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}")
287 if cla
.length
!= 1 then
288 var msg
= "Fatal Error: more than one primitive class {name} in {self}:"
289 for c
in cla
do msg
+= " {c.full_name}"
296 # Try to get the primitive method named `name` on the type `recv`
297 fun try_get_primitive_method
(name
: String, recv
: MClass): nullable MMethod
299 var props
= self.model
.get_mproperties_by_name
(name
)
300 if props
== null then return null
301 var res
: nullable MMethod = null
302 for mprop
in props
do
303 assert mprop
isa MMethod
304 var intro
= mprop
.intro_mclassdef
305 for mclassdef
in recv
.mclassdefs
do
306 if not self.in_importation
.greaters
.has
(mclassdef
.mmodule
) then continue
307 if not mclassdef
.in_hierarchy
.greaters
.has
(intro
) then continue
310 else if res
!= mprop
then
311 print
("Fatal Error: ambigous property name '{name}'; conflict between {mprop.full_name} and {res.full_name}")
320 private class MClassDefSorter
322 redef type COMPARED: MClassDef
324 redef fun compare
(a
, b
)
328 if ca
!= cb
then return mmodule
.flatten_mclass_hierarchy
.compare
(ca
, cb
)
329 return mmodule
.model
.mclassdef_hierarchy
.compare
(a
, b
)
333 private class MPropDefSorter
335 redef type COMPARED: MPropDef
337 redef fun compare
(pa
, pb
)
343 if ca
!= cb
then return mmodule
.flatten_mclass_hierarchy
.compare
(ca
, cb
)
344 return mmodule
.model
.mclassdef_hierarchy
.compare
(a
, b
)
350 # `MClass` are global to the model; it means that a `MClass` is not bound to a
351 # specific `MModule`.
353 # This characteristic helps the reasoning about classes in a program since a
354 # single `MClass` object always denote the same class.
356 # The drawback is that classes (`MClass`) contain almost nothing by themselves.
357 # These do not really have properties nor belong to a hierarchy since the property and the
358 # hierarchy of a class depends of the refinement in the modules.
360 # Most services on classes require the precision of a module, and no one can asks what are
361 # the super-classes of a class nor what are properties of a class without precising what is
362 # the module considered.
364 # For instance, during the typing of a source-file, the module considered is the module of the file.
365 # eg. the question *is the method `foo` exists in the class `Bar`?* must be reformulated into
366 # *is the method `foo` exists in the class `Bar` in the current module?*
368 # During some global analysis, the module considered may be the main module of the program.
372 # The module that introduce the class
373 # While classes are not bound to a specific module,
374 # the introducing module is used for naming an visibility
375 var intro_mmodule
: MModule
377 # The short name of the class
378 # In Nit, the name of a class cannot evolve in refinements
379 redef var name
: String
381 # The canonical name of the class
383 # It is the name of the class prefixed by the full_name of the `intro_mmodule`
384 # Example: `"owner::module::MyClass"`
385 redef var full_name
is lazy
do
386 return "{self.intro_mmodule.namespace_for(visibility)}::{name}"
389 redef var c_name
is lazy
do
390 return "{intro_mmodule.c_namespace_for(visibility)}__{name.to_cmangle}"
393 # The number of generic formal parameters
394 # 0 if the class is not generic
395 var arity
: Int is noinit
397 # Each generic formal parameters in order.
398 # is empty if the class is not generic
399 var mparameters
= new Array[MParameterType]
401 # A string version of the signature a generic class.
403 # eg. `Map[K: nullable Object, V: nullable Object]`
405 # If the class in non generic the name is just given.
408 fun signature_to_s
: String
410 if arity
== 0 then return name
411 var res
= new FlatBuffer
414 for i
in [0..arity
[ do
415 if i
> 0 then res
.append
", "
416 res
.append mparameters
[i
].name
418 res
.append intro
.bound_mtype
.arguments
[i
].to_s
424 # Initialize `mparameters` from their names.
425 protected fun setup_parameter_names
(parameter_names
: nullable Array[String]) is
428 if parameter_names
== null then
431 self.arity
= parameter_names
.length
434 # Create the formal parameter types
436 assert parameter_names
!= null
437 var mparametertypes
= new Array[MParameterType]
438 for i
in [0..arity
[ do
439 var mparametertype
= new MParameterType(self, i
, parameter_names
[i
])
440 mparametertypes
.add
(mparametertype
)
442 self.mparameters
= mparametertypes
443 var mclass_type
= new MGenericType(self, mparametertypes
)
444 self.mclass_type
= mclass_type
445 self.get_mtype_cache
[mparametertypes
] = mclass_type
447 self.mclass_type
= new MClassType(self)
451 # The kind of the class (interface, abstract class, etc.)
452 # In Nit, the kind of a class cannot evolve in refinements
455 # The visibility of the class
456 # In Nit, the visibility of a class cannot evolve in refinements
457 var visibility
: MVisibility
461 intro_mmodule
.intro_mclasses
.add
(self)
462 var model
= intro_mmodule
.model
463 model
.mclasses_by_name
.add_one
(name
, self)
464 model
.mclasses
.add
(self)
467 redef fun model
do return intro_mmodule
.model
469 # All class definitions (introduction and refinements)
470 var mclassdefs
= new Array[MClassDef]
473 redef fun to_s
do return self.name
475 # The definition that introduces the class.
477 # Warning: such a definition may not exist in the early life of the object.
478 # In this case, the method will abort.
480 # Use `try_intro` instead
481 var intro
: MClassDef is noinit
483 # The definition that introduces the class or null if not yet known.
486 fun try_intro
: nullable MClassDef do
487 if isset _intro
then return _intro
else return null
490 # Return the class `self` in the class hierarchy of the module `mmodule`.
492 # SEE: `MModule::flatten_mclass_hierarchy`
493 # REQUIRE: `mmodule.has_mclass(self)`
494 fun in_hierarchy
(mmodule
: MModule): POSetElement[MClass]
496 return mmodule
.flatten_mclass_hierarchy
[self]
499 # The principal static type of the class.
501 # For non-generic class, mclass_type is the only `MClassType` based
504 # For a generic class, the arguments are the formal parameters.
505 # i.e.: for the class Array[E:Object], the `mclass_type` is Array[E].
506 # If you want Array[Object] the see `MClassDef::bound_mtype`
508 # For generic classes, the mclass_type is also the way to get a formal
509 # generic parameter type.
511 # To get other types based on a generic class, see `get_mtype`.
513 # ENSURE: `mclass_type.mclass == self`
514 var mclass_type
: MClassType is noinit
516 # Return a generic type based on the class
517 # Is the class is not generic, then the result is `mclass_type`
519 # REQUIRE: `mtype_arguments.length == self.arity`
520 fun get_mtype
(mtype_arguments
: Array[MType]): MClassType
522 assert mtype_arguments
.length
== self.arity
523 if self.arity
== 0 then return self.mclass_type
524 var res
= get_mtype_cache
.get_or_null
(mtype_arguments
)
525 if res
!= null then return res
526 res
= new MGenericType(self, mtype_arguments
)
527 self.get_mtype_cache
[mtype_arguments
.to_a
] = res
531 private var get_mtype_cache
= new HashMap[Array[MType], MGenericType]
533 # Is there a `new` factory to allow the pseudo instantiation?
534 var has_new_factory
= false is writable
536 # Is `self` a standard or abstract class kind?
537 var is_class
: Bool is lazy
do return kind
== concrete_kind
or kind
== abstract_kind
539 # Is `self` an interface kind?
540 var is_interface
: Bool is lazy
do return kind
== interface_kind
542 # Is `self` an enum kind?
543 var is_enum
: Bool is lazy
do return kind
== enum_kind
545 # Is `self` and abstract class?
546 var is_abstract
: Bool is lazy
do return kind
== abstract_kind
550 # A definition (an introduction or a refinement) of a class in a module
552 # A `MClassDef` is associated with an explicit (or almost) definition of a
553 # class. Unlike `MClass`, a `MClassDef` is a local definition that belong to
554 # a specific class and a specific module, and contains declarations like super-classes
557 # It is the class definitions that are the backbone of most things in the model:
558 # ClassDefs are defined with regard with other classdefs.
559 # Refinement and specialization are combined to produce a big poset called the `Model::mclassdef_hierarchy`.
561 # Moreover, the extension and the intention of types is defined by looking at the MClassDefs.
565 # The module where the definition is
568 # The associated `MClass`
569 var mclass
: MClass is noinit
571 # The bounded type associated to the mclassdef
573 # For a non-generic class, `bound_mtype` and `mclass.mclass_type`
577 # For the classdef Array[E: Object], the bound_mtype is Array[Object].
578 # If you want Array[E], then see `mclass.mclass_type`
580 # ENSURE: `bound_mtype.mclass == self.mclass`
581 var bound_mtype
: MClassType
583 # The origin of the definition
584 var location
: Location
586 # Internal name combining the module and the class
587 # Example: "mymodule#MyClass"
588 redef var to_s
: String is noinit
592 self.mclass
= bound_mtype
.mclass
593 mmodule
.mclassdefs
.add
(self)
594 mclass
.mclassdefs
.add
(self)
595 if mclass
.intro_mmodule
== mmodule
then
596 assert not isset mclass
._intro
599 self.to_s
= "{mmodule}#{mclass}"
602 # Actually the name of the `mclass`
603 redef fun name
do return mclass
.name
605 # The module and class name separated by a '#'.
607 # The short-name of the class is used for introduction.
608 # Example: "my_module#MyClass"
610 # The full-name of the class is used for refinement.
611 # Example: "my_module#intro_module::MyClass"
612 redef var full_name
is lazy
do
615 # private gives 'p::m#A'
616 return "{mmodule.namespace_for(mclass.visibility)}#{mclass.name}"
617 else if mclass
.intro_mmodule
.mpackage
!= mmodule
.mpackage
then
618 # public gives 'q::n#p::A'
619 # private gives 'q::n#p::m::A'
620 return "{mmodule.full_name}#{mclass.full_name}"
621 else if mclass
.visibility
> private_visibility
then
622 # public gives 'p::n#A'
623 return "{mmodule.full_name}#{mclass.name}"
625 # private gives 'p::n#::m::A' (redundant p is omitted)
626 return "{mmodule.full_name}#::{mclass.intro_mmodule.name}::{mclass.name}"
630 redef var c_name
is lazy
do
632 return "{mmodule.c_namespace_for(mclass.visibility)}___{mclass.c_name}"
633 else if mclass
.intro_mmodule
.mpackage
== mmodule
.mpackage
and mclass
.visibility
> private_visibility
then
634 return "{mmodule.c_name}___{mclass.name.to_cmangle}"
636 return "{mmodule.c_name}___{mclass.c_name}"
640 redef fun model
do return mmodule
.model
642 # All declared super-types
643 # FIXME: quite ugly but not better idea yet
644 var supertypes
= new Array[MClassType]
646 # Register some super-types for the class (ie "super SomeType")
648 # The hierarchy must not already be set
649 # REQUIRE: `self.in_hierarchy == null`
650 fun set_supertypes
(supertypes
: Array[MClassType])
652 assert unique_invocation
: self.in_hierarchy
== null
653 var mmodule
= self.mmodule
654 var model
= mmodule
.model
655 var mtype
= self.bound_mtype
657 for supertype
in supertypes
do
658 self.supertypes
.add
(supertype
)
660 # Register in full_type_specialization_hierarchy
661 model
.full_mtype_specialization_hierarchy
.add_edge
(mtype
, supertype
)
662 # Register in intro_type_specialization_hierarchy
663 if mclass
.intro_mmodule
== mmodule
and supertype
.mclass
.intro_mmodule
== mmodule
then
664 model
.intro_mtype_specialization_hierarchy
.add_edge
(mtype
, supertype
)
670 # Collect the super-types (set by set_supertypes) to build the hierarchy
672 # This function can only invoked once by class
673 # REQUIRE: `self.in_hierarchy == null`
674 # ENSURE: `self.in_hierarchy != null`
677 assert unique_invocation
: self.in_hierarchy
== null
678 var model
= mmodule
.model
679 var res
= model
.mclassdef_hierarchy
.add_node
(self)
680 self.in_hierarchy
= res
681 var mtype
= self.bound_mtype
683 # Here we need to connect the mclassdef to its pairs in the mclassdef_hierarchy
684 # The simpliest way is to attach it to collect_mclassdefs
685 for mclassdef
in mtype
.collect_mclassdefs
(mmodule
) do
686 res
.poset
.add_edge
(self, mclassdef
)
690 # The view of the class definition in `mclassdef_hierarchy`
691 var in_hierarchy
: nullable POSetElement[MClassDef] = null
693 # Is the definition the one that introduced `mclass`?
694 fun is_intro
: Bool do return isset mclass
._intro
and mclass
.intro
== self
696 # All properties introduced by the classdef
697 var intro_mproperties
= new Array[MProperty]
699 # All property definitions in the class (introductions and redefinitions)
700 var mpropdefs
= new Array[MPropDef]
703 # A global static type
705 # MType are global to the model; it means that a `MType` is not bound to a
706 # specific `MModule`.
707 # This characteristic helps the reasoning about static types in a program
708 # since a single `MType` object always denote the same type.
710 # However, because a `MType` is global, it does not really have properties
711 # nor have subtypes to a hierarchy since the property and the class hierarchy
712 # depends of a module.
713 # Moreover, virtual types an formal generic parameter types also depends on
714 # a receiver to have sense.
716 # Therefore, most method of the types require a module and an anchor.
717 # The module is used to know what are the classes and the specialization
719 # The anchor is used to know what is the bound of the virtual types and formal
720 # generic parameter types.
722 # MType are not directly usable to get properties. See the `anchor_to` method
723 # and the `MClassType` class.
725 # FIXME: the order of the parameters is not the best. We mus pick on from:
726 # * foo(mmodule, anchor, othertype)
727 # * foo(othertype, anchor, mmodule)
728 # * foo(anchor, mmodule, othertype)
729 # * foo(othertype, mmodule, anchor)
733 redef fun name
do return to_s
735 # Return true if `self` is an subtype of `sup`.
736 # The typing is done using the standard typing policy of Nit.
738 # REQUIRE: `anchor == null implies not self.need_anchor and not sup.need_anchor`
739 # REQUIRE: `anchor != null implies self.can_resolve_for(anchor, null, mmodule) and sup.can_resolve_for(anchor, null, mmodule)`
740 fun is_subtype
(mmodule
: MModule, anchor
: nullable MClassType, sup
: MType): Bool
743 if sub
== sup
then return true
745 #print "1.is {sub} a {sup}? ===="
747 if anchor
== null then
748 assert not sub
.need_anchor
749 assert not sup
.need_anchor
751 # First, resolve the formal types to the simplest equivalent forms in the receiver
752 assert sub
.can_resolve_for
(anchor
, null, mmodule
)
753 sub
= sub
.lookup_fixed
(mmodule
, anchor
)
754 assert sup
.can_resolve_for
(anchor
, null, mmodule
)
755 sup
= sup
.lookup_fixed
(mmodule
, anchor
)
758 # Does `sup` accept null or not?
759 # Discard the nullable marker if it exists
760 var sup_accept_null
= false
761 if sup
isa MNullableType then
762 sup_accept_null
= true
764 else if sup
isa MNotNullType then
766 else if sup
isa MNullType then
767 sup_accept_null
= true
770 # Can `sub` provide null or not?
771 # Thus we can match with `sup_accept_null`
772 # Also discard the nullable marker if it exists
773 var sub_reject_null
= false
774 if sub
isa MNullableType then
775 if not sup_accept_null
then return false
777 else if sub
isa MNotNullType then
778 sub_reject_null
= true
780 else if sub
isa MNullType then
781 return sup_accept_null
783 # Now the case of direct null and nullable is over.
785 # If `sub` is a formal type, then it is accepted if its bound is accepted
786 while sub
isa MFormalType do
787 #print "3.is {sub} a {sup}?"
789 # A unfixed formal type can only accept itself
790 if sub
== sup
then return true
792 assert anchor
!= null
793 sub
= sub
.lookup_bound
(mmodule
, anchor
)
794 if sub_reject_null
then sub
= sub
.as_notnull
796 #print "3.is {sub} a {sup}?"
798 # Manage the second layer of null/nullable
799 if sub
isa MNullableType then
800 if not sup_accept_null
and not sub_reject_null
then return false
802 else if sub
isa MNotNullType then
803 sub_reject_null
= true
805 else if sub
isa MNullType then
806 return sup_accept_null
809 #print "4.is {sub} a {sup}? <- no more resolution"
811 assert sub
isa MClassType else print
"{sub} <? {sub}" # It is the only remaining type
813 # A unfixed formal type can only accept itself
814 if sup
isa MFormalType then
818 if sup
isa MNullType then
819 # `sup` accepts only null
823 assert sup
isa MClassType # It is the only remaining type
825 # Now both are MClassType, we need to dig
827 if sub
== sup
then return true
829 if anchor
== null then anchor
= sub
# UGLY: any anchor will work
830 var resolved_sub
= sub
.anchor_to
(mmodule
, anchor
)
831 var res
= resolved_sub
.collect_mclasses
(mmodule
).has
(sup
.mclass
)
832 if res
== false then return false
833 if not sup
isa MGenericType then return true
834 var sub2
= sub
.supertype_to
(mmodule
, anchor
, sup
.mclass
)
835 assert sub2
.mclass
== sup
.mclass
836 for i
in [0..sup
.mclass
.arity
[ do
837 var sub_arg
= sub2
.arguments
[i
]
838 var sup_arg
= sup
.arguments
[i
]
839 res
= sub_arg
.is_subtype
(mmodule
, anchor
, sup_arg
)
840 if res
== false then return false
845 # The base class type on which self is based
847 # This base type is used to get property (an internally to perform
848 # unsafe type comparison).
850 # Beware: some types (like null) are not based on a class thus this
853 # Basically, this function transform the virtual types and parameter
854 # types to their bounds.
859 # class B super A end
861 # class Y super X end
870 # Map[T,U] anchor_to H #-> Map[B,Y]
872 # Explanation of the example:
873 # In H, T is set to B, because "H super G[B]", and U is bound to Y,
874 # because "redef type U: Y". Therefore, Map[T, U] is bound to
877 # ENSURE: `not self.need_anchor implies result == self`
878 # ENSURE: `not result.need_anchor`
879 fun anchor_to
(mmodule
: MModule, anchor
: MClassType): MType
881 if not need_anchor
then return self
882 assert not anchor
.need_anchor
883 # Just resolve to the anchor and clear all the virtual types
884 var res
= self.resolve_for
(anchor
, null, mmodule
, true)
885 assert not res
.need_anchor
889 # Does `self` contain a virtual type or a formal generic parameter type?
890 # In order to remove those types, you usually want to use `anchor_to`.
891 fun need_anchor
: Bool do return true
893 # Return the supertype when adapted to a class.
895 # In Nit, for each super-class of a type, there is a equivalent super-type.
901 # class H[V] super G[V, Bool] end
903 # H[Int] supertype_to G #-> G[Int, Bool]
906 # REQUIRE: `super_mclass` is a super-class of `self`
907 # REQUIRE: `self.need_anchor implies anchor != null and self.can_resolve_for(anchor, null, mmodule)`
908 # ENSURE: `result.mclass = super_mclass`
909 fun supertype_to
(mmodule
: MModule, anchor
: nullable MClassType, super_mclass
: MClass): MClassType
911 if super_mclass
.arity
== 0 then return super_mclass
.mclass_type
912 if self isa MClassType and self.mclass
== super_mclass
then return self
914 if self.need_anchor
then
915 assert anchor
!= null
916 resolved_self
= self.anchor_to
(mmodule
, anchor
)
920 var supertypes
= resolved_self
.collect_mtypes
(mmodule
)
921 for supertype
in supertypes
do
922 if supertype
.mclass
== super_mclass
then
923 # FIXME: Here, we stop on the first goal. Should we check others and detect inconsistencies?
924 return supertype
.resolve_for
(self, anchor
, mmodule
, false)
930 # Replace formals generic types in self with resolved values in `mtype`
931 # If `cleanup_virtual` is true, then virtual types are also replaced
934 # This function returns self if `need_anchor` is false.
940 # class H[F] super G[F] end
944 # * Array[E].resolve_for(H[Int]) #-> Array[Int]
945 # * Array[E].resolve_for(G[Z], X[Int]) #-> Array[Z]
947 # Explanation of the example:
948 # * Array[E].need_anchor is true because there is a formal generic parameter type E
949 # * E makes sense for H[Int] because E is a formal parameter of G and H specialize G
950 # * Since "H[F] super G[F]", E is in fact F for H
951 # * More specifically, in H[Int], E is Int
952 # * So, in H[Int], Array[E] is Array[Int]
954 # This function is mainly used to inherit a signature.
955 # Because, unlike `anchor_to`, we do not want a full resolution of
956 # a type but only an adapted version of it.
962 # fun foo(e:E):E is abstract
964 # class B super A[Int] end
967 # The signature on foo is (e: E): E
968 # If we resolve the signature for B, we get (e:Int):Int
974 # fun foo(e:E):E is abstract
978 # fun bar do a.foo(x) # <- x is here
982 # The first question is: is foo available on `a`?
984 # The static type of a is `A[Array[F]]`, that is an open type.
985 # in order to find a method `foo`, whe must look at a resolved type.
987 # A[Array[F]].anchor_to(C[nullable Object]) #-> A[Array[nullable Object]]
989 # the method `foo` exists in `A[Array[nullable Object]]`, therefore `foo` exists for `a`.
991 # The next question is: what is the accepted types for `x`?
993 # the signature of `foo` is `foo(e:E)`, thus we must resolve the type E
995 # E.resolve_for(A[Array[F]],C[nullable Object]) #-> Array[F]
997 # The resolution can be done because `E` make sense for the class A (see `can_resolve_for`)
999 # FIXME: the parameter `cleanup_virtual` is just a bad idea, but having
1000 # two function instead of one seems also to be a bad idea.
1002 # REQUIRE: `can_resolve_for(mtype, anchor, mmodule)`
1003 # ENSURE: `not self.need_anchor implies result == self`
1004 fun resolve_for
(mtype
: MType, anchor
: nullable MClassType, mmodule
: MModule, cleanup_virtual
: Bool): MType is abstract
1006 # Resolve formal type to its verbatim bound.
1007 # If the type is not formal, just return self
1009 # The result is returned exactly as declared in the "type" property (verbatim).
1010 # So it could be another formal type.
1012 # In case of conflict, the method aborts.
1013 fun lookup_bound
(mmodule
: MModule, resolved_receiver
: MType): MType do return self
1015 # Resolve the formal type to its simplest equivalent form.
1017 # Formal types are either free or fixed.
1018 # When it is fixed, it means that it is equivalent with a simpler type.
1019 # When a formal type is free, it means that it is only equivalent with itself.
1020 # This method return the most simple equivalent type of `self`.
1022 # This method is mainly used for subtype test in order to sanely compare fixed.
1024 # By default, return self.
1025 # See the redefinitions for specific behavior in each kind of type.
1026 fun lookup_fixed
(mmodule
: MModule, resolved_receiver
: MType): MType do return self
1028 # Can the type be resolved?
1030 # In order to resolve open types, the formal types must make sence.
1040 # E.can_resolve_for(A[Int]) #-> true, E make sense in A
1042 # E.can_resolve_for(B[Int]) #-> false, E does not make sense in B
1044 # B[E].can_resolve_for(A[F], B[Object]) #-> true,
1045 # # B[E] is a red hearing only the E is important,
1046 # # E make sense in A
1049 # REQUIRE: `anchor != null implies not anchor.need_anchor`
1050 # REQUIRE: `mtype.need_anchor implies anchor != null and mtype.can_resolve_for(anchor, null, mmodule)`
1051 # ENSURE: `not self.need_anchor implies result == true`
1052 fun can_resolve_for
(mtype
: MType, anchor
: nullable MClassType, mmodule
: MModule): Bool is abstract
1054 # Return the nullable version of the type
1055 # If the type is already nullable then self is returned
1056 fun as_nullable
: MType
1058 var res
= self.as_nullable_cache
1059 if res
!= null then return res
1060 res
= new MNullableType(self)
1061 self.as_nullable_cache
= res
1065 # Remove the base type of a decorated (proxy) type.
1066 # Is the type is not decorated, then self is returned.
1068 # Most of the time it is used to return the not nullable version of a nullable type.
1069 # In this case, this just remove the `nullable` notation, but the result can still contains null.
1070 # For instance if `self isa MNullType` or self is a formal type bounded by a nullable type.
1071 # If you really want to exclude the `null` value, then use `as_notnull`
1072 fun undecorate
: MType
1077 # Returns the not null version of the type.
1078 # That is `self` minus the `null` value.
1080 # For most types, this return `self`.
1081 # For formal types, this returns a special `MNotNullType`
1082 fun as_notnull
: MType do return self
1084 private var as_nullable_cache
: nullable MType = null
1087 # The depth of the type seen as a tree.
1094 # Formal types have a depth of 1.
1100 # The length of the type seen as a tree.
1107 # Formal types have a length of 1.
1113 # Compute all the classdefs inherited/imported.
1114 # The returned set contains:
1115 # * the class definitions from `mmodule` and its imported modules
1116 # * the class definitions of this type and its super-types
1118 # This function is used mainly internally.
1120 # REQUIRE: `not self.need_anchor`
1121 fun collect_mclassdefs
(mmodule
: MModule): Set[MClassDef] is abstract
1123 # Compute all the super-classes.
1124 # This function is used mainly internally.
1126 # REQUIRE: `not self.need_anchor`
1127 fun collect_mclasses
(mmodule
: MModule): Set[MClass] is abstract
1129 # Compute all the declared super-types.
1130 # Super-types are returned as declared in the classdefs (verbatim).
1131 # This function is used mainly internally.
1133 # REQUIRE: `not self.need_anchor`
1134 fun collect_mtypes
(mmodule
: MModule): Set[MClassType] is abstract
1136 # Is the property in self for a given module
1137 # This method does not filter visibility or whatever
1139 # REQUIRE: `not self.need_anchor`
1140 fun has_mproperty
(mmodule
: MModule, mproperty
: MProperty): Bool
1142 assert not self.need_anchor
1143 return self.collect_mclassdefs
(mmodule
).has
(mproperty
.intro_mclassdef
)
1147 # A type based on a class.
1149 # `MClassType` have properties (see `has_mproperty`).
1153 # The associated class
1156 redef fun model
do return self.mclass
.intro_mmodule
.model
1158 # TODO: private init because strongly bounded to its mclass. see `mclass.mclass_type`
1160 # The formal arguments of the type
1161 # ENSURE: `result.length == self.mclass.arity`
1162 var arguments
= new Array[MType]
1164 redef fun to_s
do return mclass
.to_s
1166 redef fun full_name
do return mclass
.full_name
1168 redef fun c_name
do return mclass
.c_name
1170 redef fun need_anchor
do return false
1172 redef fun anchor_to
(mmodule
: MModule, anchor
: MClassType): MClassType
1174 return super.as(MClassType)
1177 redef fun resolve_for
(mtype
: MType, anchor
: nullable MClassType, mmodule
: MModule, cleanup_virtual
: Bool): MClassType do return self
1179 redef fun can_resolve_for
(mtype
, anchor
, mmodule
) do return true
1181 redef fun collect_mclassdefs
(mmodule
)
1183 assert not self.need_anchor
1184 var cache
= self.collect_mclassdefs_cache
1185 if not cache
.has_key
(mmodule
) then
1186 self.collect_things
(mmodule
)
1188 return cache
[mmodule
]
1191 redef fun collect_mclasses
(mmodule
)
1193 if collect_mclasses_last_module
== mmodule
then return collect_mclasses_last_module_cache
1194 assert not self.need_anchor
1195 var cache
= self.collect_mclasses_cache
1196 if not cache
.has_key
(mmodule
) then
1197 self.collect_things
(mmodule
)
1199 var res
= cache
[mmodule
]
1200 collect_mclasses_last_module
= mmodule
1201 collect_mclasses_last_module_cache
= res
1205 private var collect_mclasses_last_module
: nullable MModule = null
1206 private var collect_mclasses_last_module_cache
: Set[MClass] is noinit
1208 redef fun collect_mtypes
(mmodule
)
1210 assert not self.need_anchor
1211 var cache
= self.collect_mtypes_cache
1212 if not cache
.has_key
(mmodule
) then
1213 self.collect_things
(mmodule
)
1215 return cache
[mmodule
]
1218 # common implementation for `collect_mclassdefs`, `collect_mclasses`, and `collect_mtypes`.
1219 private fun collect_things
(mmodule
: MModule)
1221 var res
= new HashSet[MClassDef]
1222 var seen
= new HashSet[MClass]
1223 var types
= new HashSet[MClassType]
1224 seen
.add
(self.mclass
)
1225 var todo
= [self.mclass
]
1226 while not todo
.is_empty
do
1227 var mclass
= todo
.pop
1228 #print "process {mclass}"
1229 for mclassdef
in mclass
.mclassdefs
do
1230 if not mmodule
.in_importation
<= mclassdef
.mmodule
then continue
1231 #print " process {mclassdef}"
1233 for supertype
in mclassdef
.supertypes
do
1234 types
.add
(supertype
)
1235 var superclass
= supertype
.mclass
1236 if seen
.has
(superclass
) then continue
1237 #print " add {superclass}"
1238 seen
.add
(superclass
)
1239 todo
.add
(superclass
)
1243 collect_mclassdefs_cache
[mmodule
] = res
1244 collect_mclasses_cache
[mmodule
] = seen
1245 collect_mtypes_cache
[mmodule
] = types
1248 private var collect_mclassdefs_cache
= new HashMap[MModule, Set[MClassDef]]
1249 private var collect_mclasses_cache
= new HashMap[MModule, Set[MClass]]
1250 private var collect_mtypes_cache
= new HashMap[MModule, Set[MClassType]]
1254 # A type based on a generic class.
1255 # A generic type a just a class with additional formal generic arguments.
1261 # TODO: private init because strongly bounded to its mclass. see `mclass.get_mtype`
1265 assert self.mclass
.arity
== arguments
.length
1267 self.need_anchor
= false
1268 for t
in arguments
do
1269 if t
.need_anchor
then
1270 self.need_anchor
= true
1275 self.to_s
= "{mclass}[{arguments.join(", ")}]"
1278 # The short-name of the class, then the full-name of each type arguments within brackets.
1279 # Example: `"Map[String, List[Int]]"`
1280 redef var to_s
: String is noinit
1282 # The full-name of the class, then the full-name of each type arguments within brackets.
1283 # Example: `"core::Map[core::String, core::List[core::Int]]"`
1284 redef var full_name
is lazy
do
1285 var args
= new Array[String]
1286 for t
in arguments
do
1287 args
.add t
.full_name
1289 return "{mclass.full_name}[{args.join(", ")}]"
1292 redef var c_name
is lazy
do
1293 var res
= mclass
.c_name
1294 # Note: because the arity is known, a prefix notation is enough
1295 for t
in arguments
do
1302 redef var need_anchor
: Bool is noinit
1304 redef fun resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1306 if not need_anchor
then return self
1307 assert can_resolve_for
(mtype
, anchor
, mmodule
)
1308 var types
= new Array[MType]
1309 for t
in arguments
do
1310 types
.add
(t
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
))
1312 return mclass
.get_mtype
(types
)
1315 redef fun can_resolve_for
(mtype
, anchor
, mmodule
)
1317 if not need_anchor
then return true
1318 for t
in arguments
do
1319 if not t
.can_resolve_for
(mtype
, anchor
, mmodule
) then return false
1328 for a
in self.arguments
do
1330 if d
> dmax
then dmax
= d
1338 for a
in self.arguments
do
1345 # A formal type (either virtual of parametric).
1347 # The main issue with formal types is that they offer very little information on their own
1348 # and need a context (anchor and mmodule) to be useful.
1349 abstract class MFormalType
1352 redef var as_notnull
= new MNotNullType(self) is lazy
1355 # A virtual formal type.
1359 # The property associated with the type.
1360 # Its the definitions of this property that determine the bound or the virtual type.
1361 var mproperty
: MVirtualTypeProp
1363 redef fun model
do return self.mproperty
.intro_mclassdef
.mmodule
.model
1365 redef fun lookup_bound
(mmodule
: MModule, resolved_receiver
: MType): MType
1367 return lookup_single_definition
(mmodule
, resolved_receiver
).bound
.as(not null)
1370 private fun lookup_single_definition
(mmodule
: MModule, resolved_receiver
: MType): MVirtualTypeDef
1372 assert not resolved_receiver
.need_anchor
1373 var props
= self.mproperty
.lookup_definitions
(mmodule
, resolved_receiver
)
1374 if props
.is_empty
then
1376 else if props
.length
== 1 then
1379 var types
= new ArraySet[MType]
1380 var res
= props
.first
1382 types
.add
(p
.bound
.as(not null))
1383 if not res
.is_fixed
then res
= p
1385 if types
.length
== 1 then
1391 # A VT is fixed when:
1392 # * the VT is (re-)defined with the annotation `is fixed`
1393 # * the VT is (indirectly) bound to an enum class (see `enum_kind`) since there is no subtype possible
1394 # * the receiver is an enum class since there is no subtype possible
1395 redef fun lookup_fixed
(mmodule
: MModule, resolved_receiver
: MType): MType
1397 assert not resolved_receiver
.need_anchor
1398 resolved_receiver
= resolved_receiver
.undecorate
1399 assert resolved_receiver
isa MClassType # It is the only remaining type
1401 var prop
= lookup_single_definition
(mmodule
, resolved_receiver
)
1402 var res
= prop
.bound
.as(not null)
1404 # Recursively lookup the fixed result
1405 res
= res
.lookup_fixed
(mmodule
, resolved_receiver
)
1407 # 1. For a fixed VT, return the resolved bound
1408 if prop
.is_fixed
then return res
1410 # 2. For a enum boud, return the bound
1411 if res
isa MClassType and res
.mclass
.kind
== enum_kind
then return res
1413 # 3. for a enum receiver return the bound
1414 if resolved_receiver
.mclass
.kind
== enum_kind
then return res
1419 redef fun resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1421 if not cleanup_virtual
then return self
1422 assert can_resolve_for
(mtype
, anchor
, mmodule
)
1423 # self is a virtual type declared (or inherited) in mtype
1424 # The point of the function it to get the bound of the virtual type that make sense for mtype
1425 # But because mtype is maybe a virtual/formal type, we need to get a real receiver first
1426 #print "{class_name}: {self}/{mtype}/{anchor}?"
1427 var resolved_receiver
1428 if mtype
.need_anchor
then
1429 assert anchor
!= null
1430 resolved_receiver
= mtype
.resolve_for
(anchor
, null, mmodule
, true)
1432 resolved_receiver
= mtype
1434 # Now, we can get the bound
1435 var verbatim_bound
= lookup_bound
(mmodule
, resolved_receiver
)
1436 # The bound is exactly as declared in the "type" property, so we must resolve it again
1437 var res
= verbatim_bound
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1442 redef fun can_resolve_for
(mtype
, anchor
, mmodule
)
1444 if mtype
.need_anchor
then
1445 assert anchor
!= null
1446 mtype
= mtype
.anchor_to
(mmodule
, anchor
)
1448 return mtype
.has_mproperty
(mmodule
, mproperty
)
1451 redef fun to_s
do return self.mproperty
.to_s
1453 redef fun full_name
do return self.mproperty
.full_name
1455 redef fun c_name
do return self.mproperty
.c_name
1458 # The type associated to a formal parameter generic type of a class
1460 # Each parameter type is associated to a specific class.
1461 # It means that all refinements of a same class "share" the parameter type,
1462 # but that a generic subclass has its own parameter types.
1464 # However, in the sense of the meta-model, a parameter type of a class is
1465 # a valid type in a subclass. The "in the sense of the meta-model" is
1466 # important because, in the Nit language, the programmer cannot refers
1467 # directly to the parameter types of the super-classes.
1472 # fun e: E is abstract
1478 # In the class definition B[F], `F` is a valid type but `E` is not.
1479 # However, `self.e` is a valid method call, and the signature of `e` is
1482 # Note that parameter types are shared among class refinements.
1483 # Therefore parameter only have an internal name (see `to_s` for details).
1484 class MParameterType
1487 # The generic class where the parameter belong
1490 redef fun model
do return self.mclass
.intro_mmodule
.model
1492 # The position of the parameter (0 for the first parameter)
1493 # FIXME: is `position` a better name?
1498 redef fun to_s
do return name
1500 redef var full_name
is lazy
do return "{mclass.full_name}::{name}"
1502 redef var c_name
is lazy
do return mclass
.c_name
+ "__" + "#{name}".to_cmangle
1504 redef fun lookup_bound
(mmodule
: MModule, resolved_receiver
: MType): MType
1506 assert not resolved_receiver
.need_anchor
1507 resolved_receiver
= resolved_receiver
.undecorate
1508 assert resolved_receiver
isa MClassType # It is the only remaining type
1509 var goalclass
= self.mclass
1510 if resolved_receiver
.mclass
== goalclass
then
1511 return resolved_receiver
.arguments
[self.rank
]
1513 var supertypes
= resolved_receiver
.collect_mtypes
(mmodule
)
1514 for t
in supertypes
do
1515 if t
.mclass
== goalclass
then
1516 # Yeah! c specialize goalclass with a "super `t'". So the question is what is the argument of f
1517 # FIXME: Here, we stop on the first goal. Should we check others and detect inconsistencies?
1518 var res
= t
.arguments
[self.rank
]
1525 # A PT is fixed when:
1526 # * Its bound is a enum class (see `enum_kind`).
1527 # The PT is just useless, but it is still a case.
1528 # * More usually, the `resolved_receiver` is a subclass of `self.mclass`,
1529 # so it is necessarily fixed in a `super` clause, either with a normal type
1530 # or with another PT.
1531 # See `resolve_for` for examples about related issues.
1532 redef fun lookup_fixed
(mmodule
: MModule, resolved_receiver
: MType): MType
1534 assert not resolved_receiver
.need_anchor
1535 resolved_receiver
= resolved_receiver
.undecorate
1536 assert resolved_receiver
isa MClassType # It is the only remaining type
1537 var res
= self.resolve_for
(resolved_receiver
.mclass
.mclass_type
, resolved_receiver
, mmodule
, false)
1541 redef fun resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1543 assert can_resolve_for
(mtype
, anchor
, mmodule
)
1544 #print "{class_name}: {self}/{mtype}/{anchor}?"
1546 if mtype
isa MGenericType and mtype
.mclass
== self.mclass
then
1547 var res
= mtype
.arguments
[self.rank
]
1548 if anchor
!= null and res
.need_anchor
then
1549 # Maybe the result can be resolved more if are bound to a final class
1550 var r2
= res
.anchor_to
(mmodule
, anchor
)
1551 if r2
isa MClassType and r2
.mclass
.kind
== enum_kind
then return r2
1556 # self is a parameter type of mtype (or of a super-class of mtype)
1557 # The point of the function it to get the bound of the virtual type that make sense for mtype
1558 # But because mtype is maybe a virtual/formal type, we need to get a real receiver first
1559 # FIXME: What happens here is far from clear. Thus this part must be validated and clarified
1560 var resolved_receiver
1561 if mtype
.need_anchor
then
1562 assert anchor
!= null
1563 resolved_receiver
= mtype
.resolve_for
(anchor
.mclass
.mclass_type
, anchor
, mmodule
, true)
1565 resolved_receiver
= mtype
1567 if resolved_receiver
isa MNullableType then resolved_receiver
= resolved_receiver
.mtype
1568 if resolved_receiver
isa MParameterType then
1569 assert resolved_receiver
.mclass
== anchor
.mclass
1570 resolved_receiver
= anchor
.arguments
[resolved_receiver
.rank
]
1571 if resolved_receiver
isa MNullableType then resolved_receiver
= resolved_receiver
.mtype
1573 assert resolved_receiver
isa MClassType # It is the only remaining type
1575 # Eh! The parameter is in the current class.
1576 # So we return the corresponding argument, no mater what!
1577 if resolved_receiver
.mclass
== self.mclass
then
1578 var res
= resolved_receiver
.arguments
[self.rank
]
1579 #print "{class_name}: {self}/{mtype}/{anchor} -> direct {res}"
1583 if resolved_receiver
.need_anchor
then
1584 assert anchor
!= null
1585 resolved_receiver
= resolved_receiver
.resolve_for
(anchor
, null, mmodule
, false)
1587 # Now, we can get the bound
1588 var verbatim_bound
= lookup_bound
(mmodule
, resolved_receiver
)
1589 # The bound is exactly as declared in the "type" property, so we must resolve it again
1590 var res
= verbatim_bound
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1592 #print "{class_name}: {self}/{mtype}/{anchor} -> indirect {res}"
1597 redef fun can_resolve_for
(mtype
, anchor
, mmodule
)
1599 if mtype
.need_anchor
then
1600 assert anchor
!= null
1601 mtype
= mtype
.anchor_to
(mmodule
, anchor
)
1603 return mtype
.collect_mclassdefs
(mmodule
).has
(mclass
.intro
)
1607 # A type that decorates another type.
1609 # The point of this class is to provide a common implementation of sevices that just forward to the original type.
1610 # Specific decorator are expected to redefine (or to extend) the default implementation as this suit them.
1611 abstract class MProxyType
1616 redef fun model
do return self.mtype
.model
1617 redef fun need_anchor
do return mtype
.need_anchor
1618 redef fun as_nullable
do return mtype
.as_nullable
1619 redef fun as_notnull
do return mtype
.as_notnull
1620 redef fun undecorate
do return mtype
.undecorate
1621 redef fun resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1623 var res
= self.mtype
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1627 redef fun can_resolve_for
(mtype
, anchor
, mmodule
)
1629 return self.mtype
.can_resolve_for
(mtype
, anchor
, mmodule
)
1632 redef fun lookup_fixed
(mmodule
, resolved_receiver
)
1634 var t
= mtype
.lookup_fixed
(mmodule
, resolved_receiver
)
1638 redef fun depth
do return self.mtype
.depth
1640 redef fun length
do return self.mtype
.length
1642 redef fun collect_mclassdefs
(mmodule
)
1644 assert not self.need_anchor
1645 return self.mtype
.collect_mclassdefs
(mmodule
)
1648 redef fun collect_mclasses
(mmodule
)
1650 assert not self.need_anchor
1651 return self.mtype
.collect_mclasses
(mmodule
)
1654 redef fun collect_mtypes
(mmodule
)
1656 assert not self.need_anchor
1657 return self.mtype
.collect_mtypes
(mmodule
)
1661 # A type prefixed with "nullable"
1667 self.to_s
= "nullable {mtype}"
1670 redef var to_s
: String is noinit
1672 redef var full_name
is lazy
do return "nullable {mtype.full_name}"
1674 redef var c_name
is lazy
do return "nullable__{mtype.c_name}"
1676 redef fun as_nullable
do return self
1677 redef fun resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1680 return res
.as_nullable
1683 # Efficiently returns `mtype.lookup_fixed(mmodule, resolved_receiver).as_nullable`
1684 redef fun lookup_fixed
(mmodule
, resolved_receiver
)
1687 if t
== mtype
then return self
1688 return t
.as_nullable
1692 # A non-null version of a formal type.
1694 # When a formal type in bounded to a nullable type, this is the type of the not null version of it.
1698 redef fun to_s
do return "not null {mtype}"
1699 redef var full_name
is lazy
do return "not null {mtype.full_name}"
1700 redef var c_name
is lazy
do return "notnull__{mtype.c_name}"
1702 redef fun as_notnull
do return self
1704 redef fun resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1707 return res
.as_notnull
1710 # Efficiently returns `mtype.lookup_fixed(mmodule, resolved_receiver).as_notnull`
1711 redef fun lookup_fixed
(mmodule
, resolved_receiver
)
1714 if t
== mtype
then return self
1719 # The type of the only value null
1721 # The is only one null type per model, see `MModel::null_type`.
1724 redef var model
: Model
1725 redef fun to_s
do return "null"
1726 redef fun full_name
do return "null"
1727 redef fun c_name
do return "null"
1728 redef fun as_nullable
do return self
1730 redef var as_notnull
= new MBottomType(model
) is lazy
1731 redef fun need_anchor
do return false
1732 redef fun resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
) do return self
1733 redef fun can_resolve_for
(mtype
, anchor
, mmodule
) do return true
1735 redef fun collect_mclassdefs
(mmodule
) do return new HashSet[MClassDef]
1737 redef fun collect_mclasses
(mmodule
) do return new HashSet[MClass]
1739 redef fun collect_mtypes
(mmodule
) do return new HashSet[MClassType]
1742 # The special universal most specific type.
1744 # This type is intended to be only used internally for type computation or analysis and should not be exposed to the user.
1745 # The bottom type can de used to denote things that are absurd, dead, or the absence of knowledge.
1747 # Semantically it is the singleton `null.as_notnull`.
1750 redef var model
: Model
1751 redef fun to_s
do return "bottom"
1752 redef fun full_name
do return "bottom"
1753 redef fun c_name
do return "bottom"
1754 redef fun as_nullable
do return model
.null_type
1755 redef fun as_notnull
do return self
1756 redef fun need_anchor
do return false
1757 redef fun resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
) do return self
1758 redef fun can_resolve_for
(mtype
, anchor
, mmodule
) do return true
1760 redef fun collect_mclassdefs
(mmodule
) do return new HashSet[MClassDef]
1762 redef fun collect_mclasses
(mmodule
) do return new HashSet[MClass]
1764 redef fun collect_mtypes
(mmodule
) do return new HashSet[MClassType]
1767 # A signature of a method
1771 # The each parameter (in order)
1772 var mparameters
: Array[MParameter]
1774 # Returns a parameter named `name`, if any.
1775 fun mparameter_by_name
(name
: String): nullable MParameter
1777 for p
in mparameters
do
1778 if p
.name
== name
then return p
1783 # The return type (null for a procedure)
1784 var return_mtype
: nullable MType
1789 var t
= self.return_mtype
1790 if t
!= null then dmax
= t
.depth
1791 for p
in mparameters
do
1792 var d
= p
.mtype
.depth
1793 if d
> dmax
then dmax
= d
1801 var t
= self.return_mtype
1802 if t
!= null then res
+= t
.length
1803 for p
in mparameters
do
1804 res
+= p
.mtype
.length
1809 # REQUIRE: 1 <= mparameters.count p -> p.is_vararg
1812 var vararg_rank
= -1
1813 for i
in [0..mparameters
.length
[ do
1814 var parameter
= mparameters
[i
]
1815 if parameter
.is_vararg
then
1816 assert vararg_rank
== -1
1820 self.vararg_rank
= vararg_rank
1823 # The rank of the ellipsis (`...`) for vararg (starting from 0).
1824 # value is -1 if there is no vararg.
1825 # Example: for "(a: Int, b: Bool..., c: Char)" #-> vararg_rank=1
1826 var vararg_rank
: Int is noinit
1828 # The number of parameters
1829 fun arity
: Int do return mparameters
.length
1833 var b
= new FlatBuffer
1834 if not mparameters
.is_empty
then
1836 for i
in [0..mparameters
.length
[ do
1837 var mparameter
= mparameters
[i
]
1838 if i
> 0 then b
.append
(", ")
1839 b
.append
(mparameter
.name
)
1841 b
.append
(mparameter
.mtype
.to_s
)
1842 if mparameter
.is_vararg
then
1848 var ret
= self.return_mtype
1856 redef fun resolve_for
(mtype
: MType, anchor
: nullable MClassType, mmodule
: MModule, cleanup_virtual
: Bool): MSignature
1858 var params
= new Array[MParameter]
1859 for p
in self.mparameters
do
1860 params
.add
(p
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
))
1862 var ret
= self.return_mtype
1864 ret
= ret
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1866 var res
= new MSignature(params
, ret
)
1871 # A parameter in a signature
1875 # The name of the parameter
1876 redef var name
: String
1878 # The static type of the parameter
1881 # Is the parameter a vararg?
1887 return "{name}: {mtype}..."
1889 return "{name}: {mtype}"
1893 # Returns a new parameter with the `mtype` resolved.
1894 # See `MType::resolve_for` for details.
1895 fun resolve_for
(mtype
: MType, anchor
: nullable MClassType, mmodule
: MModule, cleanup_virtual
: Bool): MParameter
1897 if not self.mtype
.need_anchor
then return self
1898 var newtype
= self.mtype
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1899 var res
= new MParameter(self.name
, newtype
, self.is_vararg
)
1903 redef fun model
do return mtype
.model
1906 # A service (global property) that generalize method, attribute, etc.
1908 # `MProperty` are global to the model; it means that a `MProperty` is not bound
1909 # to a specific `MModule` nor a specific `MClass`.
1911 # A MProperty gather definitions (see `mpropdefs`) ; one for the introduction
1912 # and the other in subclasses and in refinements.
1914 # A `MProperty` is used to denotes services in polymorphic way (ie. independent
1915 # of any dynamic type).
1916 # For instance, a call site "x.foo" is associated to a `MProperty`.
1917 abstract class MProperty
1920 # The associated MPropDef subclass.
1921 # The two specialization hierarchy are symmetric.
1922 type MPROPDEF: MPropDef
1924 # The classdef that introduce the property
1925 # While a property is not bound to a specific module, or class,
1926 # the introducing mclassdef is used for naming and visibility
1927 var intro_mclassdef
: MClassDef
1929 # The (short) name of the property
1930 redef var name
: String
1932 # The canonical name of the property.
1934 # It is the short-`name` prefixed by the short-name of the class and the full-name of the module.
1935 # Example: "my_package::my_module::MyClass::my_method"
1936 redef var full_name
is lazy
do
1937 return "{intro_mclassdef.mmodule.namespace_for(visibility)}::{intro_mclassdef.mclass.name}::{name}"
1940 redef var c_name
is lazy
do
1941 # FIXME use `namespace_for`
1942 return "{intro_mclassdef.mmodule.c_name}__{intro_mclassdef.mclass.name.to_cmangle}__{name.to_cmangle}"
1945 # The visibility of the property
1946 var visibility
: MVisibility
1948 # Is the property usable as an initializer?
1949 var is_autoinit
= false is writable
1953 intro_mclassdef
.intro_mproperties
.add
(self)
1954 var model
= intro_mclassdef
.mmodule
.model
1955 model
.mproperties_by_name
.add_one
(name
, self)
1956 model
.mproperties
.add
(self)
1959 # All definitions of the property.
1960 # The first is the introduction,
1961 # The other are redefinitions (in refinements and in subclasses)
1962 var mpropdefs
= new Array[MPROPDEF]
1964 # The definition that introduces the property.
1966 # Warning: such a definition may not exist in the early life of the object.
1967 # In this case, the method will abort.
1968 var intro
: MPROPDEF is noinit
1970 redef fun model
do return intro
.model
1973 redef fun to_s
do return name
1975 # Return the most specific property definitions defined or inherited by a type.
1976 # The selection knows that refinement is stronger than specialization;
1977 # however, in case of conflict more than one property are returned.
1978 # If mtype does not know mproperty then an empty array is returned.
1980 # If you want the really most specific property, then look at `lookup_first_definition`
1982 # REQUIRE: `not mtype.need_anchor` to simplify the API (no `anchor` parameter)
1983 # ENSURE: `not mtype.has_mproperty(mmodule, self) == result.is_empty`
1984 fun lookup_definitions
(mmodule
: MModule, mtype
: MType): Array[MPROPDEF]
1986 assert not mtype
.need_anchor
1987 mtype
= mtype
.undecorate
1989 var cache
= self.lookup_definitions_cache
[mmodule
, mtype
]
1990 if cache
!= null then return cache
1992 #print "select prop {mproperty} for {mtype} in {self}"
1993 # First, select all candidates
1994 var candidates
= new Array[MPROPDEF]
1995 for mpropdef
in self.mpropdefs
do
1996 # If the definition is not imported by the module, then skip
1997 if not mmodule
.in_importation
<= mpropdef
.mclassdef
.mmodule
then continue
1998 # If the definition is not inherited by the type, then skip
1999 if not mtype
.is_subtype
(mmodule
, null, mpropdef
.mclassdef
.bound_mtype
) then continue
2001 candidates
.add
(mpropdef
)
2003 # Fast track for only one candidate
2004 if candidates
.length
<= 1 then
2005 self.lookup_definitions_cache
[mmodule
, mtype
] = candidates
2009 # Second, filter the most specific ones
2010 return select_most_specific
(mmodule
, candidates
)
2013 private var lookup_definitions_cache
= new HashMap2[MModule, MType, Array[MPROPDEF]]
2015 # Return the most specific property definitions inherited by a type.
2016 # The selection knows that refinement is stronger than specialization;
2017 # however, in case of conflict more than one property are returned.
2018 # If mtype does not know mproperty then an empty array is returned.
2020 # If you want the really most specific property, then look at `lookup_next_definition`
2022 # REQUIRE: `not mtype.need_anchor` to simplify the API (no `anchor` parameter)
2023 # ENSURE: `not mtype.has_mproperty(mmodule, self) implies result.is_empty`
2024 fun lookup_super_definitions
(mmodule
: MModule, mtype
: MType): Array[MPROPDEF]
2026 assert not mtype
.need_anchor
2027 mtype
= mtype
.undecorate
2029 # First, select all candidates
2030 var candidates
= new Array[MPROPDEF]
2031 for mpropdef
in self.mpropdefs
do
2032 # If the definition is not imported by the module, then skip
2033 if not mmodule
.in_importation
<= mpropdef
.mclassdef
.mmodule
then continue
2034 # If the definition is not inherited by the type, then skip
2035 if not mtype
.is_subtype
(mmodule
, null, mpropdef
.mclassdef
.bound_mtype
) then continue
2036 # If the definition is defined by the type, then skip (we want the super, so e skip the current)
2037 if mtype
== mpropdef
.mclassdef
.bound_mtype
and mmodule
== mpropdef
.mclassdef
.mmodule
then continue
2039 candidates
.add
(mpropdef
)
2041 # Fast track for only one candidate
2042 if candidates
.length
<= 1 then return candidates
2044 # Second, filter the most specific ones
2045 return select_most_specific
(mmodule
, candidates
)
2048 # Return an array containing olny the most specific property definitions
2049 # This is an helper function for `lookup_definitions` and `lookup_super_definitions`
2050 private fun select_most_specific
(mmodule
: MModule, candidates
: Array[MPROPDEF]): Array[MPROPDEF]
2052 var res
= new Array[MPROPDEF]
2053 for pd1
in candidates
do
2054 var cd1
= pd1
.mclassdef
2057 for pd2
in candidates
do
2058 if pd2
== pd1
then continue # do not compare with self!
2059 var cd2
= pd2
.mclassdef
2061 if c2
.mclass_type
== c1
.mclass_type
then
2062 if cd2
.mmodule
.in_importation
< cd1
.mmodule
then
2063 # cd2 refines cd1; therefore we skip pd1
2067 else if cd2
.bound_mtype
.is_subtype
(mmodule
, null, cd1
.bound_mtype
) and cd2
.bound_mtype
!= cd1
.bound_mtype
then
2068 # cd2 < cd1; therefore we skip pd1
2077 if res
.is_empty
then
2078 print
"All lost! {candidates.join(", ")}"
2079 # FIXME: should be abort!
2084 # Return the most specific definition in the linearization of `mtype`.
2086 # If you want to know the next properties in the linearization,
2087 # look at `MPropDef::lookup_next_definition`.
2089 # FIXME: the linearization is still unspecified
2091 # REQUIRE: `not mtype.need_anchor` to simplify the API (no `anchor` parameter)
2092 # REQUIRE: `mtype.has_mproperty(mmodule, self)`
2093 fun lookup_first_definition
(mmodule
: MModule, mtype
: MType): MPROPDEF
2095 return lookup_all_definitions
(mmodule
, mtype
).first
2098 # Return all definitions in a linearization order
2099 # Most specific first, most general last
2101 # REQUIRE: `not mtype.need_anchor` to simplify the API (no `anchor` parameter)
2102 # REQUIRE: `mtype.has_mproperty(mmodule, self)`
2103 fun lookup_all_definitions
(mmodule
: MModule, mtype
: MType): Array[MPROPDEF]
2105 mtype
= mtype
.undecorate
2107 var cache
= self.lookup_all_definitions_cache
[mmodule
, mtype
]
2108 if cache
!= null then return cache
2110 assert not mtype
.need_anchor
2111 assert mtype
.has_mproperty
(mmodule
, self)
2113 #print "select prop {mproperty} for {mtype} in {self}"
2114 # First, select all candidates
2115 var candidates
= new Array[MPROPDEF]
2116 for mpropdef
in self.mpropdefs
do
2117 # If the definition is not imported by the module, then skip
2118 if not mmodule
.in_importation
<= mpropdef
.mclassdef
.mmodule
then continue
2119 # If the definition is not inherited by the type, then skip
2120 if not mtype
.is_subtype
(mmodule
, null, mpropdef
.mclassdef
.bound_mtype
) then continue
2122 candidates
.add
(mpropdef
)
2124 # Fast track for only one candidate
2125 if candidates
.length
<= 1 then
2126 self.lookup_all_definitions_cache
[mmodule
, mtype
] = candidates
2130 mmodule
.linearize_mpropdefs
(candidates
)
2131 candidates
= candidates
.reversed
2132 self.lookup_all_definitions_cache
[mmodule
, mtype
] = candidates
2136 private var lookup_all_definitions_cache
= new HashMap2[MModule, MType, Array[MPROPDEF]]
2143 redef type MPROPDEF: MMethodDef
2145 # Is the property defined at the top_level of the module?
2146 # Currently such a property are stored in `Object`
2147 var is_toplevel
: Bool = false is writable
2149 # Is the property a constructor?
2150 # Warning, this property can be inherited by subclasses with or without being a constructor
2151 # therefore, you should use `is_init_for` the verify if the property is a legal constructor for a given class
2152 var is_init
: Bool = false is writable
2154 # The constructor is a (the) root init with empty signature but a set of initializers
2155 var is_root_init
: Bool = false is writable
2157 # Is the property a 'new' constructor?
2158 var is_new
: Bool = false is writable
2160 # Is the property a legal constructor for a given class?
2161 # As usual, visibility is not considered.
2162 # FIXME not implemented
2163 fun is_init_for
(mclass
: MClass): Bool
2168 # A specific method that is safe to call on null.
2169 # Currently, only `==`, `!=` and `is_same_instance` are safe
2170 fun is_null_safe
: Bool do return name
== "==" or name
== "!=" or name
== "is_same_instance"
2173 # A global attribute
2177 redef type MPROPDEF: MAttributeDef
2181 # A global virtual type
2182 class MVirtualTypeProp
2185 redef type MPROPDEF: MVirtualTypeDef
2187 # The formal type associated to the virtual type property
2188 var mvirtualtype
= new MVirtualType(self)
2191 # A definition of a property (local property)
2193 # Unlike `MProperty`, a `MPropDef` is a local definition that belong to a
2194 # specific class definition (which belong to a specific module)
2195 abstract class MPropDef
2198 # The associated `MProperty` subclass.
2199 # the two specialization hierarchy are symmetric
2200 type MPROPERTY: MProperty
2203 type MPROPDEF: MPropDef
2205 # The class definition where the property definition is
2206 var mclassdef
: MClassDef
2208 # The associated global property
2209 var mproperty
: MPROPERTY
2211 # The origin of the definition
2212 var location
: Location
2216 mclassdef
.mpropdefs
.add
(self)
2217 mproperty
.mpropdefs
.add
(self)
2218 if mproperty
.intro_mclassdef
== mclassdef
then
2219 assert not isset mproperty
._intro
2220 mproperty
.intro
= self
2222 self.to_s
= "{mclassdef}#{mproperty}"
2225 # Actually the name of the `mproperty`
2226 redef fun name
do return mproperty
.name
2228 # The full-name of mpropdefs combine the information about the `classdef` and the `mproperty`.
2230 # Therefore the combination of identifiers is awful,
2231 # the worst case being
2233 # * a property "p::m::A::x"
2234 # * redefined in a refinement of a class "q::n::B"
2235 # * in a module "r::o"
2236 # * so "r::o#q::n::B#p::m::A::x"
2238 # Fortunately, the full-name is simplified when entities are repeated.
2239 # For the previous case, the simplest form is "p#A#x".
2240 redef var full_name
is lazy
do
2241 var res
= new FlatBuffer
2243 # The first part is the mclassdef. Worst case is "r::o#q::n::B"
2244 res
.append mclassdef
.full_name
2248 if mclassdef
.mclass
== mproperty
.intro_mclassdef
.mclass
then
2249 # intro are unambiguous in a class
2252 # Just try to simplify each part
2253 if mclassdef
.mmodule
.mpackage
!= mproperty
.intro_mclassdef
.mmodule
.mpackage
then
2254 # precise "p::m" only if "p" != "r"
2255 res
.append mproperty
.intro_mclassdef
.mmodule
.full_name
2257 else if mproperty
.visibility
<= private_visibility
then
2258 # Same package ("p"=="q"), but private visibility,
2259 # does the module part ("::m") need to be displayed
2260 if mclassdef
.mmodule
.namespace_for
(mclassdef
.mclass
.visibility
) != mproperty
.intro_mclassdef
.mmodule
.mpackage
then
2262 res
.append mproperty
.intro_mclassdef
.mmodule
.name
2266 if mclassdef
.mclass
!= mproperty
.intro_mclassdef
.mclass
then
2267 # precise "B" only if not the same class than "A"
2268 res
.append mproperty
.intro_mclassdef
.name
2271 # Always use the property name "x"
2272 res
.append mproperty
.name
2277 redef var c_name
is lazy
do
2278 var res
= new FlatBuffer
2279 res
.append mclassdef
.c_name
2281 if mclassdef
.mclass
== mproperty
.intro_mclassdef
.mclass
then
2282 res
.append name
.to_cmangle
2284 if mclassdef
.mmodule
!= mproperty
.intro_mclassdef
.mmodule
then
2285 res
.append mproperty
.intro_mclassdef
.mmodule
.c_name
2288 if mclassdef
.mclass
!= mproperty
.intro_mclassdef
.mclass
then
2289 res
.append mproperty
.intro_mclassdef
.name
.to_cmangle
2292 res
.append mproperty
.name
.to_cmangle
2297 redef fun model
do return mclassdef
.model
2299 # Internal name combining the module, the class and the property
2300 # Example: "mymodule#MyClass#mymethod"
2301 redef var to_s
: String is noinit
2303 # Is self the definition that introduce the property?
2304 fun is_intro
: Bool do return isset mproperty
._intro
and mproperty
.intro
== self
2306 # Return the next definition in linearization of `mtype`.
2308 # This method is used to determine what method is called by a super.
2310 # REQUIRE: `not mtype.need_anchor`
2311 fun lookup_next_definition
(mmodule
: MModule, mtype
: MType): MPROPDEF
2313 assert not mtype
.need_anchor
2315 var mpropdefs
= self.mproperty
.lookup_all_definitions
(mmodule
, mtype
)
2316 var i
= mpropdefs
.iterator
2317 while i
.is_ok
and i
.item
!= self do i
.next
2318 assert has_property
: i
.is_ok
2320 assert has_next_property
: i
.is_ok
2325 # A local definition of a method
2329 redef type MPROPERTY: MMethod
2330 redef type MPROPDEF: MMethodDef
2332 # The signature attached to the property definition
2333 var msignature
: nullable MSignature = null is writable
2335 # The signature attached to the `new` call on a root-init
2336 # This is a concatenation of the signatures of the initializers
2338 # REQUIRE `mproperty.is_root_init == (new_msignature != null)`
2339 var new_msignature
: nullable MSignature = null is writable
2341 # List of initialisers to call in root-inits
2343 # They could be setters or attributes
2345 # REQUIRE `mproperty.is_root_init == (new_msignature != null)`
2346 var initializers
= new Array[MProperty]
2348 # Is the method definition abstract?
2349 var is_abstract
: Bool = false is writable
2351 # Is the method definition intern?
2352 var is_intern
= false is writable
2354 # Is the method definition extern?
2355 var is_extern
= false is writable
2357 # An optional constant value returned in functions.
2359 # Only some specific primitife value are accepted by engines.
2360 # Is used when there is no better implementation available.
2362 # Currently used only for the implementation of the `--define`
2363 # command-line option.
2364 # SEE: module `mixin`.
2365 var constant_value
: nullable Object = null is writable
2368 # A local definition of an attribute
2372 redef type MPROPERTY: MAttribute
2373 redef type MPROPDEF: MAttributeDef
2375 # The static type of the attribute
2376 var static_mtype
: nullable MType = null is writable
2379 # A local definition of a virtual type
2380 class MVirtualTypeDef
2383 redef type MPROPERTY: MVirtualTypeProp
2384 redef type MPROPDEF: MVirtualTypeDef
2386 # The bound of the virtual type
2387 var bound
: nullable MType = null is writable
2389 # Is the bound fixed?
2390 var is_fixed
= false is writable
2397 # * `interface_kind`
2401 # Note this class is basically an enum.
2402 # FIXME: use a real enum once user-defined enums are available
2404 redef var to_s
: String
2406 # Is a constructor required?
2409 # TODO: private init because enumeration.
2411 # Can a class of kind `self` specializes a class of kine `other`?
2412 fun can_specialize
(other
: MClassKind): Bool
2414 if other
== interface_kind
then return true # everybody can specialize interfaces
2415 if self == interface_kind
or self == enum_kind
then
2416 # no other case for interfaces
2418 else if self == extern_kind
then
2419 # only compatible with themselves
2420 return self == other
2421 else if other
== enum_kind
or other
== extern_kind
then
2422 # abstract_kind and concrete_kind are incompatible
2425 # remain only abstract_kind and concrete_kind
2430 # The class kind `abstract`
2431 fun abstract_kind
: MClassKind do return once
new MClassKind("abstract class", true)
2432 # The class kind `concrete`
2433 fun concrete_kind
: MClassKind do return once
new MClassKind("class", true)
2434 # The class kind `interface`
2435 fun interface_kind
: MClassKind do return once
new MClassKind("interface", false)
2436 # The class kind `enum`
2437 fun enum_kind
: MClassKind do return once
new MClassKind("enum", false)
2438 # The class kind `extern`
2439 fun extern_kind
: MClassKind do return once
new MClassKind("extern class", false)