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}")
221 # Force to get the primitive method named `name' on the type `recv' or abort
222 fun force_get_primitive_method
(name
: String, recv
: MType): MMethod
224 var res
= try_get_primitive_method
(name
, recv
)
226 print
("Fatal Error: no primitive property {name} on {recv}")
235 # MClass are global to the model; it means that a MClass is not bound to a
236 # specific `MModule`.
238 # This characteristic helps the reasoning about classes in a program since a
239 # single MClass object always denote the same class.
240 # However, because a MClass is global, it does not really have properties nor
241 # belong to a hierarchy since the property and the
242 # hierarchy of a class depends of a module.
244 # The module that introduce the class
245 # While classes are not bound to a specific module,
246 # the introducing module is used for naming an visibility
247 var intro_mmodule
: MModule
249 # The short name of the class
250 # In Nit, the name of a class cannot evolve in refinements
253 # The canonical name of the class
254 # Example: "owner::module::MyClass"
255 fun full_name
: String
257 return "{self.intro_mmodule.full_name}::{name}"
260 # The number of generic formal parameters
261 # 0 if the class is not generic
264 # The kind of the class (interface, abstract class, etc.)
265 # In Nit, the kind of a class cannot evolve in refinements
268 # The visibility of the class
269 # In Nit, the visibility of a class cannot evolve in refinements
270 var visibility
: MVisibility
272 init(intro_mmodule
: MModule, name
: String, arity
: Int, kind
: MClassKind, visibility
: MVisibility)
274 self.intro_mmodule
= intro_mmodule
278 self.visibility
= visibility
279 intro_mmodule
.intro_mclasses
.add
(self)
280 var model
= intro_mmodule
.model
281 model
.mclasses_by_name
.add_one
(name
, self)
282 model
.mclasses
.add
(self)
284 # Create the formal parameter types
286 var mparametertypes
= new Array[MParameterType]
287 for i
in [0..arity
[ do
288 var mparametertype
= new MParameterType(self, i
)
289 mparametertypes
.add
(mparametertype
)
291 var mclass_type
= new MGenericType(self, mparametertypes
)
292 self.mclass_type
= mclass_type
293 self.get_mtype_cache
.add
(mclass_type
)
295 self.mclass_type
= new MClassType(self)
299 # All class definitions (introduction and refinements)
300 var mclassdefs
: Array[MClassDef] = new Array[MClassDef]
303 redef fun to_s
do return self.name
305 # The definition that introduced the class
306 # Warning: the introduction is the first `MClassDef' object associated
307 # to self. If self is just created without having any associated
308 # definition, this method will abort
309 private fun intro
: MClassDef
311 assert has_a_first_definition
: not mclassdefs
.is_empty
312 return mclassdefs
.first
315 # The principal static type of the class.
317 # For non-generic class, mclass_type is the only MClassType based
320 # For a generic class, the arguments are the formal parameters.
321 # i.e.: for the class `Array[E:Object]', the mtype is Array[E].
322 # If you want `Array[Object]' the see `MClassDef::bound_mtype'
324 # For generic classes, the mclass_type is also the way to get a formal
325 # generic parameter type.
327 # To get other types based on a generic class, see `get_mtype'.
329 # ENSURE: mclass_type.mclass == self
330 var mclass_type
: MClassType
332 # Return a generic type based on the class
333 # Is the class is not generic, then the result is `mclass_type'
335 # REQUIRE: type_arguments.length == self.arity
336 fun get_mtype
(mtype_arguments
: Array[MType]): MClassType
338 assert mtype_arguments
.length
== self.arity
339 if self.arity
== 0 then return self.mclass_type
340 for t
in self.get_mtype_cache
do
341 if t
.arguments
== mtype_arguments
then
345 var res
= new MGenericType(self, mtype_arguments
)
346 self.get_mtype_cache
.add res
350 private var get_mtype_cache
: Array[MGenericType] = new Array[MGenericType]
354 # A definition (an introduction or a refinement) of a class in a module
356 # A MClassDef is associated with an explicit (or almost) definition of a
357 # class. Unlike MClass, a MClassDef is a local definition that belong to
360 # The module where the definition is
363 # The associated MClass
366 # The bounded type associated to the mclassdef
368 # For a non-generic class, `bound_mtype' and `mclass.mclass_type'
372 # For the classdef Array[E: Object], the bound_mtype is Array[Object].
373 # If you want Array[E], then see `mclass.mclass_type'
375 # ENSURE: bound_mtype.mclass = self.mclass
376 var bound_mtype
: MClassType
378 # Name of each formal generic parameter (in order of declaration)
379 var parameter_names
: Array[String]
381 # The origin of the definition
382 var location
: Location
384 # Internal name combining the module and the class
385 # Example: "mymodule#MyClass"
386 redef fun to_s
do return "{mmodule}#{mclass}"
388 init(mmodule
: MModule, bound_mtype
: MClassType, location
: Location, parameter_names
: Array[String])
390 assert bound_mtype
.mclass
.arity
== parameter_names
.length
391 self.bound_mtype
= bound_mtype
392 self.mmodule
= mmodule
393 self.mclass
= bound_mtype
.mclass
394 self.location
= location
395 mmodule
.mclassdefs
.add
(self)
396 mclass
.mclassdefs
.add
(self)
397 self.parameter_names
= parameter_names
400 # All declared super-types
401 # FIXME: quite ugly but not better idea yet
402 var supertypes
: Array[MClassType] = new Array[MClassType]
404 # Register the super-types for the class (ie "super SomeType")
405 # This function can only invoked once by class
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 res
= model
.mclassdef_hierarchy
.add_node
(self)
412 self.in_hierarchy
= res
413 var mtype
= self.bound_mtype
415 for supertype
in supertypes
do
416 self.supertypes
.add
(supertype
)
418 # Register in full_type_specialization_hierarchy
419 model
.full_mtype_specialization_hierarchy
.add_edge
(mtype
, supertype
)
420 # Register in intro_type_specialization_hierarchy
421 if mclass
.intro_mmodule
== mmodule
and supertype
.mclass
.intro_mmodule
== mmodule
then
422 model
.intro_mtype_specialization_hierarchy
.add_edge
(mtype
, supertype
)
426 for mclassdef
in mtype
.collect_mclassdefs
(mmodule
) do
427 res
.poset
.add_edge
(self, mclassdef
)
431 # The view of the class definition in `mclassdef_hierarchy'
432 var in_hierarchy
: nullable POSetElement[MClassDef] = null
434 # Is the definition the one that introduced `mclass`?
435 fun is_intro
: Bool do return mclass
.intro
== self
437 # All properties introduced by the classdef
438 var intro_mproperties
: Array[MProperty] = new Array[MProperty]
440 # All property definitions in the class (introductions and redefinitions)
441 var mpropdefs
: Array[MPropDef] = new Array[MPropDef]
444 # A global static type
446 # MType are global to the model; it means that a MType is not bound to a
447 # specific `MModule`.
448 # This characteristic helps the reasoning about static types in a program
449 # since a single MType object always denote the same type.
451 # However, because a MType is global, it does not really have properties
452 # nor have subtypes to a hierarchy since the property and the class hierarchy
453 # depends of a module.
454 # Moreover, virtual types an formal generic parameter types also depends on
455 # a receiver to have sense.
457 # Therefore, most method of the types require a module and an anchor.
458 # The module is used to know what are the classes and the specialization
460 # The anchor is used to know what is the bound of the virtual types and formal
461 # generic parameter types.
463 # MType are not directly usable to get properties. See the `anchor_to' method
464 # and the `MClassType' class.
466 # FIXME: the order of the parameters is not the best. We mus pick on from:
467 # * foo(mmodule, anchor, othertype)
468 # * foo(othertype, anchor, mmodule)
469 # * foo(anchor, mmodule, othertype)
470 # * foo(othertype, mmodule, anchor)
472 # FIXME: Add a 'is_valid_anchor' to improve imputability.
473 # Currently, anchors are used "as it" without check thus if the caller gives a
474 # bad anchor, then the method will likely crash (abort) in a bad case
476 # FIXME: maybe allways add an anchor with a nullable type (as in is_subtype)
479 # The model of the type
480 fun model
: Model is abstract
482 # Return true if `self' is an subtype of `sup'.
483 # The typing is done using the standard typing policy of Nit.
485 # REQUIRE: anchor == null implies not self.need_anchor and not sup.need_anchor
486 fun is_subtype
(mmodule
: MModule, anchor
: nullable MClassType, sup
: MType): Bool
489 if sub
== sup
then return true
490 if anchor
== null then
491 assert not sub
.need_anchor
492 assert not sup
.need_anchor
494 # First, resolve the types
495 if sub
isa MParameterType or sub
isa MVirtualType then
496 assert anchor
!= null
497 sub
= sub
.resolve_for
(anchor
, anchor
, mmodule
, false)
499 if sup
isa MParameterType or sup
isa MVirtualType then
500 assert anchor
!= null
501 sup
= sup
.resolve_for
(anchor
, anchor
, mmodule
, false)
504 if sup
isa MParameterType or sup
isa MVirtualType or sup
isa MNullType then
507 if sub
isa MParameterType or sub
isa MVirtualType then
508 assert anchor
!= null
509 sub
= sub
.anchor_to
(mmodule
, anchor
)
511 if sup
isa MNullableType then
512 if sub
isa MNullType then
514 else if sub
isa MNullableType then
515 return sub
.mtype
.is_subtype
(mmodule
, anchor
, sup
.mtype
)
516 else if sub
isa MClassType then
517 return sub
.is_subtype
(mmodule
, anchor
, sup
.mtype
)
523 assert sup
isa MClassType # It is the only remaining type
524 if sub
isa MNullableType or sub
isa MNullType then
528 if sub
== sup
then return true
530 assert sub
isa MClassType # It is the only remaining type
531 if anchor
== null then anchor
= sub
# UGLY: any anchor will work
532 var resolved_sub
= sub
.anchor_to
(mmodule
, anchor
)
533 var res
= resolved_sub
.collect_mclasses
(mmodule
).has
(sup
.mclass
)
534 if res
== false then return false
535 if not sup
isa MGenericType then return true
536 var sub2
= sub
.supertype_to
(mmodule
, anchor
, sup
.mclass
)
537 assert sub2
.mclass
== sup
.mclass
538 assert sub2
isa MGenericType
539 for i
in [0..sup
.mclass
.arity
[ do
540 var sub_arg
= sub2
.arguments
[i
]
541 var sup_arg
= sup
.arguments
[i
]
542 res
= sub_arg
.is_subtype
(mmodule
, anchor
, sup_arg
)
543 if res
== false then return false
548 # The base class type on which self is based
550 # This base type is used to get property (an internally to perform
551 # unsafe type comparison).
553 # Beware: some types (like null) are not based on a class thus this
556 # Basically, this function transform the virtual types and parameter
557 # types to their bounds.
567 # Map[T,U] anchor_to H #-> Map[C,Y]
569 # Explanation of the example:
570 # In H, T is set to C, because "H super G[C]", and U is bound to Y,
571 # because "redef type U: Y". Therefore, Map[T, U] is bound to
574 # ENSURE: not self.need_anchor implies return == self
575 # ENSURE: not return.need_anchor
576 fun anchor_to
(mmodule
: MModule, anchor
: MClassType): MType
578 if not need_anchor
then return self
579 assert not anchor
.need_anchor
580 # Just resolve to the anchor and clear all the virtual types
581 var res
= self.resolve_for
(anchor
, anchor
, mmodule
, true)
582 assert not res
.need_anchor
586 # Does `self' contain a virtual type or a formal generic parameter type?
587 # In order to remove those types, you usually want to use `anchor_to'.
588 fun need_anchor
: Bool do return true
590 # Return the supertype when adapted to a class.
592 # In Nit, for each super-class of a type, there is a equivalent super-type.
596 # class H[V] super G[V, Bool]
597 # H[Int] supertype_to G #-> G[Int, Bool]
599 # REQUIRE: `super_mclass' is a super-class of `self'
600 # ENSURE: return.mclass = mclass
601 fun supertype_to
(mmodule
: MModule, anchor
: MClassType, super_mclass
: MClass): MClassType
603 if super_mclass
.arity
== 0 then return super_mclass
.mclass_type
604 if self isa MClassType and self.mclass
== super_mclass
then return self
605 var resolved_self
= self.anchor_to
(mmodule
, anchor
)
606 var supertypes
= resolved_self
.collect_mtypes
(mmodule
)
607 for supertype
in supertypes
do
608 if supertype
.mclass
== super_mclass
then
609 # FIXME: Here, we stop on the first goal. Should we check others and detect inconsistencies?
610 return supertype
.resolve_for
(self, anchor
, mmodule
, false)
616 # Replace formals generic types in self with resolved values in `mtype'
617 # If `cleanup_virtual' is true, then virtual types are also replaced
620 # This function returns self if `need_anchor' is false.
624 # class H[F] super G[F]
625 # Array[E] resolve_for H[Int] #-> Array[Int]
627 # Explanation of the example:
628 # * Array[E].need_anchor is true because there is a formal generic
630 # * E makes sense for H[Int] because E is a formal parameter of G
632 # * Since "H[F] super G[F]", E is in fact F for H
633 # * More specifically, in H[Int], E is Int
634 # * So, in H[Int], Array[E] is Array[Int]
636 # This function is mainly used to inherit a signature.
637 # Because, unlike `anchor_type', we do not want a full resolution of
638 # a type but only an adapted version of it.
644 # class B super A[Int] end
646 # The signature on foo is (e: E): E
647 # If we resolve the signature for B, we get (e:Int):Int
649 # TODO: Explain the cleanup_virtual
651 # FIXME: the parameter `cleanup_virtual' is just a bad idea, but having
652 # two function instead of one seems also to be a bad idea.
654 # ENSURE: not self.need_anchor implies return == self
655 fun resolve_for
(mtype
: MType, anchor
: MClassType, mmodule
: MModule, cleanup_virtual
: Bool): MType is abstract
657 # Return the nullable version of the type
658 # If the type is already nullable then self is returned
660 # FIXME: DO NOT WORK YET
661 fun as_nullable
: MType
663 var res
= self.as_nullable_cache
664 if res
!= null then return res
665 res
= new MNullableType(self)
666 self.as_nullable_cache
= res
670 private var as_nullable_cache
: nullable MType = null
672 # Compute all the classdefs inherited/imported.
673 # The returned set contains:
674 # * the class definitions from `mmodule` and its imported modules
675 # * the class definitions of this type and its super-types
677 # This function is used mainly internally.
679 # REQUIRE: not self.need_anchor
680 fun collect_mclassdefs
(mmodule
: MModule): Set[MClassDef] is abstract
682 # Compute all the super-classes.
683 # This function is used mainly internally.
685 # REQUIRE: not self.need_anchor
686 fun collect_mclasses
(mmodule
: MModule): Set[MClass] is abstract
688 # Compute all the declared super-types.
689 # Super-types are returned as declared in the classdefs (verbatim).
690 # This function is used mainly internally.
692 # REQUIRE: not self.need_anchor
693 fun collect_mtypes
(mmodule
: MModule): Set[MClassType] is abstract
695 # Is the property in self for a given module
696 # This method does not filter visibility or whatever
698 # REQUIRE: not self.need_anchor
699 fun has_mproperty
(mmodule
: MModule, mproperty
: MProperty): Bool
701 assert not self.need_anchor
702 return self.collect_mclassdefs
(mmodule
).has
(mproperty
.intro_mclassdef
)
706 # A type based on a class.
708 # MClassType have properties (see `has_property').
712 # The associated class
715 redef fun model
do return self.mclass
.intro_mmodule
.model
717 private init(mclass
: MClass)
722 redef fun to_s
do return mclass
.to_s
724 redef fun need_anchor
do return false
726 redef fun anchor_to
(mmodule
: MModule, anchor
: MClassType): MClassType
728 return super.as(MClassType)
731 redef fun resolve_for
(mtype
: MType, anchor
: MClassType, mmodule
: MModule, cleanup_virtual
: Bool): MClassType do return self
733 redef fun collect_mclassdefs
(mmodule
)
735 assert not self.need_anchor
736 var cache
= self.collect_mclassdefs_cache
737 if not cache
.has_key
(mmodule
) then
738 self.collect_things
(mmodule
)
740 return cache
[mmodule
]
743 redef fun collect_mclasses
(mmodule
)
745 assert not self.need_anchor
746 var cache
= self.collect_mclasses_cache
747 if not cache
.has_key
(mmodule
) then
748 self.collect_things
(mmodule
)
750 return cache
[mmodule
]
753 redef fun collect_mtypes
(mmodule
)
755 assert not self.need_anchor
756 var cache
= self.collect_mtypes_cache
757 if not cache
.has_key
(mmodule
) then
758 self.collect_things
(mmodule
)
760 return cache
[mmodule
]
763 # common implementation for `collect_mclassdefs', `collect_mclasses', and `collect_mtypes'.
764 private fun collect_things
(mmodule
: MModule)
766 var res
= new HashSet[MClassDef]
767 var seen
= new HashSet[MClass]
768 var types
= new HashSet[MClassType]
769 seen
.add
(self.mclass
)
770 var todo
= [self.mclass
]
771 while not todo
.is_empty
do
772 var mclass
= todo
.pop
773 #print "process {mclass}"
774 for mclassdef
in mclass
.mclassdefs
do
775 if not mmodule
.in_importation
<= mclassdef
.mmodule
then continue
776 #print " process {mclassdef}"
778 for supertype
in mclassdef
.supertypes
do
780 var superclass
= supertype
.mclass
781 if seen
.has
(superclass
) then continue
782 #print " add {superclass}"
788 collect_mclassdefs_cache
[mmodule
] = res
789 collect_mclasses_cache
[mmodule
] = seen
790 collect_mtypes_cache
[mmodule
] = types
793 private var collect_mclassdefs_cache
: HashMap[MModule, Set[MClassDef]] = new HashMap[MModule, Set[MClassDef]]
794 private var collect_mclasses_cache
: HashMap[MModule, Set[MClass]] = new HashMap[MModule, Set[MClass]]
795 private var collect_mtypes_cache
: HashMap[MModule, Set[MClassType]] = new HashMap[MModule, Set[MClassType]]
799 # A type based on a generic class.
800 # A generic type a just a class with additional formal generic arguments.
804 private init(mclass
: MClass, arguments
: Array[MType])
807 assert self.mclass
.arity
== arguments
.length
808 self.arguments
= arguments
810 self.need_anchor
= false
811 for t
in arguments
do
812 if t
.need_anchor
then
813 self.need_anchor
= true
819 # The formal arguments of the type
820 # ENSURE: return.length == self.mclass.arity
821 var arguments
: Array[MType]
823 # Recursively print the type of the arguments within brackets.
824 # Example: "Map[String,List[Int]]"
827 return "{mclass}[{arguments.join(",")}]"
830 redef var need_anchor
: Bool
832 redef fun resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
834 if not need_anchor
then return self
835 var types
= new Array[MType]
836 for t
in arguments
do
837 types
.add
(t
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
))
839 return mclass
.get_mtype
(types
)
843 # A virtual formal type.
847 # The property associated with the type.
848 # Its the definitions of this property that determine the bound or the virtual type.
849 var mproperty
: MProperty
851 redef fun model
do return self.mproperty
.intro_mclassdef
.mmodule
.model
853 # Lookup the bound for a given resolved_receiver
854 # The result may be a other virtual type (or a parameter type)
856 # The result is returned exactly as declared in the "type" property (verbatim).
858 # In case of conflict, the method aborts.
859 fun lookup_bound
(mmodule
: MModule, resolved_receiver
: MType): MType
861 assert not resolved_receiver
.need_anchor
862 var props
= self.mproperty
.lookup_definitions
(mmodule
, resolved_receiver
)
863 if props
.is_empty
then
865 else if props
.length
== 1 then
866 return props
.first
.as(MVirtualTypeDef).bound
.as(not null)
868 var types
= new ArraySet[MType]
870 types
.add
(p
.as(MVirtualTypeDef).bound
.as(not null))
872 if types
.length
== 1 then
878 redef fun resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
880 if not cleanup_virtual
then return self
881 # self is a virtual type declared (or inherited) in mtype
882 # The point of the function it to get the bound of the virtual type that make sense for mtype
883 # But because mtype is maybe a virtual/formal type, we need to get a real receiver first
884 #print "{class_name}: {self}/{mtype}/{anchor}?"
885 var resolved_reciever
= mtype
.resolve_for
(anchor
, anchor
, mmodule
, true)
886 # Now, we can get the bound
887 var verbatim_bound
= lookup_bound
(mmodule
, resolved_reciever
)
888 # The bound is exactly as declared in the "type" property, so we must resolve it again
889 var res
= verbatim_bound
.resolve_for
(mtype
, anchor
, mmodule
, true)
890 #print "{class_name}: {self}/{mtype}/{anchor} -> {self}/{resolved_reciever}/{anchor} -> {verbatim_bound}/{mtype}/{anchor} -> {res}"
894 redef fun to_s
do return self.mproperty
.to_s
896 init(mproperty
: MProperty)
898 self.mproperty
= mproperty
902 # The type associated the a formal parameter generic type of a class
904 # Each parameter type is associated to a specific class.
905 # It's mean that all refinements of a same class "share" the parameter type,
906 # but that a generic subclass has its on parameter types.
908 # However, in the sense of the meta-model, the a parameter type of a class is
909 # a valid types in a subclass. The "in the sense of the meta-model" is
910 # important because, in the Nit language, the programmer cannot refers
911 # directly to the parameter types of the super-classes.
915 # fun e: E is abstract
920 # In the class definition B[F], `F' is a valid type but `E' is not.
921 # However, `self.e' is a valid method call, and the signature of `e' is
924 # Note that parameter types are shared among class refinements.
925 # Therefore parameter only have an internal name (see `to_s' for details).
926 # TODO: Add a 'name_for' to get better messages.
930 # The generic class where the parameter belong
933 redef fun model
do return self.mclass
.intro_mmodule
.model
935 # The position of the parameter (0 for the first parameter)
936 # FIXME: is `position' a better name?
939 # Internal name of the parameter type
940 # Names of parameter types changes in each class definition
941 # Therefore, this method return an internal name.
942 # Example: return "G#1" for the second parameter of the class G
943 # FIXME: add a way to get the real name in a classdef
944 redef fun to_s
do return "{mclass}#{rank}"
946 # Resolve the bound for a given resolved_receiver
947 # The result may be a other virtual type (or a parameter type)
948 fun lookup_bound
(mmodule
: MModule, resolved_receiver
: MType): MType
950 assert not resolved_receiver
.need_anchor
951 var goalclass
= self.mclass
952 var supertypes
= resolved_receiver
.collect_mtypes
(mmodule
)
953 for t
in supertypes
do
954 if t
.mclass
== goalclass
then
955 # Yeah! c specialize goalclass with a "super `t'". So the question is what is the argument of f
956 # FIXME: Here, we stop on the first goal. Should we check others and detect inconsistencies?
957 assert t
isa MGenericType
958 var res
= t
.arguments
[self.rank
]
965 redef fun resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
967 #print "{class_name}: {self}/{mtype}/{anchor}?"
969 if mtype
isa MGenericType and mtype
.mclass
== self.mclass
then
970 return mtype
.arguments
[self.rank
]
973 # self is a parameter type of mtype (or of a super-class of mtype)
974 # The point of the function it to get the bound of the virtual type that make sense for mtype
975 # But because mtype is maybe a virtual/formal type, we need to get a real receiver first
976 # FIXME: What happend here is far from clear. Thus this part must be validated and clarified
977 var resolved_receiver
= mtype
.resolve_for
(anchor
.mclass
.mclass_type
, anchor
, mmodule
, true)
978 if resolved_receiver
isa MNullableType then resolved_receiver
= resolved_receiver
.mtype
979 if resolved_receiver
isa MParameterType then
980 assert resolved_receiver
.mclass
== anchor
.mclass
981 resolved_receiver
= anchor
.as(MGenericType).arguments
[resolved_receiver
.rank
]
982 if resolved_receiver
isa MNullableType then resolved_receiver
= resolved_receiver
.mtype
984 assert resolved_receiver
isa MClassType else print
"{class_name}: {self}/{mtype}/{anchor}? {resolved_receiver}"
986 # Eh! The parameter is in the current class.
987 # So we return the corresponding argument, no mater what!
988 if resolved_receiver
.mclass
== self.mclass
then
989 assert resolved_receiver
isa MGenericType
990 var res
= resolved_receiver
.arguments
[self.rank
]
991 #print "{class_name}: {self}/{mtype}/{anchor} -> direct {res}"
995 resolved_receiver
= resolved_receiver
.resolve_for
(anchor
, anchor
, mmodule
, false)
996 # Now, we can get the bound
997 var verbatim_bound
= lookup_bound
(mmodule
, resolved_receiver
)
998 # The bound is exactly as declared in the "type" property, so we must resolve it again
999 var res
= verbatim_bound
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1001 #print "{class_name}: {self}/{mtype}/{anchor} -> indirect {res}"
1006 init(mclass
: MClass, rank
: Int)
1008 self.mclass
= mclass
1013 # A type prefixed with "nullable"
1014 # FIXME Stub implementation
1018 # The base type of the nullable type
1021 redef fun model
do return self.mtype
.model
1028 redef fun to_s
do return "nullable {mtype}"
1030 redef fun need_anchor
do return mtype
.need_anchor
1031 redef fun as_nullable
do return self
1032 redef fun resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1034 var res
= self.mtype
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1035 return res
.as_nullable
1038 redef fun collect_mclassdefs
(mmodule
)
1040 assert not self.need_anchor
1041 return self.mtype
.collect_mclassdefs
(mmodule
)
1044 redef fun collect_mclasses
(mmodule
)
1046 assert not self.need_anchor
1047 return self.mtype
.collect_mclasses
(mmodule
)
1050 redef fun collect_mtypes
(mmodule
)
1052 assert not self.need_anchor
1053 return self.mtype
.collect_mtypes
(mmodule
)
1057 # The type of the only value null
1059 # The is only one null type per model, see `MModel::null_type'.
1062 redef var model
: Model
1063 protected init(model
: Model)
1067 redef fun to_s
do return "null"
1068 redef fun as_nullable
do return self
1069 redef fun need_anchor
do return false
1070 redef fun resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
) do return self
1072 redef fun collect_mclassdefs
(mmodule
) do return new HashSet[MClassDef]
1074 redef fun collect_mclasses
(mmodule
) do return new HashSet[MClass]
1076 redef fun collect_mtypes
(mmodule
) do return new HashSet[MClassType]
1079 # A signature of a method (or a closure)
1083 # The each parameter (in order)
1084 var mparameters
: Array[MParameter]
1086 var mclosures
= new Array[MParameter]
1088 # The return type (null for a procedure)
1089 var return_mtype
: nullable MType
1091 # REQUIRE: 1 <= mparameters.count p -> p.is_vararg
1092 init(mparameters
: Array[MParameter], return_mtype
: nullable MType)
1094 var vararg_rank
= -1
1095 for i
in [0..mparameters
.length
[ do
1096 var parameter
= mparameters
[i
]
1097 if parameter
.is_vararg
then
1098 assert vararg_rank
== -1
1102 self.mparameters
= mparameters
1103 self.return_mtype
= return_mtype
1104 self.vararg_rank
= vararg_rank
1107 # The rank of the ellipsis (...) for vararg (starting from 0).
1108 # value is -1 if there is no vararg.
1109 # Example: for "(a: Int, b: Bool..., c: Char)" #-> vararg_rank=1
1110 var vararg_rank
: Int
1112 # The number or parameters
1113 fun arity
: Int do return mparameters
.length
1118 if not mparameters
.is_empty
then
1120 for i
in [0..mparameters
.length
[ do
1121 var mparameter
= mparameters
[i
]
1122 if i
> 0 then b
.append
(", ")
1123 b
.append
(mparameter
.name
)
1125 b
.append
(mparameter
.mtype
.to_s
)
1126 if mparameter
.is_vararg
then
1132 var ret
= self.return_mtype
1140 redef fun resolve_for
(mtype
: MType, anchor
: MClassType, mmodule
: MModule, cleanup_virtual
: Bool): MSignature
1142 var params
= new Array[MParameter]
1143 for p
in self.mparameters
do
1144 params
.add
(p
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
))
1146 var ret
= self.return_mtype
1148 ret
= ret
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1150 var res
= new MSignature(params
, ret
)
1151 for p
in self.mclosures
do
1152 res
.mclosures
.add
(p
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
))
1158 # A parameter in a signature
1160 # The name of the parameter
1163 # The static type of the parameter
1166 # Is the parameter a vararg?
1169 fun resolve_for
(mtype
: MType, anchor
: MClassType, mmodule
: MModule, cleanup_virtual
: Bool): MParameter
1171 if not self.mtype
.need_anchor
then return self
1172 var newtype
= self.mtype
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1173 var res
= new MParameter(self.name
, newtype
, self.is_vararg
)
1178 # A service (global property) that generalize method, attribute, etc.
1180 # MProperty are global to the model; it means that a MProperty is not bound
1181 # to a specific `MModule` nor a specific `MClass`.
1183 # A MProperty gather definitions (see `mpropdefs') ; one for the introduction
1184 # and the other in subclasses and in refinements.
1186 # A MProperty is used to denotes services in polymorphic way (ie. independent
1187 # of any dynamic type).
1188 # For instance, a call site "x.foo" is associated to a MProperty.
1189 abstract class MProperty
1190 # The associated MPropDef subclass.
1191 # The two specialization hierarchy are symmetric.
1192 type MPROPDEF: MPropDef
1194 # The classdef that introduce the property
1195 # While a property is not bound to a specific module, or class,
1196 # the introducing mclassdef is used for naming and visibility
1197 var intro_mclassdef
: MClassDef
1199 # The (short) name of the property
1202 # The canonical name of the property
1203 # Example: "owner::my_module::MyClass::my_method"
1204 fun full_name
: String
1206 return "{self.intro_mclassdef.mmodule.full_name}::{self.intro_mclassdef.mclass.name}::{name}"
1209 # The visibility of the property
1210 var visibility
: MVisibility
1212 init(intro_mclassdef
: MClassDef, name
: String, visibility
: MVisibility)
1214 self.intro_mclassdef
= intro_mclassdef
1216 self.visibility
= visibility
1217 intro_mclassdef
.intro_mproperties
.add
(self)
1218 var model
= intro_mclassdef
.mmodule
.model
1219 model
.mproperties_by_name
.add_one
(name
, self)
1220 model
.mproperties
.add
(self)
1223 # All definitions of the property.
1224 # The first is the introduction,
1225 # The other are redefinitions (in refinements and in subclasses)
1226 var mpropdefs
: Array[MPROPDEF] = new Array[MPROPDEF]
1228 # The definition that introduced the property
1229 # Warning: the introduction is the first `MPropDef' object
1230 # associated to self. If self is just created without having any
1231 # associated definition, this method will abort
1232 fun intro
: MPROPDEF do return mpropdefs
.first
1235 redef fun to_s
do return name
1237 # Return the most specific property definitions defined or inherited by a type.
1238 # The selection knows that refinement is stronger than specialization;
1239 # however, in case of conflict more than one property are returned.
1240 # If mtype does not know mproperty then an empty array is returned.
1242 # If you want the really most specific property, then look at `lookup_first_definition`
1243 fun lookup_definitions
(mmodule
: MModule, mtype
: MType): Array[MPROPDEF]
1245 assert not mtype
.need_anchor
1246 if mtype
isa MNullableType then mtype
= mtype
.mtype
1248 var cache
= self.lookup_definitions_cache
[mmodule
, mtype
]
1249 if cache
!= null then return cache
1251 #print "select prop {mproperty} for {mtype} in {self}"
1252 # First, select all candidates
1253 var candidates
= new Array[MPROPDEF]
1254 for mpropdef
in self.mpropdefs
do
1255 # If the definition is not imported by the module, then skip
1256 if not mmodule
.in_importation
<= mpropdef
.mclassdef
.mmodule
then continue
1257 # If the definition is not inherited by the type, then skip
1258 if not mtype
.is_subtype
(mmodule
, null, mpropdef
.mclassdef
.bound_mtype
) then continue
1260 candidates
.add
(mpropdef
)
1262 # Fast track for only one candidate
1263 if candidates
.length
<= 1 then
1264 self.lookup_definitions_cache
[mmodule
, mtype
] = candidates
1268 # Second, filter the most specific ones
1269 var res
= new Array[MPROPDEF]
1270 for pd1
in candidates
do
1271 var cd1
= pd1
.mclassdef
1274 for pd2
in candidates
do
1275 if pd2
== pd1
then continue # do not compare with self!
1276 var cd2
= pd2
.mclassdef
1278 if c2
.mclass_type
== c1
.mclass_type
then
1279 if cd2
.mmodule
.in_importation
<= cd1
.mmodule
then
1280 # cd2 refines cd1; therefore we skip pd1
1284 else if cd2
.bound_mtype
.is_subtype
(mmodule
, null, cd1
.bound_mtype
) then
1285 # cd2 < cd1; therefore we skip pd1
1294 if res
.is_empty
then
1295 print
"All lost! {candidates.join(", ")}"
1296 # FIXME: should be abort!
1298 self.lookup_definitions_cache
[mmodule
, mtype
] = res
1302 private var lookup_definitions_cache
: HashMap2[MModule, MType, Array[MPROPDEF]] = new HashMap2[MModule, MType, Array[MPROPDEF]]
1304 # Return the most specific property definitions inherited by a type.
1305 # The selection knows that refinement is stronger than specialization;
1306 # however, in case of conflict more than one property are returned.
1307 # If mtype does not know mproperty then an empty array is returned.
1309 # If you want the really most specific property, then look at `lookup_next_definition`
1311 # FIXME: Move to MPropDef?
1312 fun lookup_super_definitions
(mmodule
: MModule, mtype
: MType): Array[MPropDef]
1314 assert not mtype
.need_anchor
1315 if mtype
isa MNullableType then mtype
= mtype
.mtype
1317 # First, select all candidates
1318 var candidates
= new Array[MPropDef]
1319 for mpropdef
in self.mpropdefs
do
1320 # If the definition is not imported by the module, then skip
1321 if not mmodule
.in_importation
<= mpropdef
.mclassdef
.mmodule
then continue
1322 # If the definition is not inherited by the type, then skip
1323 if not mtype
.is_subtype
(mmodule
, null, mpropdef
.mclassdef
.bound_mtype
) then continue
1324 # If the definition is defined by the type, then skip (we want the super, so e skip the current)
1325 if mtype
== mpropdef
.mclassdef
.bound_mtype
and mmodule
== mpropdef
.mclassdef
.mmodule
then continue
1327 candidates
.add
(mpropdef
)
1329 # Fast track for only one candidate
1330 if candidates
.length
<= 1 then return candidates
1332 # Second, filter the most specific ones
1333 var res
= new Array[MPropDef]
1334 for pd1
in candidates
do
1335 var cd1
= pd1
.mclassdef
1338 for pd2
in candidates
do
1339 if pd2
== pd1
then continue # do not compare with self!
1340 var cd2
= pd2
.mclassdef
1342 if c2
.mclass_type
== c1
.mclass_type
then
1343 if cd2
.mmodule
.in_importation
<= cd1
.mmodule
then
1344 # cd2 refines cd1; therefore we skip pd1
1348 else if cd2
.bound_mtype
.is_subtype
(mmodule
, null, cd1
.bound_mtype
) then
1349 # cd2 < cd1; therefore we skip pd1
1358 if res
.is_empty
then
1359 print
"All lost! {candidates.join(", ")}"
1360 # FIXME: should be abort!
1365 # Return the most specific definition in the linearization of `mtype`.
1366 # If mtype does not know mproperty then null is returned.
1368 # If you want to know the next properties in the linearization,
1369 # look at `MPropDef::lookup_next_definition`.
1371 # FIXME: NOT YET IMPLEMENTED
1373 # REQUIRE: not mtype.need_anchor
1374 fun lookup_first_definition
(mmodule
: MModule, mtype
: MType): nullable MPROPDEF
1376 assert not mtype
.need_anchor
1385 redef type MPROPDEF: MMethodDef
1387 init(intro_mclassdef
: MClassDef, name
: String, visibility
: MVisibility)
1392 # Is the property a constructor?
1393 # Warning, this property can be inherited by subclasses with or without being a constructor
1394 # therefore, you should use `is_init_for' the verify if the property is a legal constructor for a given class
1395 var is_init
: Bool writable = false
1397 # The the property a 'new' contructor?
1398 var is_new
: Bool writable = false
1400 # Is the property a legal constructor for a given class?
1401 # As usual, visibility is not considered.
1402 # FIXME not implemented
1403 fun is_init_for
(mclass
: MClass): Bool
1409 # A global attribute
1413 redef type MPROPDEF: MAttributeDef
1415 init(intro_mclassdef
: MClassDef, name
: String, visibility
: MVisibility)
1421 # A global virtual type
1422 class MVirtualTypeProp
1425 redef type MPROPDEF: MVirtualTypeDef
1427 init(intro_mclassdef
: MClassDef, name
: String, visibility
: MVisibility)
1432 # The formal type associated to the virtual type property
1433 var mvirtualtype
: MVirtualType = new MVirtualType(self)
1436 # A definition of a property (local property)
1438 # Unlike MProperty, a MPropDef is a local definition that belong to a
1439 # specific class definition (which belong to a specific module)
1440 abstract class MPropDef
1442 # The associated MProperty subclass.
1443 # the two specialization hierarchy are symmetric
1444 type MPROPERTY: MProperty
1447 type MPROPDEF: MPropDef
1449 # The origin of the definition
1450 var location
: Location
1452 # The class definition where the property definition is
1453 var mclassdef
: MClassDef
1455 # The associated global property
1456 var mproperty
: MPROPERTY
1458 init(mclassdef
: MClassDef, mproperty
: MPROPERTY, location
: Location)
1460 self.mclassdef
= mclassdef
1461 self.mproperty
= mproperty
1462 self.location
= location
1463 mclassdef
.mpropdefs
.add
(self)
1464 mproperty
.mpropdefs
.add
(self)
1467 # Internal name combining the module, the class and the property
1468 # Example: "mymodule#MyClass#mymethod"
1471 return "{mclassdef}#{mproperty}"
1474 # Is self the definition that introduce the property?
1475 fun is_intro
: Bool do return mproperty
.intro
== self
1477 # Return the next definition in linearization of `mtype`.
1478 # If there is no next method then null is returned.
1480 # This method is used to determine what method is called by a super.
1482 # FIXME: NOT YET IMPLEMENTED
1484 # REQUIRE: not mtype.need_anchor
1485 fun lookup_next_definition
(mmodule
: MModule, mtype
: MType): nullable MPROPDEF
1487 assert not mtype
.need_anchor
1492 # A local definition of a method
1496 redef type MPROPERTY: MMethod
1497 redef type MPROPDEF: MMethodDef
1499 init(mclassdef
: MClassDef, mproperty
: MPROPERTY, location
: Location)
1504 # The signature attached to the property definition
1505 var msignature
: nullable MSignature writable = null
1508 # A local definition of an attribute
1512 redef type MPROPERTY: MAttribute
1513 redef type MPROPDEF: MAttributeDef
1515 init(mclassdef
: MClassDef, mproperty
: MPROPERTY, location
: Location)
1520 # The static type of the attribute
1521 var static_mtype
: nullable MType writable = null
1524 # A local definition of a virtual type
1525 class MVirtualTypeDef
1528 redef type MPROPERTY: MVirtualTypeProp
1529 redef type MPROPDEF: MVirtualTypeDef
1531 init(mclassdef
: MClassDef, mproperty
: MPROPERTY, location
: Location)
1536 # The bound of the virtual type
1537 var bound
: nullable MType writable = null
1548 # Note this class is basically an enum.
1549 # FIXME: use a real enum once user-defined enums are available
1551 redef var to_s
: String
1553 # Is a constructor required?
1555 private init(s
: String, need_init
: Bool)
1558 self.need_init
= need_init
1562 fun abstract_kind
: MClassKind do return once
new MClassKind("abstract class", true)
1563 fun concrete_kind
: MClassKind do return once
new MClassKind("class", true)
1564 fun interface_kind
: MClassKind do return once
new MClassKind("interface", false)
1565 fun enum_kind
: MClassKind do return once
new MClassKind("enum", false)
1566 fun extern_kind
: MClassKind do return once
new MClassKind("extern", false)