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 # Object model of the Nit language
19 # This module define the entities of the Nit meta-model like modules,
20 # classes, types and properties
22 # It also provide an API to build and query models.
24 # All model classes starts with the M letter (MModule, MClass, etc.)
28 # TODO: liearization, closures, extern stuff
29 # FIXME: better handling of the types
38 var mclasses
: Array[MClass] = new Array[MClass]
40 # All known properties
41 var mproperties
: Array[MProperty] = new Array[MProperty]
43 # Hierarchy of class definition.
45 # Each classdef is associated with its super-classdefs in regard to
46 # its module of definition.
47 var mclassdef_hierarchy
: POSet[MClassDef] = new POSet[MClassDef]
49 # Class-type hierarchy restricted to the introduction.
51 # The idea is that what is true on introduction is always true whatever
52 # the module considered.
53 # Therefore, this hierarchy is used for a fast positive subtype check.
55 # This poset will evolve in a monotonous way:
56 # * Two non connected nodes will remain unconnected
57 # * New nodes can appear with new edges
58 private var intro_mtype_specialization_hierarchy
: POSet[MClassType] = new POSet[MClassType]
60 # Global overlapped class-type hierarchy.
61 # The hierarchy when all modules are combined.
62 # Therefore, this hierarchy is used for a fast negative subtype check.
64 # This poset will evolve in an anarchic way. Loops can even be created.
66 # FIXME decide what to do on loops
67 private var full_mtype_specialization_hierarchy
: POSet[MClassType] = new POSet[MClassType]
69 # Collections of classes grouped by their short name
70 private var mclasses_by_name
: MultiHashMap[String, MClass] = new MultiHashMap[String, MClass]
72 # Return all class named `name'.
74 # If such a class does not exist, null is returned
75 # (instead of an empty array)
77 # Visibility or modules are not considered
78 fun get_mclasses_by_name
(name
: String): nullable Array[MClass]
80 if mclasses_by_name
.has_key
(name
) then
81 return mclasses_by_name
[name
]
87 # Collections of properties grouped by their short name
88 private var mproperties_by_name
: MultiHashMap[String, MProperty] = new MultiHashMap[String, MProperty]
90 # Return all properties named `name'.
92 # If such a property does not exist, null is returned
93 # (instead of an empty array)
95 # Visibility or modules are not considered
96 fun get_mproperties_by_name
(name
: String): nullable Array[MProperty]
98 if not mproperties_by_name
.has_key
(name
) then
101 return mproperties_by_name
[name
]
106 var null_type
: MNullType = new MNullType(self)
110 # All the classes introduced in the module
111 var intro_mclasses
: Array[MClass] = new Array[MClass]
113 # All the class definitions of the module
114 # (introduction and refinement)
115 var mclassdefs
: Array[MClassDef] = new Array[MClassDef]
117 # Does the current module has a given class `mclass'?
118 # Return true if the mmodule introduces, refines or imports a class.
119 # Visibility is not considered.
120 fun has_mclass
(mclass
: MClass): Bool
122 return self.in_importation
<= mclass
.intro_mmodule
125 # Full hierarchy of introduced ans imported classes.
127 # Create a new hierarchy got by flattening the classes for the module
128 # and its imported modules.
129 # Visibility is not considered.
131 # Note: this function is expensive and is usually used for the main
132 # module of a program only. Do not use it to do you own subtype
134 fun flatten_mclass_hierarchy
: POSet[MClass]
136 var res
= self.flatten_mclass_hierarchy_cache
137 if res
!= null then return res
138 res
= new POSet[MClass]
139 for m
in self.in_importation
.greaters
do
140 for cd
in m
.mclassdefs
do
142 for s
in cd
.supertypes
do
143 res
.add_edge
(c
, s
.mclass
)
147 self.flatten_mclass_hierarchy_cache
= res
151 private var flatten_mclass_hierarchy_cache
: nullable POSet[MClass] = null
156 # MClass are global to the model; it means that a MClass is not bound to a
157 # specific `MModule`.
159 # This characteristic helps the reasoning about classes in a program since a
160 # single MClass object always denote the same class.
161 # However, because a MClass is global, it does not really have properties nor
162 # belong to a hierarchy since the property and the
163 # hierarchy of a class depends of a module.
165 # The module that introduce the class
166 # While classes are not bound to a specific module,
167 # the introducing module is used for naming an visibility
168 var intro_mmodule
: MModule
170 # The short name of the class
171 # In Nit, the name of a class cannot evolve in refinements
174 # The canonical name of the class
175 # Example: "owner::module::MyClass"
176 fun full_name
: String
178 return "{self.intro_mmodule.full_name}::{name}"
181 # The number of generic formal parameters
182 # 0 if the class is not generic
185 # The kind of the class (interface, abstract class, etc.)
186 # In Nit, the kind of a class cannot evolve in refinements
189 # The visibility of the class
190 # In Nit, the visibility of a class cannot evolve in refinements
191 var visibility
: MVisibility
193 init(intro_mmodule
: MModule, name
: String, arity
: Int, kind
: MClassKind, visibility
: MVisibility)
195 self.intro_mmodule
= intro_mmodule
199 self.visibility
= visibility
200 intro_mmodule
.intro_mclasses
.add
(self)
201 var model
= intro_mmodule
.model
202 model
.mclasses_by_name
.add_one
(name
, self)
203 model
.mclasses
.add
(self)
205 # Create the formal parameter types
207 var mparametertypes
= new Array[MParameterType]
208 for i
in [0..arity
[ do
209 var mparametertype
= new MParameterType(self, i
)
210 mparametertypes
.add
(mparametertype
)
212 var mclass_type
= new MGenericType(self, mparametertypes
)
213 self.mclass_type
= mclass_type
214 self.get_mtype_cache
.add
(mclass_type
)
216 self.mclass_type
= new MClassType(self)
220 # All class definitions (introduction and refinements)
221 var mclassdefs
: Array[MClassDef] = new Array[MClassDef]
224 redef fun to_s
do return self.name
226 # The definition that introduced the class
227 # Warning: the introduction is the first `MClassDef' object associated
228 # to self. If self is just created without having any associated
229 # definition, this method will abort
230 private fun intro
: MClassDef
232 assert has_a_first_definition
: not mclassdefs
.is_empty
233 return mclassdefs
.first
236 # The principal static type of the class.
238 # For non-generic class, mclass_type is the only MClassType based
241 # For a generic class, the arguments are the formal parameters.
242 # i.e.: for the class `Array[E:Object]', the mtype is Array[E].
243 # If you want `Array[Object]' the see `MClassDef::bound_mtype'
245 # For generic classes, the mclass_type is also the way to get a formal
246 # generic parameter type.
248 # To get other types based on a generic class, see `get_mtype'.
250 # ENSURE: mclass_type.mclass == self
251 var mclass_type
: MClassType
253 # Return a generic type based on the class
254 # Is the class is not generic, then the result is `mclass_type'
256 # REQUIRE: type_arguments.length == self.arity
257 fun get_mtype
(mtype_arguments
: Array[MType]): MClassType
259 assert mtype_arguments
.length
== self.arity
260 if self.arity
== 0 then return self.mclass_type
261 for t
in self.get_mtype_cache
do
262 if t
.arguments
== mtype_arguments
then
266 var res
= new MGenericType(self, mtype_arguments
)
267 self.get_mtype_cache
.add res
271 private var get_mtype_cache
: Array[MGenericType] = new Array[MGenericType]
275 # A definition (an introduction or a refinement) of a class in a module
277 # A MClassDef is associated with an explicit (or almost) definition of a
278 # class. Unlike MClass, a MClassDef is a local definition that belong to
281 # The module where the definition is
284 # The associated MClass
287 # The bounded type associated to the mclassdef
289 # For a non-generic class, `bound_mtype' and `mclass.mclass_type'
293 # For the classdef Array[E: Object], the bound_mtype is Array[Object].
294 # If you want Array[E], then see `mclass.mclass_type'
296 # ENSURE: bound_mtype.mclass = self.mclass
297 var bound_mtype
: MClassType
299 # Name of each formal generic parameter (in order of declaration)
300 var parameter_names
: Array[String]
302 # The origin of the definition
303 var location
: Location
305 # Internal name combining the module and the class
306 # Example: "mymodule#MyClass"
307 redef fun to_s
do return "{mmodule}#{mclass}"
309 init(mmodule
: MModule, bound_mtype
: MClassType, location
: Location, parameter_names
: Array[String])
311 assert bound_mtype
.mclass
.arity
== parameter_names
.length
312 self.bound_mtype
= bound_mtype
313 self.mmodule
= mmodule
314 self.mclass
= bound_mtype
.mclass
315 self.location
= location
316 mmodule
.mclassdefs
.add
(self)
317 mclass
.mclassdefs
.add
(self)
318 self.parameter_names
= parameter_names
321 # All declared super-types
322 # FIXME: quite ugly but not better idea yet
323 var supertypes
: Array[MClassType] = new Array[MClassType]
325 # Register the super-types for the class (ie "super SomeType")
326 # This function can only invoked once by class
327 fun set_supertypes
(supertypes
: Array[MClassType])
329 assert unique_invocation
: self.in_hierarchy
== null
330 var mmodule
= self.mmodule
331 var model
= mmodule
.model
332 var res
= model
.mclassdef_hierarchy
.add_node
(self)
333 self.in_hierarchy
= res
334 var mtype
= self.bound_mtype
336 for supertype
in supertypes
do
337 self.supertypes
.add
(supertype
)
339 # Register in full_type_specialization_hierarchy
340 model
.full_mtype_specialization_hierarchy
.add_edge
(mtype
, supertype
)
341 # Register in intro_type_specialization_hierarchy
342 if mclass
.intro_mmodule
== mmodule
and supertype
.mclass
.intro_mmodule
== mmodule
then
343 model
.intro_mtype_specialization_hierarchy
.add_edge
(mtype
, supertype
)
347 for mclassdef
in mtype
.collect_mclassdefs
(mmodule
) do
348 res
.poset
.add_edge
(self, mclassdef
)
352 # The view of the class definition in `mclassdef_hierarchy'
353 var in_hierarchy
: nullable POSetElement[MClassDef] = null
355 # Is the definition the one that introduced `mclass`?
356 fun is_intro
: Bool do return mclass
.intro
== self
358 # All properties introduced by the classdef
359 var intro_mproperties
: Array[MProperty] = new Array[MProperty]
361 # All property definitions in the class (introductions and redefinitions)
362 var mpropdefs
: Array[MPropDef] = new Array[MPropDef]
365 # A global static type
367 # MType are global to the model; it means that a MType is not bound to a
368 # specific `MModule`.
369 # This characteristic helps the reasoning about static types in a program
370 # since a single MType object always denote the same type.
372 # However, because a MType is global, it does not really have properties
373 # nor have subtypes to a hierarchy since the property and the class hierarchy
374 # depends of a module.
375 # Moreover, virtual types an formal generic parameter types also depends on
376 # a receiver to have sense.
378 # Therefore, most method of the types require a module and an anchor.
379 # The module is used to know what are the classes and the specialization
381 # The anchor is used to know what is the bound of the virtual types and formal
382 # generic parameter types.
384 # MType are not directly usable to get properties. See the `anchor_to' method
385 # and the `MClassType' class.
387 # FIXME: the order of the parameters is not the best. We mus pick on from:
388 # * foo(mmodule, anchor, othertype)
389 # * foo(othertype, anchor, mmodule)
390 # * foo(anchor, mmodule, othertype)
391 # * foo(othertype, mmodule, anchor)
393 # FIXME: Add a 'is_valid_anchor' to improve imputability.
394 # Currently, anchors are used "as it" without check thus if the caller gives a
395 # bad anchor, then the method will likely crash (abort) in a bad case
397 # FIXME: maybe allways add an anchor with a nullable type (as in is_subtype)
399 # Return true if `self' is an subtype of `sup'.
400 # The typing is done using the standard typing policy of Nit.
402 # REQUIRE: anchor == null implies not self.need_anchor and not sup.need_anchor
403 fun is_subtype
(mmodule
: MModule, anchor
: nullable MClassType, sup
: MType): Bool
406 if anchor
== null then
407 assert not sub
.need_anchor
408 assert not sup
.need_anchor
410 # First, resolve the types
411 if sub
isa MParameterType or sub
isa MVirtualType then
412 assert anchor
!= null
413 sub
= sub
.resolve_for
(anchor
, anchor
, mmodule
, false)
415 if sup
isa MParameterType or sup
isa MVirtualType then
416 assert anchor
!= null
417 sup
= sup
.resolve_for
(anchor
, anchor
, mmodule
, false)
420 if sup
isa MParameterType or sup
isa MVirtualType or sup
isa MNullType then
423 if sub
isa MParameterType or sub
isa MVirtualType then
424 assert anchor
!= null
425 sub
= sub
.anchor_to
(mmodule
, anchor
)
427 if sup
isa MNullableType then
428 if sub
isa MNullType then
430 else if sub
isa MNullableType then
431 return sub
.mtype
.is_subtype
(mmodule
, anchor
, sup
.mtype
)
432 else if sub
isa MClassType then
433 return sub
.is_subtype
(mmodule
, anchor
, sup
.mtype
)
439 assert sup
isa MClassType # It is the only remaining type
440 if sub
isa MNullableType or sub
isa MNullType then
444 assert sub
isa MClassType # It is the only remaining type
445 if anchor
== null then anchor
= sub
# UGLY: any anchor will work
446 var resolved_sub
= sub
.anchor_to
(mmodule
, anchor
)
447 var res
= resolved_sub
.collect_mclasses
(mmodule
).has
(sup
.mclass
)
448 if res
== false then return false
449 if not sup
isa MGenericType then return true
450 var sub2
= sub
.supertype_to
(mmodule
, anchor
, sup
.mclass
)
451 assert sub2
.mclass
== sup
.mclass
452 assert sub2
isa MGenericType
453 for i
in [0..sup
.mclass
.arity
[ do
454 var sub_arg
= sub2
.arguments
[i
]
455 var sup_arg
= sup
.arguments
[i
]
456 res
= sub_arg
.is_subtype
(mmodule
, anchor
, sup_arg
)
457 if res
== false then return false
462 # The base class type on which self is based
464 # This base type is used to get property (an internally to perform
465 # unsafe type comparison).
467 # Beware: some types (like null) are not based on a class thus this
470 # Basically, this function transform the virtual types and parameter
471 # types to their bounds.
481 # Map[T,U] anchor_to H #-> Map[C,Y]
483 # Explanation of the example:
484 # In H, T is set to C, because "H super G[C]", and U is bound to Y,
485 # because "redef type U: Y". Therefore, Map[T, U] is bound to
488 # ENSURE: not self.need_anchor implies return == self
489 # ENSURE: not return.need_anchor
490 fun anchor_to
(mmodule
: MModule, anchor
: MClassType): MType
492 if not need_anchor
then return self
493 assert not anchor
.need_anchor
494 # Just resolve to the anchor and clear all the virtual types
495 var res
= self.resolve_for
(anchor
, anchor
, mmodule
, true)
496 assert not res
.need_anchor
500 # Does `self' contain a virtual type or a formal generic parameter type?
501 # In order to remove those types, you usually want to use `anchor_to'.
502 fun need_anchor
: Bool do return true
504 # Return the supertype when adapted to a class.
506 # In Nit, for each super-class of a type, there is a equivalent super-type.
510 # class H[V] super G[V, Bool]
511 # H[Int] supertype_to G #-> G[Int, Bool]
513 # REQUIRE: `super_mclass' is a super-class of `self'
514 # ENSURE: return.mclass = mclass
515 fun supertype_to
(mmodule
: MModule, anchor
: MClassType, super_mclass
: MClass): MClassType
517 if super_mclass
.arity
== 0 then return super_mclass
.mclass_type
518 if self isa MClassType and self.mclass
== super_mclass
then return self
519 var resolved_self
= self.anchor_to
(mmodule
, anchor
)
520 var supertypes
= resolved_self
.collect_mtypes
(mmodule
)
521 for supertype
in supertypes
do
522 if supertype
.mclass
== super_mclass
then
523 # FIXME: Here, we stop on the first goal. Should we check others and detect inconsistencies?
524 return supertype
.resolve_for
(self, anchor
, mmodule
, false)
530 # Replace formals generic types in self with resolved values in `mtype'
531 # If `cleanup_virtual' is true, then virtual types are also replaced
534 # This function returns self if `need_anchor' is false.
538 # class H[F] super G[F]
539 # Array[E] resolve_for H[Int] #-> Array[Int]
541 # Explanation of the example:
542 # * Array[E].need_anchor is true because there is a formal generic
544 # * E makes sense for H[Int] because E is a formal parameter of G
546 # * Since "H[F] super G[F]", E is in fact F for H
547 # * More specifically, in H[Int], E is Int
548 # * So, in H[Int], Array[E] is Array[Int]
550 # This function is mainly used to inherit a signature.
551 # Because, unlike `anchor_type', we do not want a full resolution of
552 # a type but only an adapted version of it.
558 # class B super A[Int] end
560 # The signature on foo is (e: E): E
561 # If we resolve the signature for B, we get (e:Int):Int
563 # TODO: Explain the cleanup_virtual
565 # FIXME: the parameter `cleanup_virtual' is just a bad idea, but having
566 # two function instead of one seems also to be a bad idea.
568 # ENSURE: not self.need_anchor implies return == self
569 fun resolve_for
(mtype
: MType, anchor
: MClassType, mmodule
: MModule, cleanup_virtual
: Bool): MType is abstract
571 # Return the nullable version of the type
572 # If the type is already nullable then self is returned
574 # FIXME: DO NOT WORK YET
575 fun as_nullable
: MType
577 var res
= self.as_nullable_cache
578 if res
!= null then return res
579 res
= new MNullableType(self)
580 self.as_nullable_cache
= res
584 private var as_nullable_cache
: nullable MType = null
586 # Compute all the classdefs inherited/imported.
587 # The returned set contains:
588 # * the class definitions from `mmodule` and its imported modules
589 # * the class definitions of this type and its super-types
591 # This function is used mainly internally.
593 # REQUIRE: not self.need_anchor
594 fun collect_mclassdefs
(mmodule
: MModule): Set[MClassDef] is abstract
596 # Compute all the super-classes.
597 # This function is used mainly internally.
599 # REQUIRE: not self.need_anchor
600 fun collect_mclasses
(mmodule
: MModule): Set[MClass] is abstract
602 # Compute all the declared super-types.
603 # Super-types are returned as declared in the classdefs (verbatim).
604 # This function is used mainly internally.
606 # REQUIRE: not self.need_anchor
607 fun collect_mtypes
(mmodule
: MModule): Set[MClassType] is abstract
609 # Is the property in self for a given module
610 # This method does not filter visibility or whatever
612 # REQUIRE: not self.need_anchor
613 fun has_mproperty
(mmodule
: MModule, mproperty
: MProperty): Bool
615 assert not self.need_anchor
616 return self.collect_mclassdefs
(mmodule
).has
(mproperty
.intro_mclassdef
)
620 # A type based on a class.
622 # MClassType have properties (see `has_property').
626 # The associated class
629 private init(mclass
: MClass)
634 redef fun to_s
do return mclass
.to_s
636 redef fun need_anchor
do return false
638 redef fun anchor_to
(mmodule
: MModule, anchor
: MClassType): MClassType
640 return super.as(MClassType)
643 redef fun resolve_for
(mtype
: MType, anchor
: MClassType, mmodule
: MModule, cleanup_virtual
: Bool): MClassType do return self
645 redef fun collect_mclassdefs
(mmodule
)
647 assert not self.need_anchor
648 if not collect_mclassdefs_cache
.has_key
(mmodule
) then
649 self.collect_things
(mmodule
)
651 return collect_mclassdefs_cache
[mmodule
]
654 redef fun collect_mclasses
(mmodule
)
656 assert not self.need_anchor
657 if not collect_mclasses_cache
.has_key
(mmodule
) then
658 self.collect_things
(mmodule
)
660 return collect_mclasses_cache
[mmodule
]
663 redef fun collect_mtypes
(mmodule
)
665 assert not self.need_anchor
666 if not collect_mtypes_cache
.has_key
(mmodule
) then
667 self.collect_things
(mmodule
)
669 return collect_mtypes_cache
[mmodule
]
672 # common implementation for `collect_mclassdefs', `collect_mclasses', and `collect_mtypes'.
673 private fun collect_things
(mmodule
: MModule)
675 var res
= new HashSet[MClassDef]
676 var seen
= new HashSet[MClass]
677 var types
= new HashSet[MClassType]
678 seen
.add
(self.mclass
)
679 var todo
= [self.mclass
]
680 while not todo
.is_empty
do
681 var mclass
= todo
.pop
682 #print "process {mclass}"
683 for mclassdef
in mclass
.mclassdefs
do
684 if not mmodule
.in_importation
<= mclassdef
.mmodule
then continue
685 #print " process {mclassdef}"
687 for supertype
in mclassdef
.supertypes
do
689 var superclass
= supertype
.mclass
690 if seen
.has
(superclass
) then continue
691 #print " add {superclass}"
697 collect_mclassdefs_cache
[mmodule
] = res
698 collect_mclasses_cache
[mmodule
] = seen
699 collect_mtypes_cache
[mmodule
] = types
702 private var collect_mclassdefs_cache
: HashMap[MModule, Set[MClassDef]] = new HashMap[MModule, Set[MClassDef]]
703 private var collect_mclasses_cache
: HashMap[MModule, Set[MClass]] = new HashMap[MModule, Set[MClass]]
704 private var collect_mtypes_cache
: HashMap[MModule, Set[MClassType]] = new HashMap[MModule, Set[MClassType]]
708 # A type based on a generic class.
709 # A generic type a just a class with additional formal generic arguments.
713 private init(mclass
: MClass, arguments
: Array[MType])
716 assert self.mclass
.arity
== arguments
.length
717 self.arguments
= arguments
719 self.need_anchor
= false
720 for t
in arguments
do
721 if t
.need_anchor
then
722 self.need_anchor
= true
728 # The formal arguments of the type
729 # ENSURE: return.length == self.mclass.arity
730 var arguments
: Array[MType]
732 # Recursively print the type of the arguments within brackets.
733 # Example: "Map[String,List[Int]]"
736 return "{mclass}[{arguments.join(",")}]"
739 redef var need_anchor
: Bool
741 redef fun resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
743 if not need_anchor
then return self
744 var types
= new Array[MType]
745 for t
in arguments
do
746 types
.add
(t
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
))
748 return mclass
.get_mtype
(types
)
752 # A virtual formal type.
756 # The property associated with the type.
757 # Its the definitions of this property that determine the bound or the virtual type.
758 var mproperty
: MProperty
760 # Lookup the bound for a given resolved_receiver
761 # The result may be a other virtual type (or a parameter type)
763 # The result is returned exactly as declared in the "type" property (verbatim).
765 # In case of conflict, the method aborts.
766 fun lookup_bound
(mmodule
: MModule, resolved_receiver
: MType): MType
768 assert not resolved_receiver
.need_anchor
769 var props
= self.mproperty
.lookup_definitions
(mmodule
, resolved_receiver
)
770 if props
.is_empty
then
772 else if props
.length
== 1 then
773 return props
.first
.as(MVirtualTypeDef).bound
.as(not null)
775 var types
= new ArraySet[MType]
777 types
.add
(p
.as(MVirtualTypeDef).bound
.as(not null))
779 if types
.length
== 1 then
785 redef fun resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
787 if not cleanup_virtual
then return self
788 # self is a virtual type declared (or inherited) in mtype
789 # The point of the function it to get the bound of the virtual type that make sense for mtype
790 # But because mtype is maybe a virtual/formal type, we need to get a real receiver first
791 #print "{class_name}: {self}/{mtype}/{anchor}?"
792 var resolved_reciever
= mtype
.resolve_for
(anchor
, anchor
, mmodule
, true)
793 # Now, we can get the bound
794 var verbatim_bound
= lookup_bound
(mmodule
, resolved_reciever
)
795 # The bound is exactly as declared in the "type" property, so we must resolve it again
796 var res
= verbatim_bound
.resolve_for
(mtype
, anchor
, mmodule
, true)
797 #print "{class_name}: {self}/{mtype}/{anchor} -> {self}/{resolved_reciever}/{anchor} -> {verbatim_bound}/{mtype}/{anchor} -> {res}"
801 redef fun to_s
do return self.mproperty
.to_s
803 init(mproperty
: MProperty)
805 self.mproperty
= mproperty
809 # The type associated the a formal parameter generic type of a class
811 # Each parameter type is associated to a specific class.
812 # It's mean that all refinements of a same class "share" the parameter type,
813 # but that a generic subclass has its on parameter types.
815 # However, in the sense of the meta-model, the a parameter type of a class is
816 # a valid types in a subclass. The "in the sense of the meta-model" is
817 # important because, in the Nit language, the programmer cannot refers
818 # directly to the parameter types of the super-classes.
822 # fun e: E is abstract
827 # In the class definition B[F], `F' is a valid type but `E' is not.
828 # However, `self.e' is a valid method call, and the signature of `e' is
831 # Note that parameter types are shared among class refinements.
832 # Therefore parameter only have an internal name (see `to_s' for details).
833 # TODO: Add a 'name_for' to get better messages.
837 # The generic class where the parameter belong
840 # The position of the parameter (0 for the first parameter)
841 # FIXME: is `position' a better name?
844 # Internal name of the parameter type
845 # Names of parameter types changes in each class definition
846 # Therefore, this method return an internal name.
847 # Example: return "G#1" for the second parameter of the class G
848 # FIXME: add a way to get the real name in a classdef
849 redef fun to_s
do return "{mclass}#{rank}"
851 # Resolve the bound for a given resolved_receiver
852 # The result may be a other virtual type (or a parameter type)
853 fun lookup_bound
(mmodule
: MModule, resolved_receiver
: MType): MType
855 assert not resolved_receiver
.need_anchor
856 var goalclass
= self.mclass
857 var supertypes
= resolved_receiver
.collect_mtypes
(mmodule
)
858 for t
in supertypes
do
859 if t
.mclass
== goalclass
then
860 # Yeah! c specialize goalclass with a "super `t'". So the question is what is the argument of f
861 # FIXME: Here, we stop on the first goal. Should we check others and detect inconsistencies?
862 assert t
isa MGenericType
863 var res
= t
.arguments
[self.rank
]
870 redef fun resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
872 #print "{class_name}: {self}/{mtype}/{anchor}?"
874 if mtype
isa MGenericType and mtype
.mclass
== self.mclass
then
875 return mtype
.arguments
[self.rank
]
878 # self is a parameter type of mtype (or of a super-class of mtype)
879 # The point of the function it to get the bound of the virtual type that make sense for mtype
880 # But because mtype is maybe a virtual/formal type, we need to get a real receiver first
881 # FIXME: What happend here is far from clear. Thus this part must be validated and clarified
882 var resolved_receiver
= mtype
.resolve_for
(anchor
.mclass
.mclass_type
, anchor
, mmodule
, true)
883 if resolved_receiver
isa MNullableType then resolved_receiver
= resolved_receiver
.mtype
884 if resolved_receiver
isa MParameterType then
885 assert resolved_receiver
.mclass
== anchor
.mclass
886 resolved_receiver
= anchor
.as(MGenericType).arguments
[resolved_receiver
.rank
]
887 if resolved_receiver
isa MNullableType then resolved_receiver
= resolved_receiver
.mtype
889 assert resolved_receiver
isa MClassType else print
"{class_name}: {self}/{mtype}/{anchor}? {resolved_receiver}"
891 # Eh! The parameter is in the current class.
892 # So we return the corresponding argument, no mater what!
893 if resolved_receiver
.mclass
== self.mclass
then
894 assert resolved_receiver
isa MGenericType
895 var res
= resolved_receiver
.arguments
[self.rank
]
896 #print "{class_name}: {self}/{mtype}/{anchor} -> direct {res}"
900 resolved_receiver
= resolved_receiver
.resolve_for
(anchor
, anchor
, mmodule
, false)
901 # Now, we can get the bound
902 var verbatim_bound
= lookup_bound
(mmodule
, resolved_receiver
)
903 # The bound is exactly as declared in the "type" property, so we must resolve it again
904 var res
= verbatim_bound
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
906 #print "{class_name}: {self}/{mtype}/{anchor} -> indirect {res}"
911 init(mclass
: MClass, rank
: Int)
918 # A type prefixed with "nullable"
919 # FIXME Stub implementation
923 # The base type of the nullable type
931 redef fun to_s
do return "nullable {mtype}"
933 redef fun need_anchor
do return mtype
.need_anchor
934 redef fun as_nullable
do return self
935 redef fun resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
937 var res
= self.mtype
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
938 return res
.as_nullable
941 redef fun collect_mclassdefs
(mmodule
)
943 assert not self.need_anchor
944 return self.mtype
.collect_mclassdefs
(mmodule
)
947 redef fun collect_mclasses
(mmodule
)
949 assert not self.need_anchor
950 return self.mtype
.collect_mclasses
(mmodule
)
953 redef fun collect_mtypes
(mmodule
)
955 assert not self.need_anchor
956 return self.mtype
.collect_mtypes
(mmodule
)
960 # The type of the only value null
962 # The is only one null type per model, see `MModel::null_type'.
966 protected init(model
: Model)
970 redef fun to_s
do return "null"
971 redef fun as_nullable
do return self
972 redef fun need_anchor
do return false
973 redef fun resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
) do return self
975 redef fun collect_mclassdefs
(mmodule
) do return new HashSet[MClassDef]
977 redef fun collect_mclasses
(mmodule
) do return new HashSet[MClass]
979 redef fun collect_mtypes
(mmodule
) do return new HashSet[MClassType]
982 # A signature of a method (or a closure)
986 # The names of each parameter (in order)
987 var parameter_names
: Array[String]
989 # The types of each parameter (in order)
990 var parameter_mtypes
: Array[MType]
992 # The return type (null for a procedure)
993 var return_mtype
: nullable MType
996 var mclosures
: Array[MClosureDecl] = new Array[MClosureDecl]
998 init(parameter_names
: Array[String], parameter_mtypes
: Array[MType], return_mtype
: nullable MType, vararg_rank
: Int)
1000 self.parameter_names
= parameter_names
1001 self.parameter_mtypes
= parameter_mtypes
1002 self.return_mtype
= return_mtype
1003 self.vararg_rank
= vararg_rank
1006 # Is there closures in the signature?
1007 fun with_mclosure
: Bool do return not self.mclosures
.is_empty
1009 # The rank of the ellipsis (...) for vararg (starting from 0).
1010 # value is -1 if there is no vararg.
1011 # Example: for "(a: Int, b: Bool..., c: Char)" #-> vararg_rank=1
1012 var vararg_rank
: Int
1014 # The number or parameters
1015 fun arity
: Int do return parameter_mtypes
.length
1020 if not parameter_names
.is_empty
then
1022 for i
in [0..parameter_names
.length
[ do
1023 if i
> 0 then b
.append
(", ")
1024 b
.append
(parameter_names
[i
])
1026 b
.append
(parameter_mtypes
[i
].to_s
)
1027 if i
== self.vararg_rank
then
1033 var ret
= self.return_mtype
1041 redef fun resolve_for
(mtype
: MType, anchor
: MClassType, mmodule
: MModule, cleanup_virtual
: Bool): MSignature
1043 var params
= new Array[MType]
1044 for t
in self.parameter_mtypes
do
1045 params
.add
(t
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
))
1047 var ret
= self.return_mtype
1049 ret
= ret
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1051 var res
= new MSignature(self.parameter_names
, params
, ret
, self.vararg_rank
)
1056 # A closure declaration is a signature
1057 # FIXME Stub implementation
1059 # Is the closure optionnal
1060 var is_optional
: Bool
1061 # Has the closure to not continue
1063 # The name of the closure (exluding the !)
1065 # The signature of the closure
1066 var msignature
: MSignature
1069 # A service (global property) that generalize method, attribute, etc.
1071 # MProperty are global to the model; it means that a MProperty is not bound
1072 # to a specific `MModule` nor a specific `MClass`.
1074 # A MProperty gather definitions (see `mpropdefs') ; one for the introduction
1075 # and the other in subclasses and in refinements.
1077 # A MProperty is used to denotes services in polymorphic way (ie. independent
1078 # of any dynamic type).
1079 # For instance, a call site "x.foo" is associated to a MProperty.
1080 abstract class MProperty
1081 # The associated MPropDef subclass.
1082 # The two specialization hierarchy are symmetric.
1083 type MPROPDEF: MPropDef
1085 # The classdef that introduce the property
1086 # While a property is not bound to a specific module, or class,
1087 # the introducing mclassdef is used for naming and visibility
1088 var intro_mclassdef
: MClassDef
1090 # The (short) name of the property
1093 # The canonical name of the property
1094 # Example: "owner::my_module::MyClass::my_method"
1095 fun full_name
: String
1097 return "{self.intro_mclassdef.mmodule.full_name}::{self.intro_mclassdef.mclass.name}::{name}"
1100 # The visibility of the property
1101 var visibility
: MVisibility
1103 init(intro_mclassdef
: MClassDef, name
: String, visibility
: MVisibility)
1105 self.intro_mclassdef
= intro_mclassdef
1107 self.visibility
= visibility
1108 intro_mclassdef
.intro_mproperties
.add
(self)
1109 var model
= intro_mclassdef
.mmodule
.model
1110 model
.mproperties_by_name
.add_one
(name
, self)
1111 model
.mproperties
.add
(self)
1114 # All definitions of the property.
1115 # The first is the introduction,
1116 # The other are redefinitions (in refinements and in subclasses)
1117 var mpropdefs
: Array[MPROPDEF] = new Array[MPROPDEF]
1119 # The definition that introduced the property
1120 # Warning: the introduction is the first `MPropDef' object
1121 # associated to self. If self is just created without having any
1122 # associated definition, this method will abort
1123 fun intro
: MPROPDEF do return mpropdefs
.first
1126 redef fun to_s
do return name
1128 # Return the most specific property definitions defined or inherited by a type.
1129 # The selection knows that refinement is stronger than specialization;
1130 # however, in case of conflict more than one property are returned.
1131 # If mtype does not know mproperty then an empty array is returned.
1133 # If you want the really most specific property, then look at `lookup_first_property`
1134 fun lookup_definitions
(mmodule
: MModule, mtype
: MType): Array[MPROPDEF]
1136 assert not mtype
.need_anchor
1137 if mtype
isa MNullableType then mtype
= mtype
.mtype
1139 var cache
= self.lookup_definitions_cache
[mmodule
, mtype
]
1140 if cache
!= null then return cache
1142 #print "select prop {mproperty} for {mtype} in {self}"
1143 # First, select all candidates
1144 var candidates
= new Array[MPROPDEF]
1145 for mpropdef
in self.mpropdefs
do
1146 # If the definition is not imported by the module, then skip
1147 if not mmodule
.in_importation
<= mpropdef
.mclassdef
.mmodule
then continue
1148 # If the definition is not inherited by the type, then skip
1149 if not mtype
.is_subtype
(mmodule
, null, mpropdef
.mclassdef
.bound_mtype
) then continue
1151 candidates
.add
(mpropdef
)
1153 # Fast track for only one candidate
1154 if candidates
.length
<= 1 then
1155 self.lookup_definitions_cache
[mmodule
, mtype
] = candidates
1159 # Second, filter the most specific ones
1160 var res
= new Array[MPROPDEF]
1161 for pd1
in candidates
do
1162 var cd1
= pd1
.mclassdef
1165 for pd2
in candidates
do
1166 if pd2
== pd1
then continue # do not compare with self!
1167 var cd2
= pd2
.mclassdef
1169 if c2
.mclass_type
== c1
.mclass_type
then
1170 if cd2
.mmodule
.in_importation
<= cd1
.mmodule
then
1171 # cd2 refines cd1; therefore we skip pd1
1175 else if cd2
.bound_mtype
.is_subtype
(mmodule
, null, cd1
.bound_mtype
) then
1176 # cd2 < cd1; therefore we skip pd1
1185 if res
.is_empty
then
1186 print
"All lost! {candidates.join(", ")}"
1187 # FIXME: should be abort!
1189 self.lookup_definitions_cache
[mmodule
, mtype
] = res
1193 private var lookup_definitions_cache
: HashMap2[MModule, MType, Array[MPropDef]] = new HashMap2[MModule, MType, Array[MPropDef]]
1195 # Return the most specific property definitions inherited by a type.
1196 # The selection knows that refinement is stronger than specialization;
1197 # however, in case of conflict more than one property are returned.
1198 # If mtype does not know mproperty then an empty array is returned.
1200 # If you want the really most specific property, then look at `lookup_next_definition`
1202 # FIXME: Move to MPropDef?
1203 fun lookup_super_definitions
(mmodule
: MModule, mtype
: MType): Array[MPropDef]
1205 assert not mtype
.need_anchor
1206 if mtype
isa MNullableType then mtype
= mtype
.mtype
1208 # First, select all candidates
1209 var candidates
= new Array[MPropDef]
1210 for mpropdef
in self.mpropdefs
do
1211 # If the definition is not imported by the module, then skip
1212 if not mmodule
.in_importation
<= mpropdef
.mclassdef
.mmodule
then continue
1213 # If the definition is not inherited by the type, then skip
1214 if not mtype
.is_subtype
(mmodule
, null, mpropdef
.mclassdef
.bound_mtype
) then continue
1215 # If the definition is defined by the type, then skip (we want the super, so e skip the current)
1216 if mtype
== mpropdef
.mclassdef
.bound_mtype
and mmodule
== mpropdef
.mclassdef
.mmodule
then continue
1218 candidates
.add
(mpropdef
)
1220 # Fast track for only one candidate
1221 if candidates
.length
<= 1 then return candidates
1223 # Second, filter the most specific ones
1224 var res
= new Array[MPropDef]
1225 for pd1
in candidates
do
1226 var cd1
= pd1
.mclassdef
1229 for pd2
in candidates
do
1230 if pd2
== pd1
then continue # do not compare with self!
1231 var cd2
= pd2
.mclassdef
1233 if c2
.mclass_type
== c1
.mclass_type
then
1234 if cd2
.mmodule
.in_importation
<= cd1
.mmodule
then
1235 # cd2 refines cd1; therefore we skip pd1
1239 else if cd2
.bound_mtype
.is_subtype
(mmodule
, null, cd1
.bound_mtype
) then
1240 # cd2 < cd1; therefore we skip pd1
1249 if res
.is_empty
then
1250 print
"All lost! {candidates.join(", ")}"
1251 # FIXME: should be abort!
1256 # Return the most specific definition in the linearization of `mtype`.
1257 # If mtype does not know mproperty then null is returned.
1259 # If you want to know the next properties in the linearization,
1260 # look at `MPropDef::lookup_next_definition`.
1262 # FIXME: NOT YET IMPLEMENTED
1264 # REQUIRE: not mtype.need_anchor
1265 fun lookup_first_property
(mmodule
: MModule, mtype
: MType): nullable MPROPDEF
1267 assert not mtype
.need_anchor
1276 redef type MPROPDEF: MMethodDef
1278 init(intro_mclassdef
: MClassDef, name
: String, visibility
: MVisibility)
1283 # Is the property a constructor?
1284 # Warning, this property can be inherited by subclasses with or without being a constructor
1285 # therefore, you should use `is_init_for' the verify if the property is a legal constructor for a given class
1286 var is_init
: Bool writable = false
1288 # Is the property a legal constructor for a given class?
1289 # As usual, visibility is not considered.
1290 # FIXME not implemented
1291 fun is_init_for
(mclass
: MClass): Bool
1297 # A global attribute
1301 redef type MPROPDEF: MAttributeDef
1303 init(intro_mclassdef
: MClassDef, name
: String, visibility
: MVisibility)
1309 # A global virtual type
1310 class MVirtualTypeProp
1313 redef type MPROPDEF: MVirtualTypeDef
1315 init(intro_mclassdef
: MClassDef, name
: String, visibility
: MVisibility)
1320 # The formal type associated to the virtual type property
1321 var mvirtualtype
: MVirtualType = new MVirtualType(self)
1324 # A definition of a property (local property)
1326 # Unlike MProperty, a MPropDef is a local definition that belong to a
1327 # specific class definition (which belong to a specific module)
1328 abstract class MPropDef
1330 # The associated MProperty subclass.
1331 # the two specialization hierarchy are symmetric
1332 type MPROPERTY: MProperty
1335 type MPROPDEF: MPropDef
1337 # The origin of the definition
1338 var location
: Location
1340 # The class definition where the property definition is
1341 var mclassdef
: MClassDef
1343 # The associated global property
1344 var mproperty
: MPROPERTY
1346 init(mclassdef
: MClassDef, mproperty
: MPROPERTY, location
: Location)
1348 self.mclassdef
= mclassdef
1349 self.mproperty
= mproperty
1350 self.location
= location
1351 mclassdef
.mpropdefs
.add
(self)
1352 mproperty
.mpropdefs
.add
(self)
1355 # Internal name combining the module, the class and the property
1356 # Example: "mymodule#MyClass#mymethod"
1359 return "{mclassdef}#{mproperty}"
1362 # Is self the definition that introduce the property?
1363 fun is_intro
: Bool do return mproperty
.intro
== self
1365 # Return the next definition in linearization of `mtype`.
1366 # If there is no next method then null is returned.
1368 # This method is used to determine what method is called by a super.
1370 # FIXME: NOT YET IMPLEMENTED
1372 # REQUIRE: not mtype.need_anchor
1373 fun lookup_next_definition
(mmodule
: MModule, mtype
: MType): nullable MPROPDEF
1375 assert not mtype
.need_anchor
1380 # A local definition of a method
1384 redef type MPROPERTY: MMethod
1385 redef type MPROPDEF: MMethodDef
1387 init(mclassdef
: MClassDef, mproperty
: MPROPERTY, location
: Location)
1392 # The signature attached to the property definition
1393 var msignature
: nullable MSignature writable = null
1396 # A local definition of an attribute
1400 redef type MPROPERTY: MAttribute
1401 redef type MPROPDEF: MAttributeDef
1403 init(mclassdef
: MClassDef, mproperty
: MPROPERTY, location
: Location)
1408 # The static type of the attribute
1409 var static_mtype
: nullable MType writable = null
1412 # A local definition of a virtual type
1413 class MVirtualTypeDef
1416 redef type MPROPERTY: MVirtualTypeProp
1417 redef type MPROPDEF: MVirtualTypeDef
1419 init(mclassdef
: MClassDef, mproperty
: MPROPERTY, location
: Location)
1424 # The bound of the virtual type
1425 var bound
: nullable MType writable = null
1436 # Note this class is basically an enum.
1437 # FIXME: use a real enum once user-defined enums are available
1439 redef var to_s
: String
1441 # Is a constructor required?
1443 private init(s
: String, need_init
: Bool)
1446 self.need_init
= need_init
1450 fun abstract_kind
: MClassKind do return once
new MClassKind("abstract class", true)
1451 fun concrete_kind
: MClassKind do return once
new MClassKind("class", true)
1452 fun interface_kind
: MClassKind do return once
new MClassKind("interface", false)
1453 fun enum_kind
: MClassKind do return once
new MClassKind("enum", false)
1454 fun extern_kind
: MClassKind do return once
new MClassKind("extern", false)