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 the super-types for the class (ie "super SomeType")
394 # This function can only invoked once by class
395 fun set_supertypes
(supertypes
: Array[MClassType])
397 assert unique_invocation
: self.in_hierarchy
== null
398 var mmodule
= self.mmodule
399 var model
= mmodule
.model
400 var res
= model
.mclassdef_hierarchy
.add_node
(self)
401 self.in_hierarchy
= res
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
)
415 for mclassdef
in mtype
.collect_mclassdefs
(mmodule
) do
416 res
.poset
.add_edge
(self, mclassdef
)
420 # The view of the class definition in `mclassdef_hierarchy'
421 var in_hierarchy
: nullable POSetElement[MClassDef] = null
423 # Is the definition the one that introduced `mclass`?
424 fun is_intro
: Bool do return mclass
.intro
== self
426 # All properties introduced by the classdef
427 var intro_mproperties
: Array[MProperty] = new Array[MProperty]
429 # All property definitions in the class (introductions and redefinitions)
430 var mpropdefs
: Array[MPropDef] = new Array[MPropDef]
433 # A global static type
435 # MType are global to the model; it means that a MType is not bound to a
436 # specific `MModule`.
437 # This characteristic helps the reasoning about static types in a program
438 # since a single MType object always denote the same type.
440 # However, because a MType is global, it does not really have properties
441 # nor have subtypes to a hierarchy since the property and the class hierarchy
442 # depends of a module.
443 # Moreover, virtual types an formal generic parameter types also depends on
444 # a receiver to have sense.
446 # Therefore, most method of the types require a module and an anchor.
447 # The module is used to know what are the classes and the specialization
449 # The anchor is used to know what is the bound of the virtual types and formal
450 # generic parameter types.
452 # MType are not directly usable to get properties. See the `anchor_to' method
453 # and the `MClassType' class.
455 # FIXME: the order of the parameters is not the best. We mus pick on from:
456 # * foo(mmodule, anchor, othertype)
457 # * foo(othertype, anchor, mmodule)
458 # * foo(anchor, mmodule, othertype)
459 # * foo(othertype, mmodule, anchor)
461 # FIXME: Add a 'is_valid_anchor' to improve imputability.
462 # Currently, anchors are used "as it" without check thus if the caller gives a
463 # bad anchor, then the method will likely crash (abort) in a bad case
465 # FIXME: maybe allways add an anchor with a nullable type (as in is_subtype)
468 # The model of the type
469 fun model
: Model is abstract
471 # Return true if `self' is an subtype of `sup'.
472 # The typing is done using the standard typing policy of Nit.
474 # REQUIRE: anchor == null implies not self.need_anchor and not sup.need_anchor
475 fun is_subtype
(mmodule
: MModule, anchor
: nullable MClassType, sup
: MType): Bool
478 if sub
== sup
then return true
479 if anchor
== null then
480 assert not sub
.need_anchor
481 assert not sup
.need_anchor
483 # First, resolve the types
484 if sub
isa MParameterType or sub
isa MVirtualType then
485 assert anchor
!= null
486 sub
= sub
.resolve_for
(anchor
, anchor
, mmodule
, false)
488 if sup
isa MParameterType or sup
isa MVirtualType then
489 assert anchor
!= null
490 sup
= sup
.resolve_for
(anchor
, anchor
, mmodule
, false)
493 if sup
isa MParameterType or sup
isa MVirtualType or sup
isa MNullType then
496 if sub
isa MParameterType or sub
isa MVirtualType then
497 assert anchor
!= null
498 sub
= sub
.anchor_to
(mmodule
, anchor
)
500 if sup
isa MNullableType then
501 if sub
isa MNullType then
503 else if sub
isa MNullableType then
504 return sub
.mtype
.is_subtype
(mmodule
, anchor
, sup
.mtype
)
505 else if sub
isa MClassType then
506 return sub
.is_subtype
(mmodule
, anchor
, sup
.mtype
)
512 assert sup
isa MClassType # It is the only remaining type
513 if sub
isa MNullableType or sub
isa MNullType then
517 if sub
== sup
then return true
519 assert sub
isa MClassType # It is the only remaining type
520 if anchor
== null then anchor
= sub
# UGLY: any anchor will work
521 var resolved_sub
= sub
.anchor_to
(mmodule
, anchor
)
522 var res
= resolved_sub
.collect_mclasses
(mmodule
).has
(sup
.mclass
)
523 if res
== false then return false
524 if not sup
isa MGenericType then return true
525 var sub2
= sub
.supertype_to
(mmodule
, anchor
, sup
.mclass
)
526 assert sub2
.mclass
== sup
.mclass
527 assert sub2
isa MGenericType
528 for i
in [0..sup
.mclass
.arity
[ do
529 var sub_arg
= sub2
.arguments
[i
]
530 var sup_arg
= sup
.arguments
[i
]
531 res
= sub_arg
.is_subtype
(mmodule
, anchor
, sup_arg
)
532 if res
== false then return false
537 # The base class type on which self is based
539 # This base type is used to get property (an internally to perform
540 # unsafe type comparison).
542 # Beware: some types (like null) are not based on a class thus this
545 # Basically, this function transform the virtual types and parameter
546 # types to their bounds.
556 # Map[T,U] anchor_to H #-> Map[C,Y]
558 # Explanation of the example:
559 # In H, T is set to C, because "H super G[C]", and U is bound to Y,
560 # because "redef type U: Y". Therefore, Map[T, U] is bound to
563 # ENSURE: not self.need_anchor implies return == self
564 # ENSURE: not return.need_anchor
565 fun anchor_to
(mmodule
: MModule, anchor
: MClassType): MType
567 if not need_anchor
then return self
568 assert not anchor
.need_anchor
569 # Just resolve to the anchor and clear all the virtual types
570 var res
= self.resolve_for
(anchor
, anchor
, mmodule
, true)
571 assert not res
.need_anchor
575 # Does `self' contain a virtual type or a formal generic parameter type?
576 # In order to remove those types, you usually want to use `anchor_to'.
577 fun need_anchor
: Bool do return true
579 # Return the supertype when adapted to a class.
581 # In Nit, for each super-class of a type, there is a equivalent super-type.
585 # class H[V] super G[V, Bool]
586 # H[Int] supertype_to G #-> G[Int, Bool]
588 # REQUIRE: `super_mclass' is a super-class of `self'
589 # ENSURE: return.mclass = mclass
590 fun supertype_to
(mmodule
: MModule, anchor
: MClassType, super_mclass
: MClass): MClassType
592 if super_mclass
.arity
== 0 then return super_mclass
.mclass_type
593 if self isa MClassType and self.mclass
== super_mclass
then return self
594 var resolved_self
= self.anchor_to
(mmodule
, anchor
)
595 var supertypes
= resolved_self
.collect_mtypes
(mmodule
)
596 for supertype
in supertypes
do
597 if supertype
.mclass
== super_mclass
then
598 # FIXME: Here, we stop on the first goal. Should we check others and detect inconsistencies?
599 return supertype
.resolve_for
(self, anchor
, mmodule
, false)
605 # Replace formals generic types in self with resolved values in `mtype'
606 # If `cleanup_virtual' is true, then virtual types are also replaced
609 # This function returns self if `need_anchor' is false.
613 # class H[F] super G[F]
614 # Array[E] resolve_for H[Int] #-> Array[Int]
616 # Explanation of the example:
617 # * Array[E].need_anchor is true because there is a formal generic
619 # * E makes sense for H[Int] because E is a formal parameter of G
621 # * Since "H[F] super G[F]", E is in fact F for H
622 # * More specifically, in H[Int], E is Int
623 # * So, in H[Int], Array[E] is Array[Int]
625 # This function is mainly used to inherit a signature.
626 # Because, unlike `anchor_type', we do not want a full resolution of
627 # a type but only an adapted version of it.
633 # class B super A[Int] end
635 # The signature on foo is (e: E): E
636 # If we resolve the signature for B, we get (e:Int):Int
638 # TODO: Explain the cleanup_virtual
640 # FIXME: the parameter `cleanup_virtual' is just a bad idea, but having
641 # two function instead of one seems also to be a bad idea.
643 # ENSURE: not self.need_anchor implies return == self
644 fun resolve_for
(mtype
: MType, anchor
: MClassType, mmodule
: MModule, cleanup_virtual
: Bool): MType is abstract
646 # Return the nullable version of the type
647 # If the type is already nullable then self is returned
649 # FIXME: DO NOT WORK YET
650 fun as_nullable
: MType
652 var res
= self.as_nullable_cache
653 if res
!= null then return res
654 res
= new MNullableType(self)
655 self.as_nullable_cache
= res
659 private var as_nullable_cache
: nullable MType = null
661 # Compute all the classdefs inherited/imported.
662 # The returned set contains:
663 # * the class definitions from `mmodule` and its imported modules
664 # * the class definitions of this type and its super-types
666 # This function is used mainly internally.
668 # REQUIRE: not self.need_anchor
669 fun collect_mclassdefs
(mmodule
: MModule): Set[MClassDef] is abstract
671 # Compute all the super-classes.
672 # This function is used mainly internally.
674 # REQUIRE: not self.need_anchor
675 fun collect_mclasses
(mmodule
: MModule): Set[MClass] is abstract
677 # Compute all the declared super-types.
678 # Super-types are returned as declared in the classdefs (verbatim).
679 # This function is used mainly internally.
681 # REQUIRE: not self.need_anchor
682 fun collect_mtypes
(mmodule
: MModule): Set[MClassType] is abstract
684 # Is the property in self for a given module
685 # This method does not filter visibility or whatever
687 # REQUIRE: not self.need_anchor
688 fun has_mproperty
(mmodule
: MModule, mproperty
: MProperty): Bool
690 assert not self.need_anchor
691 return self.collect_mclassdefs
(mmodule
).has
(mproperty
.intro_mclassdef
)
695 # A type based on a class.
697 # MClassType have properties (see `has_property').
701 # The associated class
704 redef fun model
do return self.mclass
.intro_mmodule
.model
706 private init(mclass
: MClass)
711 redef fun to_s
do return mclass
.to_s
713 redef fun need_anchor
do return false
715 redef fun anchor_to
(mmodule
: MModule, anchor
: MClassType): MClassType
717 return super.as(MClassType)
720 redef fun resolve_for
(mtype
: MType, anchor
: MClassType, mmodule
: MModule, cleanup_virtual
: Bool): MClassType do return self
722 redef fun collect_mclassdefs
(mmodule
)
724 assert not self.need_anchor
725 var cache
= self.collect_mclassdefs_cache
726 if not cache
.has_key
(mmodule
) then
727 self.collect_things
(mmodule
)
729 return cache
[mmodule
]
732 redef fun collect_mclasses
(mmodule
)
734 assert not self.need_anchor
735 var cache
= self.collect_mclasses_cache
736 if not cache
.has_key
(mmodule
) then
737 self.collect_things
(mmodule
)
739 return cache
[mmodule
]
742 redef fun collect_mtypes
(mmodule
)
744 assert not self.need_anchor
745 var cache
= self.collect_mtypes_cache
746 if not cache
.has_key
(mmodule
) then
747 self.collect_things
(mmodule
)
749 return cache
[mmodule
]
752 # common implementation for `collect_mclassdefs', `collect_mclasses', and `collect_mtypes'.
753 private fun collect_things
(mmodule
: MModule)
755 var res
= new HashSet[MClassDef]
756 var seen
= new HashSet[MClass]
757 var types
= new HashSet[MClassType]
758 seen
.add
(self.mclass
)
759 var todo
= [self.mclass
]
760 while not todo
.is_empty
do
761 var mclass
= todo
.pop
762 #print "process {mclass}"
763 for mclassdef
in mclass
.mclassdefs
do
764 if not mmodule
.in_importation
<= mclassdef
.mmodule
then continue
765 #print " process {mclassdef}"
767 for supertype
in mclassdef
.supertypes
do
769 var superclass
= supertype
.mclass
770 if seen
.has
(superclass
) then continue
771 #print " add {superclass}"
777 collect_mclassdefs_cache
[mmodule
] = res
778 collect_mclasses_cache
[mmodule
] = seen
779 collect_mtypes_cache
[mmodule
] = types
782 private var collect_mclassdefs_cache
: HashMap[MModule, Set[MClassDef]] = new HashMap[MModule, Set[MClassDef]]
783 private var collect_mclasses_cache
: HashMap[MModule, Set[MClass]] = new HashMap[MModule, Set[MClass]]
784 private var collect_mtypes_cache
: HashMap[MModule, Set[MClassType]] = new HashMap[MModule, Set[MClassType]]
788 # A type based on a generic class.
789 # A generic type a just a class with additional formal generic arguments.
793 private init(mclass
: MClass, arguments
: Array[MType])
796 assert self.mclass
.arity
== arguments
.length
797 self.arguments
= arguments
799 self.need_anchor
= false
800 for t
in arguments
do
801 if t
.need_anchor
then
802 self.need_anchor
= true
808 # The formal arguments of the type
809 # ENSURE: return.length == self.mclass.arity
810 var arguments
: Array[MType]
812 # Recursively print the type of the arguments within brackets.
813 # Example: "Map[String,List[Int]]"
816 return "{mclass}[{arguments.join(",")}]"
819 redef var need_anchor
: Bool
821 redef fun resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
823 if not need_anchor
then return self
824 var types
= new Array[MType]
825 for t
in arguments
do
826 types
.add
(t
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
))
828 return mclass
.get_mtype
(types
)
832 # A virtual formal type.
836 # The property associated with the type.
837 # Its the definitions of this property that determine the bound or the virtual type.
838 var mproperty
: MProperty
840 redef fun model
do return self.mproperty
.intro_mclassdef
.mmodule
.model
842 # Lookup the bound for a given resolved_receiver
843 # The result may be a other virtual type (or a parameter type)
845 # The result is returned exactly as declared in the "type" property (verbatim).
847 # In case of conflict, the method aborts.
848 fun lookup_bound
(mmodule
: MModule, resolved_receiver
: MType): MType
850 assert not resolved_receiver
.need_anchor
851 var props
= self.mproperty
.lookup_definitions
(mmodule
, resolved_receiver
)
852 if props
.is_empty
then
854 else if props
.length
== 1 then
855 return props
.first
.as(MVirtualTypeDef).bound
.as(not null)
857 var types
= new ArraySet[MType]
859 types
.add
(p
.as(MVirtualTypeDef).bound
.as(not null))
861 if types
.length
== 1 then
867 redef fun resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
869 if not cleanup_virtual
then return self
870 # self is a virtual type declared (or inherited) in mtype
871 # The point of the function it to get the bound of the virtual type that make sense for mtype
872 # But because mtype is maybe a virtual/formal type, we need to get a real receiver first
873 #print "{class_name}: {self}/{mtype}/{anchor}?"
874 var resolved_reciever
= mtype
.resolve_for
(anchor
, anchor
, mmodule
, true)
875 # Now, we can get the bound
876 var verbatim_bound
= lookup_bound
(mmodule
, resolved_reciever
)
877 # The bound is exactly as declared in the "type" property, so we must resolve it again
878 var res
= verbatim_bound
.resolve_for
(mtype
, anchor
, mmodule
, true)
879 #print "{class_name}: {self}/{mtype}/{anchor} -> {self}/{resolved_reciever}/{anchor} -> {verbatim_bound}/{mtype}/{anchor} -> {res}"
883 redef fun to_s
do return self.mproperty
.to_s
885 init(mproperty
: MProperty)
887 self.mproperty
= mproperty
891 # The type associated the a formal parameter generic type of a class
893 # Each parameter type is associated to a specific class.
894 # It's mean that all refinements of a same class "share" the parameter type,
895 # but that a generic subclass has its on parameter types.
897 # However, in the sense of the meta-model, the a parameter type of a class is
898 # a valid types in a subclass. The "in the sense of the meta-model" is
899 # important because, in the Nit language, the programmer cannot refers
900 # directly to the parameter types of the super-classes.
904 # fun e: E is abstract
909 # In the class definition B[F], `F' is a valid type but `E' is not.
910 # However, `self.e' is a valid method call, and the signature of `e' is
913 # Note that parameter types are shared among class refinements.
914 # Therefore parameter only have an internal name (see `to_s' for details).
915 # TODO: Add a 'name_for' to get better messages.
919 # The generic class where the parameter belong
922 redef fun model
do return self.mclass
.intro_mmodule
.model
924 # The position of the parameter (0 for the first parameter)
925 # FIXME: is `position' a better name?
928 # Internal name of the parameter type
929 # Names of parameter types changes in each class definition
930 # Therefore, this method return an internal name.
931 # Example: return "G#1" for the second parameter of the class G
932 # FIXME: add a way to get the real name in a classdef
933 redef fun to_s
do return "{mclass}#{rank}"
935 # Resolve the bound for a given resolved_receiver
936 # The result may be a other virtual type (or a parameter type)
937 fun lookup_bound
(mmodule
: MModule, resolved_receiver
: MType): MType
939 assert not resolved_receiver
.need_anchor
940 var goalclass
= self.mclass
941 var supertypes
= resolved_receiver
.collect_mtypes
(mmodule
)
942 for t
in supertypes
do
943 if t
.mclass
== goalclass
then
944 # Yeah! c specialize goalclass with a "super `t'". So the question is what is the argument of f
945 # FIXME: Here, we stop on the first goal. Should we check others and detect inconsistencies?
946 assert t
isa MGenericType
947 var res
= t
.arguments
[self.rank
]
954 redef fun resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
956 #print "{class_name}: {self}/{mtype}/{anchor}?"
958 if mtype
isa MGenericType and mtype
.mclass
== self.mclass
then
959 return mtype
.arguments
[self.rank
]
962 # self is a parameter type of mtype (or of a super-class of mtype)
963 # The point of the function it to get the bound of the virtual type that make sense for mtype
964 # But because mtype is maybe a virtual/formal type, we need to get a real receiver first
965 # FIXME: What happend here is far from clear. Thus this part must be validated and clarified
966 var resolved_receiver
= mtype
.resolve_for
(anchor
.mclass
.mclass_type
, anchor
, mmodule
, true)
967 if resolved_receiver
isa MNullableType then resolved_receiver
= resolved_receiver
.mtype
968 if resolved_receiver
isa MParameterType then
969 assert resolved_receiver
.mclass
== anchor
.mclass
970 resolved_receiver
= anchor
.as(MGenericType).arguments
[resolved_receiver
.rank
]
971 if resolved_receiver
isa MNullableType then resolved_receiver
= resolved_receiver
.mtype
973 assert resolved_receiver
isa MClassType else print
"{class_name}: {self}/{mtype}/{anchor}? {resolved_receiver}"
975 # Eh! The parameter is in the current class.
976 # So we return the corresponding argument, no mater what!
977 if resolved_receiver
.mclass
== self.mclass
then
978 assert resolved_receiver
isa MGenericType
979 var res
= resolved_receiver
.arguments
[self.rank
]
980 #print "{class_name}: {self}/{mtype}/{anchor} -> direct {res}"
984 resolved_receiver
= resolved_receiver
.resolve_for
(anchor
, anchor
, mmodule
, false)
985 # Now, we can get the bound
986 var verbatim_bound
= lookup_bound
(mmodule
, resolved_receiver
)
987 # The bound is exactly as declared in the "type" property, so we must resolve it again
988 var res
= verbatim_bound
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
990 #print "{class_name}: {self}/{mtype}/{anchor} -> indirect {res}"
995 init(mclass
: MClass, rank
: Int)
1002 # A type prefixed with "nullable"
1003 # FIXME Stub implementation
1007 # The base type of the nullable type
1010 redef fun model
do return self.mtype
.model
1017 redef fun to_s
do return "nullable {mtype}"
1019 redef fun need_anchor
do return mtype
.need_anchor
1020 redef fun as_nullable
do return self
1021 redef fun resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1023 var res
= self.mtype
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1024 return res
.as_nullable
1027 redef fun collect_mclassdefs
(mmodule
)
1029 assert not self.need_anchor
1030 return self.mtype
.collect_mclassdefs
(mmodule
)
1033 redef fun collect_mclasses
(mmodule
)
1035 assert not self.need_anchor
1036 return self.mtype
.collect_mclasses
(mmodule
)
1039 redef fun collect_mtypes
(mmodule
)
1041 assert not self.need_anchor
1042 return self.mtype
.collect_mtypes
(mmodule
)
1046 # The type of the only value null
1048 # The is only one null type per model, see `MModel::null_type'.
1051 redef var model
: Model
1052 protected init(model
: Model)
1056 redef fun to_s
do return "null"
1057 redef fun as_nullable
do return self
1058 redef fun need_anchor
do return false
1059 redef fun resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
) do return self
1061 redef fun collect_mclassdefs
(mmodule
) do return new HashSet[MClassDef]
1063 redef fun collect_mclasses
(mmodule
) do return new HashSet[MClass]
1065 redef fun collect_mtypes
(mmodule
) do return new HashSet[MClassType]
1068 # A signature of a method (or a closure)
1072 # The each parameter (in order)
1073 var mparameters
: Array[MParameter]
1075 var mclosures
= new Array[MParameter]
1077 # The return type (null for a procedure)
1078 var return_mtype
: nullable MType
1080 # REQUIRE: 1 <= mparameters.count p -> p.is_vararg
1081 init(mparameters
: Array[MParameter], return_mtype
: nullable MType)
1083 var vararg_rank
= -1
1084 for i
in [0..mparameters
.length
[ do
1085 var parameter
= mparameters
[i
]
1086 if parameter
.is_vararg
then
1087 assert vararg_rank
== -1
1091 self.mparameters
= mparameters
1092 self.return_mtype
= return_mtype
1093 self.vararg_rank
= vararg_rank
1096 # The rank of the ellipsis (...) for vararg (starting from 0).
1097 # value is -1 if there is no vararg.
1098 # Example: for "(a: Int, b: Bool..., c: Char)" #-> vararg_rank=1
1099 var vararg_rank
: Int
1101 # The number or parameters
1102 fun arity
: Int do return mparameters
.length
1107 if not mparameters
.is_empty
then
1109 for i
in [0..mparameters
.length
[ do
1110 var mparameter
= mparameters
[i
]
1111 if i
> 0 then b
.append
(", ")
1112 b
.append
(mparameter
.name
)
1114 b
.append
(mparameter
.mtype
.to_s
)
1115 if mparameter
.is_vararg
then
1121 var ret
= self.return_mtype
1129 redef fun resolve_for
(mtype
: MType, anchor
: MClassType, mmodule
: MModule, cleanup_virtual
: Bool): MSignature
1131 var params
= new Array[MParameter]
1132 for p
in self.mparameters
do
1133 params
.add
(p
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
))
1135 var ret
= self.return_mtype
1137 ret
= ret
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1139 var res
= new MSignature(params
, ret
)
1140 for p
in self.mclosures
do
1141 res
.mclosures
.add
(p
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
))
1147 # A parameter in a signature
1149 # The name of the parameter
1152 # The static type of the parameter
1155 # Is the parameter a vararg?
1158 fun resolve_for
(mtype
: MType, anchor
: MClassType, mmodule
: MModule, cleanup_virtual
: Bool): MParameter
1160 if not self.mtype
.need_anchor
then return self
1161 var newtype
= self.mtype
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1162 var res
= new MParameter(self.name
, newtype
, self.is_vararg
)
1167 # A service (global property) that generalize method, attribute, etc.
1169 # MProperty are global to the model; it means that a MProperty is not bound
1170 # to a specific `MModule` nor a specific `MClass`.
1172 # A MProperty gather definitions (see `mpropdefs') ; one for the introduction
1173 # and the other in subclasses and in refinements.
1175 # A MProperty is used to denotes services in polymorphic way (ie. independent
1176 # of any dynamic type).
1177 # For instance, a call site "x.foo" is associated to a MProperty.
1178 abstract class MProperty
1179 # The associated MPropDef subclass.
1180 # The two specialization hierarchy are symmetric.
1181 type MPROPDEF: MPropDef
1183 # The classdef that introduce the property
1184 # While a property is not bound to a specific module, or class,
1185 # the introducing mclassdef is used for naming and visibility
1186 var intro_mclassdef
: MClassDef
1188 # The (short) name of the property
1191 # The canonical name of the property
1192 # Example: "owner::my_module::MyClass::my_method"
1193 fun full_name
: String
1195 return "{self.intro_mclassdef.mmodule.full_name}::{self.intro_mclassdef.mclass.name}::{name}"
1198 # The visibility of the property
1199 var visibility
: MVisibility
1201 init(intro_mclassdef
: MClassDef, name
: String, visibility
: MVisibility)
1203 self.intro_mclassdef
= intro_mclassdef
1205 self.visibility
= visibility
1206 intro_mclassdef
.intro_mproperties
.add
(self)
1207 var model
= intro_mclassdef
.mmodule
.model
1208 model
.mproperties_by_name
.add_one
(name
, self)
1209 model
.mproperties
.add
(self)
1212 # All definitions of the property.
1213 # The first is the introduction,
1214 # The other are redefinitions (in refinements and in subclasses)
1215 var mpropdefs
: Array[MPROPDEF] = new Array[MPROPDEF]
1217 # The definition that introduced the property
1218 # Warning: the introduction is the first `MPropDef' object
1219 # associated to self. If self is just created without having any
1220 # associated definition, this method will abort
1221 fun intro
: MPROPDEF do return mpropdefs
.first
1224 redef fun to_s
do return name
1226 # Return the most specific property definitions defined or inherited by a type.
1227 # The selection knows that refinement is stronger than specialization;
1228 # however, in case of conflict more than one property are returned.
1229 # If mtype does not know mproperty then an empty array is returned.
1231 # If you want the really most specific property, then look at `lookup_first_definition`
1232 fun lookup_definitions
(mmodule
: MModule, mtype
: MType): Array[MPROPDEF]
1234 assert not mtype
.need_anchor
1235 if mtype
isa MNullableType then mtype
= mtype
.mtype
1237 var cache
= self.lookup_definitions_cache
[mmodule
, mtype
]
1238 if cache
!= null then return cache
1240 #print "select prop {mproperty} for {mtype} in {self}"
1241 # First, select all candidates
1242 var candidates
= new Array[MPROPDEF]
1243 for mpropdef
in self.mpropdefs
do
1244 # If the definition is not imported by the module, then skip
1245 if not mmodule
.in_importation
<= mpropdef
.mclassdef
.mmodule
then continue
1246 # If the definition is not inherited by the type, then skip
1247 if not mtype
.is_subtype
(mmodule
, null, mpropdef
.mclassdef
.bound_mtype
) then continue
1249 candidates
.add
(mpropdef
)
1251 # Fast track for only one candidate
1252 if candidates
.length
<= 1 then
1253 self.lookup_definitions_cache
[mmodule
, mtype
] = candidates
1257 # Second, filter the most specific ones
1258 var res
= new Array[MPROPDEF]
1259 for pd1
in candidates
do
1260 var cd1
= pd1
.mclassdef
1263 for pd2
in candidates
do
1264 if pd2
== pd1
then continue # do not compare with self!
1265 var cd2
= pd2
.mclassdef
1267 if c2
.mclass_type
== c1
.mclass_type
then
1268 if cd2
.mmodule
.in_importation
<= cd1
.mmodule
then
1269 # cd2 refines cd1; therefore we skip pd1
1273 else if cd2
.bound_mtype
.is_subtype
(mmodule
, null, cd1
.bound_mtype
) then
1274 # cd2 < cd1; therefore we skip pd1
1283 if res
.is_empty
then
1284 print
"All lost! {candidates.join(", ")}"
1285 # FIXME: should be abort!
1287 self.lookup_definitions_cache
[mmodule
, mtype
] = res
1291 private var lookup_definitions_cache
: HashMap2[MModule, MType, Array[MPROPDEF]] = new HashMap2[MModule, MType, Array[MPROPDEF]]
1293 # Return the most specific property definitions inherited by a type.
1294 # The selection knows that refinement is stronger than specialization;
1295 # however, in case of conflict more than one property are returned.
1296 # If mtype does not know mproperty then an empty array is returned.
1298 # If you want the really most specific property, then look at `lookup_next_definition`
1300 # FIXME: Move to MPropDef?
1301 fun lookup_super_definitions
(mmodule
: MModule, mtype
: MType): Array[MPropDef]
1303 assert not mtype
.need_anchor
1304 if mtype
isa MNullableType then mtype
= mtype
.mtype
1306 # First, select all candidates
1307 var candidates
= new Array[MPropDef]
1308 for mpropdef
in self.mpropdefs
do
1309 # If the definition is not imported by the module, then skip
1310 if not mmodule
.in_importation
<= mpropdef
.mclassdef
.mmodule
then continue
1311 # If the definition is not inherited by the type, then skip
1312 if not mtype
.is_subtype
(mmodule
, null, mpropdef
.mclassdef
.bound_mtype
) then continue
1313 # If the definition is defined by the type, then skip (we want the super, so e skip the current)
1314 if mtype
== mpropdef
.mclassdef
.bound_mtype
and mmodule
== mpropdef
.mclassdef
.mmodule
then continue
1316 candidates
.add
(mpropdef
)
1318 # Fast track for only one candidate
1319 if candidates
.length
<= 1 then return candidates
1321 # Second, filter the most specific ones
1322 var res
= new Array[MPropDef]
1323 for pd1
in candidates
do
1324 var cd1
= pd1
.mclassdef
1327 for pd2
in candidates
do
1328 if pd2
== pd1
then continue # do not compare with self!
1329 var cd2
= pd2
.mclassdef
1331 if c2
.mclass_type
== c1
.mclass_type
then
1332 if cd2
.mmodule
.in_importation
<= cd1
.mmodule
then
1333 # cd2 refines cd1; therefore we skip pd1
1337 else if cd2
.bound_mtype
.is_subtype
(mmodule
, null, cd1
.bound_mtype
) then
1338 # cd2 < cd1; therefore we skip pd1
1347 if res
.is_empty
then
1348 print
"All lost! {candidates.join(", ")}"
1349 # FIXME: should be abort!
1354 # Return the most specific definition in the linearization of `mtype`.
1355 # If mtype does not know mproperty then null is returned.
1357 # If you want to know the next properties in the linearization,
1358 # look at `MPropDef::lookup_next_definition`.
1360 # FIXME: NOT YET IMPLEMENTED
1362 # REQUIRE: not mtype.need_anchor
1363 fun lookup_first_definition
(mmodule
: MModule, mtype
: MType): nullable MPROPDEF
1365 assert not mtype
.need_anchor
1374 redef type MPROPDEF: MMethodDef
1376 init(intro_mclassdef
: MClassDef, name
: String, visibility
: MVisibility)
1381 # Is the property a constructor?
1382 # Warning, this property can be inherited by subclasses with or without being a constructor
1383 # therefore, you should use `is_init_for' the verify if the property is a legal constructor for a given class
1384 var is_init
: Bool writable = false
1386 # The the property a 'new' contructor?
1387 var is_new
: Bool writable = false
1389 # Is the property a legal constructor for a given class?
1390 # As usual, visibility is not considered.
1391 # FIXME not implemented
1392 fun is_init_for
(mclass
: MClass): Bool
1398 # A global attribute
1402 redef type MPROPDEF: MAttributeDef
1404 init(intro_mclassdef
: MClassDef, name
: String, visibility
: MVisibility)
1410 # A global virtual type
1411 class MVirtualTypeProp
1414 redef type MPROPDEF: MVirtualTypeDef
1416 init(intro_mclassdef
: MClassDef, name
: String, visibility
: MVisibility)
1421 # The formal type associated to the virtual type property
1422 var mvirtualtype
: MVirtualType = new MVirtualType(self)
1425 # A definition of a property (local property)
1427 # Unlike MProperty, a MPropDef is a local definition that belong to a
1428 # specific class definition (which belong to a specific module)
1429 abstract class MPropDef
1431 # The associated MProperty subclass.
1432 # the two specialization hierarchy are symmetric
1433 type MPROPERTY: MProperty
1436 type MPROPDEF: MPropDef
1438 # The origin of the definition
1439 var location
: Location
1441 # The class definition where the property definition is
1442 var mclassdef
: MClassDef
1444 # The associated global property
1445 var mproperty
: MPROPERTY
1447 init(mclassdef
: MClassDef, mproperty
: MPROPERTY, location
: Location)
1449 self.mclassdef
= mclassdef
1450 self.mproperty
= mproperty
1451 self.location
= location
1452 mclassdef
.mpropdefs
.add
(self)
1453 mproperty
.mpropdefs
.add
(self)
1456 # Internal name combining the module, the class and the property
1457 # Example: "mymodule#MyClass#mymethod"
1460 return "{mclassdef}#{mproperty}"
1463 # Is self the definition that introduce the property?
1464 fun is_intro
: Bool do return mproperty
.intro
== self
1466 # Return the next definition in linearization of `mtype`.
1467 # If there is no next method then null is returned.
1469 # This method is used to determine what method is called by a super.
1471 # FIXME: NOT YET IMPLEMENTED
1473 # REQUIRE: not mtype.need_anchor
1474 fun lookup_next_definition
(mmodule
: MModule, mtype
: MType): nullable MPROPDEF
1476 assert not mtype
.need_anchor
1481 # A local definition of a method
1485 redef type MPROPERTY: MMethod
1486 redef type MPROPDEF: MMethodDef
1488 init(mclassdef
: MClassDef, mproperty
: MPROPERTY, location
: Location)
1493 # The signature attached to the property definition
1494 var msignature
: nullable MSignature writable = null
1497 # A local definition of an attribute
1501 redef type MPROPERTY: MAttribute
1502 redef type MPROPDEF: MAttributeDef
1504 init(mclassdef
: MClassDef, mproperty
: MPROPERTY, location
: Location)
1509 # The static type of the attribute
1510 var static_mtype
: nullable MType writable = null
1513 # A local definition of a virtual type
1514 class MVirtualTypeDef
1517 redef type MPROPERTY: MVirtualTypeProp
1518 redef type MPROPDEF: MVirtualTypeDef
1520 init(mclassdef
: MClassDef, mproperty
: MPROPERTY, location
: Location)
1525 # The bound of the virtual type
1526 var bound
: nullable MType writable = null
1537 # Note this class is basically an enum.
1538 # FIXME: use a real enum once user-defined enums are available
1540 redef var to_s
: String
1542 # Is a constructor required?
1544 private init(s
: String, need_init
: Bool)
1547 self.need_init
= need_init
1551 fun abstract_kind
: MClassKind do return once
new MClassKind("abstract class", true)
1552 fun concrete_kind
: MClassKind do return once
new MClassKind("class", true)
1553 fun interface_kind
: MClassKind do return once
new MClassKind("interface", false)
1554 fun enum_kind
: MClassKind do return once
new MClassKind("enum", false)
1555 fun extern_kind
: MClassKind do return once
new MClassKind("extern", false)