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 # 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 assert sub2
isa MGenericType
554 for i
in [0..sup
.mclass
.arity
[ do
555 var sub_arg
= sub2
.arguments
[i
]
556 var sup_arg
= sup
.arguments
[i
]
557 res
= sub_arg
.is_subtype
(mmodule
, anchor
, sup_arg
)
558 if res
== false then return false
563 # The base class type on which self is based
565 # This base type is used to get property (an internally to perform
566 # unsafe type comparison).
568 # Beware: some types (like null) are not based on a class thus this
571 # Basically, this function transform the virtual types and parameter
572 # types to their bounds.
582 # Map[T,U] anchor_to H #-> Map[C,Y]
584 # Explanation of the example:
585 # In H, T is set to C, because "H super G[C]", and U is bound to Y,
586 # because "redef type U: Y". Therefore, Map[T, U] is bound to
589 # ENSURE: not self.need_anchor implies return == self
590 # ENSURE: not return.need_anchor
591 fun anchor_to
(mmodule
: MModule, anchor
: MClassType): MType
593 if not need_anchor
then return self
594 assert not anchor
.need_anchor
595 # Just resolve to the anchor and clear all the virtual types
596 var res
= self.resolve_for
(anchor
, anchor
, mmodule
, true)
597 assert not res
.need_anchor
601 # Does `self' contain a virtual type or a formal generic parameter type?
602 # In order to remove those types, you usually want to use `anchor_to'.
603 fun need_anchor
: Bool do return true
605 # Return the supertype when adapted to a class.
607 # In Nit, for each super-class of a type, there is a equivalent super-type.
611 # class H[V] super G[V, Bool]
612 # H[Int] supertype_to G #-> G[Int, Bool]
614 # REQUIRE: `super_mclass' is a super-class of `self'
615 # ENSURE: return.mclass = mclass
616 fun supertype_to
(mmodule
: MModule, anchor
: MClassType, super_mclass
: MClass): MClassType
618 if super_mclass
.arity
== 0 then return super_mclass
.mclass_type
619 if self isa MClassType and self.mclass
== super_mclass
then return self
620 var resolved_self
= self.anchor_to
(mmodule
, anchor
)
621 var supertypes
= resolved_self
.collect_mtypes
(mmodule
)
622 for supertype
in supertypes
do
623 if supertype
.mclass
== super_mclass
then
624 # FIXME: Here, we stop on the first goal. Should we check others and detect inconsistencies?
625 return supertype
.resolve_for
(self, anchor
, mmodule
, false)
631 # Replace formals generic types in self with resolved values in `mtype'
632 # If `cleanup_virtual' is true, then virtual types are also replaced
635 # This function returns self if `need_anchor' is false.
639 # class H[F] super G[F]
640 # Array[E] resolve_for H[Int] #-> Array[Int]
642 # Explanation of the example:
643 # * Array[E].need_anchor is true because there is a formal generic
645 # * E makes sense for H[Int] because E is a formal parameter of G
647 # * Since "H[F] super G[F]", E is in fact F for H
648 # * More specifically, in H[Int], E is Int
649 # * So, in H[Int], Array[E] is Array[Int]
651 # This function is mainly used to inherit a signature.
652 # Because, unlike `anchor_type', we do not want a full resolution of
653 # a type but only an adapted version of it.
659 # class B super A[Int] end
661 # The signature on foo is (e: E): E
662 # If we resolve the signature for B, we get (e:Int):Int
664 # TODO: Explain the cleanup_virtual
666 # FIXME: the parameter `cleanup_virtual' is just a bad idea, but having
667 # two function instead of one seems also to be a bad idea.
669 # ENSURE: not self.need_anchor implies return == self
670 fun resolve_for
(mtype
: MType, anchor
: MClassType, mmodule
: MModule, cleanup_virtual
: Bool): MType is abstract
672 # Return the nullable version of the type
673 # If the type is already nullable then self is returned
675 # FIXME: DO NOT WORK YET
676 fun as_nullable
: MType
678 var res
= self.as_nullable_cache
679 if res
!= null then return res
680 res
= new MNullableType(self)
681 self.as_nullable_cache
= res
685 private var as_nullable_cache
: nullable MType = null
687 # Compute all the classdefs inherited/imported.
688 # The returned set contains:
689 # * the class definitions from `mmodule` and its imported modules
690 # * the class definitions of this type and its super-types
692 # This function is used mainly internally.
694 # REQUIRE: not self.need_anchor
695 fun collect_mclassdefs
(mmodule
: MModule): Set[MClassDef] is abstract
697 # Compute all the super-classes.
698 # This function is used mainly internally.
700 # REQUIRE: not self.need_anchor
701 fun collect_mclasses
(mmodule
: MModule): Set[MClass] is abstract
703 # Compute all the declared super-types.
704 # Super-types are returned as declared in the classdefs (verbatim).
705 # This function is used mainly internally.
707 # REQUIRE: not self.need_anchor
708 fun collect_mtypes
(mmodule
: MModule): Set[MClassType] is abstract
710 # Is the property in self for a given module
711 # This method does not filter visibility or whatever
713 # REQUIRE: not self.need_anchor
714 fun has_mproperty
(mmodule
: MModule, mproperty
: MProperty): Bool
716 assert not self.need_anchor
717 return self.collect_mclassdefs
(mmodule
).has
(mproperty
.intro_mclassdef
)
721 # A type based on a class.
723 # MClassType have properties (see `has_property').
727 # The associated class
730 redef fun model
do return self.mclass
.intro_mmodule
.model
732 private init(mclass
: MClass)
737 redef fun to_s
do return mclass
.to_s
739 redef fun need_anchor
do return false
741 redef fun anchor_to
(mmodule
: MModule, anchor
: MClassType): MClassType
743 return super.as(MClassType)
746 redef fun resolve_for
(mtype
: MType, anchor
: MClassType, mmodule
: MModule, cleanup_virtual
: Bool): MClassType do return self
748 redef fun collect_mclassdefs
(mmodule
)
750 assert not self.need_anchor
751 var cache
= self.collect_mclassdefs_cache
752 if not cache
.has_key
(mmodule
) then
753 self.collect_things
(mmodule
)
755 return cache
[mmodule
]
758 redef fun collect_mclasses
(mmodule
)
760 assert not self.need_anchor
761 var cache
= self.collect_mclasses_cache
762 if not cache
.has_key
(mmodule
) then
763 self.collect_things
(mmodule
)
765 return cache
[mmodule
]
768 redef fun collect_mtypes
(mmodule
)
770 assert not self.need_anchor
771 var cache
= self.collect_mtypes_cache
772 if not cache
.has_key
(mmodule
) then
773 self.collect_things
(mmodule
)
775 return cache
[mmodule
]
778 # common implementation for `collect_mclassdefs', `collect_mclasses', and `collect_mtypes'.
779 private fun collect_things
(mmodule
: MModule)
781 var res
= new HashSet[MClassDef]
782 var seen
= new HashSet[MClass]
783 var types
= new HashSet[MClassType]
784 seen
.add
(self.mclass
)
785 var todo
= [self.mclass
]
786 while not todo
.is_empty
do
787 var mclass
= todo
.pop
788 #print "process {mclass}"
789 for mclassdef
in mclass
.mclassdefs
do
790 if not mmodule
.in_importation
<= mclassdef
.mmodule
then continue
791 #print " process {mclassdef}"
793 for supertype
in mclassdef
.supertypes
do
795 var superclass
= supertype
.mclass
796 if seen
.has
(superclass
) then continue
797 #print " add {superclass}"
803 collect_mclassdefs_cache
[mmodule
] = res
804 collect_mclasses_cache
[mmodule
] = seen
805 collect_mtypes_cache
[mmodule
] = types
808 private var collect_mclassdefs_cache
: HashMap[MModule, Set[MClassDef]] = new HashMap[MModule, Set[MClassDef]]
809 private var collect_mclasses_cache
: HashMap[MModule, Set[MClass]] = new HashMap[MModule, Set[MClass]]
810 private var collect_mtypes_cache
: HashMap[MModule, Set[MClassType]] = new HashMap[MModule, Set[MClassType]]
814 # A type based on a generic class.
815 # A generic type a just a class with additional formal generic arguments.
819 private init(mclass
: MClass, arguments
: Array[MType])
822 assert self.mclass
.arity
== arguments
.length
823 self.arguments
= arguments
825 self.need_anchor
= false
826 for t
in arguments
do
827 if t
.need_anchor
then
828 self.need_anchor
= true
834 # The formal arguments of the type
835 # ENSURE: return.length == self.mclass.arity
836 var arguments
: Array[MType]
838 # Recursively print the type of the arguments within brackets.
839 # Example: "Map[String,List[Int]]"
842 return "{mclass}[{arguments.join(",")}]"
845 redef var need_anchor
: Bool
847 redef fun resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
849 if not need_anchor
then return self
850 var types
= new Array[MType]
851 for t
in arguments
do
852 types
.add
(t
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
))
854 return mclass
.get_mtype
(types
)
858 # A virtual formal type.
862 # The property associated with the type.
863 # Its the definitions of this property that determine the bound or the virtual type.
864 var mproperty
: MProperty
866 redef fun model
do return self.mproperty
.intro_mclassdef
.mmodule
.model
868 # Lookup the bound for a given resolved_receiver
869 # The result may be a other virtual type (or a parameter type)
871 # The result is returned exactly as declared in the "type" property (verbatim).
873 # In case of conflict, the method aborts.
874 fun lookup_bound
(mmodule
: MModule, resolved_receiver
: MType): MType
876 assert not resolved_receiver
.need_anchor
877 var props
= self.mproperty
.lookup_definitions
(mmodule
, resolved_receiver
)
878 if props
.is_empty
then
880 else if props
.length
== 1 then
881 return props
.first
.as(MVirtualTypeDef).bound
.as(not null)
883 var types
= new ArraySet[MType]
885 types
.add
(p
.as(MVirtualTypeDef).bound
.as(not null))
887 if types
.length
== 1 then
893 redef fun resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
895 if not cleanup_virtual
then return self
896 # self is a virtual type declared (or inherited) in mtype
897 # The point of the function it to get the bound of the virtual type that make sense for mtype
898 # But because mtype is maybe a virtual/formal type, we need to get a real receiver first
899 #print "{class_name}: {self}/{mtype}/{anchor}?"
900 var resolved_reciever
= mtype
.resolve_for
(anchor
, anchor
, mmodule
, true)
901 # Now, we can get the bound
902 var verbatim_bound
= lookup_bound
(mmodule
, resolved_reciever
)
903 # The bound is exactly as declared in the "type" property, so we must resolve it again
904 var res
= verbatim_bound
.resolve_for
(mtype
, anchor
, mmodule
, true)
905 #print "{class_name}: {self}/{mtype}/{anchor} -> {self}/{resolved_reciever}/{anchor} -> {verbatim_bound}/{mtype}/{anchor} -> {res}"
909 redef fun to_s
do return self.mproperty
.to_s
911 init(mproperty
: MProperty)
913 self.mproperty
= mproperty
917 # The type associated the a formal parameter generic type of a class
919 # Each parameter type is associated to a specific class.
920 # It's mean that all refinements of a same class "share" the parameter type,
921 # but that a generic subclass has its on parameter types.
923 # However, in the sense of the meta-model, the a parameter type of a class is
924 # a valid types in a subclass. The "in the sense of the meta-model" is
925 # important because, in the Nit language, the programmer cannot refers
926 # directly to the parameter types of the super-classes.
930 # fun e: E is abstract
935 # In the class definition B[F], `F' is a valid type but `E' is not.
936 # However, `self.e' is a valid method call, and the signature of `e' is
939 # Note that parameter types are shared among class refinements.
940 # Therefore parameter only have an internal name (see `to_s' for details).
941 # TODO: Add a 'name_for' to get better messages.
945 # The generic class where the parameter belong
948 redef fun model
do return self.mclass
.intro_mmodule
.model
950 # The position of the parameter (0 for the first parameter)
951 # FIXME: is `position' a better name?
954 # Internal name of the parameter type
955 # Names of parameter types changes in each class definition
956 # Therefore, this method return an internal name.
957 # Example: return "G#1" for the second parameter of the class G
958 # FIXME: add a way to get the real name in a classdef
959 redef fun to_s
do return "{mclass}#{rank}"
961 # Resolve the bound for a given resolved_receiver
962 # The result may be a other virtual type (or a parameter type)
963 fun lookup_bound
(mmodule
: MModule, resolved_receiver
: MType): MType
965 assert not resolved_receiver
.need_anchor
966 var goalclass
= self.mclass
967 var supertypes
= resolved_receiver
.collect_mtypes
(mmodule
)
968 for t
in supertypes
do
969 if t
.mclass
== goalclass
then
970 # Yeah! c specialize goalclass with a "super `t'". So the question is what is the argument of f
971 # FIXME: Here, we stop on the first goal. Should we check others and detect inconsistencies?
972 assert t
isa MGenericType
973 var res
= t
.arguments
[self.rank
]
980 redef fun resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
982 #print "{class_name}: {self}/{mtype}/{anchor}?"
984 if mtype
isa MGenericType and mtype
.mclass
== self.mclass
then
985 return mtype
.arguments
[self.rank
]
988 # self is a parameter type of mtype (or of a super-class of mtype)
989 # The point of the function it to get the bound of the virtual type that make sense for mtype
990 # But because mtype is maybe a virtual/formal type, we need to get a real receiver first
991 # FIXME: What happend here is far from clear. Thus this part must be validated and clarified
992 var resolved_receiver
= mtype
.resolve_for
(anchor
.mclass
.mclass_type
, anchor
, mmodule
, true)
993 if resolved_receiver
isa MNullableType then resolved_receiver
= resolved_receiver
.mtype
994 if resolved_receiver
isa MParameterType then
995 assert resolved_receiver
.mclass
== anchor
.mclass
996 resolved_receiver
= anchor
.as(MGenericType).arguments
[resolved_receiver
.rank
]
997 if resolved_receiver
isa MNullableType then resolved_receiver
= resolved_receiver
.mtype
999 assert resolved_receiver
isa MClassType else print
"{class_name}: {self}/{mtype}/{anchor}? {resolved_receiver}"
1001 # Eh! The parameter is in the current class.
1002 # So we return the corresponding argument, no mater what!
1003 if resolved_receiver
.mclass
== self.mclass
then
1004 assert resolved_receiver
isa MGenericType
1005 var res
= resolved_receiver
.arguments
[self.rank
]
1006 #print "{class_name}: {self}/{mtype}/{anchor} -> direct {res}"
1010 resolved_receiver
= resolved_receiver
.resolve_for
(anchor
, anchor
, mmodule
, false)
1011 # Now, we can get the bound
1012 var verbatim_bound
= lookup_bound
(mmodule
, resolved_receiver
)
1013 # The bound is exactly as declared in the "type" property, so we must resolve it again
1014 var res
= verbatim_bound
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1016 #print "{class_name}: {self}/{mtype}/{anchor} -> indirect {res}"
1021 init(mclass
: MClass, rank
: Int)
1023 self.mclass
= mclass
1028 # A type prefixed with "nullable"
1029 # FIXME Stub implementation
1033 # The base type of the nullable type
1036 redef fun model
do return self.mtype
.model
1043 redef fun to_s
do return "nullable {mtype}"
1045 redef fun need_anchor
do return mtype
.need_anchor
1046 redef fun as_nullable
do return self
1047 redef fun resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1049 var res
= self.mtype
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1050 return res
.as_nullable
1053 redef fun collect_mclassdefs
(mmodule
)
1055 assert not self.need_anchor
1056 return self.mtype
.collect_mclassdefs
(mmodule
)
1059 redef fun collect_mclasses
(mmodule
)
1061 assert not self.need_anchor
1062 return self.mtype
.collect_mclasses
(mmodule
)
1065 redef fun collect_mtypes
(mmodule
)
1067 assert not self.need_anchor
1068 return self.mtype
.collect_mtypes
(mmodule
)
1072 # The type of the only value null
1074 # The is only one null type per model, see `MModel::null_type'.
1077 redef var model
: Model
1078 protected init(model
: Model)
1082 redef fun to_s
do return "null"
1083 redef fun as_nullable
do return self
1084 redef fun need_anchor
do return false
1085 redef fun resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
) do return self
1087 redef fun collect_mclassdefs
(mmodule
) do return new HashSet[MClassDef]
1089 redef fun collect_mclasses
(mmodule
) do return new HashSet[MClass]
1091 redef fun collect_mtypes
(mmodule
) do return new HashSet[MClassType]
1094 # A signature of a method (or a closure)
1098 # The each parameter (in order)
1099 var mparameters
: Array[MParameter]
1101 var mclosures
= new Array[MParameter]
1103 # The return type (null for a procedure)
1104 var return_mtype
: nullable MType
1106 # REQUIRE: 1 <= mparameters.count p -> p.is_vararg
1107 init(mparameters
: Array[MParameter], return_mtype
: nullable MType)
1109 var vararg_rank
= -1
1110 for i
in [0..mparameters
.length
[ do
1111 var parameter
= mparameters
[i
]
1112 if parameter
.is_vararg
then
1113 assert vararg_rank
== -1
1117 self.mparameters
= mparameters
1118 self.return_mtype
= return_mtype
1119 self.vararg_rank
= vararg_rank
1122 # The rank of the ellipsis (...) for vararg (starting from 0).
1123 # value is -1 if there is no vararg.
1124 # Example: for "(a: Int, b: Bool..., c: Char)" #-> vararg_rank=1
1125 var vararg_rank
: Int
1127 # The number or parameters
1128 fun arity
: Int do return mparameters
.length
1133 if not mparameters
.is_empty
then
1135 for i
in [0..mparameters
.length
[ do
1136 var mparameter
= mparameters
[i
]
1137 if i
> 0 then b
.append
(", ")
1138 b
.append
(mparameter
.name
)
1140 b
.append
(mparameter
.mtype
.to_s
)
1141 if mparameter
.is_vararg
then
1147 var ret
= self.return_mtype
1155 redef fun resolve_for
(mtype
: MType, anchor
: MClassType, mmodule
: MModule, cleanup_virtual
: Bool): MSignature
1157 var params
= new Array[MParameter]
1158 for p
in self.mparameters
do
1159 params
.add
(p
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
))
1161 var ret
= self.return_mtype
1163 ret
= ret
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1165 var res
= new MSignature(params
, ret
)
1166 for p
in self.mclosures
do
1167 res
.mclosures
.add
(p
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
))
1173 # A parameter in a signature
1175 # The name of the parameter
1178 # The static type of the parameter
1181 # Is the parameter a vararg?
1184 fun resolve_for
(mtype
: MType, anchor
: MClassType, mmodule
: MModule, cleanup_virtual
: Bool): MParameter
1186 if not self.mtype
.need_anchor
then return self
1187 var newtype
= self.mtype
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1188 var res
= new MParameter(self.name
, newtype
, self.is_vararg
)
1193 # A service (global property) that generalize method, attribute, etc.
1195 # MProperty are global to the model; it means that a MProperty is not bound
1196 # to a specific `MModule` nor a specific `MClass`.
1198 # A MProperty gather definitions (see `mpropdefs') ; one for the introduction
1199 # and the other in subclasses and in refinements.
1201 # A MProperty is used to denotes services in polymorphic way (ie. independent
1202 # of any dynamic type).
1203 # For instance, a call site "x.foo" is associated to a MProperty.
1204 abstract class MProperty
1205 # The associated MPropDef subclass.
1206 # The two specialization hierarchy are symmetric.
1207 type MPROPDEF: MPropDef
1209 # The classdef that introduce the property
1210 # While a property is not bound to a specific module, or class,
1211 # the introducing mclassdef is used for naming and visibility
1212 var intro_mclassdef
: MClassDef
1214 # The (short) name of the property
1217 # The canonical name of the property
1218 # Example: "owner::my_module::MyClass::my_method"
1219 fun full_name
: String
1221 return "{self.intro_mclassdef.mmodule.full_name}::{self.intro_mclassdef.mclass.name}::{name}"
1224 # The visibility of the property
1225 var visibility
: MVisibility
1227 init(intro_mclassdef
: MClassDef, name
: String, visibility
: MVisibility)
1229 self.intro_mclassdef
= intro_mclassdef
1231 self.visibility
= visibility
1232 intro_mclassdef
.intro_mproperties
.add
(self)
1233 var model
= intro_mclassdef
.mmodule
.model
1234 model
.mproperties_by_name
.add_one
(name
, self)
1235 model
.mproperties
.add
(self)
1238 # All definitions of the property.
1239 # The first is the introduction,
1240 # The other are redefinitions (in refinements and in subclasses)
1241 var mpropdefs
: Array[MPROPDEF] = new Array[MPROPDEF]
1243 # The definition that introduced the property
1244 # Warning: the introduction is the first `MPropDef' object
1245 # associated to self. If self is just created without having any
1246 # associated definition, this method will abort
1247 fun intro
: MPROPDEF do return mpropdefs
.first
1250 redef fun to_s
do return name
1252 # Return the most specific property definitions defined or inherited by a type.
1253 # The selection knows that refinement is stronger than specialization;
1254 # however, in case of conflict more than one property are returned.
1255 # If mtype does not know mproperty then an empty array is returned.
1257 # If you want the really most specific property, then look at `lookup_first_definition`
1258 fun lookup_definitions
(mmodule
: MModule, mtype
: MType): Array[MPROPDEF]
1260 assert not mtype
.need_anchor
1261 if mtype
isa MNullableType then mtype
= mtype
.mtype
1263 var cache
= self.lookup_definitions_cache
[mmodule
, mtype
]
1264 if cache
!= null then return cache
1266 #print "select prop {mproperty} for {mtype} in {self}"
1267 # First, select all candidates
1268 var candidates
= new Array[MPROPDEF]
1269 for mpropdef
in self.mpropdefs
do
1270 # If the definition is not imported by the module, then skip
1271 if not mmodule
.in_importation
<= mpropdef
.mclassdef
.mmodule
then continue
1272 # If the definition is not inherited by the type, then skip
1273 if not mtype
.is_subtype
(mmodule
, null, mpropdef
.mclassdef
.bound_mtype
) then continue
1275 candidates
.add
(mpropdef
)
1277 # Fast track for only one candidate
1278 if candidates
.length
<= 1 then
1279 self.lookup_definitions_cache
[mmodule
, mtype
] = candidates
1283 # Second, filter the most specific ones
1284 var res
= new Array[MPROPDEF]
1285 for pd1
in candidates
do
1286 var cd1
= pd1
.mclassdef
1289 for pd2
in candidates
do
1290 if pd2
== pd1
then continue # do not compare with self!
1291 var cd2
= pd2
.mclassdef
1293 if c2
.mclass_type
== c1
.mclass_type
then
1294 if cd2
.mmodule
.in_importation
<= cd1
.mmodule
then
1295 # cd2 refines cd1; therefore we skip pd1
1299 else if cd2
.bound_mtype
.is_subtype
(mmodule
, null, cd1
.bound_mtype
) then
1300 # cd2 < cd1; therefore we skip pd1
1309 if res
.is_empty
then
1310 print
"All lost! {candidates.join(", ")}"
1311 # FIXME: should be abort!
1313 self.lookup_definitions_cache
[mmodule
, mtype
] = res
1317 private var lookup_definitions_cache
: HashMap2[MModule, MType, Array[MPROPDEF]] = new HashMap2[MModule, MType, Array[MPROPDEF]]
1319 # Return the most specific property definitions inherited by a type.
1320 # The selection knows that refinement is stronger than specialization;
1321 # however, in case of conflict more than one property are returned.
1322 # If mtype does not know mproperty then an empty array is returned.
1324 # If you want the really most specific property, then look at `lookup_next_definition`
1326 # FIXME: Move to MPropDef?
1327 fun lookup_super_definitions
(mmodule
: MModule, mtype
: MType): Array[MPropDef]
1329 assert not mtype
.need_anchor
1330 if mtype
isa MNullableType then mtype
= mtype
.mtype
1332 # First, select all candidates
1333 var candidates
= new Array[MPropDef]
1334 for mpropdef
in self.mpropdefs
do
1335 # If the definition is not imported by the module, then skip
1336 if not mmodule
.in_importation
<= mpropdef
.mclassdef
.mmodule
then continue
1337 # If the definition is not inherited by the type, then skip
1338 if not mtype
.is_subtype
(mmodule
, null, mpropdef
.mclassdef
.bound_mtype
) then continue
1339 # If the definition is defined by the type, then skip (we want the super, so e skip the current)
1340 if mtype
== mpropdef
.mclassdef
.bound_mtype
and mmodule
== mpropdef
.mclassdef
.mmodule
then continue
1342 candidates
.add
(mpropdef
)
1344 # Fast track for only one candidate
1345 if candidates
.length
<= 1 then return candidates
1347 # Second, filter the most specific ones
1348 var res
= new Array[MPropDef]
1349 for pd1
in candidates
do
1350 var cd1
= pd1
.mclassdef
1353 for pd2
in candidates
do
1354 if pd2
== pd1
then continue # do not compare with self!
1355 var cd2
= pd2
.mclassdef
1357 if c2
.mclass_type
== c1
.mclass_type
then
1358 if cd2
.mmodule
.in_importation
<= cd1
.mmodule
then
1359 # cd2 refines cd1; therefore we skip pd1
1363 else if cd2
.bound_mtype
.is_subtype
(mmodule
, null, cd1
.bound_mtype
) then
1364 # cd2 < cd1; therefore we skip pd1
1373 if res
.is_empty
then
1374 print
"All lost! {candidates.join(", ")}"
1375 # FIXME: should be abort!
1380 # Return the most specific definition in the linearization of `mtype`.
1381 # If mtype does not know mproperty then null is returned.
1383 # If you want to know the next properties in the linearization,
1384 # look at `MPropDef::lookup_next_definition`.
1386 # FIXME: NOT YET IMPLEMENTED
1388 # REQUIRE: not mtype.need_anchor
1389 fun lookup_first_definition
(mmodule
: MModule, mtype
: MType): nullable MPROPDEF
1391 assert not mtype
.need_anchor
1400 redef type MPROPDEF: MMethodDef
1402 init(intro_mclassdef
: MClassDef, name
: String, visibility
: MVisibility)
1407 # Is the property a constructor?
1408 # Warning, this property can be inherited by subclasses with or without being a constructor
1409 # therefore, you should use `is_init_for' the verify if the property is a legal constructor for a given class
1410 var is_init
: Bool writable = false
1412 # The the property a 'new' contructor?
1413 var is_new
: Bool writable = false
1415 # Is the property a legal constructor for a given class?
1416 # As usual, visibility is not considered.
1417 # FIXME not implemented
1418 fun is_init_for
(mclass
: MClass): Bool
1424 # A global attribute
1428 redef type MPROPDEF: MAttributeDef
1430 init(intro_mclassdef
: MClassDef, name
: String, visibility
: MVisibility)
1436 # A global virtual type
1437 class MVirtualTypeProp
1440 redef type MPROPDEF: MVirtualTypeDef
1442 init(intro_mclassdef
: MClassDef, name
: String, visibility
: MVisibility)
1447 # The formal type associated to the virtual type property
1448 var mvirtualtype
: MVirtualType = new MVirtualType(self)
1451 # A definition of a property (local property)
1453 # Unlike MProperty, a MPropDef is a local definition that belong to a
1454 # specific class definition (which belong to a specific module)
1455 abstract class MPropDef
1457 # The associated MProperty subclass.
1458 # the two specialization hierarchy are symmetric
1459 type MPROPERTY: MProperty
1462 type MPROPDEF: MPropDef
1464 # The origin of the definition
1465 var location
: Location
1467 # The class definition where the property definition is
1468 var mclassdef
: MClassDef
1470 # The associated global property
1471 var mproperty
: MPROPERTY
1473 init(mclassdef
: MClassDef, mproperty
: MPROPERTY, location
: Location)
1475 self.mclassdef
= mclassdef
1476 self.mproperty
= mproperty
1477 self.location
= location
1478 mclassdef
.mpropdefs
.add
(self)
1479 mproperty
.mpropdefs
.add
(self)
1482 # Internal name combining the module, the class and the property
1483 # Example: "mymodule#MyClass#mymethod"
1486 return "{mclassdef}#{mproperty}"
1489 # Is self the definition that introduce the property?
1490 fun is_intro
: Bool do return mproperty
.intro
== self
1492 # Return the next definition in linearization of `mtype`.
1493 # If there is no next method then null is returned.
1495 # This method is used to determine what method is called by a super.
1497 # FIXME: NOT YET IMPLEMENTED
1499 # REQUIRE: not mtype.need_anchor
1500 fun lookup_next_definition
(mmodule
: MModule, mtype
: MType): nullable MPROPDEF
1502 assert not mtype
.need_anchor
1507 # A local definition of a method
1511 redef type MPROPERTY: MMethod
1512 redef type MPROPDEF: MMethodDef
1514 init(mclassdef
: MClassDef, mproperty
: MPROPERTY, location
: Location)
1519 # The signature attached to the property definition
1520 var msignature
: nullable MSignature writable = null
1523 # A local definition of an attribute
1527 redef type MPROPERTY: MAttribute
1528 redef type MPROPDEF: MAttributeDef
1530 init(mclassdef
: MClassDef, mproperty
: MPROPERTY, location
: Location)
1535 # The static type of the attribute
1536 var static_mtype
: nullable MType writable = null
1539 # A local definition of a virtual type
1540 class MVirtualTypeDef
1543 redef type MPROPERTY: MVirtualTypeProp
1544 redef type MPROPDEF: MVirtualTypeDef
1546 init(mclassdef
: MClassDef, mproperty
: MPROPERTY, location
: Location)
1551 # The bound of the virtual type
1552 var bound
: nullable MType writable = null
1563 # Note this class is basically an enum.
1564 # FIXME: use a real enum once user-defined enums are available
1566 redef var to_s
: String
1568 # Is a constructor required?
1570 private init(s
: String, need_init
: Bool)
1573 self.need_init
= need_init
1577 fun abstract_kind
: MClassKind do return once
new MClassKind("abstract class", true)
1578 fun concrete_kind
: MClassKind do return once
new MClassKind("class", true)
1579 fun interface_kind
: MClassKind do return once
new MClassKind("interface", false)
1580 fun enum_kind
: MClassKind do return once
new MClassKind("enum", false)
1581 fun extern_kind
: MClassKind do return once
new MClassKind("extern", false)