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 `Int8`
213 var int8_type
: MClassType = self.get_primitive_class
("Int8").mclass_type
is lazy
215 # The primitive type `Int16`
216 var int16_type
: MClassType = self.get_primitive_class
("Int16").mclass_type
is lazy
218 # The primitive type `UInt16`
219 var uint16_type
: MClassType = self.get_primitive_class
("UInt16").mclass_type
is lazy
221 # The primitive type `Int32`
222 var int32_type
: MClassType = self.get_primitive_class
("Int32").mclass_type
is lazy
224 # The primitive type `UInt32`
225 var uint32_type
: MClassType = self.get_primitive_class
("UInt32").mclass_type
is lazy
227 # The primitive type `Char`
228 var char_type
: MClassType = self.get_primitive_class
("Char").mclass_type
is lazy
230 # The primitive type `Float`
231 var float_type
: MClassType = self.get_primitive_class
("Float").mclass_type
is lazy
233 # The primitive type `String`
234 var string_type
: MClassType = self.get_primitive_class
("String").mclass_type
is lazy
236 # The primitive type `NativeString`
237 var native_string_type
: MClassType = self.get_primitive_class
("NativeString").mclass_type
is lazy
239 # A primitive type of `Array`
240 fun array_type
(elt_type
: MType): MClassType do return array_class
.get_mtype
([elt_type
])
242 # The primitive class `Array`
243 var array_class
: MClass = self.get_primitive_class
("Array") is lazy
245 # A primitive type of `NativeArray`
246 fun native_array_type
(elt_type
: MType): MClassType do return native_array_class
.get_mtype
([elt_type
])
248 # The primitive class `NativeArray`
249 var native_array_class
: MClass = self.get_primitive_class
("NativeArray") is lazy
251 # The primitive type `Sys`, the main type of the program, if any
252 fun sys_type
: nullable MClassType
254 var clas
= self.model
.get_mclasses_by_name
("Sys")
255 if clas
== null then return null
256 return get_primitive_class
("Sys").mclass_type
259 # The primitive type `Finalizable`
260 # Used to tag classes that need to be finalized.
261 fun finalizable_type
: nullable MClassType
263 var clas
= self.model
.get_mclasses_by_name
("Finalizable")
264 if clas
== null then return null
265 return get_primitive_class
("Finalizable").mclass_type
268 # Force to get the primitive class named `name` or abort
269 fun get_primitive_class
(name
: String): MClass
271 var cla
= self.model
.get_mclasses_by_name
(name
)
272 # Filter classes by introducing module
273 if cla
!= null then cla
= [for c
in cla
do if self.in_importation
<= c
.intro_mmodule
then c
]
274 if cla
== null or cla
.is_empty
then
275 if name
== "Bool" and self.model
.get_mclasses_by_name
("Object") != null then
276 # Bool is injected because it is needed by engine to code the result
277 # of the implicit casts.
278 var c
= new MClass(self, name
, null, enum_kind
, public_visibility
)
279 var cladef
= new MClassDef(self, c
.mclass_type
, new Location(null, 0,0,0,0))
280 cladef
.set_supertypes
([object_type
])
281 cladef
.add_in_hierarchy
284 print
("Fatal Error: no primitive class {name} in {self}")
288 if cla
.length
!= 1 then
289 var msg
= "Fatal Error: more than one primitive class {name} in {self}:"
290 for c
in cla
do msg
+= " {c.full_name}"
297 # Try to get the primitive method named `name` on the type `recv`
298 fun try_get_primitive_method
(name
: String, recv
: MClass): nullable MMethod
300 var props
= self.model
.get_mproperties_by_name
(name
)
301 if props
== null then return null
302 var res
: nullable MMethod = null
303 for mprop
in props
do
304 assert mprop
isa MMethod
305 var intro
= mprop
.intro_mclassdef
306 for mclassdef
in recv
.mclassdefs
do
307 if not self.in_importation
.greaters
.has
(mclassdef
.mmodule
) then continue
308 if not mclassdef
.in_hierarchy
.greaters
.has
(intro
) then continue
311 else if res
!= mprop
then
312 print
("Fatal Error: ambigous property name '{name}'; conflict between {mprop.full_name} and {res.full_name}")
321 private class MClassDefSorter
323 redef type COMPARED: MClassDef
325 redef fun compare
(a
, b
)
329 if ca
!= cb
then return mmodule
.flatten_mclass_hierarchy
.compare
(ca
, cb
)
330 return mmodule
.model
.mclassdef_hierarchy
.compare
(a
, b
)
334 private class MPropDefSorter
336 redef type COMPARED: MPropDef
338 redef fun compare
(pa
, pb
)
344 if ca
!= cb
then return mmodule
.flatten_mclass_hierarchy
.compare
(ca
, cb
)
345 return mmodule
.model
.mclassdef_hierarchy
.compare
(a
, b
)
351 # `MClass` are global to the model; it means that a `MClass` is not bound to a
352 # specific `MModule`.
354 # This characteristic helps the reasoning about classes in a program since a
355 # single `MClass` object always denote the same class.
357 # The drawback is that classes (`MClass`) contain almost nothing by themselves.
358 # These do not really have properties nor belong to a hierarchy since the property and the
359 # hierarchy of a class depends of the refinement in the modules.
361 # Most services on classes require the precision of a module, and no one can asks what are
362 # the super-classes of a class nor what are properties of a class without precising what is
363 # the module considered.
365 # For instance, during the typing of a source-file, the module considered is the module of the file.
366 # eg. the question *is the method `foo` exists in the class `Bar`?* must be reformulated into
367 # *is the method `foo` exists in the class `Bar` in the current module?*
369 # During some global analysis, the module considered may be the main module of the program.
373 # The module that introduce the class
374 # While classes are not bound to a specific module,
375 # the introducing module is used for naming an visibility
376 var intro_mmodule
: MModule
378 # The short name of the class
379 # In Nit, the name of a class cannot evolve in refinements
380 redef var name
: String
382 # The canonical name of the class
384 # It is the name of the class prefixed by the full_name of the `intro_mmodule`
385 # Example: `"owner::module::MyClass"`
386 redef var full_name
is lazy
do
387 return "{self.intro_mmodule.namespace_for(visibility)}::{name}"
390 redef var c_name
is lazy
do
391 return "{intro_mmodule.c_namespace_for(visibility)}__{name.to_cmangle}"
394 # The number of generic formal parameters
395 # 0 if the class is not generic
396 var arity
: Int is noinit
398 # Each generic formal parameters in order.
399 # is empty if the class is not generic
400 var mparameters
= new Array[MParameterType]
402 # A string version of the signature a generic class.
404 # eg. `Map[K: nullable Object, V: nullable Object]`
406 # If the class in non generic the name is just given.
409 fun signature_to_s
: String
411 if arity
== 0 then return name
412 var res
= new FlatBuffer
415 for i
in [0..arity
[ do
416 if i
> 0 then res
.append
", "
417 res
.append mparameters
[i
].name
419 res
.append intro
.bound_mtype
.arguments
[i
].to_s
425 # Initialize `mparameters` from their names.
426 protected fun setup_parameter_names
(parameter_names
: nullable Array[String]) is
429 if parameter_names
== null then
432 self.arity
= parameter_names
.length
435 # Create the formal parameter types
437 assert parameter_names
!= null
438 var mparametertypes
= new Array[MParameterType]
439 for i
in [0..arity
[ do
440 var mparametertype
= new MParameterType(self, i
, parameter_names
[i
])
441 mparametertypes
.add
(mparametertype
)
443 self.mparameters
= mparametertypes
444 var mclass_type
= new MGenericType(self, mparametertypes
)
445 self.mclass_type
= mclass_type
446 self.get_mtype_cache
[mparametertypes
] = mclass_type
448 self.mclass_type
= new MClassType(self)
452 # The kind of the class (interface, abstract class, etc.)
453 # In Nit, the kind of a class cannot evolve in refinements
456 # The visibility of the class
457 # In Nit, the visibility of a class cannot evolve in refinements
458 var visibility
: MVisibility
462 intro_mmodule
.intro_mclasses
.add
(self)
463 var model
= intro_mmodule
.model
464 model
.mclasses_by_name
.add_one
(name
, self)
465 model
.mclasses
.add
(self)
468 redef fun model
do return intro_mmodule
.model
470 # All class definitions (introduction and refinements)
471 var mclassdefs
= new Array[MClassDef]
474 redef fun to_s
do return self.name
476 # The definition that introduces the class.
478 # Warning: such a definition may not exist in the early life of the object.
479 # In this case, the method will abort.
481 # Use `try_intro` instead
482 var intro
: MClassDef is noinit
484 # The definition that introduces the class or null if not yet known.
487 fun try_intro
: nullable MClassDef do
488 if isset _intro
then return _intro
else return null
491 # Return the class `self` in the class hierarchy of the module `mmodule`.
493 # SEE: `MModule::flatten_mclass_hierarchy`
494 # REQUIRE: `mmodule.has_mclass(self)`
495 fun in_hierarchy
(mmodule
: MModule): POSetElement[MClass]
497 return mmodule
.flatten_mclass_hierarchy
[self]
500 # The principal static type of the class.
502 # For non-generic class, mclass_type is the only `MClassType` based
505 # For a generic class, the arguments are the formal parameters.
506 # i.e.: for the class Array[E:Object], the `mclass_type` is Array[E].
507 # If you want Array[Object] the see `MClassDef::bound_mtype`
509 # For generic classes, the mclass_type is also the way to get a formal
510 # generic parameter type.
512 # To get other types based on a generic class, see `get_mtype`.
514 # ENSURE: `mclass_type.mclass == self`
515 var mclass_type
: MClassType is noinit
517 # Return a generic type based on the class
518 # Is the class is not generic, then the result is `mclass_type`
520 # REQUIRE: `mtype_arguments.length == self.arity`
521 fun get_mtype
(mtype_arguments
: Array[MType]): MClassType
523 assert mtype_arguments
.length
== self.arity
524 if self.arity
== 0 then return self.mclass_type
525 var res
= get_mtype_cache
.get_or_null
(mtype_arguments
)
526 if res
!= null then return res
527 res
= new MGenericType(self, mtype_arguments
)
528 self.get_mtype_cache
[mtype_arguments
.to_a
] = res
532 private var get_mtype_cache
= new HashMap[Array[MType], MGenericType]
534 # Is there a `new` factory to allow the pseudo instantiation?
535 var has_new_factory
= false is writable
537 # Is `self` a standard or abstract class kind?
538 var is_class
: Bool is lazy
do return kind
== concrete_kind
or kind
== abstract_kind
540 # Is `self` an interface kind?
541 var is_interface
: Bool is lazy
do return kind
== interface_kind
543 # Is `self` an enum kind?
544 var is_enum
: Bool is lazy
do return kind
== enum_kind
546 # Is `self` and abstract class?
547 var is_abstract
: Bool is lazy
do return kind
== abstract_kind
551 # A definition (an introduction or a refinement) of a class in a module
553 # A `MClassDef` is associated with an explicit (or almost) definition of a
554 # class. Unlike `MClass`, a `MClassDef` is a local definition that belong to
555 # a specific class and a specific module, and contains declarations like super-classes
558 # It is the class definitions that are the backbone of most things in the model:
559 # ClassDefs are defined with regard with other classdefs.
560 # Refinement and specialization are combined to produce a big poset called the `Model::mclassdef_hierarchy`.
562 # Moreover, the extension and the intention of types is defined by looking at the MClassDefs.
566 # The module where the definition is
569 # The associated `MClass`
570 var mclass
: MClass is noinit
572 # The bounded type associated to the mclassdef
574 # For a non-generic class, `bound_mtype` and `mclass.mclass_type`
578 # For the classdef Array[E: Object], the bound_mtype is Array[Object].
579 # If you want Array[E], then see `mclass.mclass_type`
581 # ENSURE: `bound_mtype.mclass == self.mclass`
582 var bound_mtype
: MClassType
584 # The origin of the definition
585 var location
: Location
587 # Internal name combining the module and the class
588 # Example: "mymodule#MyClass"
589 redef var to_s
: String is noinit
593 self.mclass
= bound_mtype
.mclass
594 mmodule
.mclassdefs
.add
(self)
595 mclass
.mclassdefs
.add
(self)
596 if mclass
.intro_mmodule
== mmodule
then
597 assert not isset mclass
._intro
600 self.to_s
= "{mmodule}#{mclass}"
603 # Actually the name of the `mclass`
604 redef fun name
do return mclass
.name
606 # The module and class name separated by a '#'.
608 # The short-name of the class is used for introduction.
609 # Example: "my_module#MyClass"
611 # The full-name of the class is used for refinement.
612 # Example: "my_module#intro_module::MyClass"
613 redef var full_name
is lazy
do
616 # private gives 'p::m#A'
617 return "{mmodule.namespace_for(mclass.visibility)}#{mclass.name}"
618 else if mclass
.intro_mmodule
.mpackage
!= mmodule
.mpackage
then
619 # public gives 'q::n#p::A'
620 # private gives 'q::n#p::m::A'
621 return "{mmodule.full_name}#{mclass.full_name}"
622 else if mclass
.visibility
> private_visibility
then
623 # public gives 'p::n#A'
624 return "{mmodule.full_name}#{mclass.name}"
626 # private gives 'p::n#::m::A' (redundant p is omitted)
627 return "{mmodule.full_name}#::{mclass.intro_mmodule.name}::{mclass.name}"
631 redef var c_name
is lazy
do
633 return "{mmodule.c_namespace_for(mclass.visibility)}___{mclass.c_name}"
634 else if mclass
.intro_mmodule
.mpackage
== mmodule
.mpackage
and mclass
.visibility
> private_visibility
then
635 return "{mmodule.c_name}___{mclass.name.to_cmangle}"
637 return "{mmodule.c_name}___{mclass.c_name}"
641 redef fun model
do return mmodule
.model
643 # All declared super-types
644 # FIXME: quite ugly but not better idea yet
645 var supertypes
= new Array[MClassType]
647 # Register some super-types for the class (ie "super SomeType")
649 # The hierarchy must not already be set
650 # REQUIRE: `self.in_hierarchy == null`
651 fun set_supertypes
(supertypes
: Array[MClassType])
653 assert unique_invocation
: self.in_hierarchy
== null
654 var mmodule
= self.mmodule
655 var model
= mmodule
.model
656 var mtype
= self.bound_mtype
658 for supertype
in supertypes
do
659 self.supertypes
.add
(supertype
)
661 # Register in full_type_specialization_hierarchy
662 model
.full_mtype_specialization_hierarchy
.add_edge
(mtype
, supertype
)
663 # Register in intro_type_specialization_hierarchy
664 if mclass
.intro_mmodule
== mmodule
and supertype
.mclass
.intro_mmodule
== mmodule
then
665 model
.intro_mtype_specialization_hierarchy
.add_edge
(mtype
, supertype
)
671 # Collect the super-types (set by set_supertypes) to build the hierarchy
673 # This function can only invoked once by class
674 # REQUIRE: `self.in_hierarchy == null`
675 # ENSURE: `self.in_hierarchy != null`
678 assert unique_invocation
: self.in_hierarchy
== null
679 var model
= mmodule
.model
680 var res
= model
.mclassdef_hierarchy
.add_node
(self)
681 self.in_hierarchy
= res
682 var mtype
= self.bound_mtype
684 # Here we need to connect the mclassdef to its pairs in the mclassdef_hierarchy
685 # The simpliest way is to attach it to collect_mclassdefs
686 for mclassdef
in mtype
.collect_mclassdefs
(mmodule
) do
687 res
.poset
.add_edge
(self, mclassdef
)
691 # The view of the class definition in `mclassdef_hierarchy`
692 var in_hierarchy
: nullable POSetElement[MClassDef] = null
694 # Is the definition the one that introduced `mclass`?
695 fun is_intro
: Bool do return isset mclass
._intro
and mclass
.intro
== self
697 # All properties introduced by the classdef
698 var intro_mproperties
= new Array[MProperty]
700 # All property definitions in the class (introductions and redefinitions)
701 var mpropdefs
= new Array[MPropDef]
704 # A global static type
706 # MType are global to the model; it means that a `MType` is not bound to a
707 # specific `MModule`.
708 # This characteristic helps the reasoning about static types in a program
709 # since a single `MType` object always denote the same type.
711 # However, because a `MType` is global, it does not really have properties
712 # nor have subtypes to a hierarchy since the property and the class hierarchy
713 # depends of a module.
714 # Moreover, virtual types an formal generic parameter types also depends on
715 # a receiver to have sense.
717 # Therefore, most method of the types require a module and an anchor.
718 # The module is used to know what are the classes and the specialization
720 # The anchor is used to know what is the bound of the virtual types and formal
721 # generic parameter types.
723 # MType are not directly usable to get properties. See the `anchor_to` method
724 # and the `MClassType` class.
726 # FIXME: the order of the parameters is not the best. We mus pick on from:
727 # * foo(mmodule, anchor, othertype)
728 # * foo(othertype, anchor, mmodule)
729 # * foo(anchor, mmodule, othertype)
730 # * foo(othertype, mmodule, anchor)
734 redef fun name
do return to_s
736 # Return true if `self` is an subtype of `sup`.
737 # The typing is done using the standard typing policy of Nit.
739 # REQUIRE: `anchor == null implies not self.need_anchor and not sup.need_anchor`
740 # REQUIRE: `anchor != null implies self.can_resolve_for(anchor, null, mmodule) and sup.can_resolve_for(anchor, null, mmodule)`
741 fun is_subtype
(mmodule
: MModule, anchor
: nullable MClassType, sup
: MType): Bool
744 if sub
== sup
then return true
746 #print "1.is {sub} a {sup}? ===="
748 if anchor
== null then
749 assert not sub
.need_anchor
750 assert not sup
.need_anchor
752 # First, resolve the formal types to the simplest equivalent forms in the receiver
753 assert sub
.can_resolve_for
(anchor
, null, mmodule
)
754 sub
= sub
.lookup_fixed
(mmodule
, anchor
)
755 assert sup
.can_resolve_for
(anchor
, null, mmodule
)
756 sup
= sup
.lookup_fixed
(mmodule
, anchor
)
759 # Does `sup` accept null or not?
760 # Discard the nullable marker if it exists
761 var sup_accept_null
= false
762 if sup
isa MNullableType then
763 sup_accept_null
= true
765 else if sup
isa MNotNullType then
767 else if sup
isa MNullType then
768 sup_accept_null
= true
771 # Can `sub` provide null or not?
772 # Thus we can match with `sup_accept_null`
773 # Also discard the nullable marker if it exists
774 var sub_reject_null
= false
775 if sub
isa MNullableType then
776 if not sup_accept_null
then return false
778 else if sub
isa MNotNullType then
779 sub_reject_null
= true
781 else if sub
isa MNullType then
782 return sup_accept_null
784 # Now the case of direct null and nullable is over.
786 # If `sub` is a formal type, then it is accepted if its bound is accepted
787 while sub
isa MFormalType do
788 #print "3.is {sub} a {sup}?"
790 # A unfixed formal type can only accept itself
791 if sub
== sup
then return true
793 assert anchor
!= null
794 sub
= sub
.lookup_bound
(mmodule
, anchor
)
795 if sub_reject_null
then sub
= sub
.as_notnull
797 #print "3.is {sub} a {sup}?"
799 # Manage the second layer of null/nullable
800 if sub
isa MNullableType then
801 if not sup_accept_null
and not sub_reject_null
then return false
803 else if sub
isa MNotNullType then
804 sub_reject_null
= true
806 else if sub
isa MNullType then
807 return sup_accept_null
810 #print "4.is {sub} a {sup}? <- no more resolution"
812 assert sub
isa MClassType else print
"{sub} <? {sub}" # It is the only remaining type
814 # A unfixed formal type can only accept itself
815 if sup
isa MFormalType then
819 if sup
isa MNullType then
820 # `sup` accepts only null
824 assert sup
isa MClassType # It is the only remaining type
826 # Now both are MClassType, we need to dig
828 if sub
== sup
then return true
830 if anchor
== null then anchor
= sub
# UGLY: any anchor will work
831 var resolved_sub
= sub
.anchor_to
(mmodule
, anchor
)
832 var res
= resolved_sub
.collect_mclasses
(mmodule
).has
(sup
.mclass
)
833 if res
== false then return false
834 if not sup
isa MGenericType then return true
835 var sub2
= sub
.supertype_to
(mmodule
, anchor
, sup
.mclass
)
836 assert sub2
.mclass
== sup
.mclass
837 for i
in [0..sup
.mclass
.arity
[ do
838 var sub_arg
= sub2
.arguments
[i
]
839 var sup_arg
= sup
.arguments
[i
]
840 res
= sub_arg
.is_subtype
(mmodule
, anchor
, sup_arg
)
841 if res
== false then return false
846 # The base class type on which self is based
848 # This base type is used to get property (an internally to perform
849 # unsafe type comparison).
851 # Beware: some types (like null) are not based on a class thus this
854 # Basically, this function transform the virtual types and parameter
855 # types to their bounds.
860 # class B super A end
862 # class Y super X end
871 # Map[T,U] anchor_to H #-> Map[B,Y]
873 # Explanation of the example:
874 # In H, T is set to B, because "H super G[B]", and U is bound to Y,
875 # because "redef type U: Y". Therefore, Map[T, U] is bound to
878 # ENSURE: `not self.need_anchor implies result == self`
879 # ENSURE: `not result.need_anchor`
880 fun anchor_to
(mmodule
: MModule, anchor
: MClassType): MType
882 if not need_anchor
then return self
883 assert not anchor
.need_anchor
884 # Just resolve to the anchor and clear all the virtual types
885 var res
= self.resolve_for
(anchor
, null, mmodule
, true)
886 assert not res
.need_anchor
890 # Does `self` contain a virtual type or a formal generic parameter type?
891 # In order to remove those types, you usually want to use `anchor_to`.
892 fun need_anchor
: Bool do return true
894 # Return the supertype when adapted to a class.
896 # In Nit, for each super-class of a type, there is a equivalent super-type.
902 # class H[V] super G[V, Bool] end
904 # H[Int] supertype_to G #-> G[Int, Bool]
907 # REQUIRE: `super_mclass` is a super-class of `self`
908 # REQUIRE: `self.need_anchor implies anchor != null and self.can_resolve_for(anchor, null, mmodule)`
909 # ENSURE: `result.mclass = super_mclass`
910 fun supertype_to
(mmodule
: MModule, anchor
: nullable MClassType, super_mclass
: MClass): MClassType
912 if super_mclass
.arity
== 0 then return super_mclass
.mclass_type
913 if self isa MClassType and self.mclass
== super_mclass
then return self
915 if self.need_anchor
then
916 assert anchor
!= null
917 resolved_self
= self.anchor_to
(mmodule
, anchor
)
921 var supertypes
= resolved_self
.collect_mtypes
(mmodule
)
922 for supertype
in supertypes
do
923 if supertype
.mclass
== super_mclass
then
924 # FIXME: Here, we stop on the first goal. Should we check others and detect inconsistencies?
925 return supertype
.resolve_for
(self, anchor
, mmodule
, false)
931 # Replace formals generic types in self with resolved values in `mtype`
932 # If `cleanup_virtual` is true, then virtual types are also replaced
935 # This function returns self if `need_anchor` is false.
941 # class H[F] super G[F] end
945 # * Array[E].resolve_for(H[Int]) #-> Array[Int]
946 # * Array[E].resolve_for(G[Z], X[Int]) #-> Array[Z]
948 # Explanation of the example:
949 # * Array[E].need_anchor is true because there is a formal generic parameter type E
950 # * E makes sense for H[Int] because E is a formal parameter of G and H specialize G
951 # * Since "H[F] super G[F]", E is in fact F for H
952 # * More specifically, in H[Int], E is Int
953 # * So, in H[Int], Array[E] is Array[Int]
955 # This function is mainly used to inherit a signature.
956 # Because, unlike `anchor_to`, we do not want a full resolution of
957 # a type but only an adapted version of it.
963 # fun foo(e:E):E is abstract
965 # class B super A[Int] end
968 # The signature on foo is (e: E): E
969 # If we resolve the signature for B, we get (e:Int):Int
975 # fun foo(e:E):E is abstract
979 # fun bar do a.foo(x) # <- x is here
983 # The first question is: is foo available on `a`?
985 # The static type of a is `A[Array[F]]`, that is an open type.
986 # in order to find a method `foo`, whe must look at a resolved type.
988 # A[Array[F]].anchor_to(C[nullable Object]) #-> A[Array[nullable Object]]
990 # the method `foo` exists in `A[Array[nullable Object]]`, therefore `foo` exists for `a`.
992 # The next question is: what is the accepted types for `x`?
994 # the signature of `foo` is `foo(e:E)`, thus we must resolve the type E
996 # E.resolve_for(A[Array[F]],C[nullable Object]) #-> Array[F]
998 # The resolution can be done because `E` make sense for the class A (see `can_resolve_for`)
1000 # FIXME: the parameter `cleanup_virtual` is just a bad idea, but having
1001 # two function instead of one seems also to be a bad idea.
1003 # REQUIRE: `can_resolve_for(mtype, anchor, mmodule)`
1004 # ENSURE: `not self.need_anchor implies result == self`
1005 fun resolve_for
(mtype
: MType, anchor
: nullable MClassType, mmodule
: MModule, cleanup_virtual
: Bool): MType is abstract
1007 # Resolve formal type to its verbatim bound.
1008 # If the type is not formal, just return self
1010 # The result is returned exactly as declared in the "type" property (verbatim).
1011 # So it could be another formal type.
1013 # In case of conflict, the method aborts.
1014 fun lookup_bound
(mmodule
: MModule, resolved_receiver
: MType): MType do return self
1016 # Resolve the formal type to its simplest equivalent form.
1018 # Formal types are either free or fixed.
1019 # When it is fixed, it means that it is equivalent with a simpler type.
1020 # When a formal type is free, it means that it is only equivalent with itself.
1021 # This method return the most simple equivalent type of `self`.
1023 # This method is mainly used for subtype test in order to sanely compare fixed.
1025 # By default, return self.
1026 # See the redefinitions for specific behavior in each kind of type.
1027 fun lookup_fixed
(mmodule
: MModule, resolved_receiver
: MType): MType do return self
1029 # Can the type be resolved?
1031 # In order to resolve open types, the formal types must make sence.
1041 # E.can_resolve_for(A[Int]) #-> true, E make sense in A
1043 # E.can_resolve_for(B[Int]) #-> false, E does not make sense in B
1045 # B[E].can_resolve_for(A[F], B[Object]) #-> true,
1046 # # B[E] is a red hearing only the E is important,
1047 # # E make sense in A
1050 # REQUIRE: `anchor != null implies not anchor.need_anchor`
1051 # REQUIRE: `mtype.need_anchor implies anchor != null and mtype.can_resolve_for(anchor, null, mmodule)`
1052 # ENSURE: `not self.need_anchor implies result == true`
1053 fun can_resolve_for
(mtype
: MType, anchor
: nullable MClassType, mmodule
: MModule): Bool is abstract
1055 # Return the nullable version of the type
1056 # If the type is already nullable then self is returned
1057 fun as_nullable
: MType
1059 var res
= self.as_nullable_cache
1060 if res
!= null then return res
1061 res
= new MNullableType(self)
1062 self.as_nullable_cache
= res
1066 # Remove the base type of a decorated (proxy) type.
1067 # Is the type is not decorated, then self is returned.
1069 # Most of the time it is used to return the not nullable version of a nullable type.
1070 # In this case, this just remove the `nullable` notation, but the result can still contains null.
1071 # For instance if `self isa MNullType` or self is a formal type bounded by a nullable type.
1072 # If you really want to exclude the `null` value, then use `as_notnull`
1073 fun undecorate
: MType
1078 # Returns the not null version of the type.
1079 # That is `self` minus the `null` value.
1081 # For most types, this return `self`.
1082 # For formal types, this returns a special `MNotNullType`
1083 fun as_notnull
: MType do return self
1085 private var as_nullable_cache
: nullable MType = null
1088 # The depth of the type seen as a tree.
1095 # Formal types have a depth of 1.
1101 # The length of the type seen as a tree.
1108 # Formal types have a length of 1.
1114 # Compute all the classdefs inherited/imported.
1115 # The returned set contains:
1116 # * the class definitions from `mmodule` and its imported modules
1117 # * the class definitions of this type and its super-types
1119 # This function is used mainly internally.
1121 # REQUIRE: `not self.need_anchor`
1122 fun collect_mclassdefs
(mmodule
: MModule): Set[MClassDef] is abstract
1124 # Compute all the super-classes.
1125 # This function is used mainly internally.
1127 # REQUIRE: `not self.need_anchor`
1128 fun collect_mclasses
(mmodule
: MModule): Set[MClass] is abstract
1130 # Compute all the declared super-types.
1131 # Super-types are returned as declared in the classdefs (verbatim).
1132 # This function is used mainly internally.
1134 # REQUIRE: `not self.need_anchor`
1135 fun collect_mtypes
(mmodule
: MModule): Set[MClassType] is abstract
1137 # Is the property in self for a given module
1138 # This method does not filter visibility or whatever
1140 # REQUIRE: `not self.need_anchor`
1141 fun has_mproperty
(mmodule
: MModule, mproperty
: MProperty): Bool
1143 assert not self.need_anchor
1144 return self.collect_mclassdefs
(mmodule
).has
(mproperty
.intro_mclassdef
)
1148 # A type based on a class.
1150 # `MClassType` have properties (see `has_mproperty`).
1154 # The associated class
1157 redef fun model
do return self.mclass
.intro_mmodule
.model
1159 # TODO: private init because strongly bounded to its mclass. see `mclass.mclass_type`
1161 # The formal arguments of the type
1162 # ENSURE: `result.length == self.mclass.arity`
1163 var arguments
= new Array[MType]
1165 redef fun to_s
do return mclass
.to_s
1167 redef fun full_name
do return mclass
.full_name
1169 redef fun c_name
do return mclass
.c_name
1171 redef fun need_anchor
do return false
1173 redef fun anchor_to
(mmodule
: MModule, anchor
: MClassType): MClassType
1175 return super.as(MClassType)
1178 redef fun resolve_for
(mtype
: MType, anchor
: nullable MClassType, mmodule
: MModule, cleanup_virtual
: Bool): MClassType do return self
1180 redef fun can_resolve_for
(mtype
, anchor
, mmodule
) do return true
1182 redef fun collect_mclassdefs
(mmodule
)
1184 assert not self.need_anchor
1185 var cache
= self.collect_mclassdefs_cache
1186 if not cache
.has_key
(mmodule
) then
1187 self.collect_things
(mmodule
)
1189 return cache
[mmodule
]
1192 redef fun collect_mclasses
(mmodule
)
1194 if collect_mclasses_last_module
== mmodule
then return collect_mclasses_last_module_cache
1195 assert not self.need_anchor
1196 var cache
= self.collect_mclasses_cache
1197 if not cache
.has_key
(mmodule
) then
1198 self.collect_things
(mmodule
)
1200 var res
= cache
[mmodule
]
1201 collect_mclasses_last_module
= mmodule
1202 collect_mclasses_last_module_cache
= res
1206 private var collect_mclasses_last_module
: nullable MModule = null
1207 private var collect_mclasses_last_module_cache
: Set[MClass] is noinit
1209 redef fun collect_mtypes
(mmodule
)
1211 assert not self.need_anchor
1212 var cache
= self.collect_mtypes_cache
1213 if not cache
.has_key
(mmodule
) then
1214 self.collect_things
(mmodule
)
1216 return cache
[mmodule
]
1219 # common implementation for `collect_mclassdefs`, `collect_mclasses`, and `collect_mtypes`.
1220 private fun collect_things
(mmodule
: MModule)
1222 var res
= new HashSet[MClassDef]
1223 var seen
= new HashSet[MClass]
1224 var types
= new HashSet[MClassType]
1225 seen
.add
(self.mclass
)
1226 var todo
= [self.mclass
]
1227 while not todo
.is_empty
do
1228 var mclass
= todo
.pop
1229 #print "process {mclass}"
1230 for mclassdef
in mclass
.mclassdefs
do
1231 if not mmodule
.in_importation
<= mclassdef
.mmodule
then continue
1232 #print " process {mclassdef}"
1234 for supertype
in mclassdef
.supertypes
do
1235 types
.add
(supertype
)
1236 var superclass
= supertype
.mclass
1237 if seen
.has
(superclass
) then continue
1238 #print " add {superclass}"
1239 seen
.add
(superclass
)
1240 todo
.add
(superclass
)
1244 collect_mclassdefs_cache
[mmodule
] = res
1245 collect_mclasses_cache
[mmodule
] = seen
1246 collect_mtypes_cache
[mmodule
] = types
1249 private var collect_mclassdefs_cache
= new HashMap[MModule, Set[MClassDef]]
1250 private var collect_mclasses_cache
= new HashMap[MModule, Set[MClass]]
1251 private var collect_mtypes_cache
= new HashMap[MModule, Set[MClassType]]
1255 # A type based on a generic class.
1256 # A generic type a just a class with additional formal generic arguments.
1262 # TODO: private init because strongly bounded to its mclass. see `mclass.get_mtype`
1266 assert self.mclass
.arity
== arguments
.length
1268 self.need_anchor
= false
1269 for t
in arguments
do
1270 if t
.need_anchor
then
1271 self.need_anchor
= true
1276 self.to_s
= "{mclass}[{arguments.join(", ")}]"
1279 # The short-name of the class, then the full-name of each type arguments within brackets.
1280 # Example: `"Map[String, List[Int]]"`
1281 redef var to_s
: String is noinit
1283 # The full-name of the class, then the full-name of each type arguments within brackets.
1284 # Example: `"core::Map[core::String, core::List[core::Int]]"`
1285 redef var full_name
is lazy
do
1286 var args
= new Array[String]
1287 for t
in arguments
do
1288 args
.add t
.full_name
1290 return "{mclass.full_name}[{args.join(", ")}]"
1293 redef var c_name
is lazy
do
1294 var res
= mclass
.c_name
1295 # Note: because the arity is known, a prefix notation is enough
1296 for t
in arguments
do
1303 redef var need_anchor
: Bool is noinit
1305 redef fun resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1307 if not need_anchor
then return self
1308 assert can_resolve_for
(mtype
, anchor
, mmodule
)
1309 var types
= new Array[MType]
1310 for t
in arguments
do
1311 types
.add
(t
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
))
1313 return mclass
.get_mtype
(types
)
1316 redef fun can_resolve_for
(mtype
, anchor
, mmodule
)
1318 if not need_anchor
then return true
1319 for t
in arguments
do
1320 if not t
.can_resolve_for
(mtype
, anchor
, mmodule
) then return false
1329 for a
in self.arguments
do
1331 if d
> dmax
then dmax
= d
1339 for a
in self.arguments
do
1346 # A formal type (either virtual of parametric).
1348 # The main issue with formal types is that they offer very little information on their own
1349 # and need a context (anchor and mmodule) to be useful.
1350 abstract class MFormalType
1353 redef var as_notnull
= new MNotNullType(self) is lazy
1356 # A virtual formal type.
1360 # The property associated with the type.
1361 # Its the definitions of this property that determine the bound or the virtual type.
1362 var mproperty
: MVirtualTypeProp
1364 redef fun model
do return self.mproperty
.intro_mclassdef
.mmodule
.model
1366 redef fun lookup_bound
(mmodule
: MModule, resolved_receiver
: MType): MType
1368 return lookup_single_definition
(mmodule
, resolved_receiver
).bound
.as(not null)
1371 private fun lookup_single_definition
(mmodule
: MModule, resolved_receiver
: MType): MVirtualTypeDef
1373 assert not resolved_receiver
.need_anchor
1374 var props
= self.mproperty
.lookup_definitions
(mmodule
, resolved_receiver
)
1375 if props
.is_empty
then
1377 else if props
.length
== 1 then
1380 var types
= new ArraySet[MType]
1381 var res
= props
.first
1383 types
.add
(p
.bound
.as(not null))
1384 if not res
.is_fixed
then res
= p
1386 if types
.length
== 1 then
1392 # A VT is fixed when:
1393 # * the VT is (re-)defined with the annotation `is fixed`
1394 # * the VT is (indirectly) bound to an enum class (see `enum_kind`) since there is no subtype possible
1395 # * the receiver is an enum class since there is no subtype possible
1396 redef fun lookup_fixed
(mmodule
: MModule, resolved_receiver
: MType): MType
1398 assert not resolved_receiver
.need_anchor
1399 resolved_receiver
= resolved_receiver
.undecorate
1400 assert resolved_receiver
isa MClassType # It is the only remaining type
1402 var prop
= lookup_single_definition
(mmodule
, resolved_receiver
)
1403 var res
= prop
.bound
.as(not null)
1405 # Recursively lookup the fixed result
1406 res
= res
.lookup_fixed
(mmodule
, resolved_receiver
)
1408 # 1. For a fixed VT, return the resolved bound
1409 if prop
.is_fixed
then return res
1411 # 2. For a enum boud, return the bound
1412 if res
isa MClassType and res
.mclass
.kind
== enum_kind
then return res
1414 # 3. for a enum receiver return the bound
1415 if resolved_receiver
.mclass
.kind
== enum_kind
then return res
1420 redef fun resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1422 if not cleanup_virtual
then return self
1423 assert can_resolve_for
(mtype
, anchor
, mmodule
)
1424 # self is a virtual type declared (or inherited) in mtype
1425 # The point of the function it to get the bound of the virtual type that make sense for mtype
1426 # But because mtype is maybe a virtual/formal type, we need to get a real receiver first
1427 #print "{class_name}: {self}/{mtype}/{anchor}?"
1428 var resolved_receiver
1429 if mtype
.need_anchor
then
1430 assert anchor
!= null
1431 resolved_receiver
= mtype
.resolve_for
(anchor
, null, mmodule
, true)
1433 resolved_receiver
= mtype
1435 # Now, we can get the bound
1436 var verbatim_bound
= lookup_bound
(mmodule
, resolved_receiver
)
1437 # The bound is exactly as declared in the "type" property, so we must resolve it again
1438 var res
= verbatim_bound
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1443 redef fun can_resolve_for
(mtype
, anchor
, mmodule
)
1445 if mtype
.need_anchor
then
1446 assert anchor
!= null
1447 mtype
= mtype
.anchor_to
(mmodule
, anchor
)
1449 return mtype
.has_mproperty
(mmodule
, mproperty
)
1452 redef fun to_s
do return self.mproperty
.to_s
1454 redef fun full_name
do return self.mproperty
.full_name
1456 redef fun c_name
do return self.mproperty
.c_name
1459 # The type associated to a formal parameter generic type of a class
1461 # Each parameter type is associated to a specific class.
1462 # It means that all refinements of a same class "share" the parameter type,
1463 # but that a generic subclass has its own parameter types.
1465 # However, in the sense of the meta-model, a parameter type of a class is
1466 # a valid type in a subclass. The "in the sense of the meta-model" is
1467 # important because, in the Nit language, the programmer cannot refers
1468 # directly to the parameter types of the super-classes.
1473 # fun e: E is abstract
1479 # In the class definition B[F], `F` is a valid type but `E` is not.
1480 # However, `self.e` is a valid method call, and the signature of `e` is
1483 # Note that parameter types are shared among class refinements.
1484 # Therefore parameter only have an internal name (see `to_s` for details).
1485 class MParameterType
1488 # The generic class where the parameter belong
1491 redef fun model
do return self.mclass
.intro_mmodule
.model
1493 # The position of the parameter (0 for the first parameter)
1494 # FIXME: is `position` a better name?
1499 redef fun to_s
do return name
1501 redef var full_name
is lazy
do return "{mclass.full_name}::{name}"
1503 redef var c_name
is lazy
do return mclass
.c_name
+ "__" + "#{name}".to_cmangle
1505 redef fun lookup_bound
(mmodule
: MModule, resolved_receiver
: MType): MType
1507 assert not resolved_receiver
.need_anchor
1508 resolved_receiver
= resolved_receiver
.undecorate
1509 assert resolved_receiver
isa MClassType # It is the only remaining type
1510 var goalclass
= self.mclass
1511 if resolved_receiver
.mclass
== goalclass
then
1512 return resolved_receiver
.arguments
[self.rank
]
1514 var supertypes
= resolved_receiver
.collect_mtypes
(mmodule
)
1515 for t
in supertypes
do
1516 if t
.mclass
== goalclass
then
1517 # Yeah! c specialize goalclass with a "super `t'". So the question is what is the argument of f
1518 # FIXME: Here, we stop on the first goal. Should we check others and detect inconsistencies?
1519 var res
= t
.arguments
[self.rank
]
1526 # A PT is fixed when:
1527 # * Its bound is a enum class (see `enum_kind`).
1528 # The PT is just useless, but it is still a case.
1529 # * More usually, the `resolved_receiver` is a subclass of `self.mclass`,
1530 # so it is necessarily fixed in a `super` clause, either with a normal type
1531 # or with another PT.
1532 # See `resolve_for` for examples about related issues.
1533 redef fun lookup_fixed
(mmodule
: MModule, resolved_receiver
: MType): MType
1535 assert not resolved_receiver
.need_anchor
1536 resolved_receiver
= resolved_receiver
.undecorate
1537 assert resolved_receiver
isa MClassType # It is the only remaining type
1538 var res
= self.resolve_for
(resolved_receiver
.mclass
.mclass_type
, resolved_receiver
, mmodule
, false)
1542 redef fun resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1544 assert can_resolve_for
(mtype
, anchor
, mmodule
)
1545 #print "{class_name}: {self}/{mtype}/{anchor}?"
1547 if mtype
isa MGenericType and mtype
.mclass
== self.mclass
then
1548 var res
= mtype
.arguments
[self.rank
]
1549 if anchor
!= null and res
.need_anchor
then
1550 # Maybe the result can be resolved more if are bound to a final class
1551 var r2
= res
.anchor_to
(mmodule
, anchor
)
1552 if r2
isa MClassType and r2
.mclass
.kind
== enum_kind
then return r2
1557 # self is a parameter type of mtype (or of a super-class of mtype)
1558 # The point of the function it to get the bound of the virtual type that make sense for mtype
1559 # But because mtype is maybe a virtual/formal type, we need to get a real receiver first
1560 # FIXME: What happens here is far from clear. Thus this part must be validated and clarified
1561 var resolved_receiver
1562 if mtype
.need_anchor
then
1563 assert anchor
!= null
1564 resolved_receiver
= mtype
.resolve_for
(anchor
.mclass
.mclass_type
, anchor
, mmodule
, true)
1566 resolved_receiver
= mtype
1568 if resolved_receiver
isa MNullableType then resolved_receiver
= resolved_receiver
.mtype
1569 if resolved_receiver
isa MParameterType then
1570 assert anchor
!= null
1571 assert resolved_receiver
.mclass
== anchor
.mclass
1572 resolved_receiver
= anchor
.arguments
[resolved_receiver
.rank
]
1573 if resolved_receiver
isa MNullableType then resolved_receiver
= resolved_receiver
.mtype
1575 assert resolved_receiver
isa MClassType # It is the only remaining type
1577 # Eh! The parameter is in the current class.
1578 # So we return the corresponding argument, no mater what!
1579 if resolved_receiver
.mclass
== self.mclass
then
1580 var res
= resolved_receiver
.arguments
[self.rank
]
1581 #print "{class_name}: {self}/{mtype}/{anchor} -> direct {res}"
1585 if resolved_receiver
.need_anchor
then
1586 assert anchor
!= null
1587 resolved_receiver
= resolved_receiver
.resolve_for
(anchor
, null, mmodule
, false)
1589 # Now, we can get the bound
1590 var verbatim_bound
= lookup_bound
(mmodule
, resolved_receiver
)
1591 # The bound is exactly as declared in the "type" property, so we must resolve it again
1592 var res
= verbatim_bound
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1594 #print "{class_name}: {self}/{mtype}/{anchor} -> indirect {res}"
1599 redef fun can_resolve_for
(mtype
, anchor
, mmodule
)
1601 if mtype
.need_anchor
then
1602 assert anchor
!= null
1603 mtype
= mtype
.anchor_to
(mmodule
, anchor
)
1605 return mtype
.collect_mclassdefs
(mmodule
).has
(mclass
.intro
)
1609 # A type that decorates another type.
1611 # The point of this class is to provide a common implementation of sevices that just forward to the original type.
1612 # Specific decorator are expected to redefine (or to extend) the default implementation as this suit them.
1613 abstract class MProxyType
1618 redef fun model
do return self.mtype
.model
1619 redef fun need_anchor
do return mtype
.need_anchor
1620 redef fun as_nullable
do return mtype
.as_nullable
1621 redef fun as_notnull
do return mtype
.as_notnull
1622 redef fun undecorate
do return mtype
.undecorate
1623 redef fun resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1625 var res
= self.mtype
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1629 redef fun can_resolve_for
(mtype
, anchor
, mmodule
)
1631 return self.mtype
.can_resolve_for
(mtype
, anchor
, mmodule
)
1634 redef fun lookup_fixed
(mmodule
, resolved_receiver
)
1636 var t
= mtype
.lookup_fixed
(mmodule
, resolved_receiver
)
1640 redef fun depth
do return self.mtype
.depth
1642 redef fun length
do return self.mtype
.length
1644 redef fun collect_mclassdefs
(mmodule
)
1646 assert not self.need_anchor
1647 return self.mtype
.collect_mclassdefs
(mmodule
)
1650 redef fun collect_mclasses
(mmodule
)
1652 assert not self.need_anchor
1653 return self.mtype
.collect_mclasses
(mmodule
)
1656 redef fun collect_mtypes
(mmodule
)
1658 assert not self.need_anchor
1659 return self.mtype
.collect_mtypes
(mmodule
)
1663 # A type prefixed with "nullable"
1669 self.to_s
= "nullable {mtype}"
1672 redef var to_s
: String is noinit
1674 redef var full_name
is lazy
do return "nullable {mtype.full_name}"
1676 redef var c_name
is lazy
do return "nullable__{mtype.c_name}"
1678 redef fun as_nullable
do return self
1679 redef fun resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1682 return res
.as_nullable
1685 # Efficiently returns `mtype.lookup_fixed(mmodule, resolved_receiver).as_nullable`
1686 redef fun lookup_fixed
(mmodule
, resolved_receiver
)
1689 if t
== mtype
then return self
1690 return t
.as_nullable
1694 # A non-null version of a formal type.
1696 # When a formal type in bounded to a nullable type, this is the type of the not null version of it.
1700 redef fun to_s
do return "not null {mtype}"
1701 redef var full_name
is lazy
do return "not null {mtype.full_name}"
1702 redef var c_name
is lazy
do return "notnull__{mtype.c_name}"
1704 redef fun as_notnull
do return self
1706 redef fun resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1709 return res
.as_notnull
1712 # Efficiently returns `mtype.lookup_fixed(mmodule, resolved_receiver).as_notnull`
1713 redef fun lookup_fixed
(mmodule
, resolved_receiver
)
1716 if t
== mtype
then return self
1721 # The type of the only value null
1723 # The is only one null type per model, see `MModel::null_type`.
1726 redef var model
: Model
1727 redef fun to_s
do return "null"
1728 redef fun full_name
do return "null"
1729 redef fun c_name
do return "null"
1730 redef fun as_nullable
do return self
1732 redef var as_notnull
= new MBottomType(model
) is lazy
1733 redef fun need_anchor
do return false
1734 redef fun resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
) do return self
1735 redef fun can_resolve_for
(mtype
, anchor
, mmodule
) do return true
1737 redef fun collect_mclassdefs
(mmodule
) do return new HashSet[MClassDef]
1739 redef fun collect_mclasses
(mmodule
) do return new HashSet[MClass]
1741 redef fun collect_mtypes
(mmodule
) do return new HashSet[MClassType]
1744 # The special universal most specific type.
1746 # This type is intended to be only used internally for type computation or analysis and should not be exposed to the user.
1747 # The bottom type can de used to denote things that are absurd, dead, or the absence of knowledge.
1749 # Semantically it is the singleton `null.as_notnull`.
1752 redef var model
: Model
1753 redef fun to_s
do return "bottom"
1754 redef fun full_name
do return "bottom"
1755 redef fun c_name
do return "bottom"
1756 redef fun as_nullable
do return model
.null_type
1757 redef fun as_notnull
do return self
1758 redef fun need_anchor
do return false
1759 redef fun resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
) do return self
1760 redef fun can_resolve_for
(mtype
, anchor
, mmodule
) do return true
1762 redef fun collect_mclassdefs
(mmodule
) do return new HashSet[MClassDef]
1764 redef fun collect_mclasses
(mmodule
) do return new HashSet[MClass]
1766 redef fun collect_mtypes
(mmodule
) do return new HashSet[MClassType]
1769 # A signature of a method
1773 # The each parameter (in order)
1774 var mparameters
: Array[MParameter]
1776 # Returns a parameter named `name`, if any.
1777 fun mparameter_by_name
(name
: String): nullable MParameter
1779 for p
in mparameters
do
1780 if p
.name
== name
then return p
1785 # The return type (null for a procedure)
1786 var return_mtype
: nullable MType
1791 var t
= self.return_mtype
1792 if t
!= null then dmax
= t
.depth
1793 for p
in mparameters
do
1794 var d
= p
.mtype
.depth
1795 if d
> dmax
then dmax
= d
1803 var t
= self.return_mtype
1804 if t
!= null then res
+= t
.length
1805 for p
in mparameters
do
1806 res
+= p
.mtype
.length
1811 # REQUIRE: 1 <= mparameters.count p -> p.is_vararg
1814 var vararg_rank
= -1
1815 for i
in [0..mparameters
.length
[ do
1816 var parameter
= mparameters
[i
]
1817 if parameter
.is_vararg
then
1818 assert vararg_rank
== -1
1822 self.vararg_rank
= vararg_rank
1825 # The rank of the ellipsis (`...`) for vararg (starting from 0).
1826 # value is -1 if there is no vararg.
1827 # Example: for "(a: Int, b: Bool..., c: Char)" #-> vararg_rank=1
1828 var vararg_rank
: Int is noinit
1830 # The number of parameters
1831 fun arity
: Int do return mparameters
.length
1835 var b
= new FlatBuffer
1836 if not mparameters
.is_empty
then
1838 for i
in [0..mparameters
.length
[ do
1839 var mparameter
= mparameters
[i
]
1840 if i
> 0 then b
.append
(", ")
1841 b
.append
(mparameter
.name
)
1843 b
.append
(mparameter
.mtype
.to_s
)
1844 if mparameter
.is_vararg
then
1850 var ret
= self.return_mtype
1858 redef fun resolve_for
(mtype
: MType, anchor
: nullable MClassType, mmodule
: MModule, cleanup_virtual
: Bool): MSignature
1860 var params
= new Array[MParameter]
1861 for p
in self.mparameters
do
1862 params
.add
(p
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
))
1864 var ret
= self.return_mtype
1866 ret
= ret
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1868 var res
= new MSignature(params
, ret
)
1873 # A parameter in a signature
1877 # The name of the parameter
1878 redef var name
: String
1880 # The static type of the parameter
1883 # Is the parameter a vararg?
1889 return "{name}: {mtype}..."
1891 return "{name}: {mtype}"
1895 # Returns a new parameter with the `mtype` resolved.
1896 # See `MType::resolve_for` for details.
1897 fun resolve_for
(mtype
: MType, anchor
: nullable MClassType, mmodule
: MModule, cleanup_virtual
: Bool): MParameter
1899 if not self.mtype
.need_anchor
then return self
1900 var newtype
= self.mtype
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1901 var res
= new MParameter(self.name
, newtype
, self.is_vararg
)
1905 redef fun model
do return mtype
.model
1908 # A service (global property) that generalize method, attribute, etc.
1910 # `MProperty` are global to the model; it means that a `MProperty` is not bound
1911 # to a specific `MModule` nor a specific `MClass`.
1913 # A MProperty gather definitions (see `mpropdefs`) ; one for the introduction
1914 # and the other in subclasses and in refinements.
1916 # A `MProperty` is used to denotes services in polymorphic way (ie. independent
1917 # of any dynamic type).
1918 # For instance, a call site "x.foo" is associated to a `MProperty`.
1919 abstract class MProperty
1922 # The associated MPropDef subclass.
1923 # The two specialization hierarchy are symmetric.
1924 type MPROPDEF: MPropDef
1926 # The classdef that introduce the property
1927 # While a property is not bound to a specific module, or class,
1928 # the introducing mclassdef is used for naming and visibility
1929 var intro_mclassdef
: MClassDef
1931 # The (short) name of the property
1932 redef var name
: String
1934 # The canonical name of the property.
1936 # It is the short-`name` prefixed by the short-name of the class and the full-name of the module.
1937 # Example: "my_package::my_module::MyClass::my_method"
1938 redef var full_name
is lazy
do
1939 return "{intro_mclassdef.mmodule.namespace_for(visibility)}::{intro_mclassdef.mclass.name}::{name}"
1942 redef var c_name
is lazy
do
1943 # FIXME use `namespace_for`
1944 return "{intro_mclassdef.mmodule.c_name}__{intro_mclassdef.mclass.name.to_cmangle}__{name.to_cmangle}"
1947 # The visibility of the property
1948 var visibility
: MVisibility
1950 # Is the property usable as an initializer?
1951 var is_autoinit
= false is writable
1955 intro_mclassdef
.intro_mproperties
.add
(self)
1956 var model
= intro_mclassdef
.mmodule
.model
1957 model
.mproperties_by_name
.add_one
(name
, self)
1958 model
.mproperties
.add
(self)
1961 # All definitions of the property.
1962 # The first is the introduction,
1963 # The other are redefinitions (in refinements and in subclasses)
1964 var mpropdefs
= new Array[MPROPDEF]
1966 # The definition that introduces the property.
1968 # Warning: such a definition may not exist in the early life of the object.
1969 # In this case, the method will abort.
1970 var intro
: MPROPDEF is noinit
1972 redef fun model
do return intro
.model
1975 redef fun to_s
do return name
1977 # Return the most specific property definitions defined or inherited by a type.
1978 # The selection knows that refinement is stronger than specialization;
1979 # however, in case of conflict more than one property are returned.
1980 # If mtype does not know mproperty then an empty array is returned.
1982 # If you want the really most specific property, then look at `lookup_first_definition`
1984 # REQUIRE: `not mtype.need_anchor` to simplify the API (no `anchor` parameter)
1985 # ENSURE: `not mtype.has_mproperty(mmodule, self) == result.is_empty`
1986 fun lookup_definitions
(mmodule
: MModule, mtype
: MType): Array[MPROPDEF]
1988 assert not mtype
.need_anchor
1989 mtype
= mtype
.undecorate
1991 var cache
= self.lookup_definitions_cache
[mmodule
, mtype
]
1992 if cache
!= null then return cache
1994 #print "select prop {mproperty} for {mtype} in {self}"
1995 # First, select all candidates
1996 var candidates
= new Array[MPROPDEF]
1997 for mpropdef
in self.mpropdefs
do
1998 # If the definition is not imported by the module, then skip
1999 if not mmodule
.in_importation
<= mpropdef
.mclassdef
.mmodule
then continue
2000 # If the definition is not inherited by the type, then skip
2001 if not mtype
.is_subtype
(mmodule
, null, mpropdef
.mclassdef
.bound_mtype
) then continue
2003 candidates
.add
(mpropdef
)
2005 # Fast track for only one candidate
2006 if candidates
.length
<= 1 then
2007 self.lookup_definitions_cache
[mmodule
, mtype
] = candidates
2011 # Second, filter the most specific ones
2012 return select_most_specific
(mmodule
, candidates
)
2015 private var lookup_definitions_cache
= new HashMap2[MModule, MType, Array[MPROPDEF]]
2017 # Return the most specific property definitions inherited by a type.
2018 # The selection knows that refinement is stronger than specialization;
2019 # however, in case of conflict more than one property are returned.
2020 # If mtype does not know mproperty then an empty array is returned.
2022 # If you want the really most specific property, then look at `lookup_next_definition`
2024 # REQUIRE: `not mtype.need_anchor` to simplify the API (no `anchor` parameter)
2025 # ENSURE: `not mtype.has_mproperty(mmodule, self) implies result.is_empty`
2026 fun lookup_super_definitions
(mmodule
: MModule, mtype
: MType): Array[MPROPDEF]
2028 assert not mtype
.need_anchor
2029 mtype
= mtype
.undecorate
2031 # First, select all candidates
2032 var candidates
= new Array[MPROPDEF]
2033 for mpropdef
in self.mpropdefs
do
2034 # If the definition is not imported by the module, then skip
2035 if not mmodule
.in_importation
<= mpropdef
.mclassdef
.mmodule
then continue
2036 # If the definition is not inherited by the type, then skip
2037 if not mtype
.is_subtype
(mmodule
, null, mpropdef
.mclassdef
.bound_mtype
) then continue
2038 # If the definition is defined by the type, then skip (we want the super, so e skip the current)
2039 if mtype
== mpropdef
.mclassdef
.bound_mtype
and mmodule
== mpropdef
.mclassdef
.mmodule
then continue
2041 candidates
.add
(mpropdef
)
2043 # Fast track for only one candidate
2044 if candidates
.length
<= 1 then return candidates
2046 # Second, filter the most specific ones
2047 return select_most_specific
(mmodule
, candidates
)
2050 # Return an array containing olny the most specific property definitions
2051 # This is an helper function for `lookup_definitions` and `lookup_super_definitions`
2052 private fun select_most_specific
(mmodule
: MModule, candidates
: Array[MPROPDEF]): Array[MPROPDEF]
2054 var res
= new Array[MPROPDEF]
2055 for pd1
in candidates
do
2056 var cd1
= pd1
.mclassdef
2059 for pd2
in candidates
do
2060 if pd2
== pd1
then continue # do not compare with self!
2061 var cd2
= pd2
.mclassdef
2063 if c2
.mclass_type
== c1
.mclass_type
then
2064 if cd2
.mmodule
.in_importation
< cd1
.mmodule
then
2065 # cd2 refines cd1; therefore we skip pd1
2069 else if cd2
.bound_mtype
.is_subtype
(mmodule
, null, cd1
.bound_mtype
) and cd2
.bound_mtype
!= cd1
.bound_mtype
then
2070 # cd2 < cd1; therefore we skip pd1
2079 if res
.is_empty
then
2080 print
"All lost! {candidates.join(", ")}"
2081 # FIXME: should be abort!
2086 # Return the most specific definition in the linearization of `mtype`.
2088 # If you want to know the next properties in the linearization,
2089 # look at `MPropDef::lookup_next_definition`.
2091 # FIXME: the linearization is still unspecified
2093 # REQUIRE: `not mtype.need_anchor` to simplify the API (no `anchor` parameter)
2094 # REQUIRE: `mtype.has_mproperty(mmodule, self)`
2095 fun lookup_first_definition
(mmodule
: MModule, mtype
: MType): MPROPDEF
2097 return lookup_all_definitions
(mmodule
, mtype
).first
2100 # Return all definitions in a linearization order
2101 # Most specific first, most general last
2103 # REQUIRE: `not mtype.need_anchor` to simplify the API (no `anchor` parameter)
2104 # REQUIRE: `mtype.has_mproperty(mmodule, self)`
2105 fun lookup_all_definitions
(mmodule
: MModule, mtype
: MType): Array[MPROPDEF]
2107 mtype
= mtype
.undecorate
2109 var cache
= self.lookup_all_definitions_cache
[mmodule
, mtype
]
2110 if cache
!= null then return cache
2112 assert not mtype
.need_anchor
2113 assert mtype
.has_mproperty
(mmodule
, self)
2115 #print "select prop {mproperty} for {mtype} in {self}"
2116 # First, select all candidates
2117 var candidates
= new Array[MPROPDEF]
2118 for mpropdef
in self.mpropdefs
do
2119 # If the definition is not imported by the module, then skip
2120 if not mmodule
.in_importation
<= mpropdef
.mclassdef
.mmodule
then continue
2121 # If the definition is not inherited by the type, then skip
2122 if not mtype
.is_subtype
(mmodule
, null, mpropdef
.mclassdef
.bound_mtype
) then continue
2124 candidates
.add
(mpropdef
)
2126 # Fast track for only one candidate
2127 if candidates
.length
<= 1 then
2128 self.lookup_all_definitions_cache
[mmodule
, mtype
] = candidates
2132 mmodule
.linearize_mpropdefs
(candidates
)
2133 candidates
= candidates
.reversed
2134 self.lookup_all_definitions_cache
[mmodule
, mtype
] = candidates
2138 private var lookup_all_definitions_cache
= new HashMap2[MModule, MType, Array[MPROPDEF]]
2145 redef type MPROPDEF: MMethodDef
2147 # Is the property defined at the top_level of the module?
2148 # Currently such a property are stored in `Object`
2149 var is_toplevel
: Bool = false is writable
2151 # Is the property a constructor?
2152 # Warning, this property can be inherited by subclasses with or without being a constructor
2153 # therefore, you should use `is_init_for` the verify if the property is a legal constructor for a given class
2154 var is_init
: Bool = false is writable
2156 # The constructor is a (the) root init with empty signature but a set of initializers
2157 var is_root_init
: Bool = false is writable
2159 # Is the property a 'new' constructor?
2160 var is_new
: Bool = false is writable
2162 # Is the property a legal constructor for a given class?
2163 # As usual, visibility is not considered.
2164 # FIXME not implemented
2165 fun is_init_for
(mclass
: MClass): Bool
2170 # A specific method that is safe to call on null.
2171 # Currently, only `==`, `!=` and `is_same_instance` are safe
2172 fun is_null_safe
: Bool do return name
== "==" or name
== "!=" or name
== "is_same_instance"
2175 # A global attribute
2179 redef type MPROPDEF: MAttributeDef
2183 # A global virtual type
2184 class MVirtualTypeProp
2187 redef type MPROPDEF: MVirtualTypeDef
2189 # The formal type associated to the virtual type property
2190 var mvirtualtype
= new MVirtualType(self)
2193 # A definition of a property (local property)
2195 # Unlike `MProperty`, a `MPropDef` is a local definition that belong to a
2196 # specific class definition (which belong to a specific module)
2197 abstract class MPropDef
2200 # The associated `MProperty` subclass.
2201 # the two specialization hierarchy are symmetric
2202 type MPROPERTY: MProperty
2205 type MPROPDEF: MPropDef
2207 # The class definition where the property definition is
2208 var mclassdef
: MClassDef
2210 # The associated global property
2211 var mproperty
: MPROPERTY
2213 # The origin of the definition
2214 var location
: Location
2218 mclassdef
.mpropdefs
.add
(self)
2219 mproperty
.mpropdefs
.add
(self)
2220 if mproperty
.intro_mclassdef
== mclassdef
then
2221 assert not isset mproperty
._intro
2222 mproperty
.intro
= self
2224 self.to_s
= "{mclassdef}#{mproperty}"
2227 # Actually the name of the `mproperty`
2228 redef fun name
do return mproperty
.name
2230 # The full-name of mpropdefs combine the information about the `classdef` and the `mproperty`.
2232 # Therefore the combination of identifiers is awful,
2233 # the worst case being
2235 # * a property "p::m::A::x"
2236 # * redefined in a refinement of a class "q::n::B"
2237 # * in a module "r::o"
2238 # * so "r::o#q::n::B#p::m::A::x"
2240 # Fortunately, the full-name is simplified when entities are repeated.
2241 # For the previous case, the simplest form is "p#A#x".
2242 redef var full_name
is lazy
do
2243 var res
= new FlatBuffer
2245 # The first part is the mclassdef. Worst case is "r::o#q::n::B"
2246 res
.append mclassdef
.full_name
2250 if mclassdef
.mclass
== mproperty
.intro_mclassdef
.mclass
then
2251 # intro are unambiguous in a class
2254 # Just try to simplify each part
2255 if mclassdef
.mmodule
.mpackage
!= mproperty
.intro_mclassdef
.mmodule
.mpackage
then
2256 # precise "p::m" only if "p" != "r"
2257 res
.append mproperty
.intro_mclassdef
.mmodule
.full_name
2259 else if mproperty
.visibility
<= private_visibility
then
2260 # Same package ("p"=="q"), but private visibility,
2261 # does the module part ("::m") need to be displayed
2262 if mclassdef
.mmodule
.namespace_for
(mclassdef
.mclass
.visibility
) != mproperty
.intro_mclassdef
.mmodule
.mpackage
then
2264 res
.append mproperty
.intro_mclassdef
.mmodule
.name
2268 if mclassdef
.mclass
!= mproperty
.intro_mclassdef
.mclass
then
2269 # precise "B" only if not the same class than "A"
2270 res
.append mproperty
.intro_mclassdef
.name
2273 # Always use the property name "x"
2274 res
.append mproperty
.name
2279 redef var c_name
is lazy
do
2280 var res
= new FlatBuffer
2281 res
.append mclassdef
.c_name
2283 if mclassdef
.mclass
== mproperty
.intro_mclassdef
.mclass
then
2284 res
.append name
.to_cmangle
2286 if mclassdef
.mmodule
!= mproperty
.intro_mclassdef
.mmodule
then
2287 res
.append mproperty
.intro_mclassdef
.mmodule
.c_name
2290 if mclassdef
.mclass
!= mproperty
.intro_mclassdef
.mclass
then
2291 res
.append mproperty
.intro_mclassdef
.name
.to_cmangle
2294 res
.append mproperty
.name
.to_cmangle
2299 redef fun model
do return mclassdef
.model
2301 # Internal name combining the module, the class and the property
2302 # Example: "mymodule#MyClass#mymethod"
2303 redef var to_s
: String is noinit
2305 # Is self the definition that introduce the property?
2306 fun is_intro
: Bool do return isset mproperty
._intro
and mproperty
.intro
== self
2308 # Return the next definition in linearization of `mtype`.
2310 # This method is used to determine what method is called by a super.
2312 # REQUIRE: `not mtype.need_anchor`
2313 fun lookup_next_definition
(mmodule
: MModule, mtype
: MType): MPROPDEF
2315 assert not mtype
.need_anchor
2317 var mpropdefs
= self.mproperty
.lookup_all_definitions
(mmodule
, mtype
)
2318 var i
= mpropdefs
.iterator
2319 while i
.is_ok
and i
.item
!= self do i
.next
2320 assert has_property
: i
.is_ok
2322 assert has_next_property
: i
.is_ok
2327 # A local definition of a method
2331 redef type MPROPERTY: MMethod
2332 redef type MPROPDEF: MMethodDef
2334 # The signature attached to the property definition
2335 var msignature
: nullable MSignature = null is writable
2337 # The signature attached to the `new` call on a root-init
2338 # This is a concatenation of the signatures of the initializers
2340 # REQUIRE `mproperty.is_root_init == (new_msignature != null)`
2341 var new_msignature
: nullable MSignature = null is writable
2343 # List of initialisers to call in root-inits
2345 # They could be setters or attributes
2347 # REQUIRE `mproperty.is_root_init == (new_msignature != null)`
2348 var initializers
= new Array[MProperty]
2350 # Is the method definition abstract?
2351 var is_abstract
: Bool = false is writable
2353 # Is the method definition intern?
2354 var is_intern
= false is writable
2356 # Is the method definition extern?
2357 var is_extern
= false is writable
2359 # An optional constant value returned in functions.
2361 # Only some specific primitife value are accepted by engines.
2362 # Is used when there is no better implementation available.
2364 # Currently used only for the implementation of the `--define`
2365 # command-line option.
2366 # SEE: module `mixin`.
2367 var constant_value
: nullable Object = null is writable
2370 # A local definition of an attribute
2374 redef type MPROPERTY: MAttribute
2375 redef type MPROPDEF: MAttributeDef
2377 # The static type of the attribute
2378 var static_mtype
: nullable MType = null is writable
2381 # A local definition of a virtual type
2382 class MVirtualTypeDef
2385 redef type MPROPERTY: MVirtualTypeProp
2386 redef type MPROPDEF: MVirtualTypeDef
2388 # The bound of the virtual type
2389 var bound
: nullable MType = null is writable
2391 # Is the bound fixed?
2392 var is_fixed
= false is writable
2399 # * `interface_kind`
2403 # Note this class is basically an enum.
2404 # FIXME: use a real enum once user-defined enums are available
2406 redef var to_s
: String
2408 # Is a constructor required?
2411 # TODO: private init because enumeration.
2413 # Can a class of kind `self` specializes a class of kine `other`?
2414 fun can_specialize
(other
: MClassKind): Bool
2416 if other
== interface_kind
then return true # everybody can specialize interfaces
2417 if self == interface_kind
or self == enum_kind
then
2418 # no other case for interfaces
2420 else if self == extern_kind
then
2421 # only compatible with themselves
2422 return self == other
2423 else if other
== enum_kind
or other
== extern_kind
then
2424 # abstract_kind and concrete_kind are incompatible
2427 # remain only abstract_kind and concrete_kind
2432 # The class kind `abstract`
2433 fun abstract_kind
: MClassKind do return once
new MClassKind("abstract class", true)
2434 # The class kind `concrete`
2435 fun concrete_kind
: MClassKind do return once
new MClassKind("class", true)
2436 # The class kind `interface`
2437 fun interface_kind
: MClassKind do return once
new MClassKind("interface", false)
2438 # The class kind `enum`
2439 fun enum_kind
: MClassKind do return once
new MClassKind("enum", false)
2440 # The class kind `extern`
2441 fun extern_kind
: MClassKind do return once
new MClassKind("extern class", false)