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, extern stuff
29 # FIXME: better handling of the types
35 private import more_collections
39 var mclasses
: Array[MClass] = new Array[MClass]
41 # All known properties
42 var mproperties
: Array[MProperty] = new Array[MProperty]
44 # Hierarchy of class definition.
46 # Each classdef is associated with its super-classdefs in regard to
47 # its module of definition.
48 var mclassdef_hierarchy
: POSet[MClassDef] = new POSet[MClassDef]
50 # Class-type hierarchy restricted to the introduction.
52 # The idea is that what is true on introduction is always true whatever
53 # the module considered.
54 # Therefore, this hierarchy is used for a fast positive subtype check.
56 # This poset will evolve in a monotonous way:
57 # * Two non connected nodes will remain unconnected
58 # * New nodes can appear with new edges
59 private var intro_mtype_specialization_hierarchy
: POSet[MClassType] = new POSet[MClassType]
61 # Global overlapped class-type hierarchy.
62 # The hierarchy when all modules are combined.
63 # Therefore, this hierarchy is used for a fast negative subtype check.
65 # This poset will evolve in an anarchic way. Loops can even be created.
67 # FIXME decide what to do on loops
68 private var full_mtype_specialization_hierarchy
: POSet[MClassType] = new POSet[MClassType]
70 # Collections of classes grouped by their short name
71 private var mclasses_by_name
: MultiHashMap[String, MClass] = new MultiHashMap[String, MClass]
73 # Return all class named `name`.
75 # If such a class does not exist, null is returned
76 # (instead of an empty array)
78 # Visibility or modules are not considered
79 fun get_mclasses_by_name
(name
: String): nullable Array[MClass]
81 if mclasses_by_name
.has_key
(name
) then
82 return mclasses_by_name
[name
]
88 # Collections of properties grouped by their short name
89 private var mproperties_by_name
: MultiHashMap[String, MProperty] = new MultiHashMap[String, MProperty]
91 # Return all properties named `name`.
93 # If such a property does not exist, null is returned
94 # (instead of an empty array)
96 # Visibility or modules are not considered
97 fun get_mproperties_by_name
(name
: String): nullable Array[MProperty]
99 if not mproperties_by_name
.has_key
(name
) then
102 return mproperties_by_name
[name
]
107 var null_type
: MNullType = new MNullType(self)
111 # All the classes introduced in the module
112 var intro_mclasses
: Array[MClass] = new Array[MClass]
114 # All the class definitions of the module
115 # (introduction and refinement)
116 var mclassdefs
: Array[MClassDef] = new Array[MClassDef]
118 # Does the current module has a given class `mclass`?
119 # Return true if the mmodule introduces, refines or imports a class.
120 # Visibility is not considered.
121 fun has_mclass
(mclass
: MClass): Bool
123 return self.in_importation
<= mclass
.intro_mmodule
126 # Full hierarchy of introduced ans imported classes.
128 # Create a new hierarchy got by flattening the classes for the module
129 # and its imported modules.
130 # Visibility is not considered.
132 # Note: this function is expensive and is usually used for the main
133 # module of a program only. Do not use it to do you own subtype
135 fun flatten_mclass_hierarchy
: POSet[MClass]
137 var res
= self.flatten_mclass_hierarchy_cache
138 if res
!= null then return res
139 res
= new POSet[MClass]
140 for m
in self.in_importation
.greaters
do
141 for cd
in m
.mclassdefs
do
144 for s
in cd
.supertypes
do
145 res
.add_edge
(c
, s
.mclass
)
149 self.flatten_mclass_hierarchy_cache
= res
153 # Sort a given array of classes using the linerarization order of the module
154 # The most general is first, the most specific is last
155 fun linearize_mclasses
(mclasses
: Array[MClass])
157 self.flatten_mclass_hierarchy
.sort
(mclasses
)
160 # Sort a given array of class definitions using the linerarization order of the module
161 # the refinement link is stronger than the specialisation link
162 # The most general is first, the most specific is last
163 fun linearize_mclassdefs
(mclassdefs
: Array[MClassDef])
165 var sorter
= new MClassDefSorter(self)
166 sorter
.sort
(mclassdefs
)
169 # Sort a given array of property definitions using the linerarization order of the module
170 # the refinement link is stronger than the specialisation link
171 # The most general is first, the most specific is last
172 fun linearize_mpropdefs
(mpropdefs
: Array[MPropDef])
174 var sorter
= new MPropDefSorter(self)
175 sorter
.sort
(mpropdefs
)
178 private var flatten_mclass_hierarchy_cache
: nullable POSet[MClass] = null
180 # The primitive type `Object`, the root of the class hierarchy
181 fun object_type
: MClassType
183 var res
= self.object_type_cache
184 if res
!= null then return res
185 res
= self.get_primitive_class
("Object").mclass_type
186 self.object_type_cache
= res
190 private var object_type_cache
: nullable MClassType
192 # The primitive type `Bool`
193 fun bool_type
: MClassType
195 var res
= self.bool_type_cache
196 if res
!= null then return res
197 res
= self.get_primitive_class
("Bool").mclass_type
198 self.bool_type_cache
= res
202 private var bool_type_cache
: nullable MClassType
204 # The primitive type `Sys`, the main type of the program, if any
205 fun sys_type
: nullable MClassType
207 var clas
= self.model
.get_mclasses_by_name
("Sys")
208 if clas
== null then return null
209 return get_primitive_class
("Sys").mclass_type
212 # Force to get the primitive class named `name` or abort
213 fun get_primitive_class
(name
: String): MClass
215 var cla
= self.model
.get_mclasses_by_name
(name
)
217 if name
== "Bool" then
218 var c
= new MClass(self, name
, 0, enum_kind
, public_visibility
)
219 var cladef
= new MClassDef(self, c
.mclass_type
, new Location(null, 0,0,0,0), new Array[String])
222 print
("Fatal Error: no primitive class {name}")
225 assert cla
.length
== 1 else print cla
.join
(", ")
229 # Try to get the primitive method named `name` on the type `recv`
230 fun try_get_primitive_method
(name
: String, recv
: MClass): nullable MMethod
232 var props
= self.model
.get_mproperties_by_name
(name
)
233 if props
== null then return null
234 var res
: nullable MMethod = null
235 for mprop
in props
do
236 assert mprop
isa MMethod
237 var intro
= mprop
.intro_mclassdef
238 for mclassdef
in recv
.mclassdefs
do
239 if not self.in_importation
.greaters
.has
(mclassdef
.mmodule
) then continue
240 if not mclassdef
.in_hierarchy
.greaters
.has
(intro
) then continue
243 else if res
!= mprop
then
244 print
("Fatal Error: ambigous property name '{name}'; conflict between {mprop.full_name} and {res.full_name}")
253 private class MClassDefSorter
254 super AbstractSorter[MClassDef]
256 redef fun compare
(a
, b
)
260 if ca
!= cb
then return mmodule
.flatten_mclass_hierarchy
.compare
(ca
, cb
)
261 return mmodule
.model
.mclassdef_hierarchy
.compare
(a
, b
)
265 private class MPropDefSorter
266 super AbstractSorter[MPropDef]
268 redef fun compare
(pa
, pb
)
274 if ca
!= cb
then return mmodule
.flatten_mclass_hierarchy
.compare
(ca
, cb
)
275 return mmodule
.model
.mclassdef_hierarchy
.compare
(a
, b
)
281 # `MClass` are global to the model; it means that a `MClass` is not bound to a
282 # specific `MModule`.
284 # This characteristic helps the reasoning about classes in a program since a
285 # single `MClass` object always denote the same class.
286 # However, because a `MClass` is global, it does not really have properties nor
287 # belong to a hierarchy since the property and the
288 # hierarchy of a class depends of a module.
290 # The module that introduce the class
291 # While classes are not bound to a specific module,
292 # the introducing module is used for naming an visibility
293 var intro_mmodule
: MModule
295 # The short name of the class
296 # In Nit, the name of a class cannot evolve in refinements
299 # The canonical name of the class
300 # Example: `"owner::module::MyClass"`
301 fun full_name
: String
303 return "{self.intro_mmodule.full_name}::{name}"
306 # The number of generic formal parameters
307 # 0 if the class is not generic
310 # The kind of the class (interface, abstract class, etc.)
311 # In Nit, the kind of a class cannot evolve in refinements
314 # The visibility of the class
315 # In Nit, the visibility of a class cannot evolve in refinements
316 var visibility
: MVisibility
318 init(intro_mmodule
: MModule, name
: String, arity
: Int, kind
: MClassKind, visibility
: MVisibility)
320 self.intro_mmodule
= intro_mmodule
324 self.visibility
= visibility
325 intro_mmodule
.intro_mclasses
.add
(self)
326 var model
= intro_mmodule
.model
327 model
.mclasses_by_name
.add_one
(name
, self)
328 model
.mclasses
.add
(self)
330 # Create the formal parameter types
332 var mparametertypes
= new Array[MParameterType]
333 for i
in [0..arity
[ do
334 var mparametertype
= new MParameterType(self, i
)
335 mparametertypes
.add
(mparametertype
)
337 var mclass_type
= new MGenericType(self, mparametertypes
)
338 self.mclass_type
= mclass_type
339 self.get_mtype_cache
.add
(mclass_type
)
341 self.mclass_type
= new MClassType(self)
345 # All class definitions (introduction and refinements)
346 var mclassdefs
: Array[MClassDef] = new Array[MClassDef]
349 redef fun to_s
do return self.name
351 # The definition that introduced the class
352 # Warning: the introduction is the first `MClassDef` object associated
353 # to self. If self is just created without having any associated
354 # definition, this method will abort
357 assert has_a_first_definition
: not mclassdefs
.is_empty
358 return mclassdefs
.first
361 # Return the class `self` in the class hierarchy of the module `mmodule`.
363 # SEE: `MModule::flatten_mclass_hierarchy`
364 # REQUIRE: `mmodule.has_mclass(self)`
365 fun in_hierarchy
(mmodule
: MModule): POSetElement[MClass]
367 return mmodule
.flatten_mclass_hierarchy
[self]
370 # The principal static type of the class.
372 # For non-generic class, mclass_type is the only `MClassType` based
375 # For a generic class, the arguments are the formal parameters.
376 # i.e.: for the class Array[E:Object], the `mclass_type` is Array[E].
377 # If you want Array[Object] the see `MClassDef::bound_mtype`
379 # For generic classes, the mclass_type is also the way to get a formal
380 # generic parameter type.
382 # To get other types based on a generic class, see `get_mtype`.
384 # ENSURE: `mclass_type.mclass == self`
385 var mclass_type
: MClassType
387 # Return a generic type based on the class
388 # Is the class is not generic, then the result is `mclass_type`
390 # REQUIRE: `mtype_arguments.length == self.arity`
391 fun get_mtype
(mtype_arguments
: Array[MType]): MClassType
393 assert mtype_arguments
.length
== self.arity
394 if self.arity
== 0 then return self.mclass_type
395 for t
in self.get_mtype_cache
do
396 if t
.arguments
== mtype_arguments
then
400 var res
= new MGenericType(self, mtype_arguments
)
401 self.get_mtype_cache
.add res
405 private var get_mtype_cache
: Array[MGenericType] = new Array[MGenericType]
409 # A definition (an introduction or a refinement) of a class in a module
411 # A `MClassDef` is associated with an explicit (or almost) definition of a
412 # class. Unlike `MClass`, a `MClassDef` is a local definition that belong to
415 # The module where the definition is
418 # The associated `MClass`
421 # The bounded type associated to the mclassdef
423 # For a non-generic class, `bound_mtype` and `mclass.mclass_type`
427 # For the classdef Array[E: Object], the bound_mtype is Array[Object].
428 # If you want Array[E], then see `mclass.mclass_type`
430 # ENSURE: `bound_mtype.mclass == self.mclass`
431 var bound_mtype
: MClassType
433 # Name of each formal generic parameter (in order of declaration)
434 var parameter_names
: Array[String]
436 # The origin of the definition
437 var location
: Location
439 # Internal name combining the module and the class
440 # Example: "mymodule#MyClass"
441 redef var to_s
: String
443 init(mmodule
: MModule, bound_mtype
: MClassType, location
: Location, parameter_names
: Array[String])
445 assert bound_mtype
.mclass
.arity
== parameter_names
.length
446 self.bound_mtype
= bound_mtype
447 self.mmodule
= mmodule
448 self.mclass
= bound_mtype
.mclass
449 self.location
= location
450 mmodule
.mclassdefs
.add
(self)
451 mclass
.mclassdefs
.add
(self)
452 self.parameter_names
= parameter_names
453 self.to_s
= "{mmodule}#{mclass}"
456 # All declared super-types
457 # FIXME: quite ugly but not better idea yet
458 var supertypes
: Array[MClassType] = new Array[MClassType]
460 # Register some super-types for the class (ie "super SomeType")
462 # The hierarchy must not already be set
463 # REQUIRE: `self.in_hierarchy == null`
464 fun set_supertypes
(supertypes
: Array[MClassType])
466 assert unique_invocation
: self.in_hierarchy
== null
467 var mmodule
= self.mmodule
468 var model
= mmodule
.model
469 var mtype
= self.bound_mtype
471 for supertype
in supertypes
do
472 self.supertypes
.add
(supertype
)
474 # Register in full_type_specialization_hierarchy
475 model
.full_mtype_specialization_hierarchy
.add_edge
(mtype
, supertype
)
476 # Register in intro_type_specialization_hierarchy
477 if mclass
.intro_mmodule
== mmodule
and supertype
.mclass
.intro_mmodule
== mmodule
then
478 model
.intro_mtype_specialization_hierarchy
.add_edge
(mtype
, supertype
)
484 # Collect the super-types (set by set_supertypes) to build the hierarchy
486 # This function can only invoked once by class
487 # REQUIRE: `self.in_hierarchy == null`
488 # ENSURE: `self.in_hierarchy != null`
491 assert unique_invocation
: self.in_hierarchy
== null
492 var model
= mmodule
.model
493 var res
= model
.mclassdef_hierarchy
.add_node
(self)
494 self.in_hierarchy
= res
495 var mtype
= self.bound_mtype
497 # Here we need to connect the mclassdef to its pairs in the mclassdef_hierarchy
498 # The simpliest way is to attach it to collect_mclassdefs
499 for mclassdef
in mtype
.collect_mclassdefs
(mmodule
) do
500 res
.poset
.add_edge
(self, mclassdef
)
504 # The view of the class definition in `mclassdef_hierarchy`
505 var in_hierarchy
: nullable POSetElement[MClassDef] = null
507 # Is the definition the one that introduced `mclass`?
508 fun is_intro
: Bool do return mclass
.intro
== self
510 # All properties introduced by the classdef
511 var intro_mproperties
: Array[MProperty] = new Array[MProperty]
513 # All property definitions in the class (introductions and redefinitions)
514 var mpropdefs
: Array[MPropDef] = new Array[MPropDef]
517 # A global static type
519 # MType are global to the model; it means that a `MType` is not bound to a
520 # specific `MModule`.
521 # This characteristic helps the reasoning about static types in a program
522 # since a single `MType` object always denote the same type.
524 # However, because a `MType` is global, it does not really have properties
525 # nor have subtypes to a hierarchy since the property and the class hierarchy
526 # depends of a module.
527 # Moreover, virtual types an formal generic parameter types also depends on
528 # a receiver to have sense.
530 # Therefore, most method of the types require a module and an anchor.
531 # The module is used to know what are the classes and the specialization
533 # The anchor is used to know what is the bound of the virtual types and formal
534 # generic parameter types.
536 # MType are not directly usable to get properties. See the `anchor_to` method
537 # and the `MClassType` class.
539 # FIXME: the order of the parameters is not the best. We mus pick on from:
540 # * foo(mmodule, anchor, othertype)
541 # * foo(othertype, anchor, mmodule)
542 # * foo(anchor, mmodule, othertype)
543 # * foo(othertype, mmodule, anchor)
546 # The model of the type
547 fun model
: Model is abstract
549 # Return true if `self` is an subtype of `sup`.
550 # The typing is done using the standard typing policy of Nit.
552 # REQUIRE: `anchor == null implies not self.need_anchor and not sup.need_anchor`
553 # REQUIRE: `anchor != null implies self.can_resolve_for(anchor, null, mmodule) and sup.can_resolve_for(anchor, null, mmodule)`
554 fun is_subtype
(mmodule
: MModule, anchor
: nullable MClassType, sup
: MType): Bool
557 if sub
== sup
then return true
558 if anchor
== null then
559 assert not sub
.need_anchor
560 assert not sup
.need_anchor
562 assert sub
.can_resolve_for
(anchor
, null, mmodule
)
563 assert sup
.can_resolve_for
(anchor
, null, mmodule
)
566 # First, resolve the formal types to a common version in the receiver
567 # The trick here is that fixed formal type will be associed to the bound
568 # And unfixed formal types will be associed to a canonical formal type.
569 if sub
isa MParameterType or sub
isa MVirtualType then
570 assert anchor
!= null
571 sub
= sub
.resolve_for
(anchor
.mclass
.mclass_type
, anchor
, mmodule
, false)
573 if sup
isa MParameterType or sup
isa MVirtualType then
574 assert anchor
!= null
575 sup
= sup
.resolve_for
(anchor
.mclass
.mclass_type
, anchor
, mmodule
, false)
578 # Does `sup` accept null or not?
579 # Discard the nullable marker if it exists
580 var sup_accept_null
= false
581 if sup
isa MNullableType then
582 sup_accept_null
= true
584 else if sup
isa MNullType then
585 sup_accept_null
= true
588 # Can `sub` provide null or not?
589 # Thus we can match with `sup_accept_null`
590 # Also discard the nullable marker if it exists
591 if sub
isa MNullableType then
592 if not sup_accept_null
then return false
594 else if sub
isa MNullType then
595 return sup_accept_null
597 # Now the case of direct null and nullable is over.
599 # A unfixed formal type can only accept itself
600 if sup
isa MParameterType or sup
isa MVirtualType then
604 # If `sub` is a formal type, then it is accepted if its bound is accepted
605 if sub
isa MParameterType or sub
isa MVirtualType then
606 assert anchor
!= null
607 sub
= sub
.anchor_to
(mmodule
, anchor
)
609 # Manage the second layer of null/nullable
610 if sub
isa MNullableType then
611 if not sup_accept_null
then return false
613 else if sub
isa MNullType then
614 return sup_accept_null
618 assert sub
isa MClassType # It is the only remaining type
620 if sup
isa MNullType then
621 # `sup` accepts only null
625 assert sup
isa MClassType # It is the only remaining type
627 # Now both are MClassType, we need to dig
629 if sub
== sup
then return true
631 if anchor
== null then anchor
= sub
# UGLY: any anchor will work
632 var resolved_sub
= sub
.anchor_to
(mmodule
, anchor
)
633 var res
= resolved_sub
.collect_mclasses
(mmodule
).has
(sup
.mclass
)
634 if res
== false then return false
635 if not sup
isa MGenericType then return true
636 var sub2
= sub
.supertype_to
(mmodule
, anchor
, sup
.mclass
)
637 assert sub2
.mclass
== sup
.mclass
638 for i
in [0..sup
.mclass
.arity
[ do
639 var sub_arg
= sub2
.arguments
[i
]
640 var sup_arg
= sup
.arguments
[i
]
641 res
= sub_arg
.is_subtype
(mmodule
, anchor
, sup_arg
)
642 if res
== false then return false
647 # The base class type on which self is based
649 # This base type is used to get property (an internally to perform
650 # unsafe type comparison).
652 # Beware: some types (like null) are not based on a class thus this
655 # Basically, this function transform the virtual types and parameter
656 # types to their bounds.
660 # class B super A end
662 # class Y super X end
670 # Map[T,U] anchor_to H #-> Map[B,Y]
672 # Explanation of the example:
673 # In H, T is set to B, because "H super G[B]", and U is bound to Y,
674 # because "redef type U: Y". Therefore, Map[T, U] is bound to
677 # ENSURE: `not self.need_anchor implies result == self`
678 # ENSURE: `not result.need_anchor`
679 fun anchor_to
(mmodule
: MModule, anchor
: MClassType): MType
681 if not need_anchor
then return self
682 assert not anchor
.need_anchor
683 # Just resolve to the anchor and clear all the virtual types
684 var res
= self.resolve_for
(anchor
, null, mmodule
, true)
685 assert not res
.need_anchor
689 # Does `self` contain a virtual type or a formal generic parameter type?
690 # In order to remove those types, you usually want to use `anchor_to`.
691 fun need_anchor
: Bool do return true
693 # Return the supertype when adapted to a class.
695 # In Nit, for each super-class of a type, there is a equivalent super-type.
699 # class H[V] super G[V, Bool] end
700 # H[Int] supertype_to G #-> G[Int, Bool]
702 # REQUIRE: `super_mclass` is a super-class of `self`
703 # REQUIRE: `self.need_anchor implies anchor != null and self.can_resolve_for(anchor, null, mmodule)`
704 # ENSURE: `result.mclass = super_mclass`
705 fun supertype_to
(mmodule
: MModule, anchor
: nullable MClassType, super_mclass
: MClass): MClassType
707 if super_mclass
.arity
== 0 then return super_mclass
.mclass_type
708 if self isa MClassType and self.mclass
== super_mclass
then return self
710 if self.need_anchor
then
711 assert anchor
!= null
712 resolved_self
= self.anchor_to
(mmodule
, anchor
)
716 var supertypes
= resolved_self
.collect_mtypes
(mmodule
)
717 for supertype
in supertypes
do
718 if supertype
.mclass
== super_mclass
then
719 # FIXME: Here, we stop on the first goal. Should we check others and detect inconsistencies?
720 return supertype
.resolve_for
(self, anchor
, mmodule
, false)
726 # Replace formals generic types in self with resolved values in `mtype`
727 # If `cleanup_virtual` is true, then virtual types are also replaced
730 # This function returns self if `need_anchor` is false.
735 # class H[F] super G[F] end
738 # * Array[E].resolve_for(H[Int]) #-> Array[Int]
739 # * Array[E].resolve_for(G[Z], X[Int]) #-> Array[Z]
741 # Explanation of the example:
742 # * Array[E].need_anchor is true because there is a formal generic parameter type E
743 # * E makes sense for H[Int] because E is a formal parameter of G and H specialize G
744 # * Since "H[F] super G[F]", E is in fact F for H
745 # * More specifically, in H[Int], E is Int
746 # * So, in H[Int], Array[E] is Array[Int]
748 # This function is mainly used to inherit a signature.
749 # Because, unlike `anchor_to`, we do not want a full resolution of
750 # a type but only an adapted version of it.
755 # fun foo(e:E):E is abstract
757 # class B super A[Int] end
759 # The signature on foo is (e: E): E
760 # If we resolve the signature for B, we get (e:Int):Int
765 # fun foo(e:E) is abstract
769 # fun bar do a.foo(x) # <- x is here
772 # The first question is: is foo available on `a`?
774 # The static type of a is `A[Array[F]]`, that is an open type.
775 # in order to find a method `foo`, whe must look at a resolved type.
777 # A[Array[F]].anchor_to(B[nullable Object]) #-> A[Array[nullable Object]]
779 # the method `foo` exists in `A[Array[nullable Object]]`, therefore `foo` exists for `a`.
781 # The next question is: what is the accepted types for `x`?
783 # the signature of `foo` is `foo(e:E)`, thus we must resolve the type E
785 # E.resolve_for(A[Array[F]],B[nullable Object]) #-> Array[F]
787 # The resolution can be done because `E` make sense for the class A (see `can_resolve_for`)
789 # TODO: Explain the cleanup_virtual
791 # FIXME: the parameter `cleanup_virtual` is just a bad idea, but having
792 # two function instead of one seems also to be a bad idea.
794 # REQUIRE: `can_resolve_for(mtype, anchor, mmodule)`
795 # ENSURE: `not self.need_anchor implies result == self`
796 fun resolve_for
(mtype
: MType, anchor
: nullable MClassType, mmodule
: MModule, cleanup_virtual
: Bool): MType is abstract
798 # Can the type be resolved?
800 # In order to resolve open types, the formal types must make sence.
809 # * E.can_resolve_for(A[Int]) #-> true, E make sense in A
810 # * E.can_resolve_for(B[Int]) #-> false, E does not make sense in B
811 # * B[E].can_resolve_for(A[F], B[Object]) #-> true,
812 # B[E] is a red hearing only the E is important,
815 # REQUIRE: `anchor != null implies not anchor.need_anchor`
816 # REQUIRE: `mtype.need_anchor implies anchor != null and mtype.can_resolve_for(anchor, null, mmodule)`
817 # ENSURE: `not self.need_anchor implies result == true`
818 fun can_resolve_for
(mtype
: MType, anchor
: nullable MClassType, mmodule
: MModule): Bool is abstract
820 # Return the nullable version of the type
821 # If the type is already nullable then self is returned
822 fun as_nullable
: MType
824 var res
= self.as_nullable_cache
825 if res
!= null then return res
826 res
= new MNullableType(self)
827 self.as_nullable_cache
= res
831 private var as_nullable_cache
: nullable MType = null
834 # The deph of the type seen as a tree.
841 # Formal types have a depth of 1.
847 # The length of the type seen as a tree.
854 # Formal types have a length of 1.
860 # Compute all the classdefs inherited/imported.
861 # The returned set contains:
862 # * the class definitions from `mmodule` and its imported modules
863 # * the class definitions of this type and its super-types
865 # This function is used mainly internally.
867 # REQUIRE: `not self.need_anchor`
868 fun collect_mclassdefs
(mmodule
: MModule): Set[MClassDef] is abstract
870 # Compute all the super-classes.
871 # This function is used mainly internally.
873 # REQUIRE: `not self.need_anchor`
874 fun collect_mclasses
(mmodule
: MModule): Set[MClass] is abstract
876 # Compute all the declared super-types.
877 # Super-types are returned as declared in the classdefs (verbatim).
878 # This function is used mainly internally.
880 # REQUIRE: `not self.need_anchor`
881 fun collect_mtypes
(mmodule
: MModule): Set[MClassType] is abstract
883 # Is the property in self for a given module
884 # This method does not filter visibility or whatever
886 # REQUIRE: `not self.need_anchor`
887 fun has_mproperty
(mmodule
: MModule, mproperty
: MProperty): Bool
889 assert not self.need_anchor
890 return self.collect_mclassdefs
(mmodule
).has
(mproperty
.intro_mclassdef
)
894 # A type based on a class.
896 # `MClassType` have properties (see `has_mproperty`).
900 # The associated class
903 redef fun model
do return self.mclass
.intro_mmodule
.model
905 private init(mclass
: MClass)
910 # The formal arguments of the type
911 # ENSURE: `result.length == self.mclass.arity`
912 var arguments
: Array[MType] = new Array[MType]
914 redef fun to_s
do return mclass
.to_s
916 redef fun need_anchor
do return false
918 redef fun anchor_to
(mmodule
: MModule, anchor
: MClassType): MClassType
920 return super.as(MClassType)
923 redef fun resolve_for
(mtype
: MType, anchor
: nullable MClassType, mmodule
: MModule, cleanup_virtual
: Bool): MClassType do return self
925 redef fun can_resolve_for
(mtype
, anchor
, mmodule
) do return true
927 redef fun collect_mclassdefs
(mmodule
)
929 assert not self.need_anchor
930 var cache
= self.collect_mclassdefs_cache
931 if not cache
.has_key
(mmodule
) then
932 self.collect_things
(mmodule
)
934 return cache
[mmodule
]
937 redef fun collect_mclasses
(mmodule
)
939 assert not self.need_anchor
940 var cache
= self.collect_mclasses_cache
941 if not cache
.has_key
(mmodule
) then
942 self.collect_things
(mmodule
)
944 return cache
[mmodule
]
947 redef fun collect_mtypes
(mmodule
)
949 assert not self.need_anchor
950 var cache
= self.collect_mtypes_cache
951 if not cache
.has_key
(mmodule
) then
952 self.collect_things
(mmodule
)
954 return cache
[mmodule
]
957 # common implementation for `collect_mclassdefs`, `collect_mclasses`, and `collect_mtypes`.
958 private fun collect_things
(mmodule
: MModule)
960 var res
= new HashSet[MClassDef]
961 var seen
= new HashSet[MClass]
962 var types
= new HashSet[MClassType]
963 seen
.add
(self.mclass
)
964 var todo
= [self.mclass
]
965 while not todo
.is_empty
do
966 var mclass
= todo
.pop
967 #print "process {mclass}"
968 for mclassdef
in mclass
.mclassdefs
do
969 if not mmodule
.in_importation
<= mclassdef
.mmodule
then continue
970 #print " process {mclassdef}"
972 for supertype
in mclassdef
.supertypes
do
974 var superclass
= supertype
.mclass
975 if seen
.has
(superclass
) then continue
976 #print " add {superclass}"
982 collect_mclassdefs_cache
[mmodule
] = res
983 collect_mclasses_cache
[mmodule
] = seen
984 collect_mtypes_cache
[mmodule
] = types
987 private var collect_mclassdefs_cache
: HashMap[MModule, Set[MClassDef]] = new HashMap[MModule, Set[MClassDef]]
988 private var collect_mclasses_cache
: HashMap[MModule, Set[MClass]] = new HashMap[MModule, Set[MClass]]
989 private var collect_mtypes_cache
: HashMap[MModule, Set[MClassType]] = new HashMap[MModule, Set[MClassType]]
993 # A type based on a generic class.
994 # A generic type a just a class with additional formal generic arguments.
998 private init(mclass
: MClass, arguments
: Array[MType])
1001 assert self.mclass
.arity
== arguments
.length
1002 self.arguments
= arguments
1004 self.need_anchor
= false
1005 for t
in arguments
do
1006 if t
.need_anchor
then
1007 self.need_anchor
= true
1012 self.to_s
= "{mclass}[{arguments.join(", ")}]"
1015 # Recursively print the type of the arguments within brackets.
1016 # Example: `"Map[String, List[Int]]"`
1017 redef var to_s
: String
1019 redef var need_anchor
: Bool
1021 redef fun resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1023 if not need_anchor
then return self
1024 assert can_resolve_for
(mtype
, anchor
, mmodule
)
1025 var types
= new Array[MType]
1026 for t
in arguments
do
1027 types
.add
(t
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
))
1029 return mclass
.get_mtype
(types
)
1032 redef fun can_resolve_for
(mtype
, anchor
, mmodule
)
1034 if not need_anchor
then return true
1035 for t
in arguments
do
1036 if not t
.can_resolve_for
(mtype
, anchor
, mmodule
) then return false
1045 for a
in self.arguments
do
1047 if d
> dmax
then dmax
= d
1055 for a
in self.arguments
do
1062 # A virtual formal type.
1066 # The property associated with the type.
1067 # Its the definitions of this property that determine the bound or the virtual type.
1068 var mproperty
: MProperty
1070 redef fun model
do return self.mproperty
.intro_mclassdef
.mmodule
.model
1072 # Lookup the bound for a given resolved_receiver
1073 # The result may be a other virtual type (or a parameter type)
1075 # The result is returned exactly as declared in the "type" property (verbatim).
1077 # In case of conflict, the method aborts.
1078 fun lookup_bound
(mmodule
: MModule, resolved_receiver
: MType): MType
1080 assert not resolved_receiver
.need_anchor
1081 var props
= self.mproperty
.lookup_definitions
(mmodule
, resolved_receiver
)
1082 if props
.is_empty
then
1084 else if props
.length
== 1 then
1085 return props
.first
.as(MVirtualTypeDef).bound
.as(not null)
1087 var types
= new ArraySet[MType]
1089 types
.add
(p
.as(MVirtualTypeDef).bound
.as(not null))
1091 if types
.length
== 1 then
1097 redef fun resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1099 assert can_resolve_for
(mtype
, anchor
, mmodule
)
1100 # self is a virtual type declared (or inherited) in mtype
1101 # The point of the function it to get the bound of the virtual type that make sense for mtype
1102 # But because mtype is maybe a virtual/formal type, we need to get a real receiver first
1103 #print "{class_name}: {self}/{mtype}/{anchor}?"
1104 var resolved_reciever
1105 if mtype
.need_anchor
then
1106 assert anchor
!= null
1107 resolved_reciever
= mtype
.resolve_for
(anchor
, null, mmodule
, true)
1109 resolved_reciever
= mtype
1111 # Now, we can get the bound
1112 var verbatim_bound
= lookup_bound
(mmodule
, resolved_reciever
)
1113 # The bound is exactly as declared in the "type" property, so we must resolve it again
1114 var res
= verbatim_bound
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1115 #print "{class_name}: {self}/{mtype}/{anchor} -> {self}/{resolved_reciever}/{anchor} -> {verbatim_bound}/{mtype}/{anchor} -> {res}"
1117 # What to return here? There is a bunch a special cases:
1118 # If 'cleanup_virtual' we must return the resolved type, since we cannot return self
1119 if cleanup_virtual
then return res
1120 # If the reciever is a intern class, then the virtual type cannot be redefined since there is no possible subclass. self is just fixed. so simply return the resolution
1121 if resolved_reciever
isa MNullableType then resolved_reciever
= resolved_reciever
.mtype
1122 if resolved_reciever
.as(MClassType).mclass
.kind
== enum_kind
then return res
1123 # If the resolved type isa MVirtualType, it means that self was bound to it, and cannot be unbound. self is just fixed. so return the resolution.
1124 if res
isa MVirtualType then return res
1125 # It the resolved type isa intern class, then there is no possible valid redefinition is any potentiel subclass. self is just fixed. so simply return the resolution
1126 if res
isa MClassType and res
.mclass
.kind
== enum_kind
then return res
1127 # TODO: Add 'fixed' virtual type in the specification.
1128 # TODO: What if bound to a MParameterType?
1129 # Note that Nullable types can always be redefined by the non nullable version, so there is no specific case on it.
1131 # If anything apply, then `self' cannot be resolved, so return self
1135 redef fun can_resolve_for
(mtype
, anchor
, mmodule
)
1137 if mtype
.need_anchor
then
1138 assert anchor
!= null
1139 mtype
= mtype
.anchor_to
(mmodule
, anchor
)
1141 return mtype
.has_mproperty
(mmodule
, mproperty
)
1144 redef fun to_s
do return self.mproperty
.to_s
1146 init(mproperty
: MProperty)
1148 self.mproperty
= mproperty
1152 # The type associated the a formal parameter generic type of a class
1154 # Each parameter type is associated to a specific class.
1155 # It's mean that all refinements of a same class "share" the parameter type,
1156 # but that a generic subclass has its on parameter types.
1158 # However, in the sense of the meta-model, the a parameter type of a class is
1159 # a valid types in a subclass. The "in the sense of the meta-model" is
1160 # important because, in the Nit language, the programmer cannot refers
1161 # directly to the parameter types of the super-classes.
1165 # fun e: E is abstract
1170 # In the class definition B[F], `F` is a valid type but `E` is not.
1171 # However, `self.e` is a valid method call, and the signature of `e` is
1174 # Note that parameter types are shared among class refinements.
1175 # Therefore parameter only have an internal name (see `to_s` for details).
1176 # TODO: Add a `name_for` to get better messages.
1177 class MParameterType
1180 # The generic class where the parameter belong
1183 redef fun model
do return self.mclass
.intro_mmodule
.model
1185 # The position of the parameter (0 for the first parameter)
1186 # FIXME: is `position` a better name?
1189 # Internal name of the parameter type
1190 # Names of parameter types changes in each class definition
1191 # Therefore, this method return an internal name.
1192 # Example: return "G#1" for the second parameter of the class G
1193 # FIXME: add a way to get the real name in a classdef
1194 redef fun to_s
do return "{mclass}#{rank}"
1196 # Resolve the bound for a given resolved_receiver
1197 # The result may be a other virtual type (or a parameter type)
1198 fun lookup_bound
(mmodule
: MModule, resolved_receiver
: MType): MType
1200 assert not resolved_receiver
.need_anchor
1201 var goalclass
= self.mclass
1202 var supertypes
= resolved_receiver
.collect_mtypes
(mmodule
)
1203 for t
in supertypes
do
1204 if t
.mclass
== goalclass
then
1205 # Yeah! c specialize goalclass with a "super `t'". So the question is what is the argument of f
1206 # FIXME: Here, we stop on the first goal. Should we check others and detect inconsistencies?
1207 var res
= t
.arguments
[self.rank
]
1214 redef fun resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1216 assert can_resolve_for
(mtype
, anchor
, mmodule
)
1217 #print "{class_name}: {self}/{mtype}/{anchor}?"
1219 if mtype
isa MGenericType and mtype
.mclass
== self.mclass
then
1220 return mtype
.arguments
[self.rank
]
1223 # self is a parameter type of mtype (or of a super-class of mtype)
1224 # The point of the function it to get the bound of the virtual type that make sense for mtype
1225 # But because mtype is maybe a virtual/formal type, we need to get a real receiver first
1226 # FIXME: What happend here is far from clear. Thus this part must be validated and clarified
1227 var resolved_receiver
1228 if mtype
.need_anchor
then
1229 assert anchor
!= null
1230 resolved_receiver
= mtype
.resolve_for
(anchor
.mclass
.mclass_type
, anchor
, mmodule
, true)
1232 resolved_receiver
= mtype
1234 if resolved_receiver
isa MNullableType then resolved_receiver
= resolved_receiver
.mtype
1235 if resolved_receiver
isa MParameterType then
1236 assert resolved_receiver
.mclass
== anchor
.mclass
1237 resolved_receiver
= anchor
.arguments
[resolved_receiver
.rank
]
1238 if resolved_receiver
isa MNullableType then resolved_receiver
= resolved_receiver
.mtype
1240 assert resolved_receiver
isa MClassType
1242 # Eh! The parameter is in the current class.
1243 # So we return the corresponding argument, no mater what!
1244 if resolved_receiver
.mclass
== self.mclass
then
1245 var res
= resolved_receiver
.arguments
[self.rank
]
1246 #print "{class_name}: {self}/{mtype}/{anchor} -> direct {res}"
1250 if resolved_receiver
.need_anchor
then
1251 assert anchor
!= null
1252 resolved_receiver
= resolved_receiver
.resolve_for
(anchor
, null, mmodule
, false)
1254 # Now, we can get the bound
1255 var verbatim_bound
= lookup_bound
(mmodule
, resolved_receiver
)
1256 # The bound is exactly as declared in the "type" property, so we must resolve it again
1257 var res
= verbatim_bound
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1259 #print "{class_name}: {self}/{mtype}/{anchor} -> indirect {res}"
1264 redef fun can_resolve_for
(mtype
, anchor
, mmodule
)
1266 if mtype
.need_anchor
then
1267 assert anchor
!= null
1268 mtype
= mtype
.anchor_to
(mmodule
, anchor
)
1270 return mtype
.collect_mclassdefs
(mmodule
).has
(mclass
.intro
)
1273 init(mclass
: MClass, rank
: Int)
1275 self.mclass
= mclass
1280 # A type prefixed with "nullable"
1284 # The base type of the nullable type
1287 redef fun model
do return self.mtype
.model
1292 self.to_s
= "nullable {mtype}"
1295 redef var to_s
: String
1297 redef fun need_anchor
do return mtype
.need_anchor
1298 redef fun as_nullable
do return self
1299 redef fun resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1301 var res
= self.mtype
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1302 return res
.as_nullable
1305 redef fun can_resolve_for
(mtype
, anchor
, mmodule
)
1307 return self.mtype
.can_resolve_for
(mtype
, anchor
, mmodule
)
1310 redef fun depth
do return self.mtype
.depth
1312 redef fun length
do return self.mtype
.length
1314 redef fun collect_mclassdefs
(mmodule
)
1316 assert not self.need_anchor
1317 return self.mtype
.collect_mclassdefs
(mmodule
)
1320 redef fun collect_mclasses
(mmodule
)
1322 assert not self.need_anchor
1323 return self.mtype
.collect_mclasses
(mmodule
)
1326 redef fun collect_mtypes
(mmodule
)
1328 assert not self.need_anchor
1329 return self.mtype
.collect_mtypes
(mmodule
)
1333 # The type of the only value null
1335 # The is only one null type per model, see `MModel::null_type`.
1338 redef var model
: Model
1339 protected init(model
: Model)
1343 redef fun to_s
do return "null"
1344 redef fun as_nullable
do return self
1345 redef fun need_anchor
do return false
1346 redef fun resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
) do return self
1347 redef fun can_resolve_for
(mtype
, anchor
, mmodule
) do return true
1349 redef fun collect_mclassdefs
(mmodule
) do return new HashSet[MClassDef]
1351 redef fun collect_mclasses
(mmodule
) do return new HashSet[MClass]
1353 redef fun collect_mtypes
(mmodule
) do return new HashSet[MClassType]
1356 # A signature of a method
1360 # The each parameter (in order)
1361 var mparameters
: Array[MParameter]
1363 # The return type (null for a procedure)
1364 var return_mtype
: nullable MType
1369 var t
= self.return_mtype
1370 if t
!= null then dmax
= t
.depth
1371 for p
in mparameters
do
1372 var d
= p
.mtype
.depth
1373 if d
> dmax
then dmax
= d
1381 var t
= self.return_mtype
1382 if t
!= null then res
+= t
.length
1383 for p
in mparameters
do
1384 res
+= p
.mtype
.length
1389 # REQUIRE: 1 <= mparameters.count p -> p.is_vararg
1390 init(mparameters
: Array[MParameter], return_mtype
: nullable MType)
1392 var vararg_rank
= -1
1393 for i
in [0..mparameters
.length
[ do
1394 var parameter
= mparameters
[i
]
1395 if parameter
.is_vararg
then
1396 assert vararg_rank
== -1
1400 self.mparameters
= mparameters
1401 self.return_mtype
= return_mtype
1402 self.vararg_rank
= vararg_rank
1405 # The rank of the ellipsis (`...`) for vararg (starting from 0).
1406 # value is -1 if there is no vararg.
1407 # Example: for "(a: Int, b: Bool..., c: Char)" #-> vararg_rank=1
1408 var vararg_rank
: Int
1410 # The number or parameters
1411 fun arity
: Int do return mparameters
.length
1416 if not mparameters
.is_empty
then
1418 for i
in [0..mparameters
.length
[ do
1419 var mparameter
= mparameters
[i
]
1420 if i
> 0 then b
.append
(", ")
1421 b
.append
(mparameter
.name
)
1423 b
.append
(mparameter
.mtype
.to_s
)
1424 if mparameter
.is_vararg
then
1430 var ret
= self.return_mtype
1438 redef fun resolve_for
(mtype
: MType, anchor
: nullable MClassType, mmodule
: MModule, cleanup_virtual
: Bool): MSignature
1440 var params
= new Array[MParameter]
1441 for p
in self.mparameters
do
1442 params
.add
(p
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
))
1444 var ret
= self.return_mtype
1446 ret
= ret
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1448 var res
= new MSignature(params
, ret
)
1453 # A parameter in a signature
1455 # The name of the parameter
1458 # The static type of the parameter
1461 # Is the parameter a vararg?
1464 fun resolve_for
(mtype
: MType, anchor
: nullable MClassType, mmodule
: MModule, cleanup_virtual
: Bool): MParameter
1466 if not self.mtype
.need_anchor
then return self
1467 var newtype
= self.mtype
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1468 var res
= new MParameter(self.name
, newtype
, self.is_vararg
)
1473 # A service (global property) that generalize method, attribute, etc.
1475 # `MProperty` are global to the model; it means that a `MProperty` is not bound
1476 # to a specific `MModule` nor a specific `MClass`.
1478 # A MProperty gather definitions (see `mpropdefs`) ; one for the introduction
1479 # and the other in subclasses and in refinements.
1481 # A `MProperty` is used to denotes services in polymorphic way (ie. independent
1482 # of any dynamic type).
1483 # For instance, a call site "x.foo" is associated to a `MProperty`.
1484 abstract class MProperty
1485 # The associated MPropDef subclass.
1486 # The two specialization hierarchy are symmetric.
1487 type MPROPDEF: MPropDef
1489 # The classdef that introduce the property
1490 # While a property is not bound to a specific module, or class,
1491 # the introducing mclassdef is used for naming and visibility
1492 var intro_mclassdef
: MClassDef
1494 # The (short) name of the property
1497 # The canonical name of the property
1498 # Example: "owner::my_module::MyClass::my_method"
1499 fun full_name
: String
1501 return "{self.intro_mclassdef.mmodule.full_name}::{self.intro_mclassdef.mclass.name}::{name}"
1504 # The visibility of the property
1505 var visibility
: MVisibility
1507 init(intro_mclassdef
: MClassDef, name
: String, visibility
: MVisibility)
1509 self.intro_mclassdef
= intro_mclassdef
1511 self.visibility
= visibility
1512 intro_mclassdef
.intro_mproperties
.add
(self)
1513 var model
= intro_mclassdef
.mmodule
.model
1514 model
.mproperties_by_name
.add_one
(name
, self)
1515 model
.mproperties
.add
(self)
1518 # All definitions of the property.
1519 # The first is the introduction,
1520 # The other are redefinitions (in refinements and in subclasses)
1521 var mpropdefs
: Array[MPROPDEF] = new Array[MPROPDEF]
1523 # The definition that introduced the property
1524 # Warning: the introduction is the first `MPropDef` object
1525 # associated to self. If self is just created without having any
1526 # associated definition, this method will abort
1527 fun intro
: MPROPDEF do return mpropdefs
.first
1530 redef fun to_s
do return name
1532 # Return the most specific property definitions defined or inherited by a type.
1533 # The selection knows that refinement is stronger than specialization;
1534 # however, in case of conflict more than one property are returned.
1535 # If mtype does not know mproperty then an empty array is returned.
1537 # If you want the really most specific property, then look at `lookup_first_definition`
1538 fun lookup_definitions
(mmodule
: MModule, mtype
: MType): Array[MPROPDEF]
1540 assert not mtype
.need_anchor
1541 if mtype
isa MNullableType then mtype
= mtype
.mtype
1543 var cache
= self.lookup_definitions_cache
[mmodule
, mtype
]
1544 if cache
!= null then return cache
1546 #print "select prop {mproperty} for {mtype} in {self}"
1547 # First, select all candidates
1548 var candidates
= new Array[MPROPDEF]
1549 for mpropdef
in self.mpropdefs
do
1550 # If the definition is not imported by the module, then skip
1551 if not mmodule
.in_importation
<= mpropdef
.mclassdef
.mmodule
then continue
1552 # If the definition is not inherited by the type, then skip
1553 if not mtype
.is_subtype
(mmodule
, null, mpropdef
.mclassdef
.bound_mtype
) then continue
1555 candidates
.add
(mpropdef
)
1557 # Fast track for only one candidate
1558 if candidates
.length
<= 1 then
1559 self.lookup_definitions_cache
[mmodule
, mtype
] = candidates
1563 # Second, filter the most specific ones
1564 var res
= new Array[MPROPDEF]
1565 for pd1
in candidates
do
1566 var cd1
= pd1
.mclassdef
1569 for pd2
in candidates
do
1570 if pd2
== pd1
then continue # do not compare with self!
1571 var cd2
= pd2
.mclassdef
1573 if c2
.mclass_type
== c1
.mclass_type
then
1574 if cd2
.mmodule
.in_importation
<= cd1
.mmodule
then
1575 # cd2 refines cd1; therefore we skip pd1
1579 else if cd2
.bound_mtype
.is_subtype
(mmodule
, null, cd1
.bound_mtype
) then
1580 # cd2 < cd1; therefore we skip pd1
1589 if res
.is_empty
then
1590 print
"All lost! {candidates.join(", ")}"
1591 # FIXME: should be abort!
1593 self.lookup_definitions_cache
[mmodule
, mtype
] = res
1597 private var lookup_definitions_cache
: HashMap2[MModule, MType, Array[MPROPDEF]] = new HashMap2[MModule, MType, Array[MPROPDEF]]
1599 # Return the most specific property definitions inherited by a type.
1600 # The selection knows that refinement is stronger than specialization;
1601 # however, in case of conflict more than one property are returned.
1602 # If mtype does not know mproperty then an empty array is returned.
1604 # If you want the really most specific property, then look at `lookup_next_definition`
1606 # FIXME: Move to `MPropDef`?
1607 fun lookup_super_definitions
(mmodule
: MModule, mtype
: MType): Array[MPropDef]
1609 assert not mtype
.need_anchor
1610 if mtype
isa MNullableType then mtype
= mtype
.mtype
1612 # First, select all candidates
1613 var candidates
= new Array[MPropDef]
1614 for mpropdef
in self.mpropdefs
do
1615 # If the definition is not imported by the module, then skip
1616 if not mmodule
.in_importation
<= mpropdef
.mclassdef
.mmodule
then continue
1617 # If the definition is not inherited by the type, then skip
1618 if not mtype
.is_subtype
(mmodule
, null, mpropdef
.mclassdef
.bound_mtype
) then continue
1619 # If the definition is defined by the type, then skip (we want the super, so e skip the current)
1620 if mtype
== mpropdef
.mclassdef
.bound_mtype
and mmodule
== mpropdef
.mclassdef
.mmodule
then continue
1622 candidates
.add
(mpropdef
)
1624 # Fast track for only one candidate
1625 if candidates
.length
<= 1 then return candidates
1627 # Second, filter the most specific ones
1628 var res
= new Array[MPropDef]
1629 for pd1
in candidates
do
1630 var cd1
= pd1
.mclassdef
1633 for pd2
in candidates
do
1634 if pd2
== pd1
then continue # do not compare with self!
1635 var cd2
= pd2
.mclassdef
1637 if c2
.mclass_type
== c1
.mclass_type
then
1638 if cd2
.mmodule
.in_importation
<= cd1
.mmodule
then
1639 # cd2 refines cd1; therefore we skip pd1
1643 else if cd2
.bound_mtype
.is_subtype
(mmodule
, null, cd1
.bound_mtype
) then
1644 # cd2 < cd1; therefore we skip pd1
1653 if res
.is_empty
then
1654 print
"All lost! {candidates.join(", ")}"
1655 # FIXME: should be abort!
1660 # Return the most specific definition in the linearization of `mtype`.
1662 # If you want to know the next properties in the linearization,
1663 # look at `MPropDef::lookup_next_definition`.
1665 # FIXME: the linearisation is still unspecified
1667 # REQUIRE: `not mtype.need_anchor`
1668 # REQUIRE: `mtype.has_mproperty(mmodule, self)`
1669 fun lookup_first_definition
(mmodule
: MModule, mtype
: MType): MPROPDEF
1671 assert mtype
.has_mproperty
(mmodule
, self)
1672 return lookup_all_definitions
(mmodule
, mtype
).first
1675 # Return all definitions in a linearisation order
1676 # Most speficic first, most general last
1677 fun lookup_all_definitions
(mmodule
: MModule, mtype
: MType): Array[MPROPDEF]
1679 assert not mtype
.need_anchor
1680 if mtype
isa MNullableType then mtype
= mtype
.mtype
1682 var cache
= self.lookup_all_definitions_cache
[mmodule
, mtype
]
1683 if cache
!= null then return cache
1685 #print "select prop {mproperty} for {mtype} in {self}"
1686 # First, select all candidates
1687 var candidates
= new Array[MPROPDEF]
1688 for mpropdef
in self.mpropdefs
do
1689 # If the definition is not imported by the module, then skip
1690 if not mmodule
.in_importation
<= mpropdef
.mclassdef
.mmodule
then continue
1691 # If the definition is not inherited by the type, then skip
1692 if not mtype
.is_subtype
(mmodule
, null, mpropdef
.mclassdef
.bound_mtype
) then continue
1694 candidates
.add
(mpropdef
)
1696 # Fast track for only one candidate
1697 if candidates
.length
<= 1 then
1698 self.lookup_all_definitions_cache
[mmodule
, mtype
] = candidates
1702 mmodule
.linearize_mpropdefs
(candidates
)
1703 candidates
= candidates
.reversed
1704 self.lookup_all_definitions_cache
[mmodule
, mtype
] = candidates
1708 private var lookup_all_definitions_cache
: HashMap2[MModule, MType, Array[MPROPDEF]] = new HashMap2[MModule, MType, Array[MPROPDEF]]
1715 redef type MPROPDEF: MMethodDef
1717 init(intro_mclassdef
: MClassDef, name
: String, visibility
: MVisibility)
1722 # Is the property a constructor?
1723 # Warning, this property can be inherited by subclasses with or without being a constructor
1724 # therefore, you should use `is_init_for` the verify if the property is a legal constructor for a given class
1725 var is_init
: Bool writable = false
1727 # The the property a 'new' contructor?
1728 var is_new
: Bool writable = false
1730 # Is the property a legal constructor for a given class?
1731 # As usual, visibility is not considered.
1732 # FIXME not implemented
1733 fun is_init_for
(mclass
: MClass): Bool
1739 # A global attribute
1743 redef type MPROPDEF: MAttributeDef
1745 init(intro_mclassdef
: MClassDef, name
: String, visibility
: MVisibility)
1751 # A global virtual type
1752 class MVirtualTypeProp
1755 redef type MPROPDEF: MVirtualTypeDef
1757 init(intro_mclassdef
: MClassDef, name
: String, visibility
: MVisibility)
1762 # The formal type associated to the virtual type property
1763 var mvirtualtype
: MVirtualType = new MVirtualType(self)
1766 # A definition of a property (local property)
1768 # Unlike `MProperty`, a `MPropDef` is a local definition that belong to a
1769 # specific class definition (which belong to a specific module)
1770 abstract class MPropDef
1772 # The associated `MProperty` subclass.
1773 # the two specialization hierarchy are symmetric
1774 type MPROPERTY: MProperty
1777 type MPROPDEF: MPropDef
1779 # The origin of the definition
1780 var location
: Location
1782 # The class definition where the property definition is
1783 var mclassdef
: MClassDef
1785 # The associated global property
1786 var mproperty
: MPROPERTY
1788 init(mclassdef
: MClassDef, mproperty
: MPROPERTY, location
: Location)
1790 self.mclassdef
= mclassdef
1791 self.mproperty
= mproperty
1792 self.location
= location
1793 mclassdef
.mpropdefs
.add
(self)
1794 mproperty
.mpropdefs
.add
(self)
1795 self.to_s
= "{mclassdef}#{mproperty}"
1798 # Internal name combining the module, the class and the property
1799 # Example: "mymodule#MyClass#mymethod"
1800 redef var to_s
: String
1802 # Is self the definition that introduce the property?
1803 fun is_intro
: Bool do return mproperty
.intro
== self
1805 # Return the next definition in linearization of `mtype`.
1807 # This method is used to determine what method is called by a super.
1809 # REQUIRE: `not mtype.need_anchor`
1810 fun lookup_next_definition
(mmodule
: MModule, mtype
: MType): MPROPDEF
1812 assert not mtype
.need_anchor
1814 var mpropdefs
= self.mproperty
.lookup_all_definitions
(mmodule
, mtype
)
1815 var i
= mpropdefs
.iterator
1816 while i
.is_ok
and i
.item
!= self do i
.next
1817 assert has_property
: i
.is_ok
1819 assert has_next_property
: i
.is_ok
1824 # A local definition of a method
1828 redef type MPROPERTY: MMethod
1829 redef type MPROPDEF: MMethodDef
1831 init(mclassdef
: MClassDef, mproperty
: MPROPERTY, location
: Location)
1836 # The signature attached to the property definition
1837 var msignature
: nullable MSignature writable = null
1839 # The the method definition abstract?
1840 var is_abstract
: Bool writable = false
1843 # A local definition of an attribute
1847 redef type MPROPERTY: MAttribute
1848 redef type MPROPDEF: MAttributeDef
1850 init(mclassdef
: MClassDef, mproperty
: MPROPERTY, location
: Location)
1855 # The static type of the attribute
1856 var static_mtype
: nullable MType writable = null
1859 # A local definition of a virtual type
1860 class MVirtualTypeDef
1863 redef type MPROPERTY: MVirtualTypeProp
1864 redef type MPROPDEF: MVirtualTypeDef
1866 init(mclassdef
: MClassDef, mproperty
: MPROPERTY, location
: Location)
1871 # The bound of the virtual type
1872 var bound
: nullable MType writable = null
1879 # * `interface_kind`
1883 # Note this class is basically an enum.
1884 # FIXME: use a real enum once user-defined enums are available
1886 redef var to_s
: String
1888 # Is a constructor required?
1890 private init(s
: String, need_init
: Bool)
1893 self.need_init
= need_init
1897 fun abstract_kind
: MClassKind do return once
new MClassKind("abstract class", true)
1898 fun concrete_kind
: MClassKind do return once
new MClassKind("class", true)
1899 fun interface_kind
: MClassKind do return once
new MClassKind("interface", false)
1900 fun enum_kind
: MClassKind do return once
new MClassKind("enum", false)
1901 fun extern_kind
: MClassKind do return once
new MClassKind("extern", false)