
1657 redef var full_name
is lazy
do return "nullable {mtype.full_name}"
1659 redef var c_name
is lazy
do return "nullable__{mtype.c_name}"
1661 redef fun as_nullable
do return self
1662 redef fun resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1665 return res
.as_nullable
1668 # Efficiently returns `mtype.lookup_fixed(mmodule, resolved_receiver).as_nullable`
1669 redef fun lookup_fixed
(mmodule
, resolved_receiver
)
1672 if t
== mtype
then return self
1673 return t
.as_nullable
1677 # A non-null version of a formal type.
1679 # When a formal type in bounded to a nullable type, this is the type of the not null version of it.
1683 redef fun to_s
do return "not null {mtype}"
1684 redef var full_name
is lazy
do return "not null {mtype.full_name}"
1685 redef var c_name
is lazy
do return "notnull__{mtype.c_name}"
1687 redef fun as_notnull
do return self
1689 redef fun resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1692 return res
.as_notnull
1695 # Efficiently returns `mtype.lookup_fixed(mmodule, resolved_receiver).as_notnull`
1696 redef fun lookup_fixed
(mmodule
, resolved_receiver
)
1699 if t
== mtype
then return self
1704 # The type of the only value null
1706 # The is only one null type per model, see `MModel::null_type`.
1709 redef var model
: Model
1710 redef fun to_s
do return "null"
1711 redef fun full_name
do return "null"
1712 redef fun c_name
do return "null"
1713 redef fun as_nullable
do return self
1715 redef var as_notnull
= new MBottomType(model
) is lazy
1716 redef fun need_anchor
do return false
1717 redef fun resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
) do return self
1718 redef fun can_resolve_for
(mtype
, anchor
, mmodule
) do return true
1720 redef fun collect_mclassdefs
(mmodule
) do return new HashSet[MClassDef]
1722 redef fun collect_mclasses
(mmodule
) do return new HashSet[MClass]
1724 redef fun collect_mtypes
(mmodule
) do return new HashSet[MClassType]
1727 # The special universal most specific type.
1729 # This type is intended to be only used internally for type computation or analysis and should not be exposed to the user.
1730 # The bottom type can de used to denote things that are absurd, dead, or the absence of knowledge.
1732 # Semantically it is the singleton `null.as_notnull`.
1735 redef var model
: Model
1736 redef fun to_s
do return "bottom"
1737 redef fun full_name
do return "bottom"
1738 redef fun c_name
do return "bottom"
1739 redef fun as_nullable
do return model
.null_type
1740 redef fun as_notnull
do return self
1741 redef fun need_anchor
do return false
1742 redef fun resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
) do return self
1743 redef fun can_resolve_for
(mtype
, anchor
, mmodule
) do return true
1745 redef fun collect_mclassdefs
(mmodule
) do return new HashSet[MClassDef]
1747 redef fun collect_mclasses
(mmodule
) do return new HashSet[MClass]
1749 redef fun collect_mtypes
(mmodule
) do return new HashSet[MClassType]
1752 # A signature of a method
1756 # The each parameter (in order)
1757 var mparameters
: Array[MParameter]
1759 # Returns a parameter named `name`, if any.
1760 fun mparameter_by_name
(name
: String): nullable MParameter
1762 for p
in mparameters
do
1763 if p
.name
== name
then return p
1768 # The return type (null for a procedure)
1769 var return_mtype
: nullable MType
1774 var t
= self.return_mtype
1775 if t
!= null then dmax
= t
.depth
1776 for p
in mparameters
do
1777 var d
= p
.mtype
.depth
1778 if d
> dmax
then dmax
= d
1786 var t
= self.return_mtype
1787 if t
!= null then res
+= t
.length
1788 for p
in mparameters
do
1789 res
+= p
.mtype
.length
1794 # REQUIRE: 1 <= mparameters.count p -> p.is_vararg
1797 var vararg_rank
= -1
1798 for i
in [0..mparameters
.length
[ do
1799 var parameter
= mparameters
[i
]
1800 if parameter
.is_vararg
then
1801 assert vararg_rank
== -1
1805 self.vararg_rank
= vararg_rank
1808 # The rank of the ellipsis (`...`) for vararg (starting from 0).
1809 # value is -1 if there is no vararg.
1810 # Example: for "(a: Int, b: Bool..., c: Char)" #-> vararg_rank=1
1811 var vararg_rank
: Int is noinit
1813 # The number of parameters
1814 fun arity
: Int do return mparameters
.length
1816 # The number of non-default parameters
1818 # The number of default parameters is then `arity-min_arity`.
1820 # Note that there cannot be both varargs and default prameters, thus
1821 # if `vararg_rank != -1` then `min_arity` == `arity`
1824 if vararg_rank
!= -1 then return arity
1826 for p
in mparameters
do
1827 if not p
.is_default
then res
+= 1
1834 var b
= new FlatBuffer
1835 if not mparameters
.is_empty
then
1837 for i
in [0..mparameters
.length
[ do
1838 var mparameter
= mparameters
[i
]
1839 if i
> 0 then b
.append
(", ")
1840 b
.append
(mparameter
.name
)
1842 b
.append
(mparameter
.mtype
.to_s
)
1843 if mparameter
.is_vararg
then
1849 var ret
= self.return_mtype
1857 redef fun resolve_for
(mtype
: MType, anchor
: nullable MClassType, mmodule
: MModule, cleanup_virtual
: Bool): MSignature
1859 var params
= new Array[MParameter]
1860 for p
in self.mparameters
do
1861 params
.add
(p
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
))
1863 var ret
= self.return_mtype
1865 ret
= ret
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1867 var res
= new MSignature(params
, ret
)
1872 # A parameter in a signature
1876 # The name of the parameter
1877 redef var name
: String
1879 # The static type of the parameter
1882 # Is the parameter a vararg?
1885 # Is the parameter a default one?
1886 var is_default
: Bool
1891 return "{name}: {mtype}..."
1893 return "{name}: {mtype}"
1897 # Returns a new parameter with the `mtype` resolved.
1898 # See `MType::resolve_for` for details.
1899 fun resolve_for
(mtype
: MType, anchor
: nullable MClassType, mmodule
: MModule, cleanup_virtual
: Bool): MParameter
1901 if not self.mtype
.need_anchor
then return self
1902 var newtype
= self.mtype
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1903 var res
= new MParameter(self.name
, newtype
, self.is_vararg
, self.is_default
)
1907 redef fun model
do return mtype
.model
1910 # A service (global property) that generalize method, attribute, etc.
1912 # `MProperty` are global to the model; it means that a `MProperty` is not bound
1913 # to a specific `MModule` nor a specific `MClass`.
1915 # A MProperty gather definitions (see `mpropdefs`) ; one for the introduction
1916 # and the other in subclasses and in refinements.
1918 # A `MProperty` is used to denotes services in polymorphic way (ie. independent
1919 # of any dynamic type).
1920 # For instance, a call site "x.foo" is associated to a `MProperty`.
1921 abstract class MProperty
1924 # The associated MPropDef subclass.
1925 # The two specialization hierarchy are symmetric.
1926 type MPROPDEF: MPropDef
1928 # The classdef that introduce the property
1929 # While a property is not bound to a specific module, or class,
1930 # the introducing mclassdef is used for naming and visibility
1931 var intro_mclassdef
: MClassDef
1933 # The (short) name of the property
1934 redef var name
: String
1936 # The canonical name of the property.
1938 # It is the short-`name` prefixed by the short-name of the class and the full-name of the module.
1939 # Example: "my_project::my_module::MyClass::my_method"
1940 redef var full_name
is lazy
do
1941 return "{intro_mclassdef.mmodule.namespace_for(visibility)}::{intro_mclassdef.mclass.name}::{name}"
1944 redef var c_name
is lazy
do
1945 # FIXME use `namespace_for`
1946 return "{intro_mclassdef.mmodule.c_name}__{intro_mclassdef.mclass.name.to_cmangle}__{name.to_cmangle}"
1949 # The visibility of the property
1950 var visibility
: MVisibility
1952 # Is the property usable as an initializer?
1953 var is_autoinit
= false is writable
1957 intro_mclassdef
.intro_mproperties
.add
(self)
1958 var model
= intro_mclassdef
.mmodule
.model
1959 model
.mproperties_by_name
.add_one
(name
, self)
1960 model
.mproperties
.add
(self)
1963 # All definitions of the property.
1964 # The first is the introduction,
1965 # The other are redefinitions (in refinements and in subclasses)
1966 var mpropdefs
= new Array[MPROPDEF]
1968 # The definition that introduces the property.
1970 # Warning: such a definition may not exist in the early life of the object.
1971 # In this case, the method will abort.
1972 var intro
: MPROPDEF is noinit
1974 redef fun model
do return intro
.model
1977 redef fun to_s
do return name
1979 # Return the most specific property definitions defined or inherited by a type.
1980 # The selection knows that refinement is stronger than specialization;
1981 # however, in case of conflict more than one property are returned.
1982 # If mtype does not know mproperty then an empty array is returned.
1984 # If you want the really most specific property, then look at `lookup_first_definition`
1986 # REQUIRE: `not mtype.need_anchor` to simplify the API (no `anchor` parameter)
1987 # ENSURE: `not mtype.has_mproperty(mmodule, self) == result.is_empty`
1988 fun lookup_definitions
(mmodule
: MModule, mtype
: MType): Array[MPROPDEF]
1990 assert not mtype
.need_anchor
1991 mtype
= mtype
.undecorate
1993 var cache
= self.lookup_definitions_cache
[mmodule
, mtype
]
1994 if cache
!= null then return cache
1996 #print "select prop {mproperty} for {mtype} in {self}"
1997 # First, select all candidates
1998 var candidates
= new Array[MPROPDEF]
1999 for mpropdef
in self.mpropdefs
do
2000 # If the definition is not imported by the module, then skip
2001 if not mmodule
.in_importation
<= mpropdef
.mclassdef
.mmodule
then continue
2002 # If the definition is not inherited by the type, then skip
2003 if not mtype
.is_subtype
(mmodule
, null, mpropdef
.mclassdef
.bound_mtype
) then continue
2005 candidates
.add
(mpropdef
)
2007 # Fast track for only one candidate
2008 if candidates
.length
<= 1 then
2009 self.lookup_definitions_cache
[mmodule
, mtype
] = candidates
2013 # Second, filter the most specific ones
2014 return select_most_specific
(mmodule
, candidates
)
2017 private var lookup_definitions_cache
= new HashMap2[MModule, MType, Array[MPROPDEF]]
2019 # Return the most specific property definitions inherited by a type.
2020 # The selection knows that refinement is stronger than specialization;
2021 # however, in case of conflict more than one property are returned.
2022 # If mtype does not know mproperty then an empty array is returned.
2024 # If you want the really most specific property, then look at `lookup_next_definition`
2026 # REQUIRE: `not mtype.need_anchor` to simplify the API (no `anchor` parameter)
2027 # ENSURE: `not mtype.has_mproperty(mmodule, self) implies result.is_empty`
2028 fun lookup_super_definitions
(mmodule
: MModule, mtype
: MType): Array[MPROPDEF]
2030 assert not mtype
.need_anchor
2031 mtype
= mtype
.undecorate
2033 # First, select all candidates
2034 var candidates
= new Array[MPROPDEF]
2035 for mpropdef
in self.mpropdefs
do
2036 # If the definition is not imported by the module, then skip
2037 if not mmodule
.in_importation
<= mpropdef
.mclassdef
.mmodule
then continue
2038 # If the definition is not inherited by the type, then skip
2039 if not mtype
.is_subtype
(mmodule
, null, mpropdef
.mclassdef
.bound_mtype
) then continue
2040 # If the definition is defined by the type, then skip (we want the super, so e skip the current)
2041 if mtype
== mpropdef
.mclassdef
.bound_mtype
and mmodule
== mpropdef
.mclassdef
.mmodule
then continue
2043 candidates
.add
(mpropdef
)
2045 # Fast track for only one candidate
2046 if candidates
.length
<= 1 then return candidates
2048 # Second, filter the most specific ones
2049 return select_most_specific
(mmodule
, candidates
)
2052 # Return an array containing olny the most specific property definitions
2053 # This is an helper function for `lookup_definitions` and `lookup_super_definitions`
2054 private fun select_most_specific
(mmodule
: MModule, candidates
: Array[MPROPDEF]): Array[MPROPDEF]
2056 var res
= new Array[MPROPDEF]
2057 for pd1
in candidates
do
2058 var cd1
= pd1
.mclassdef
2061 for pd2
in candidates
do
2062 if pd2
== pd1
then continue # do not compare with self!
2063 var cd2
= pd2
.mclassdef
2065 if c2
.mclass_type
== c1
.mclass_type
then
2066 if cd2
.mmodule
.in_importation
< cd1
.mmodule
then
2067 # cd2 refines cd1; therefore we skip pd1
2071 else if cd2
.bound_mtype
.is_subtype
(mmodule
, null, cd1
.bound_mtype
) and cd2
.bound_mtype
!= cd1
.bound_mtype
then
2072 # cd2 < cd1; therefore we skip pd1
2081 if res
.is_empty
then
2082 print
"All lost! {candidates.join(", ")}"
2083 # FIXME: should be abort!
2088 # Return the most specific definition in the linearization of `mtype`.
2090 # If you want to know the next properties in the linearization,
2091 # look at `MPropDef::lookup_next_definition`.
2093 # FIXME: the linearization is still unspecified
2095 # REQUIRE: `not mtype.need_anchor` to simplify the API (no `anchor` parameter)
2096 # REQUIRE: `mtype.has_mproperty(mmodule, self)`
2097 fun lookup_first_definition
(mmodule
: MModule, mtype
: MType): MPROPDEF
2099 return lookup_all_definitions
(mmodule
, mtype
).first
2102 # Return all definitions in a linearization order
2103 # Most specific first, most general last
2105 # REQUIRE: `not mtype.need_anchor` to simplify the API (no `anchor` parameter)
2106 # REQUIRE: `mtype.has_mproperty(mmodule, self)`
2107 fun lookup_all_definitions
(mmodule
: MModule, mtype
: MType): Array[MPROPDEF]
2109 mtype
= mtype
.undecorate
2111 var cache
= self.lookup_all_definitions_cache
[mmodule
, mtype
]
2112 if cache
!= null then return cache
2114 assert not mtype
.need_anchor
2115 assert mtype
.has_mproperty
(mmodule
, self)
2117 #print "select prop {mproperty} for {mtype} in {self}"
2118 # First, select all candidates
2119 var candidates
= new Array[MPROPDEF]
2120 for mpropdef
in self.mpropdefs
do
2121 # If the definition is not imported by the module, then skip
2122 if not mmodule
.in_importation
<= mpropdef
.mclassdef
.mmodule
then continue
2123 # If the definition is not inherited by the type, then skip
2124 if not mtype
.is_subtype
(mmodule
, null, mpropdef
.mclassdef
.bound_mtype
) then continue
2126 candidates
.add
(mpropdef
)
2128 # Fast track for only one candidate
2129 if candidates
.length
<= 1 then
2130 self.lookup_all_definitions_cache
[mmodule
, mtype
] = candidates
2134 mmodule
.linearize_mpropdefs
(candidates
)
2135 candidates
= candidates
.reversed
2136 self.lookup_all_definitions_cache
[mmodule
, mtype
] = candidates
2140 private var lookup_all_definitions_cache
= new HashMap2[MModule, MType, Array[MPROPDEF]]
2147 redef type MPROPDEF: MMethodDef
2149 # Is the property defined at the top_level of the module?
2150 # Currently such a property are stored in `Object`
2151 var is_toplevel
: Bool = false is writable
2153 # Is the property a constructor?
2154 # Warning, this property can be inherited by subclasses with or without being a constructor
2155 # therefore, you should use `is_init_for` the verify if the property is a legal constructor for a given class
2156 var is_init
: Bool = false is writable
2158 # The constructor is a (the) root init with empty signature but a set of initializers
2159 var is_root_init
: Bool = false is writable
2161 # Is the property a 'new' constructor?
2162 var is_new
: Bool = false is writable
2164 # Is the property a legal constructor for a given class?
2165 # As usual, visibility is not considered.
2166 # FIXME not implemented
2167 fun is_init_for
(mclass
: MClass): Bool
2172 # A specific method that is safe to call on null.
2173 # Currently, only `==`, `!=` and `is_same_instance` are safe
2174 fun is_null_safe
: Bool do return name
== "==" or name
== "!=" or name
== "is_same_instance"
2177 # A global attribute
2181 redef type MPROPDEF: MAttributeDef
2185 # A global virtual type
2186 class MVirtualTypeProp
2189 redef type MPROPDEF: MVirtualTypeDef
2191 # The formal type associated to the virtual type property
2192 var mvirtualtype
= new MVirtualType(self)
2195 # A definition of a property (local property)
2197 # Unlike `MProperty`, a `MPropDef` is a local definition that belong to a
2198 # specific class definition (which belong to a specific module)
2199 abstract class MPropDef
2202 # The associated `MProperty` subclass.
2203 # the two specialization hierarchy are symmetric
2204 type MPROPERTY: MProperty
2207 type MPROPDEF: MPropDef
2209 # The class definition where the property definition is
2210 var mclassdef
: MClassDef
2212 # The associated global property
2213 var mproperty
: MPROPERTY
2215 # The origin of the definition
2216 var location
: Location
2220 mclassdef
.mpropdefs
.add
(self)
2221 mproperty
.mpropdefs
.add
(self)
2222 if mproperty
.intro_mclassdef
== mclassdef
then
2223 assert not isset mproperty
._intro
2224 mproperty
.intro
= self
2226 self.to_s
= "{mclassdef}#{mproperty}"
2229 # Actually the name of the `mproperty`
2230 redef fun name
do return mproperty
.name
2232 # The full-name of mpropdefs combine the information about the `classdef` and the `mproperty`.
2234 # Therefore the combination of identifiers is awful,
2235 # the worst case being
2237 # * a property "p::m::A::x"
2238 # * redefined in a refinement of a class "q::n::B"
2239 # * in a module "r::o"
2240 # * so "r::o#q::n::B#p::m::A::x"
2242 # Fortunately, the full-name is simplified when entities are repeated.
2243 # For the previous case, the simplest form is "p#A#x".
2244 redef var full_name
is lazy
do
2245 var res
= new FlatBuffer
2247 # The first part is the mclassdef. Worst case is "r::o#q::n::B"
2248 res
.append mclassdef
.full_name
2252 if mclassdef
.mclass
== mproperty
.intro_mclassdef
.mclass
then
2253 # intro are unambiguous in a class
2256 # Just try to simplify each part
2257 if mclassdef
.mmodule
.mproject
!= mproperty
.intro_mclassdef
.mmodule
.mproject
then
2258 # precise "p::m" only if "p" != "r"
2259 res
.append mproperty
.intro_mclassdef
.mmodule
.full_name
2261 else if mproperty
.visibility
<= private_visibility
then
2262 # Same project ("p"=="q"), but private visibility,
2263 # does the module part ("::m") need to be displayed
2264 if mclassdef
.mmodule
.namespace_for
(mclassdef
.mclass
.visibility
) != mproperty
.intro_mclassdef
.mmodule
.mproject
then
2266 res
.append mproperty
.intro_mclassdef
.mmodule
.name
2270 if mclassdef
.mclass
!= mproperty
.intro_mclassdef
.mclass
then
2271 # precise "B" only if not the same class than "A"
2272 res
.append mproperty
.intro_mclassdef
.name
2275 # Always use the property name "x"
2276 res
.append mproperty
.name
2281 redef var c_name
is lazy
do
2282 var res
= new FlatBuffer
2283 res
.append mclassdef
.c_name
2285 if mclassdef
.mclass
== mproperty
.intro_mclassdef
.mclass
then
2286 res
.append name
.to_cmangle
2288 if mclassdef
.mmodule
!= mproperty
.intro_mclassdef
.mmodule
then
2289 res
.append mproperty
.intro_mclassdef
.mmodule
.c_name
2292 if mclassdef
.mclass
!= mproperty
.intro_mclassdef
.mclass
then
2293 res
.append mproperty
.intro_mclassdef
.name
.to_cmangle
2296 res
.append mproperty
.name
.to_cmangle
2301 redef fun model
do return mclassdef
.model
2303 # Internal name combining the module, the class and the property
2304 # Example: "mymodule#MyClass#mymethod"
2305 redef var to_s
: String is noinit
2307 # Is self the definition that introduce the property?
2308 fun is_intro
: Bool do return mproperty
.intro
== self
2310 # Return the next definition in linearization of `mtype`.
2312 # This method is used to determine what method is called by a super.
2314 # REQUIRE: `not mtype.need_anchor`
2315 fun lookup_next_definition
(mmodule
: MModule, mtype
: MType): MPROPDEF
2317 assert not mtype
.need_anchor
2319 var mpropdefs
= self.mproperty
.lookup_all_definitions
(mmodule
, mtype
)
2320 var i
= mpropdefs
.iterator
2321 while i
.is_ok
and i
.item
!= self do i
.next
2322 assert has_property
: i
.is_ok
2324 assert has_next_property
: i
.is_ok
2329 # A local definition of a method
2333 redef type MPROPERTY: MMethod
2334 redef type MPROPDEF: MMethodDef
2336 # The signature attached to the property definition
2337 var msignature
: nullable MSignature = null is writable
2339 # The signature attached to the `new` call on a root-init
2340 # This is a concatenation of the signatures of the initializers
2342 # REQUIRE `mproperty.is_root_init == (new_msignature != null)`
2343 var new_msignature
: nullable MSignature = null is writable
2345 # List of initialisers to call in root-inits
2347 # They could be setters or attributes
2349 # REQUIRE `mproperty.is_root_init == (new_msignature != null)`
2350 var initializers
= new Array[MProperty]
2352 # Is the method definition abstract?
2353 var is_abstract
: Bool = false is writable
2355 # Is the method definition intern?
2356 var is_intern
= false is writable
2358 # Is the method definition extern?
2359 var is_extern
= false is writable
2361 # An optional constant value returned in functions.
2363 # Only some specific primitife value are accepted by engines.
2364 # Is used when there is no better implementation available.
2366 # Currently used only for the implementation of the `--define`
2367 # command-line option.
2368 # SEE: module `mixin`.
2369 var constant_value
: nullable Object = null is writable
2372 # A local definition of an attribute
2376 redef type MPROPERTY: MAttribute
2377 redef type MPROPDEF: MAttributeDef
2379 # The static type of the attribute
2380 var static_mtype
: nullable MType = null is writable
2383 # A local definition of a virtual type
2384 class MVirtualTypeDef
2387 redef type MPROPERTY: MVirtualTypeProp
2388 redef type MPROPDEF: MVirtualTypeDef
2390 # The bound of the virtual type
2391 var bound
: nullable MType = null is writable
2393 # Is the bound fixed?
2394 var is_fixed
= false is writable
2401 # * `interface_kind`
2405 # Note this class is basically an enum.
2406 # FIXME: use a real enum once user-defined enums are available
2408 redef var to_s
: String
2410 # Is a constructor required?
2413 # TODO: private init because enumeration.
2415 # Can a class of kind `self` specializes a class of kine `other`?
2416 fun can_specialize
(other
: MClassKind): Bool
2418 if other
== interface_kind
then return true # everybody can specialize interfaces
2419 if self == interface_kind
or self == enum_kind
then
2420 # no other case for interfaces
2422 else if self == extern_kind
then
2423 # only compatible with themselves
2424 return self == other
2425 else if other
== enum_kind
or other
== extern_kind
then
2426 # abstract_kind and concrete_kind are incompatible
2429 # remain only abstract_kind and concrete_kind
2434 # The class kind `abstract`
2435 fun abstract_kind
: MClassKind do return once
new MClassKind("abstract class", true)
2436 # The class kind `concrete`
2437 fun concrete_kind
: MClassKind do return once
new MClassKind("class", true)
2438 # The class kind `interface`
2439 fun interface_kind
: MClassKind do return once
new MClassKind("interface", false)
2440 # The class kind `enum`
2441 fun enum_kind
: MClassKind do return once
new MClassKind("enum", false)
2442 # The class kind `extern`
2443 fun extern_kind
: MClassKind do return once
new MClassKind("extern class", false)