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
153 # The primitive type Object, the root of the class hierarchy
154 fun object_type
: MClassType
156 var res
= self.object_type_cache
157 if res
!= null then return res
158 res
= self.get_primitive_class
("Object").mclass_type
159 self.object_type_cache
= res
163 private var object_type_cache
: nullable MClassType
165 # The primitive type Bool
166 fun bool_type
: MClassType
168 var res
= self.bool_type_cache
169 if res
!= null then return res
170 res
= self.get_primitive_class
("Bool").mclass_type
171 self.bool_type_cache
= res
175 private var bool_type_cache
: nullable MClassType
177 # The primitive type Sys, the main type of the program, if any
178 fun sys_type
: nullable MClassType
180 var clas
= self.model
.get_mclasses_by_name
("Sys")
181 if clas
== null then return null
182 return get_primitive_class
("Sys").mclass_type
185 # Force to get the primitive class named `name' or abort
186 fun get_primitive_class
(name
: String): MClass
188 var cla
= self.model
.get_mclasses_by_name
(name
)
190 if name
== "Bool" then
191 var c
= new MClass(self, name
, 0, enum_kind
, public_visibility
)
192 var cladef
= new MClassDef(self, c
.mclass_type
, new Location(null, 0,0,0,0), new Array[String])
195 print
("Fatal Error: no primitive class {name}")
198 assert cla
.length
== 1 else print cla
.join
(", ")
202 # Try to get the primitive method named `name' on the type `recv'
203 fun try_get_primitive_method
(name
: String, recv
: MType): nullable MMethod
205 var props
= self.model
.get_mproperties_by_name
(name
)
206 if props
== null then return null
207 var res
: nullable MMethod = null
208 for mprop
in props
do
209 assert mprop
isa MMethod
210 if not recv
.has_mproperty
(self, mprop
) then continue
214 print
("Fatal Error: ambigous property name '{name}'; conflict between {mprop.full_name} and {res.full_name}")
224 # MClass are global to the model; it means that a MClass is not bound to a
225 # specific `MModule`.
227 # This characteristic helps the reasoning about classes in a program since a
228 # single MClass object always denote the same class.
229 # However, because a MClass is global, it does not really have properties nor
230 # belong to a hierarchy since the property and the
231 # hierarchy of a class depends of a module.
233 # The module that introduce the class
234 # While classes are not bound to a specific module,
235 # the introducing module is used for naming an visibility
236 var intro_mmodule
: MModule
238 # The short name of the class
239 # In Nit, the name of a class cannot evolve in refinements
242 # The canonical name of the class
243 # Example: "owner::module::MyClass"
244 fun full_name
: String
246 return "{self.intro_mmodule.full_name}::{name}"
249 # The number of generic formal parameters
250 # 0 if the class is not generic
253 # The kind of the class (interface, abstract class, etc.)
254 # In Nit, the kind of a class cannot evolve in refinements
257 # The visibility of the class
258 # In Nit, the visibility of a class cannot evolve in refinements
259 var visibility
: MVisibility
261 init(intro_mmodule
: MModule, name
: String, arity
: Int, kind
: MClassKind, visibility
: MVisibility)
263 self.intro_mmodule
= intro_mmodule
267 self.visibility
= visibility
268 intro_mmodule
.intro_mclasses
.add
(self)
269 var model
= intro_mmodule
.model
270 model
.mclasses_by_name
.add_one
(name
, self)
271 model
.mclasses
.add
(self)
273 # Create the formal parameter types
275 var mparametertypes
= new Array[MParameterType]
276 for i
in [0..arity
[ do
277 var mparametertype
= new MParameterType(self, i
)
278 mparametertypes
.add
(mparametertype
)
280 var mclass_type
= new MGenericType(self, mparametertypes
)
281 self.mclass_type
= mclass_type
282 self.get_mtype_cache
.add
(mclass_type
)
284 self.mclass_type
= new MClassType(self)
288 # All class definitions (introduction and refinements)
289 var mclassdefs
: Array[MClassDef] = new Array[MClassDef]
292 redef fun to_s
do return self.name
294 # The definition that introduced the class
295 # Warning: the introduction is the first `MClassDef' object associated
296 # to self. If self is just created without having any associated
297 # definition, this method will abort
298 private fun intro
: MClassDef
300 assert has_a_first_definition
: not mclassdefs
.is_empty
301 return mclassdefs
.first
304 # The principal static type of the class.
306 # For non-generic class, mclass_type is the only MClassType based
309 # For a generic class, the arguments are the formal parameters.
310 # i.e.: for the class `Array[E:Object]', the mtype is Array[E].
311 # If you want `Array[Object]' the see `MClassDef::bound_mtype'
313 # For generic classes, the mclass_type is also the way to get a formal
314 # generic parameter type.
316 # To get other types based on a generic class, see `get_mtype'.
318 # ENSURE: mclass_type.mclass == self
319 var mclass_type
: MClassType
321 # Return a generic type based on the class
322 # Is the class is not generic, then the result is `mclass_type'
324 # REQUIRE: type_arguments.length == self.arity
325 fun get_mtype
(mtype_arguments
: Array[MType]): MClassType
327 assert mtype_arguments
.length
== self.arity
328 if self.arity
== 0 then return self.mclass_type
329 for t
in self.get_mtype_cache
do
330 if t
.arguments
== mtype_arguments
then
334 var res
= new MGenericType(self, mtype_arguments
)
335 self.get_mtype_cache
.add res
339 private var get_mtype_cache
: Array[MGenericType] = new Array[MGenericType]
343 # A definition (an introduction or a refinement) of a class in a module
345 # A MClassDef is associated with an explicit (or almost) definition of a
346 # class. Unlike MClass, a MClassDef is a local definition that belong to
349 # The module where the definition is
352 # The associated MClass
355 # The bounded type associated to the mclassdef
357 # For a non-generic class, `bound_mtype' and `mclass.mclass_type'
361 # For the classdef Array[E: Object], the bound_mtype is Array[Object].
362 # If you want Array[E], then see `mclass.mclass_type'
364 # ENSURE: bound_mtype.mclass = self.mclass
365 var bound_mtype
: MClassType
367 # Name of each formal generic parameter (in order of declaration)
368 var parameter_names
: Array[String]
370 # The origin of the definition
371 var location
: Location
373 # Internal name combining the module and the class
374 # Example: "mymodule#MyClass"
375 redef fun to_s
do return "{mmodule}#{mclass}"
377 init(mmodule
: MModule, bound_mtype
: MClassType, location
: Location, parameter_names
: Array[String])
379 assert bound_mtype
.mclass
.arity
== parameter_names
.length
380 self.bound_mtype
= bound_mtype
381 self.mmodule
= mmodule
382 self.mclass
= bound_mtype
.mclass
383 self.location
= location
384 mmodule
.mclassdefs
.add
(self)
385 mclass
.mclassdefs
.add
(self)
386 self.parameter_names
= parameter_names
389 # All declared super-types
390 # FIXME: quite ugly but not better idea yet
391 var supertypes
: Array[MClassType] = new Array[MClassType]
393 # Register some super-types for the class (ie "super SomeType")
395 # The hierarchy must not already be set
396 # REQUIRE: self.in_hierarchy == null
397 fun set_supertypes
(supertypes
: Array[MClassType])
399 assert unique_invocation
: self.in_hierarchy
== null
400 var mmodule
= self.mmodule
401 var model
= mmodule
.model
402 var mtype
= self.bound_mtype
404 for supertype
in supertypes
do
405 self.supertypes
.add
(supertype
)
407 # Register in full_type_specialization_hierarchy
408 model
.full_mtype_specialization_hierarchy
.add_edge
(mtype
, supertype
)
409 # Register in intro_type_specialization_hierarchy
410 if mclass
.intro_mmodule
== mmodule
and supertype
.mclass
.intro_mmodule
== mmodule
then
411 model
.intro_mtype_specialization_hierarchy
.add_edge
(mtype
, supertype
)
417 # Collect the super-types (set by set_supertypes) to build the hierarchy
419 # This function can only invoked once by class
420 # REQUIRE: self.in_hierarchy == null
421 # ENSURE: self.in_hierarchy != null
424 assert unique_invocation
: self.in_hierarchy
== null
425 var model
= mmodule
.model
426 var res
= model
.mclassdef_hierarchy
.add_node
(self)
427 self.in_hierarchy
= res
428 var mtype
= self.bound_mtype
430 # Here we need to connect the mclassdef to its pairs in the mclassdef_hierarchy
431 # The simpliest way is to attach it to collect_mclassdefs
432 for mclassdef
in mtype
.collect_mclassdefs
(mmodule
) do
433 res
.poset
.add_edge
(self, mclassdef
)
437 # The view of the class definition in `mclassdef_hierarchy'
438 var in_hierarchy
: nullable POSetElement[MClassDef] = null
440 # Is the definition the one that introduced `mclass`?
441 fun is_intro
: Bool do return mclass
.intro
== self
443 # All properties introduced by the classdef
444 var intro_mproperties
: Array[MProperty] = new Array[MProperty]
446 # All property definitions in the class (introductions and redefinitions)
447 var mpropdefs
: Array[MPropDef] = new Array[MPropDef]
450 # A global static type
452 # MType are global to the model; it means that a MType is not bound to a
453 # specific `MModule`.
454 # This characteristic helps the reasoning about static types in a program
455 # since a single MType object always denote the same type.
457 # However, because a MType is global, it does not really have properties
458 # nor have subtypes to a hierarchy since the property and the class hierarchy
459 # depends of a module.
460 # Moreover, virtual types an formal generic parameter types also depends on
461 # a receiver to have sense.
463 # Therefore, most method of the types require a module and an anchor.
464 # The module is used to know what are the classes and the specialization
466 # The anchor is used to know what is the bound of the virtual types and formal
467 # generic parameter types.
469 # MType are not directly usable to get properties. See the `anchor_to' method
470 # and the `MClassType' class.
472 # FIXME: the order of the parameters is not the best. We mus pick on from:
473 # * foo(mmodule, anchor, othertype)
474 # * foo(othertype, anchor, mmodule)
475 # * foo(anchor, mmodule, othertype)
476 # * foo(othertype, mmodule, anchor)
478 # FIXME: Add a 'is_valid_anchor' to improve imputability.
479 # Currently, anchors are used "as it" without check thus if the caller gives a
480 # bad anchor, then the method will likely crash (abort) in a bad case
482 # FIXME: maybe allways add an anchor with a nullable type (as in is_subtype)
485 # The model of the type
486 fun model
: Model is abstract
488 # Return true if `self' is an subtype of `sup'.
489 # The typing is done using the standard typing policy of Nit.
491 # REQUIRE: anchor == null implies not self.need_anchor and not sup.need_anchor
492 fun is_subtype
(mmodule
: MModule, anchor
: nullable MClassType, sup
: MType): Bool
495 if sub
== sup
then return true
496 if anchor
== null then
497 assert not sub
.need_anchor
498 assert not sup
.need_anchor
500 # First, resolve the types
501 if sub
isa MParameterType or sub
isa MVirtualType then
502 assert anchor
!= null
503 sub
= sub
.resolve_for
(anchor
, anchor
, mmodule
, false)
505 if sup
isa MParameterType or sup
isa MVirtualType then
506 assert anchor
!= null
507 sup
= sup
.resolve_for
(anchor
, anchor
, mmodule
, false)
510 if sup
isa MParameterType or sup
isa MVirtualType or sup
isa MNullType then
513 if sub
isa MParameterType or sub
isa MVirtualType then
514 assert anchor
!= null
515 sub
= sub
.anchor_to
(mmodule
, anchor
)
517 if sup
isa MNullableType then
518 if sub
isa MNullType then
520 else if sub
isa MNullableType then
521 return sub
.mtype
.is_subtype
(mmodule
, anchor
, sup
.mtype
)
522 else if sub
isa MClassType then
523 return sub
.is_subtype
(mmodule
, anchor
, sup
.mtype
)
529 assert sup
isa MClassType # It is the only remaining type
530 if sub
isa MNullableType or sub
isa MNullType then
534 if sub
== sup
then return true
536 assert sub
isa MClassType # It is the only remaining type
537 if anchor
== null then anchor
= sub
# UGLY: any anchor will work
538 var resolved_sub
= sub
.anchor_to
(mmodule
, anchor
)
539 var res
= resolved_sub
.collect_mclasses
(mmodule
).has
(sup
.mclass
)
540 if res
== false then return false
541 if not sup
isa MGenericType then return true
542 var sub2
= sub
.supertype_to
(mmodule
, anchor
, sup
.mclass
)
543 assert sub2
.mclass
== sup
.mclass
544 assert sub2
isa MGenericType
545 for i
in [0..sup
.mclass
.arity
[ do
546 var sub_arg
= sub2
.arguments
[i
]
547 var sup_arg
= sup
.arguments
[i
]
548 res
= sub_arg
.is_subtype
(mmodule
, anchor
, sup_arg
)
549 if res
== false then return false
554 # The base class type on which self is based
556 # This base type is used to get property (an internally to perform
557 # unsafe type comparison).
559 # Beware: some types (like null) are not based on a class thus this
562 # Basically, this function transform the virtual types and parameter
563 # types to their bounds.
573 # Map[T,U] anchor_to H #-> Map[C,Y]
575 # Explanation of the example:
576 # In H, T is set to C, because "H super G[C]", and U is bound to Y,
577 # because "redef type U: Y". Therefore, Map[T, U] is bound to
580 # ENSURE: not self.need_anchor implies return == self
581 # ENSURE: not return.need_anchor
582 fun anchor_to
(mmodule
: MModule, anchor
: MClassType): MType
584 if not need_anchor
then return self
585 assert not anchor
.need_anchor
586 # Just resolve to the anchor and clear all the virtual types
587 var res
= self.resolve_for
(anchor
, anchor
, mmodule
, true)
588 assert not res
.need_anchor
592 # Does `self' contain a virtual type or a formal generic parameter type?
593 # In order to remove those types, you usually want to use `anchor_to'.
594 fun need_anchor
: Bool do return true
596 # Return the supertype when adapted to a class.
598 # In Nit, for each super-class of a type, there is a equivalent super-type.
602 # class H[V] super G[V, Bool]
603 # H[Int] supertype_to G #-> G[Int, Bool]
605 # REQUIRE: `super_mclass' is a super-class of `self'
606 # ENSURE: return.mclass = mclass
607 fun supertype_to
(mmodule
: MModule, anchor
: MClassType, super_mclass
: MClass): MClassType
609 if super_mclass
.arity
== 0 then return super_mclass
.mclass_type
610 if self isa MClassType and self.mclass
== super_mclass
then return self
611 var resolved_self
= self.anchor_to
(mmodule
, anchor
)
612 var supertypes
= resolved_self
.collect_mtypes
(mmodule
)
613 for supertype
in supertypes
do
614 if supertype
.mclass
== super_mclass
then
615 # FIXME: Here, we stop on the first goal. Should we check others and detect inconsistencies?
616 return supertype
.resolve_for
(self, anchor
, mmodule
, false)
622 # Replace formals generic types in self with resolved values in `mtype'
623 # If `cleanup_virtual' is true, then virtual types are also replaced
626 # This function returns self if `need_anchor' is false.
630 # class H[F] super G[F]
631 # Array[E] resolve_for H[Int] #-> Array[Int]
633 # Explanation of the example:
634 # * Array[E].need_anchor is true because there is a formal generic
636 # * E makes sense for H[Int] because E is a formal parameter of G
638 # * Since "H[F] super G[F]", E is in fact F for H
639 # * More specifically, in H[Int], E is Int
640 # * So, in H[Int], Array[E] is Array[Int]
642 # This function is mainly used to inherit a signature.
643 # Because, unlike `anchor_type', we do not want a full resolution of
644 # a type but only an adapted version of it.
650 # class B super A[Int] end
652 # The signature on foo is (e: E): E
653 # If we resolve the signature for B, we get (e:Int):Int
655 # TODO: Explain the cleanup_virtual
657 # FIXME: the parameter `cleanup_virtual' is just a bad idea, but having
658 # two function instead of one seems also to be a bad idea.
660 # ENSURE: not self.need_anchor implies return == self
661 fun resolve_for
(mtype
: MType, anchor
: MClassType, mmodule
: MModule, cleanup_virtual
: Bool): MType is abstract
663 # Return the nullable version of the type
664 # If the type is already nullable then self is returned
666 # FIXME: DO NOT WORK YET
667 fun as_nullable
: MType
669 var res
= self.as_nullable_cache
670 if res
!= null then return res
671 res
= new MNullableType(self)
672 self.as_nullable_cache
= res
676 private var as_nullable_cache
: nullable MType = null
678 # Compute all the classdefs inherited/imported.
679 # The returned set contains:
680 # * the class definitions from `mmodule` and its imported modules
681 # * the class definitions of this type and its super-types
683 # This function is used mainly internally.
685 # REQUIRE: not self.need_anchor
686 fun collect_mclassdefs
(mmodule
: MModule): Set[MClassDef] is abstract
688 # Compute all the super-classes.
689 # This function is used mainly internally.
691 # REQUIRE: not self.need_anchor
692 fun collect_mclasses
(mmodule
: MModule): Set[MClass] is abstract
694 # Compute all the declared super-types.
695 # Super-types are returned as declared in the classdefs (verbatim).
696 # This function is used mainly internally.
698 # REQUIRE: not self.need_anchor
699 fun collect_mtypes
(mmodule
: MModule): Set[MClassType] is abstract
701 # Is the property in self for a given module
702 # This method does not filter visibility or whatever
704 # REQUIRE: not self.need_anchor
705 fun has_mproperty
(mmodule
: MModule, mproperty
: MProperty): Bool
707 assert not self.need_anchor
708 return self.collect_mclassdefs
(mmodule
).has
(mproperty
.intro_mclassdef
)
712 # A type based on a class.
714 # MClassType have properties (see `has_property').
718 # The associated class
721 redef fun model
do return self.mclass
.intro_mmodule
.model
723 private init(mclass
: MClass)
728 redef fun to_s
do return mclass
.to_s
730 redef fun need_anchor
do return false
732 redef fun anchor_to
(mmodule
: MModule, anchor
: MClassType): MClassType
734 return super.as(MClassType)
737 redef fun resolve_for
(mtype
: MType, anchor
: MClassType, mmodule
: MModule, cleanup_virtual
: Bool): MClassType do return self
739 redef fun collect_mclassdefs
(mmodule
)
741 assert not self.need_anchor
742 var cache
= self.collect_mclassdefs_cache
743 if not cache
.has_key
(mmodule
) then
744 self.collect_things
(mmodule
)
746 return cache
[mmodule
]
749 redef fun collect_mclasses
(mmodule
)
751 assert not self.need_anchor
752 var cache
= self.collect_mclasses_cache
753 if not cache
.has_key
(mmodule
) then
754 self.collect_things
(mmodule
)
756 return cache
[mmodule
]
759 redef fun collect_mtypes
(mmodule
)
761 assert not self.need_anchor
762 var cache
= self.collect_mtypes_cache
763 if not cache
.has_key
(mmodule
) then
764 self.collect_things
(mmodule
)
766 return cache
[mmodule
]
769 # common implementation for `collect_mclassdefs', `collect_mclasses', and `collect_mtypes'.
770 private fun collect_things
(mmodule
: MModule)
772 var res
= new HashSet[MClassDef]
773 var seen
= new HashSet[MClass]
774 var types
= new HashSet[MClassType]
775 seen
.add
(self.mclass
)
776 var todo
= [self.mclass
]
777 while not todo
.is_empty
do
778 var mclass
= todo
.pop
779 #print "process {mclass}"
780 for mclassdef
in mclass
.mclassdefs
do
781 if not mmodule
.in_importation
<= mclassdef
.mmodule
then continue
782 #print " process {mclassdef}"
784 for supertype
in mclassdef
.supertypes
do
786 var superclass
= supertype
.mclass
787 if seen
.has
(superclass
) then continue
788 #print " add {superclass}"
794 collect_mclassdefs_cache
[mmodule
] = res
795 collect_mclasses_cache
[mmodule
] = seen
796 collect_mtypes_cache
[mmodule
] = types
799 private var collect_mclassdefs_cache
: HashMap[MModule, Set[MClassDef]] = new HashMap[MModule, Set[MClassDef]]
800 private var collect_mclasses_cache
: HashMap[MModule, Set[MClass]] = new HashMap[MModule, Set[MClass]]
801 private var collect_mtypes_cache
: HashMap[MModule, Set[MClassType]] = new HashMap[MModule, Set[MClassType]]
805 # A type based on a generic class.
806 # A generic type a just a class with additional formal generic arguments.
810 private init(mclass
: MClass, arguments
: Array[MType])
813 assert self.mclass
.arity
== arguments
.length
814 self.arguments
= arguments
816 self.need_anchor
= false
817 for t
in arguments
do
818 if t
.need_anchor
then
819 self.need_anchor
= true
825 # The formal arguments of the type
826 # ENSURE: return.length == self.mclass.arity
827 var arguments
: Array[MType]
829 # Recursively print the type of the arguments within brackets.
830 # Example: "Map[String,List[Int]]"
833 return "{mclass}[{arguments.join(",")}]"
836 redef var need_anchor
: Bool
838 redef fun resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
840 if not need_anchor
then return self
841 var types
= new Array[MType]
842 for t
in arguments
do
843 types
.add
(t
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
))
845 return mclass
.get_mtype
(types
)
849 # A virtual formal type.
853 # The property associated with the type.
854 # Its the definitions of this property that determine the bound or the virtual type.
855 var mproperty
: MProperty
857 redef fun model
do return self.mproperty
.intro_mclassdef
.mmodule
.model
859 # Lookup the bound for a given resolved_receiver
860 # The result may be a other virtual type (or a parameter type)
862 # The result is returned exactly as declared in the "type" property (verbatim).
864 # In case of conflict, the method aborts.
865 fun lookup_bound
(mmodule
: MModule, resolved_receiver
: MType): MType
867 assert not resolved_receiver
.need_anchor
868 var props
= self.mproperty
.lookup_definitions
(mmodule
, resolved_receiver
)
869 if props
.is_empty
then
871 else if props
.length
== 1 then
872 return props
.first
.as(MVirtualTypeDef).bound
.as(not null)
874 var types
= new ArraySet[MType]
876 types
.add
(p
.as(MVirtualTypeDef).bound
.as(not null))
878 if types
.length
== 1 then
884 redef fun resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
886 if not cleanup_virtual
then return self
887 # self is a virtual type declared (or inherited) in mtype
888 # The point of the function it to get the bound of the virtual type that make sense for mtype
889 # But because mtype is maybe a virtual/formal type, we need to get a real receiver first
890 #print "{class_name}: {self}/{mtype}/{anchor}?"
891 var resolved_reciever
= mtype
.resolve_for
(anchor
, anchor
, mmodule
, true)
892 # Now, we can get the bound
893 var verbatim_bound
= lookup_bound
(mmodule
, resolved_reciever
)
894 # The bound is exactly as declared in the "type" property, so we must resolve it again
895 var res
= verbatim_bound
.resolve_for
(mtype
, anchor
, mmodule
, true)
896 #print "{class_name}: {self}/{mtype}/{anchor} -> {self}/{resolved_reciever}/{anchor} -> {verbatim_bound}/{mtype}/{anchor} -> {res}"
900 redef fun to_s
do return self.mproperty
.to_s
902 init(mproperty
: MProperty)
904 self.mproperty
= mproperty
908 # The type associated the a formal parameter generic type of a class
910 # Each parameter type is associated to a specific class.
911 # It's mean that all refinements of a same class "share" the parameter type,
912 # but that a generic subclass has its on parameter types.
914 # However, in the sense of the meta-model, the a parameter type of a class is
915 # a valid types in a subclass. The "in the sense of the meta-model" is
916 # important because, in the Nit language, the programmer cannot refers
917 # directly to the parameter types of the super-classes.
921 # fun e: E is abstract
926 # In the class definition B[F], `F' is a valid type but `E' is not.
927 # However, `self.e' is a valid method call, and the signature of `e' is
930 # Note that parameter types are shared among class refinements.
931 # Therefore parameter only have an internal name (see `to_s' for details).
932 # TODO: Add a 'name_for' to get better messages.
936 # The generic class where the parameter belong
939 redef fun model
do return self.mclass
.intro_mmodule
.model
941 # The position of the parameter (0 for the first parameter)
942 # FIXME: is `position' a better name?
945 # Internal name of the parameter type
946 # Names of parameter types changes in each class definition
947 # Therefore, this method return an internal name.
948 # Example: return "G#1" for the second parameter of the class G
949 # FIXME: add a way to get the real name in a classdef
950 redef fun to_s
do return "{mclass}#{rank}"
952 # Resolve the bound for a given resolved_receiver
953 # The result may be a other virtual type (or a parameter type)
954 fun lookup_bound
(mmodule
: MModule, resolved_receiver
: MType): MType
956 assert not resolved_receiver
.need_anchor
957 var goalclass
= self.mclass
958 var supertypes
= resolved_receiver
.collect_mtypes
(mmodule
)
959 for t
in supertypes
do
960 if t
.mclass
== goalclass
then
961 # Yeah! c specialize goalclass with a "super `t'". So the question is what is the argument of f
962 # FIXME: Here, we stop on the first goal. Should we check others and detect inconsistencies?
963 assert t
isa MGenericType
964 var res
= t
.arguments
[self.rank
]
971 redef fun resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
973 #print "{class_name}: {self}/{mtype}/{anchor}?"
975 if mtype
isa MGenericType and mtype
.mclass
== self.mclass
then
976 return mtype
.arguments
[self.rank
]
979 # self is a parameter type of mtype (or of a super-class of mtype)
980 # The point of the function it to get the bound of the virtual type that make sense for mtype
981 # But because mtype is maybe a virtual/formal type, we need to get a real receiver first
982 # FIXME: What happend here is far from clear. Thus this part must be validated and clarified
983 var resolved_receiver
= mtype
.resolve_for
(anchor
.mclass
.mclass_type
, anchor
, mmodule
, true)
984 if resolved_receiver
isa MNullableType then resolved_receiver
= resolved_receiver
.mtype
985 if resolved_receiver
isa MParameterType then
986 assert resolved_receiver
.mclass
== anchor
.mclass
987 resolved_receiver
= anchor
.as(MGenericType).arguments
[resolved_receiver
.rank
]
988 if resolved_receiver
isa MNullableType then resolved_receiver
= resolved_receiver
.mtype
990 assert resolved_receiver
isa MClassType else print
"{class_name}: {self}/{mtype}/{anchor}? {resolved_receiver}"
992 # Eh! The parameter is in the current class.
993 # So we return the corresponding argument, no mater what!
994 if resolved_receiver
.mclass
== self.mclass
then
995 assert resolved_receiver
isa MGenericType
996 var res
= resolved_receiver
.arguments
[self.rank
]
997 #print "{class_name}: {self}/{mtype}/{anchor} -> direct {res}"
1001 resolved_receiver
= resolved_receiver
.resolve_for
(anchor
, anchor
, mmodule
, false)
1002 # Now, we can get the bound
1003 var verbatim_bound
= lookup_bound
(mmodule
, resolved_receiver
)
1004 # The bound is exactly as declared in the "type" property, so we must resolve it again
1005 var res
= verbatim_bound
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1007 #print "{class_name}: {self}/{mtype}/{anchor} -> indirect {res}"
1012 init(mclass
: MClass, rank
: Int)
1014 self.mclass
= mclass
1019 # A type prefixed with "nullable"
1020 # FIXME Stub implementation
1024 # The base type of the nullable type
1027 redef fun model
do return self.mtype
.model
1034 redef fun to_s
do return "nullable {mtype}"
1036 redef fun need_anchor
do return mtype
.need_anchor
1037 redef fun as_nullable
do return self
1038 redef fun resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1040 var res
= self.mtype
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1041 return res
.as_nullable
1044 redef fun collect_mclassdefs
(mmodule
)
1046 assert not self.need_anchor
1047 return self.mtype
.collect_mclassdefs
(mmodule
)
1050 redef fun collect_mclasses
(mmodule
)
1052 assert not self.need_anchor
1053 return self.mtype
.collect_mclasses
(mmodule
)
1056 redef fun collect_mtypes
(mmodule
)
1058 assert not self.need_anchor
1059 return self.mtype
.collect_mtypes
(mmodule
)
1063 # The type of the only value null
1065 # The is only one null type per model, see `MModel::null_type'.
1068 redef var model
: Model
1069 protected init(model
: Model)
1073 redef fun to_s
do return "null"
1074 redef fun as_nullable
do return self
1075 redef fun need_anchor
do return false
1076 redef fun resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
) do return self
1078 redef fun collect_mclassdefs
(mmodule
) do return new HashSet[MClassDef]
1080 redef fun collect_mclasses
(mmodule
) do return new HashSet[MClass]
1082 redef fun collect_mtypes
(mmodule
) do return new HashSet[MClassType]
1085 # A signature of a method (or a closure)
1089 # The each parameter (in order)
1090 var mparameters
: Array[MParameter]
1092 var mclosures
= new Array[MParameter]
1094 # The return type (null for a procedure)
1095 var return_mtype
: nullable MType
1097 # REQUIRE: 1 <= mparameters.count p -> p.is_vararg
1098 init(mparameters
: Array[MParameter], return_mtype
: nullable MType)
1100 var vararg_rank
= -1
1101 for i
in [0..mparameters
.length
[ do
1102 var parameter
= mparameters
[i
]
1103 if parameter
.is_vararg
then
1104 assert vararg_rank
== -1
1108 self.mparameters
= mparameters
1109 self.return_mtype
= return_mtype
1110 self.vararg_rank
= vararg_rank
1113 # The rank of the ellipsis (...) for vararg (starting from 0).
1114 # value is -1 if there is no vararg.
1115 # Example: for "(a: Int, b: Bool..., c: Char)" #-> vararg_rank=1
1116 var vararg_rank
: Int
1118 # The number or parameters
1119 fun arity
: Int do return mparameters
.length
1124 if not mparameters
.is_empty
then
1126 for i
in [0..mparameters
.length
[ do
1127 var mparameter
= mparameters
[i
]
1128 if i
> 0 then b
.append
(", ")
1129 b
.append
(mparameter
.name
)
1131 b
.append
(mparameter
.mtype
.to_s
)
1132 if mparameter
.is_vararg
then
1138 var ret
= self.return_mtype
1146 redef fun resolve_for
(mtype
: MType, anchor
: MClassType, mmodule
: MModule, cleanup_virtual
: Bool): MSignature
1148 var params
= new Array[MParameter]
1149 for p
in self.mparameters
do
1150 params
.add
(p
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
))
1152 var ret
= self.return_mtype
1154 ret
= ret
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1156 var res
= new MSignature(params
, ret
)
1157 for p
in self.mclosures
do
1158 res
.mclosures
.add
(p
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
))
1164 # A parameter in a signature
1166 # The name of the parameter
1169 # The static type of the parameter
1172 # Is the parameter a vararg?
1175 fun resolve_for
(mtype
: MType, anchor
: MClassType, mmodule
: MModule, cleanup_virtual
: Bool): MParameter
1177 if not self.mtype
.need_anchor
then return self
1178 var newtype
= self.mtype
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1179 var res
= new MParameter(self.name
, newtype
, self.is_vararg
)
1184 # A service (global property) that generalize method, attribute, etc.
1186 # MProperty are global to the model; it means that a MProperty is not bound
1187 # to a specific `MModule` nor a specific `MClass`.
1189 # A MProperty gather definitions (see `mpropdefs') ; one for the introduction
1190 # and the other in subclasses and in refinements.
1192 # A MProperty is used to denotes services in polymorphic way (ie. independent
1193 # of any dynamic type).
1194 # For instance, a call site "x.foo" is associated to a MProperty.
1195 abstract class MProperty
1196 # The associated MPropDef subclass.
1197 # The two specialization hierarchy are symmetric.
1198 type MPROPDEF: MPropDef
1200 # The classdef that introduce the property
1201 # While a property is not bound to a specific module, or class,
1202 # the introducing mclassdef is used for naming and visibility
1203 var intro_mclassdef
: MClassDef
1205 # The (short) name of the property
1208 # The canonical name of the property
1209 # Example: "owner::my_module::MyClass::my_method"
1210 fun full_name
: String
1212 return "{self.intro_mclassdef.mmodule.full_name}::{self.intro_mclassdef.mclass.name}::{name}"
1215 # The visibility of the property
1216 var visibility
: MVisibility
1218 init(intro_mclassdef
: MClassDef, name
: String, visibility
: MVisibility)
1220 self.intro_mclassdef
= intro_mclassdef
1222 self.visibility
= visibility
1223 intro_mclassdef
.intro_mproperties
.add
(self)
1224 var model
= intro_mclassdef
.mmodule
.model
1225 model
.mproperties_by_name
.add_one
(name
, self)
1226 model
.mproperties
.add
(self)
1229 # All definitions of the property.
1230 # The first is the introduction,
1231 # The other are redefinitions (in refinements and in subclasses)
1232 var mpropdefs
: Array[MPROPDEF] = new Array[MPROPDEF]
1234 # The definition that introduced the property
1235 # Warning: the introduction is the first `MPropDef' object
1236 # associated to self. If self is just created without having any
1237 # associated definition, this method will abort
1238 fun intro
: MPROPDEF do return mpropdefs
.first
1241 redef fun to_s
do return name
1243 # Return the most specific property definitions defined or inherited by a type.
1244 # The selection knows that refinement is stronger than specialization;
1245 # however, in case of conflict more than one property are returned.
1246 # If mtype does not know mproperty then an empty array is returned.
1248 # If you want the really most specific property, then look at `lookup_first_definition`
1249 fun lookup_definitions
(mmodule
: MModule, mtype
: MType): Array[MPROPDEF]
1251 assert not mtype
.need_anchor
1252 if mtype
isa MNullableType then mtype
= mtype
.mtype
1254 var cache
= self.lookup_definitions_cache
[mmodule
, mtype
]
1255 if cache
!= null then return cache
1257 #print "select prop {mproperty} for {mtype} in {self}"
1258 # First, select all candidates
1259 var candidates
= new Array[MPROPDEF]
1260 for mpropdef
in self.mpropdefs
do
1261 # If the definition is not imported by the module, then skip
1262 if not mmodule
.in_importation
<= mpropdef
.mclassdef
.mmodule
then continue
1263 # If the definition is not inherited by the type, then skip
1264 if not mtype
.is_subtype
(mmodule
, null, mpropdef
.mclassdef
.bound_mtype
) then continue
1266 candidates
.add
(mpropdef
)
1268 # Fast track for only one candidate
1269 if candidates
.length
<= 1 then
1270 self.lookup_definitions_cache
[mmodule
, mtype
] = candidates
1274 # Second, filter the most specific ones
1275 var res
= new Array[MPROPDEF]
1276 for pd1
in candidates
do
1277 var cd1
= pd1
.mclassdef
1280 for pd2
in candidates
do
1281 if pd2
== pd1
then continue # do not compare with self!
1282 var cd2
= pd2
.mclassdef
1284 if c2
.mclass_type
== c1
.mclass_type
then
1285 if cd2
.mmodule
.in_importation
<= cd1
.mmodule
then
1286 # cd2 refines cd1; therefore we skip pd1
1290 else if cd2
.bound_mtype
.is_subtype
(mmodule
, null, cd1
.bound_mtype
) then
1291 # cd2 < cd1; therefore we skip pd1
1300 if res
.is_empty
then
1301 print
"All lost! {candidates.join(", ")}"
1302 # FIXME: should be abort!
1304 self.lookup_definitions_cache
[mmodule
, mtype
] = res
1308 private var lookup_definitions_cache
: HashMap2[MModule, MType, Array[MPROPDEF]] = new HashMap2[MModule, MType, Array[MPROPDEF]]
1310 # Return the most specific property definitions inherited by a type.
1311 # The selection knows that refinement is stronger than specialization;
1312 # however, in case of conflict more than one property are returned.
1313 # If mtype does not know mproperty then an empty array is returned.
1315 # If you want the really most specific property, then look at `lookup_next_definition`
1317 # FIXME: Move to MPropDef?
1318 fun lookup_super_definitions
(mmodule
: MModule, mtype
: MType): Array[MPropDef]
1320 assert not mtype
.need_anchor
1321 if mtype
isa MNullableType then mtype
= mtype
.mtype
1323 # First, select all candidates
1324 var candidates
= new Array[MPropDef]
1325 for mpropdef
in self.mpropdefs
do
1326 # If the definition is not imported by the module, then skip
1327 if not mmodule
.in_importation
<= mpropdef
.mclassdef
.mmodule
then continue
1328 # If the definition is not inherited by the type, then skip
1329 if not mtype
.is_subtype
(mmodule
, null, mpropdef
.mclassdef
.bound_mtype
) then continue
1330 # If the definition is defined by the type, then skip (we want the super, so e skip the current)
1331 if mtype
== mpropdef
.mclassdef
.bound_mtype
and mmodule
== mpropdef
.mclassdef
.mmodule
then continue
1333 candidates
.add
(mpropdef
)
1335 # Fast track for only one candidate
1336 if candidates
.length
<= 1 then return candidates
1338 # Second, filter the most specific ones
1339 var res
= new Array[MPropDef]
1340 for pd1
in candidates
do
1341 var cd1
= pd1
.mclassdef
1344 for pd2
in candidates
do
1345 if pd2
== pd1
then continue # do not compare with self!
1346 var cd2
= pd2
.mclassdef
1348 if c2
.mclass_type
== c1
.mclass_type
then
1349 if cd2
.mmodule
.in_importation
<= cd1
.mmodule
then
1350 # cd2 refines cd1; therefore we skip pd1
1354 else if cd2
.bound_mtype
.is_subtype
(mmodule
, null, cd1
.bound_mtype
) then
1355 # cd2 < cd1; therefore we skip pd1
1364 if res
.is_empty
then
1365 print
"All lost! {candidates.join(", ")}"
1366 # FIXME: should be abort!
1371 # Return the most specific definition in the linearization of `mtype`.
1372 # If mtype does not know mproperty then null is returned.
1374 # If you want to know the next properties in the linearization,
1375 # look at `MPropDef::lookup_next_definition`.
1377 # FIXME: NOT YET IMPLEMENTED
1379 # REQUIRE: not mtype.need_anchor
1380 fun lookup_first_definition
(mmodule
: MModule, mtype
: MType): nullable MPROPDEF
1382 assert not mtype
.need_anchor
1391 redef type MPROPDEF: MMethodDef
1393 init(intro_mclassdef
: MClassDef, name
: String, visibility
: MVisibility)
1398 # Is the property a constructor?
1399 # Warning, this property can be inherited by subclasses with or without being a constructor
1400 # therefore, you should use `is_init_for' the verify if the property is a legal constructor for a given class
1401 var is_init
: Bool writable = false
1403 # The the property a 'new' contructor?
1404 var is_new
: Bool writable = false
1406 # Is the property a legal constructor for a given class?
1407 # As usual, visibility is not considered.
1408 # FIXME not implemented
1409 fun is_init_for
(mclass
: MClass): Bool
1415 # A global attribute
1419 redef type MPROPDEF: MAttributeDef
1421 init(intro_mclassdef
: MClassDef, name
: String, visibility
: MVisibility)
1427 # A global virtual type
1428 class MVirtualTypeProp
1431 redef type MPROPDEF: MVirtualTypeDef
1433 init(intro_mclassdef
: MClassDef, name
: String, visibility
: MVisibility)
1438 # The formal type associated to the virtual type property
1439 var mvirtualtype
: MVirtualType = new MVirtualType(self)
1442 # A definition of a property (local property)
1444 # Unlike MProperty, a MPropDef is a local definition that belong to a
1445 # specific class definition (which belong to a specific module)
1446 abstract class MPropDef
1448 # The associated MProperty subclass.
1449 # the two specialization hierarchy are symmetric
1450 type MPROPERTY: MProperty
1453 type MPROPDEF: MPropDef
1455 # The origin of the definition
1456 var location
: Location
1458 # The class definition where the property definition is
1459 var mclassdef
: MClassDef
1461 # The associated global property
1462 var mproperty
: MPROPERTY
1464 init(mclassdef
: MClassDef, mproperty
: MPROPERTY, location
: Location)
1466 self.mclassdef
= mclassdef
1467 self.mproperty
= mproperty
1468 self.location
= location
1469 mclassdef
.mpropdefs
.add
(self)
1470 mproperty
.mpropdefs
.add
(self)
1473 # Internal name combining the module, the class and the property
1474 # Example: "mymodule#MyClass#mymethod"
1477 return "{mclassdef}#{mproperty}"
1480 # Is self the definition that introduce the property?
1481 fun is_intro
: Bool do return mproperty
.intro
== self
1483 # Return the next definition in linearization of `mtype`.
1484 # If there is no next method then null is returned.
1486 # This method is used to determine what method is called by a super.
1488 # FIXME: NOT YET IMPLEMENTED
1490 # REQUIRE: not mtype.need_anchor
1491 fun lookup_next_definition
(mmodule
: MModule, mtype
: MType): nullable MPROPDEF
1493 assert not mtype
.need_anchor
1498 # A local definition of a method
1502 redef type MPROPERTY: MMethod
1503 redef type MPROPDEF: MMethodDef
1505 init(mclassdef
: MClassDef, mproperty
: MPROPERTY, location
: Location)
1510 # The signature attached to the property definition
1511 var msignature
: nullable MSignature writable = null
1514 # A local definition of an attribute
1518 redef type MPROPERTY: MAttribute
1519 redef type MPROPDEF: MAttributeDef
1521 init(mclassdef
: MClassDef, mproperty
: MPROPERTY, location
: Location)
1526 # The static type of the attribute
1527 var static_mtype
: nullable MType writable = null
1530 # A local definition of a virtual type
1531 class MVirtualTypeDef
1534 redef type MPROPERTY: MVirtualTypeProp
1535 redef type MPROPDEF: MVirtualTypeDef
1537 init(mclassdef
: MClassDef, mproperty
: MPROPERTY, location
: Location)
1542 # The bound of the virtual type
1543 var bound
: nullable MType writable = null
1554 # Note this class is basically an enum.
1555 # FIXME: use a real enum once user-defined enums are available
1557 redef var to_s
: String
1559 # Is a constructor required?
1561 private init(s
: String, need_init
: Bool)
1564 self.need_init
= need_init
1568 fun abstract_kind
: MClassKind do return once
new MClassKind("abstract class", true)
1569 fun concrete_kind
: MClassKind do return once
new MClassKind("class", true)
1570 fun interface_kind
: MClassKind do return once
new MClassKind("interface", false)
1571 fun enum_kind
: MClassKind do return once
new MClassKind("enum", false)
1572 fun extern_kind
: MClassKind do return once
new MClassKind("extern", false)