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
300 assert has_a_first_definition
: not mclassdefs
.is_empty
301 return mclassdefs
.first
304 # Return the class `self' in the class hierarchy of the module `mmodule'.
306 # SEE: MModule::flatten_mclass_hierarchy
307 # REQUIRE: mmodule.has_mclass(self)
308 fun in_hierarchy
(mmodule
: MModule): POSetElement[MClass]
310 return mmodule
.flatten_mclass_hierarchy
[self]
313 # The principal static type of the class.
315 # For non-generic class, mclass_type is the only MClassType based
318 # For a generic class, the arguments are the formal parameters.
319 # i.e.: for the class `Array[E:Object]', the mtype is Array[E].
320 # If you want `Array[Object]' the see `MClassDef::bound_mtype'
322 # For generic classes, the mclass_type is also the way to get a formal
323 # generic parameter type.
325 # To get other types based on a generic class, see `get_mtype'.
327 # ENSURE: mclass_type.mclass == self
328 var mclass_type
: MClassType
330 # Return a generic type based on the class
331 # Is the class is not generic, then the result is `mclass_type'
333 # REQUIRE: type_arguments.length == self.arity
334 fun get_mtype
(mtype_arguments
: Array[MType]): MClassType
336 assert mtype_arguments
.length
== self.arity
337 if self.arity
== 0 then return self.mclass_type
338 for t
in self.get_mtype_cache
do
339 if t
.arguments
== mtype_arguments
then
343 var res
= new MGenericType(self, mtype_arguments
)
344 self.get_mtype_cache
.add res
348 private var get_mtype_cache
: Array[MGenericType] = new Array[MGenericType]
352 # A definition (an introduction or a refinement) of a class in a module
354 # A MClassDef is associated with an explicit (or almost) definition of a
355 # class. Unlike MClass, a MClassDef is a local definition that belong to
358 # The module where the definition is
361 # The associated MClass
364 # The bounded type associated to the mclassdef
366 # For a non-generic class, `bound_mtype' and `mclass.mclass_type'
370 # For the classdef Array[E: Object], the bound_mtype is Array[Object].
371 # If you want Array[E], then see `mclass.mclass_type'
373 # ENSURE: bound_mtype.mclass = self.mclass
374 var bound_mtype
: MClassType
376 # Name of each formal generic parameter (in order of declaration)
377 var parameter_names
: Array[String]
379 # The origin of the definition
380 var location
: Location
382 # Internal name combining the module and the class
383 # Example: "mymodule#MyClass"
384 redef fun to_s
do return "{mmodule}#{mclass}"
386 init(mmodule
: MModule, bound_mtype
: MClassType, location
: Location, parameter_names
: Array[String])
388 assert bound_mtype
.mclass
.arity
== parameter_names
.length
389 self.bound_mtype
= bound_mtype
390 self.mmodule
= mmodule
391 self.mclass
= bound_mtype
.mclass
392 self.location
= location
393 mmodule
.mclassdefs
.add
(self)
394 mclass
.mclassdefs
.add
(self)
395 self.parameter_names
= parameter_names
398 # All declared super-types
399 # FIXME: quite ugly but not better idea yet
400 var supertypes
: Array[MClassType] = new Array[MClassType]
402 # Register some super-types for the class (ie "super SomeType")
404 # The hierarchy must not already be set
405 # REQUIRE: self.in_hierarchy == null
406 fun set_supertypes
(supertypes
: Array[MClassType])
408 assert unique_invocation
: self.in_hierarchy
== null
409 var mmodule
= self.mmodule
410 var model
= mmodule
.model
411 var mtype
= self.bound_mtype
413 for supertype
in supertypes
do
414 self.supertypes
.add
(supertype
)
416 # Register in full_type_specialization_hierarchy
417 model
.full_mtype_specialization_hierarchy
.add_edge
(mtype
, supertype
)
418 # Register in intro_type_specialization_hierarchy
419 if mclass
.intro_mmodule
== mmodule
and supertype
.mclass
.intro_mmodule
== mmodule
then
420 model
.intro_mtype_specialization_hierarchy
.add_edge
(mtype
, supertype
)
426 # Collect the super-types (set by set_supertypes) to build the hierarchy
428 # This function can only invoked once by class
429 # REQUIRE: self.in_hierarchy == null
430 # ENSURE: self.in_hierarchy != null
433 assert unique_invocation
: self.in_hierarchy
== null
434 var model
= mmodule
.model
435 var res
= model
.mclassdef_hierarchy
.add_node
(self)
436 self.in_hierarchy
= res
437 var mtype
= self.bound_mtype
439 # Here we need to connect the mclassdef to its pairs in the mclassdef_hierarchy
440 # The simpliest way is to attach it to collect_mclassdefs
441 for mclassdef
in mtype
.collect_mclassdefs
(mmodule
) do
442 res
.poset
.add_edge
(self, mclassdef
)
446 # The view of the class definition in `mclassdef_hierarchy'
447 var in_hierarchy
: nullable POSetElement[MClassDef] = null
449 # Is the definition the one that introduced `mclass`?
450 fun is_intro
: Bool do return mclass
.intro
== self
452 # All properties introduced by the classdef
453 var intro_mproperties
: Array[MProperty] = new Array[MProperty]
455 # All property definitions in the class (introductions and redefinitions)
456 var mpropdefs
: Array[MPropDef] = new Array[MPropDef]
459 # A global static type
461 # MType are global to the model; it means that a MType is not bound to a
462 # specific `MModule`.
463 # This characteristic helps the reasoning about static types in a program
464 # since a single MType object always denote the same type.
466 # However, because a MType is global, it does not really have properties
467 # nor have subtypes to a hierarchy since the property and the class hierarchy
468 # depends of a module.
469 # Moreover, virtual types an formal generic parameter types also depends on
470 # a receiver to have sense.
472 # Therefore, most method of the types require a module and an anchor.
473 # The module is used to know what are the classes and the specialization
475 # The anchor is used to know what is the bound of the virtual types and formal
476 # generic parameter types.
478 # MType are not directly usable to get properties. See the `anchor_to' method
479 # and the `MClassType' class.
481 # FIXME: the order of the parameters is not the best. We mus pick on from:
482 # * foo(mmodule, anchor, othertype)
483 # * foo(othertype, anchor, mmodule)
484 # * foo(anchor, mmodule, othertype)
485 # * foo(othertype, mmodule, anchor)
487 # FIXME: Add a 'is_valid_anchor' to improve imputability.
488 # Currently, anchors are used "as it" without check thus if the caller gives a
489 # bad anchor, then the method will likely crash (abort) in a bad case
491 # FIXME: maybe allways add an anchor with a nullable type (as in is_subtype)
494 # The model of the type
495 fun model
: Model is abstract
497 # Return true if `self' is an subtype of `sup'.
498 # The typing is done using the standard typing policy of Nit.
500 # REQUIRE: anchor == null implies not self.need_anchor and not sup.need_anchor
501 fun is_subtype
(mmodule
: MModule, anchor
: nullable MClassType, sup
: MType): Bool
504 if sub
== sup
then return true
505 if anchor
== null then
506 assert not sub
.need_anchor
507 assert not sup
.need_anchor
509 # First, resolve the types
510 if sub
isa MParameterType or sub
isa MVirtualType then
511 assert anchor
!= null
512 sub
= sub
.resolve_for
(anchor
, anchor
, mmodule
, false)
514 if sup
isa MParameterType or sup
isa MVirtualType then
515 assert anchor
!= null
516 sup
= sup
.resolve_for
(anchor
, anchor
, mmodule
, false)
519 if sup
isa MParameterType or sup
isa MVirtualType or sup
isa MNullType then
522 if sub
isa MParameterType or sub
isa MVirtualType then
523 assert anchor
!= null
524 sub
= sub
.anchor_to
(mmodule
, anchor
)
526 if sup
isa MNullableType then
527 if sub
isa MNullType then
529 else if sub
isa MNullableType then
530 return sub
.mtype
.is_subtype
(mmodule
, anchor
, sup
.mtype
)
531 else if sub
isa MClassType then
532 return sub
.is_subtype
(mmodule
, anchor
, sup
.mtype
)
538 assert sup
isa MClassType # It is the only remaining type
539 if sub
isa MNullableType or sub
isa MNullType then
543 if sub
== sup
then return true
545 assert sub
isa MClassType # It is the only remaining type
546 if anchor
== null then anchor
= sub
# UGLY: any anchor will work
547 var resolved_sub
= sub
.anchor_to
(mmodule
, anchor
)
548 var res
= resolved_sub
.collect_mclasses
(mmodule
).has
(sup
.mclass
)
549 if res
== false then return false
550 if not sup
isa MGenericType then return true
551 var sub2
= sub
.supertype_to
(mmodule
, anchor
, sup
.mclass
)
552 assert sub2
.mclass
== sup
.mclass
553 for i
in [0..sup
.mclass
.arity
[ do
554 var sub_arg
= sub2
.arguments
[i
]
555 var sup_arg
= sup
.arguments
[i
]
556 res
= sub_arg
.is_subtype
(mmodule
, anchor
, sup_arg
)
557 if res
== false then return false
562 # The base class type on which self is based
564 # This base type is used to get property (an internally to perform
565 # unsafe type comparison).
567 # Beware: some types (like null) are not based on a class thus this
570 # Basically, this function transform the virtual types and parameter
571 # types to their bounds.
581 # Map[T,U] anchor_to H #-> Map[C,Y]
583 # Explanation of the example:
584 # In H, T is set to C, because "H super G[C]", and U is bound to Y,
585 # because "redef type U: Y". Therefore, Map[T, U] is bound to
588 # ENSURE: not self.need_anchor implies return == self
589 # ENSURE: not return.need_anchor
590 fun anchor_to
(mmodule
: MModule, anchor
: MClassType): MType
592 if not need_anchor
then return self
593 assert not anchor
.need_anchor
594 # Just resolve to the anchor and clear all the virtual types
595 var res
= self.resolve_for
(anchor
, anchor
, mmodule
, true)
596 assert not res
.need_anchor
600 # Does `self' contain a virtual type or a formal generic parameter type?
601 # In order to remove those types, you usually want to use `anchor_to'.
602 fun need_anchor
: Bool do return true
604 # Return the supertype when adapted to a class.
606 # In Nit, for each super-class of a type, there is a equivalent super-type.
610 # class H[V] super G[V, Bool]
611 # H[Int] supertype_to G #-> G[Int, Bool]
613 # REQUIRE: `super_mclass' is a super-class of `self'
614 # ENSURE: return.mclass = mclass
615 fun supertype_to
(mmodule
: MModule, anchor
: MClassType, super_mclass
: MClass): MClassType
617 if super_mclass
.arity
== 0 then return super_mclass
.mclass_type
618 if self isa MClassType and self.mclass
== super_mclass
then return self
619 var resolved_self
= self.anchor_to
(mmodule
, anchor
)
620 var supertypes
= resolved_self
.collect_mtypes
(mmodule
)
621 for supertype
in supertypes
do
622 if supertype
.mclass
== super_mclass
then
623 # FIXME: Here, we stop on the first goal. Should we check others and detect inconsistencies?
624 return supertype
.resolve_for
(self, anchor
, mmodule
, false)
630 # Replace formals generic types in self with resolved values in `mtype'
631 # If `cleanup_virtual' is true, then virtual types are also replaced
634 # This function returns self if `need_anchor' is false.
638 # class H[F] super G[F]
639 # Array[E] resolve_for H[Int] #-> Array[Int]
641 # Explanation of the example:
642 # * Array[E].need_anchor is true because there is a formal generic
644 # * E makes sense for H[Int] because E is a formal parameter of G
646 # * Since "H[F] super G[F]", E is in fact F for H
647 # * More specifically, in H[Int], E is Int
648 # * So, in H[Int], Array[E] is Array[Int]
650 # This function is mainly used to inherit a signature.
651 # Because, unlike `anchor_type', we do not want a full resolution of
652 # a type but only an adapted version of it.
658 # class B super A[Int] end
660 # The signature on foo is (e: E): E
661 # If we resolve the signature for B, we get (e:Int):Int
663 # TODO: Explain the cleanup_virtual
665 # FIXME: the parameter `cleanup_virtual' is just a bad idea, but having
666 # two function instead of one seems also to be a bad idea.
668 # ENSURE: not self.need_anchor implies return == self
669 fun resolve_for
(mtype
: MType, anchor
: MClassType, mmodule
: MModule, cleanup_virtual
: Bool): MType is abstract
671 # Return the nullable version of the type
672 # If the type is already nullable then self is returned
674 # FIXME: DO NOT WORK YET
675 fun as_nullable
: MType
677 var res
= self.as_nullable_cache
678 if res
!= null then return res
679 res
= new MNullableType(self)
680 self.as_nullable_cache
= res
684 private var as_nullable_cache
: nullable MType = null
686 # Compute all the classdefs inherited/imported.
687 # The returned set contains:
688 # * the class definitions from `mmodule` and its imported modules
689 # * the class definitions of this type and its super-types
691 # This function is used mainly internally.
693 # REQUIRE: not self.need_anchor
694 fun collect_mclassdefs
(mmodule
: MModule): Set[MClassDef] is abstract
696 # Compute all the super-classes.
697 # This function is used mainly internally.
699 # REQUIRE: not self.need_anchor
700 fun collect_mclasses
(mmodule
: MModule): Set[MClass] is abstract
702 # Compute all the declared super-types.
703 # Super-types are returned as declared in the classdefs (verbatim).
704 # This function is used mainly internally.
706 # REQUIRE: not self.need_anchor
707 fun collect_mtypes
(mmodule
: MModule): Set[MClassType] is abstract
709 # Is the property in self for a given module
710 # This method does not filter visibility or whatever
712 # REQUIRE: not self.need_anchor
713 fun has_mproperty
(mmodule
: MModule, mproperty
: MProperty): Bool
715 assert not self.need_anchor
716 return self.collect_mclassdefs
(mmodule
).has
(mproperty
.intro_mclassdef
)
720 # A type based on a class.
722 # MClassType have properties (see `has_property').
726 # The associated class
729 redef fun model
do return self.mclass
.intro_mmodule
.model
731 private init(mclass
: MClass)
736 # The formal arguments of the type
737 # ENSURE: return.length == self.mclass.arity
738 var arguments
: Array[MType] = new Array[MType]
740 redef fun to_s
do return mclass
.to_s
742 redef fun need_anchor
do return false
744 redef fun anchor_to
(mmodule
: MModule, anchor
: MClassType): MClassType
746 return super.as(MClassType)
749 redef fun resolve_for
(mtype
: MType, anchor
: MClassType, mmodule
: MModule, cleanup_virtual
: Bool): MClassType do return self
751 redef fun collect_mclassdefs
(mmodule
)
753 assert not self.need_anchor
754 var cache
= self.collect_mclassdefs_cache
755 if not cache
.has_key
(mmodule
) then
756 self.collect_things
(mmodule
)
758 return cache
[mmodule
]
761 redef fun collect_mclasses
(mmodule
)
763 assert not self.need_anchor
764 var cache
= self.collect_mclasses_cache
765 if not cache
.has_key
(mmodule
) then
766 self.collect_things
(mmodule
)
768 return cache
[mmodule
]
771 redef fun collect_mtypes
(mmodule
)
773 assert not self.need_anchor
774 var cache
= self.collect_mtypes_cache
775 if not cache
.has_key
(mmodule
) then
776 self.collect_things
(mmodule
)
778 return cache
[mmodule
]
781 # common implementation for `collect_mclassdefs', `collect_mclasses', and `collect_mtypes'.
782 private fun collect_things
(mmodule
: MModule)
784 var res
= new HashSet[MClassDef]
785 var seen
= new HashSet[MClass]
786 var types
= new HashSet[MClassType]
787 seen
.add
(self.mclass
)
788 var todo
= [self.mclass
]
789 while not todo
.is_empty
do
790 var mclass
= todo
.pop
791 #print "process {mclass}"
792 for mclassdef
in mclass
.mclassdefs
do
793 if not mmodule
.in_importation
<= mclassdef
.mmodule
then continue
794 #print " process {mclassdef}"
796 for supertype
in mclassdef
.supertypes
do
798 var superclass
= supertype
.mclass
799 if seen
.has
(superclass
) then continue
800 #print " add {superclass}"
806 collect_mclassdefs_cache
[mmodule
] = res
807 collect_mclasses_cache
[mmodule
] = seen
808 collect_mtypes_cache
[mmodule
] = types
811 private var collect_mclassdefs_cache
: HashMap[MModule, Set[MClassDef]] = new HashMap[MModule, Set[MClassDef]]
812 private var collect_mclasses_cache
: HashMap[MModule, Set[MClass]] = new HashMap[MModule, Set[MClass]]
813 private var collect_mtypes_cache
: HashMap[MModule, Set[MClassType]] = new HashMap[MModule, Set[MClassType]]
817 # A type based on a generic class.
818 # A generic type a just a class with additional formal generic arguments.
822 private init(mclass
: MClass, arguments
: Array[MType])
825 assert self.mclass
.arity
== arguments
.length
826 self.arguments
= arguments
828 self.need_anchor
= false
829 for t
in arguments
do
830 if t
.need_anchor
then
831 self.need_anchor
= true
837 # Recursively print the type of the arguments within brackets.
838 # Example: "Map[String,List[Int]]"
841 return "{mclass}[{arguments.join(",")}]"
844 redef var need_anchor
: Bool
846 redef fun resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
848 if not need_anchor
then return self
849 var types
= new Array[MType]
850 for t
in arguments
do
851 types
.add
(t
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
))
853 return mclass
.get_mtype
(types
)
857 # A virtual formal type.
861 # The property associated with the type.
862 # Its the definitions of this property that determine the bound or the virtual type.
863 var mproperty
: MProperty
865 redef fun model
do return self.mproperty
.intro_mclassdef
.mmodule
.model
867 # Lookup the bound for a given resolved_receiver
868 # The result may be a other virtual type (or a parameter type)
870 # The result is returned exactly as declared in the "type" property (verbatim).
872 # In case of conflict, the method aborts.
873 fun lookup_bound
(mmodule
: MModule, resolved_receiver
: MType): MType
875 assert not resolved_receiver
.need_anchor
876 var props
= self.mproperty
.lookup_definitions
(mmodule
, resolved_receiver
)
877 if props
.is_empty
then
879 else if props
.length
== 1 then
880 return props
.first
.as(MVirtualTypeDef).bound
.as(not null)
882 var types
= new ArraySet[MType]
884 types
.add
(p
.as(MVirtualTypeDef).bound
.as(not null))
886 if types
.length
== 1 then
892 redef fun resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
894 if not cleanup_virtual
then return self
895 # self is a virtual type declared (or inherited) in mtype
896 # The point of the function it to get the bound of the virtual type that make sense for mtype
897 # But because mtype is maybe a virtual/formal type, we need to get a real receiver first
898 #print "{class_name}: {self}/{mtype}/{anchor}?"
899 var resolved_reciever
= mtype
.resolve_for
(anchor
, anchor
, mmodule
, true)
900 # Now, we can get the bound
901 var verbatim_bound
= lookup_bound
(mmodule
, resolved_reciever
)
902 # The bound is exactly as declared in the "type" property, so we must resolve it again
903 var res
= verbatim_bound
.resolve_for
(mtype
, anchor
, mmodule
, true)
904 #print "{class_name}: {self}/{mtype}/{anchor} -> {self}/{resolved_reciever}/{anchor} -> {verbatim_bound}/{mtype}/{anchor} -> {res}"
908 redef fun to_s
do return self.mproperty
.to_s
910 init(mproperty
: MProperty)
912 self.mproperty
= mproperty
916 # The type associated the a formal parameter generic type of a class
918 # Each parameter type is associated to a specific class.
919 # It's mean that all refinements of a same class "share" the parameter type,
920 # but that a generic subclass has its on parameter types.
922 # However, in the sense of the meta-model, the a parameter type of a class is
923 # a valid types in a subclass. The "in the sense of the meta-model" is
924 # important because, in the Nit language, the programmer cannot refers
925 # directly to the parameter types of the super-classes.
929 # fun e: E is abstract
934 # In the class definition B[F], `F' is a valid type but `E' is not.
935 # However, `self.e' is a valid method call, and the signature of `e' is
938 # Note that parameter types are shared among class refinements.
939 # Therefore parameter only have an internal name (see `to_s' for details).
940 # TODO: Add a 'name_for' to get better messages.
944 # The generic class where the parameter belong
947 redef fun model
do return self.mclass
.intro_mmodule
.model
949 # The position of the parameter (0 for the first parameter)
950 # FIXME: is `position' a better name?
953 # Internal name of the parameter type
954 # Names of parameter types changes in each class definition
955 # Therefore, this method return an internal name.
956 # Example: return "G#1" for the second parameter of the class G
957 # FIXME: add a way to get the real name in a classdef
958 redef fun to_s
do return "{mclass}#{rank}"
960 # Resolve the bound for a given resolved_receiver
961 # The result may be a other virtual type (or a parameter type)
962 fun lookup_bound
(mmodule
: MModule, resolved_receiver
: MType): MType
964 assert not resolved_receiver
.need_anchor
965 var goalclass
= self.mclass
966 var supertypes
= resolved_receiver
.collect_mtypes
(mmodule
)
967 for t
in supertypes
do
968 if t
.mclass
== goalclass
then
969 # Yeah! c specialize goalclass with a "super `t'". So the question is what is the argument of f
970 # FIXME: Here, we stop on the first goal. Should we check others and detect inconsistencies?
971 var res
= t
.arguments
[self.rank
]
978 redef fun resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
980 #print "{class_name}: {self}/{mtype}/{anchor}?"
982 if mtype
isa MGenericType and mtype
.mclass
== self.mclass
then
983 return mtype
.arguments
[self.rank
]
986 # self is a parameter type of mtype (or of a super-class of mtype)
987 # The point of the function it to get the bound of the virtual type that make sense for mtype
988 # But because mtype is maybe a virtual/formal type, we need to get a real receiver first
989 # FIXME: What happend here is far from clear. Thus this part must be validated and clarified
990 var resolved_receiver
= mtype
.resolve_for
(anchor
.mclass
.mclass_type
, anchor
, mmodule
, true)
991 if resolved_receiver
isa MNullableType then resolved_receiver
= resolved_receiver
.mtype
992 if resolved_receiver
isa MParameterType then
993 assert resolved_receiver
.mclass
== anchor
.mclass
994 resolved_receiver
= anchor
.arguments
[resolved_receiver
.rank
]
995 if resolved_receiver
isa MNullableType then resolved_receiver
= resolved_receiver
.mtype
997 assert resolved_receiver
isa MClassType else print
"{class_name}: {self}/{mtype}/{anchor}? {resolved_receiver}"
999 # Eh! The parameter is in the current class.
1000 # So we return the corresponding argument, no mater what!
1001 if resolved_receiver
.mclass
== self.mclass
then
1002 var res
= resolved_receiver
.arguments
[self.rank
]
1003 #print "{class_name}: {self}/{mtype}/{anchor} -> direct {res}"
1007 resolved_receiver
= resolved_receiver
.resolve_for
(anchor
, anchor
, mmodule
, false)
1008 # Now, we can get the bound
1009 var verbatim_bound
= lookup_bound
(mmodule
, resolved_receiver
)
1010 # The bound is exactly as declared in the "type" property, so we must resolve it again
1011 var res
= verbatim_bound
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1013 #print "{class_name}: {self}/{mtype}/{anchor} -> indirect {res}"
1018 init(mclass
: MClass, rank
: Int)
1020 self.mclass
= mclass
1025 # A type prefixed with "nullable"
1026 # FIXME Stub implementation
1030 # The base type of the nullable type
1033 redef fun model
do return self.mtype
.model
1040 redef fun to_s
do return "nullable {mtype}"
1042 redef fun need_anchor
do return mtype
.need_anchor
1043 redef fun as_nullable
do return self
1044 redef fun resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1046 var res
= self.mtype
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1047 return res
.as_nullable
1050 redef fun collect_mclassdefs
(mmodule
)
1052 assert not self.need_anchor
1053 return self.mtype
.collect_mclassdefs
(mmodule
)
1056 redef fun collect_mclasses
(mmodule
)
1058 assert not self.need_anchor
1059 return self.mtype
.collect_mclasses
(mmodule
)
1062 redef fun collect_mtypes
(mmodule
)
1064 assert not self.need_anchor
1065 return self.mtype
.collect_mtypes
(mmodule
)
1069 # The type of the only value null
1071 # The is only one null type per model, see `MModel::null_type'.
1074 redef var model
: Model
1075 protected init(model
: Model)
1079 redef fun to_s
do return "null"
1080 redef fun as_nullable
do return self
1081 redef fun need_anchor
do return false
1082 redef fun resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
) do return self
1084 redef fun collect_mclassdefs
(mmodule
) do return new HashSet[MClassDef]
1086 redef fun collect_mclasses
(mmodule
) do return new HashSet[MClass]
1088 redef fun collect_mtypes
(mmodule
) do return new HashSet[MClassType]
1091 # A signature of a method (or a closure)
1095 # The each parameter (in order)
1096 var mparameters
: Array[MParameter]
1098 var mclosures
= new Array[MParameter]
1100 # The return type (null for a procedure)
1101 var return_mtype
: nullable MType
1103 # REQUIRE: 1 <= mparameters.count p -> p.is_vararg
1104 init(mparameters
: Array[MParameter], return_mtype
: nullable MType)
1106 var vararg_rank
= -1
1107 for i
in [0..mparameters
.length
[ do
1108 var parameter
= mparameters
[i
]
1109 if parameter
.is_vararg
then
1110 assert vararg_rank
== -1
1114 self.mparameters
= mparameters
1115 self.return_mtype
= return_mtype
1116 self.vararg_rank
= vararg_rank
1119 # The rank of the ellipsis (...) for vararg (starting from 0).
1120 # value is -1 if there is no vararg.
1121 # Example: for "(a: Int, b: Bool..., c: Char)" #-> vararg_rank=1
1122 var vararg_rank
: Int
1124 # The number or parameters
1125 fun arity
: Int do return mparameters
.length
1130 if not mparameters
.is_empty
then
1132 for i
in [0..mparameters
.length
[ do
1133 var mparameter
= mparameters
[i
]
1134 if i
> 0 then b
.append
(", ")
1135 b
.append
(mparameter
.name
)
1137 b
.append
(mparameter
.mtype
.to_s
)
1138 if mparameter
.is_vararg
then
1144 var ret
= self.return_mtype
1152 redef fun resolve_for
(mtype
: MType, anchor
: MClassType, mmodule
: MModule, cleanup_virtual
: Bool): MSignature
1154 var params
= new Array[MParameter]
1155 for p
in self.mparameters
do
1156 params
.add
(p
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
))
1158 var ret
= self.return_mtype
1160 ret
= ret
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1162 var res
= new MSignature(params
, ret
)
1163 for p
in self.mclosures
do
1164 res
.mclosures
.add
(p
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
))
1170 # A parameter in a signature
1172 # The name of the parameter
1175 # The static type of the parameter
1178 # Is the parameter a vararg?
1181 fun resolve_for
(mtype
: MType, anchor
: MClassType, mmodule
: MModule, cleanup_virtual
: Bool): MParameter
1183 if not self.mtype
.need_anchor
then return self
1184 var newtype
= self.mtype
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1185 var res
= new MParameter(self.name
, newtype
, self.is_vararg
)
1190 # A service (global property) that generalize method, attribute, etc.
1192 # MProperty are global to the model; it means that a MProperty is not bound
1193 # to a specific `MModule` nor a specific `MClass`.
1195 # A MProperty gather definitions (see `mpropdefs') ; one for the introduction
1196 # and the other in subclasses and in refinements.
1198 # A MProperty is used to denotes services in polymorphic way (ie. independent
1199 # of any dynamic type).
1200 # For instance, a call site "x.foo" is associated to a MProperty.
1201 abstract class MProperty
1202 # The associated MPropDef subclass.
1203 # The two specialization hierarchy are symmetric.
1204 type MPROPDEF: MPropDef
1206 # The classdef that introduce the property
1207 # While a property is not bound to a specific module, or class,
1208 # the introducing mclassdef is used for naming and visibility
1209 var intro_mclassdef
: MClassDef
1211 # The (short) name of the property
1214 # The canonical name of the property
1215 # Example: "owner::my_module::MyClass::my_method"
1216 fun full_name
: String
1218 return "{self.intro_mclassdef.mmodule.full_name}::{self.intro_mclassdef.mclass.name}::{name}"
1221 # The visibility of the property
1222 var visibility
: MVisibility
1224 init(intro_mclassdef
: MClassDef, name
: String, visibility
: MVisibility)
1226 self.intro_mclassdef
= intro_mclassdef
1228 self.visibility
= visibility
1229 intro_mclassdef
.intro_mproperties
.add
(self)
1230 var model
= intro_mclassdef
.mmodule
.model
1231 model
.mproperties_by_name
.add_one
(name
, self)
1232 model
.mproperties
.add
(self)
1235 # All definitions of the property.
1236 # The first is the introduction,
1237 # The other are redefinitions (in refinements and in subclasses)
1238 var mpropdefs
: Array[MPROPDEF] = new Array[MPROPDEF]
1240 # The definition that introduced the property
1241 # Warning: the introduction is the first `MPropDef' object
1242 # associated to self. If self is just created without having any
1243 # associated definition, this method will abort
1244 fun intro
: MPROPDEF do return mpropdefs
.first
1247 redef fun to_s
do return name
1249 # Return the most specific property definitions defined or inherited by a type.
1250 # The selection knows that refinement is stronger than specialization;
1251 # however, in case of conflict more than one property are returned.
1252 # If mtype does not know mproperty then an empty array is returned.
1254 # If you want the really most specific property, then look at `lookup_first_definition`
1255 fun lookup_definitions
(mmodule
: MModule, mtype
: MType): Array[MPROPDEF]
1257 assert not mtype
.need_anchor
1258 if mtype
isa MNullableType then mtype
= mtype
.mtype
1260 var cache
= self.lookup_definitions_cache
[mmodule
, mtype
]
1261 if cache
!= null then return cache
1263 #print "select prop {mproperty} for {mtype} in {self}"
1264 # First, select all candidates
1265 var candidates
= new Array[MPROPDEF]
1266 for mpropdef
in self.mpropdefs
do
1267 # If the definition is not imported by the module, then skip
1268 if not mmodule
.in_importation
<= mpropdef
.mclassdef
.mmodule
then continue
1269 # If the definition is not inherited by the type, then skip
1270 if not mtype
.is_subtype
(mmodule
, null, mpropdef
.mclassdef
.bound_mtype
) then continue
1272 candidates
.add
(mpropdef
)
1274 # Fast track for only one candidate
1275 if candidates
.length
<= 1 then
1276 self.lookup_definitions_cache
[mmodule
, mtype
] = candidates
1280 # Second, filter the most specific ones
1281 var res
= new Array[MPROPDEF]
1282 for pd1
in candidates
do
1283 var cd1
= pd1
.mclassdef
1286 for pd2
in candidates
do
1287 if pd2
== pd1
then continue # do not compare with self!
1288 var cd2
= pd2
.mclassdef
1290 if c2
.mclass_type
== c1
.mclass_type
then
1291 if cd2
.mmodule
.in_importation
<= cd1
.mmodule
then
1292 # cd2 refines cd1; therefore we skip pd1
1296 else if cd2
.bound_mtype
.is_subtype
(mmodule
, null, cd1
.bound_mtype
) then
1297 # cd2 < cd1; therefore we skip pd1
1306 if res
.is_empty
then
1307 print
"All lost! {candidates.join(", ")}"
1308 # FIXME: should be abort!
1310 self.lookup_definitions_cache
[mmodule
, mtype
] = res
1314 private var lookup_definitions_cache
: HashMap2[MModule, MType, Array[MPROPDEF]] = new HashMap2[MModule, MType, Array[MPROPDEF]]
1316 # Return the most specific property definitions inherited by a type.
1317 # The selection knows that refinement is stronger than specialization;
1318 # however, in case of conflict more than one property are returned.
1319 # If mtype does not know mproperty then an empty array is returned.
1321 # If you want the really most specific property, then look at `lookup_next_definition`
1323 # FIXME: Move to MPropDef?
1324 fun lookup_super_definitions
(mmodule
: MModule, mtype
: MType): Array[MPropDef]
1326 assert not mtype
.need_anchor
1327 if mtype
isa MNullableType then mtype
= mtype
.mtype
1329 # First, select all candidates
1330 var candidates
= new Array[MPropDef]
1331 for mpropdef
in self.mpropdefs
do
1332 # If the definition is not imported by the module, then skip
1333 if not mmodule
.in_importation
<= mpropdef
.mclassdef
.mmodule
then continue
1334 # If the definition is not inherited by the type, then skip
1335 if not mtype
.is_subtype
(mmodule
, null, mpropdef
.mclassdef
.bound_mtype
) then continue
1336 # If the definition is defined by the type, then skip (we want the super, so e skip the current)
1337 if mtype
== mpropdef
.mclassdef
.bound_mtype
and mmodule
== mpropdef
.mclassdef
.mmodule
then continue
1339 candidates
.add
(mpropdef
)
1341 # Fast track for only one candidate
1342 if candidates
.length
<= 1 then return candidates
1344 # Second, filter the most specific ones
1345 var res
= new Array[MPropDef]
1346 for pd1
in candidates
do
1347 var cd1
= pd1
.mclassdef
1350 for pd2
in candidates
do
1351 if pd2
== pd1
then continue # do not compare with self!
1352 var cd2
= pd2
.mclassdef
1354 if c2
.mclass_type
== c1
.mclass_type
then
1355 if cd2
.mmodule
.in_importation
<= cd1
.mmodule
then
1356 # cd2 refines cd1; therefore we skip pd1
1360 else if cd2
.bound_mtype
.is_subtype
(mmodule
, null, cd1
.bound_mtype
) then
1361 # cd2 < cd1; therefore we skip pd1
1370 if res
.is_empty
then
1371 print
"All lost! {candidates.join(", ")}"
1372 # FIXME: should be abort!
1377 # Return the most specific definition in the linearization of `mtype`.
1378 # If mtype does not know mproperty then null is returned.
1380 # If you want to know the next properties in the linearization,
1381 # look at `MPropDef::lookup_next_definition`.
1383 # FIXME: NOT YET IMPLEMENTED
1385 # REQUIRE: not mtype.need_anchor
1386 fun lookup_first_definition
(mmodule
: MModule, mtype
: MType): nullable MPROPDEF
1388 assert not mtype
.need_anchor
1397 redef type MPROPDEF: MMethodDef
1399 init(intro_mclassdef
: MClassDef, name
: String, visibility
: MVisibility)
1404 # Is the property a constructor?
1405 # Warning, this property can be inherited by subclasses with or without being a constructor
1406 # therefore, you should use `is_init_for' the verify if the property is a legal constructor for a given class
1407 var is_init
: Bool writable = false
1409 # The the property a 'new' contructor?
1410 var is_new
: Bool writable = false
1412 # Is the property a legal constructor for a given class?
1413 # As usual, visibility is not considered.
1414 # FIXME not implemented
1415 fun is_init_for
(mclass
: MClass): Bool
1421 # A global attribute
1425 redef type MPROPDEF: MAttributeDef
1427 init(intro_mclassdef
: MClassDef, name
: String, visibility
: MVisibility)
1433 # A global virtual type
1434 class MVirtualTypeProp
1437 redef type MPROPDEF: MVirtualTypeDef
1439 init(intro_mclassdef
: MClassDef, name
: String, visibility
: MVisibility)
1444 # The formal type associated to the virtual type property
1445 var mvirtualtype
: MVirtualType = new MVirtualType(self)
1448 # A definition of a property (local property)
1450 # Unlike MProperty, a MPropDef is a local definition that belong to a
1451 # specific class definition (which belong to a specific module)
1452 abstract class MPropDef
1454 # The associated MProperty subclass.
1455 # the two specialization hierarchy are symmetric
1456 type MPROPERTY: MProperty
1459 type MPROPDEF: MPropDef
1461 # The origin of the definition
1462 var location
: Location
1464 # The class definition where the property definition is
1465 var mclassdef
: MClassDef
1467 # The associated global property
1468 var mproperty
: MPROPERTY
1470 init(mclassdef
: MClassDef, mproperty
: MPROPERTY, location
: Location)
1472 self.mclassdef
= mclassdef
1473 self.mproperty
= mproperty
1474 self.location
= location
1475 mclassdef
.mpropdefs
.add
(self)
1476 mproperty
.mpropdefs
.add
(self)
1479 # Internal name combining the module, the class and the property
1480 # Example: "mymodule#MyClass#mymethod"
1483 return "{mclassdef}#{mproperty}"
1486 # Is self the definition that introduce the property?
1487 fun is_intro
: Bool do return mproperty
.intro
== self
1489 # Return the next definition in linearization of `mtype`.
1490 # If there is no next method then null is returned.
1492 # This method is used to determine what method is called by a super.
1494 # FIXME: NOT YET IMPLEMENTED
1496 # REQUIRE: not mtype.need_anchor
1497 fun lookup_next_definition
(mmodule
: MModule, mtype
: MType): nullable MPROPDEF
1499 assert not mtype
.need_anchor
1504 # A local definition of a method
1508 redef type MPROPERTY: MMethod
1509 redef type MPROPDEF: MMethodDef
1511 init(mclassdef
: MClassDef, mproperty
: MPROPERTY, location
: Location)
1516 # The signature attached to the property definition
1517 var msignature
: nullable MSignature writable = null
1520 # A local definition of an attribute
1524 redef type MPROPERTY: MAttribute
1525 redef type MPROPDEF: MAttributeDef
1527 init(mclassdef
: MClassDef, mproperty
: MPROPERTY, location
: Location)
1532 # The static type of the attribute
1533 var static_mtype
: nullable MType writable = null
1536 # A local definition of a virtual type
1537 class MVirtualTypeDef
1540 redef type MPROPERTY: MVirtualTypeProp
1541 redef type MPROPDEF: MVirtualTypeDef
1543 init(mclassdef
: MClassDef, mproperty
: MPROPERTY, location
: Location)
1548 # The bound of the virtual type
1549 var bound
: nullable MType writable = null
1560 # Note this class is basically an enum.
1561 # FIXME: use a real enum once user-defined enums are available
1563 redef var to_s
: String
1565 # Is a constructor required?
1567 private init(s
: String, need_init
: Bool)
1570 self.need_init
= need_init
1574 fun abstract_kind
: MClassKind do return once
new MClassKind("abstract class", true)
1575 fun concrete_kind
: MClassKind do return once
new MClassKind("class", true)
1576 fun interface_kind
: MClassKind do return once
new MClassKind("interface", false)
1577 fun enum_kind
: MClassKind do return once
new MClassKind("enum", false)
1578 fun extern_kind
: MClassKind do return once
new MClassKind("extern", false)