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
37 private import more_collections
41 var mclasses
: Array[MClass] = new Array[MClass]
43 # All known properties
44 var mproperties
: Array[MProperty] = new Array[MProperty]
46 # Hierarchy of class definition.
48 # Each classdef is associated with its super-classdefs in regard to
49 # its module of definition.
50 var mclassdef_hierarchy
: POSet[MClassDef] = new POSet[MClassDef]
52 # Class-type hierarchy restricted to the introduction.
54 # The idea is that what is true on introduction is always true whatever
55 # the module considered.
56 # Therefore, this hierarchy is used for a fast positive subtype check.
58 # This poset will evolve in a monotonous way:
59 # * Two non connected nodes will remain unconnected
60 # * New nodes can appear with new edges
61 private var intro_mtype_specialization_hierarchy
: POSet[MClassType] = new POSet[MClassType]
63 # Global overlapped class-type hierarchy.
64 # The hierarchy when all modules are combined.
65 # Therefore, this hierarchy is used for a fast negative subtype check.
67 # This poset will evolve in an anarchic way. Loops can even be created.
69 # FIXME decide what to do on loops
70 private var full_mtype_specialization_hierarchy
: POSet[MClassType] = new POSet[MClassType]
72 # Collections of classes grouped by their short name
73 private var mclasses_by_name
: MultiHashMap[String, MClass] = new MultiHashMap[String, MClass]
75 # Return all class named `name`.
77 # If such a class does not exist, null is returned
78 # (instead of an empty array)
80 # Visibility or modules are not considered
81 fun get_mclasses_by_name
(name
: String): nullable Array[MClass]
83 if mclasses_by_name
.has_key
(name
) then
84 return mclasses_by_name
[name
]
90 # Collections of properties grouped by their short name
91 private var mproperties_by_name
: MultiHashMap[String, MProperty] = new MultiHashMap[String, MProperty]
93 # Return all properties named `name`.
95 # If such a property does not exist, null is returned
96 # (instead of an empty array)
98 # Visibility or modules are not considered
99 fun get_mproperties_by_name
(name
: String): nullable Array[MProperty]
101 if not mproperties_by_name
.has_key
(name
) then
104 return mproperties_by_name
[name
]
109 var null_type
: MNullType = new MNullType(self)
111 # Build an ordered tree with from `concerns`
112 fun concerns_tree
(mconcerns
: Collection[MConcern]): ConcernsTree do
113 var seen
= new HashSet[MConcern]
114 var res
= new ConcernsTree
116 var todo
= new Array[MConcern]
117 todo
.add_all mconcerns
119 while not todo
.is_empty
do
121 if seen
.has
(c
) then continue
122 var pc
= c
.parent_concern
136 # An OrderedTree that can be easily refined for display purposes
138 super OrderedTree[MConcern]
142 # All the classes introduced in the module
143 var intro_mclasses
: Array[MClass] = new Array[MClass]
145 # All the class definitions of the module
146 # (introduction and refinement)
147 var mclassdefs
: Array[MClassDef] = new Array[MClassDef]
149 # Does the current module has a given class `mclass`?
150 # Return true if the mmodule introduces, refines or imports a class.
151 # Visibility is not considered.
152 fun has_mclass
(mclass
: MClass): Bool
154 return self.in_importation
<= mclass
.intro_mmodule
157 # Full hierarchy of introduced ans imported classes.
159 # Create a new hierarchy got by flattening the classes for the module
160 # and its imported modules.
161 # Visibility is not considered.
163 # Note: this function is expensive and is usually used for the main
164 # module of a program only. Do not use it to do you own subtype
166 fun flatten_mclass_hierarchy
: POSet[MClass]
168 var res
= self.flatten_mclass_hierarchy_cache
169 if res
!= null then return res
170 res
= new POSet[MClass]
171 for m
in self.in_importation
.greaters
do
172 for cd
in m
.mclassdefs
do
175 for s
in cd
.supertypes
do
176 res
.add_edge
(c
, s
.mclass
)
180 self.flatten_mclass_hierarchy_cache
= res
184 # Sort a given array of classes using the linerarization order of the module
185 # The most general is first, the most specific is last
186 fun linearize_mclasses
(mclasses
: Array[MClass])
188 self.flatten_mclass_hierarchy
.sort
(mclasses
)
191 # Sort a given array of class definitions using the linerarization order of the module
192 # the refinement link is stronger than the specialisation link
193 # The most general is first, the most specific is last
194 fun linearize_mclassdefs
(mclassdefs
: Array[MClassDef])
196 var sorter
= new MClassDefSorter(self)
197 sorter
.sort
(mclassdefs
)
200 # Sort a given array of property definitions using the linerarization order of the module
201 # the refinement link is stronger than the specialisation link
202 # The most general is first, the most specific is last
203 fun linearize_mpropdefs
(mpropdefs
: Array[MPropDef])
205 var sorter
= new MPropDefSorter(self)
206 sorter
.sort
(mpropdefs
)
209 private var flatten_mclass_hierarchy_cache
: nullable POSet[MClass] = null
211 # The primitive type `Object`, the root of the class hierarchy
212 fun object_type
: MClassType
214 var res
= self.object_type_cache
215 if res
!= null then return res
216 res
= self.get_primitive_class
("Object").mclass_type
217 self.object_type_cache
= res
221 private var object_type_cache
: nullable MClassType
223 # The primitive type `Bool`
224 fun bool_type
: MClassType
226 var res
= self.bool_type_cache
227 if res
!= null then return res
228 res
= self.get_primitive_class
("Bool").mclass_type
229 self.bool_type_cache
= res
233 private var bool_type_cache
: nullable MClassType
235 # The primitive type `Sys`, the main type of the program, if any
236 fun sys_type
: nullable MClassType
238 var clas
= self.model
.get_mclasses_by_name
("Sys")
239 if clas
== null then return null
240 return get_primitive_class
("Sys").mclass_type
243 # Force to get the primitive class named `name` or abort
244 fun get_primitive_class
(name
: String): MClass
246 var cla
= self.model
.get_mclasses_by_name
(name
)
248 if name
== "Bool" then
249 var c
= new MClass(self, name
, 0, enum_kind
, public_visibility
)
250 var cladef
= new MClassDef(self, c
.mclass_type
, new Location(null, 0,0,0,0), new Array[String])
253 print
("Fatal Error: no primitive class {name}")
256 if cla
.length
!= 1 then
257 var msg
= "Fatal Error: more than one primitive class {name}:"
258 for c
in cla
do msg
+= " {c.full_name}"
265 # Try to get the primitive method named `name` on the type `recv`
266 fun try_get_primitive_method
(name
: String, recv
: MClass): nullable MMethod
268 var props
= self.model
.get_mproperties_by_name
(name
)
269 if props
== null then return null
270 var res
: nullable MMethod = null
271 for mprop
in props
do
272 assert mprop
isa MMethod
273 var intro
= mprop
.intro_mclassdef
274 for mclassdef
in recv
.mclassdefs
do
275 if not self.in_importation
.greaters
.has
(mclassdef
.mmodule
) then continue
276 if not mclassdef
.in_hierarchy
.greaters
.has
(intro
) then continue
279 else if res
!= mprop
then
280 print
("Fatal Error: ambigous property name '{name}'; conflict between {mprop.full_name} and {res.full_name}")
289 private class MClassDefSorter
290 super AbstractSorter[MClassDef]
292 redef fun compare
(a
, b
)
296 if ca
!= cb
then return mmodule
.flatten_mclass_hierarchy
.compare
(ca
, cb
)
297 return mmodule
.model
.mclassdef_hierarchy
.compare
(a
, b
)
301 private class MPropDefSorter
302 super AbstractSorter[MPropDef]
304 redef fun compare
(pa
, pb
)
310 if ca
!= cb
then return mmodule
.flatten_mclass_hierarchy
.compare
(ca
, cb
)
311 return mmodule
.model
.mclassdef_hierarchy
.compare
(a
, b
)
317 # `MClass` are global to the model; it means that a `MClass` is not bound to a
318 # specific `MModule`.
320 # This characteristic helps the reasoning about classes in a program since a
321 # single `MClass` object always denote the same class.
322 # However, because a `MClass` is global, it does not really have properties nor
323 # belong to a hierarchy since the property and the
324 # hierarchy of a class depends of a module.
328 # The module that introduce the class
329 # While classes are not bound to a specific module,
330 # the introducing module is used for naming an visibility
331 var intro_mmodule
: MModule
333 # The short name of the class
334 # In Nit, the name of a class cannot evolve in refinements
335 redef var name
: String
337 # The canonical name of the class
338 # Example: `"owner::module::MyClass"`
339 fun full_name
: String
341 return "{self.intro_mmodule.full_name}::{name}"
344 # The number of generic formal parameters
345 # 0 if the class is not generic
348 # The kind of the class (interface, abstract class, etc.)
349 # In Nit, the kind of a class cannot evolve in refinements
352 # The visibility of the class
353 # In Nit, the visibility of a class cannot evolve in refinements
354 var visibility
: MVisibility
356 init(intro_mmodule
: MModule, name
: String, arity
: Int, kind
: MClassKind, visibility
: MVisibility)
358 self.intro_mmodule
= intro_mmodule
362 self.visibility
= visibility
363 intro_mmodule
.intro_mclasses
.add
(self)
364 var model
= intro_mmodule
.model
365 model
.mclasses_by_name
.add_one
(name
, self)
366 model
.mclasses
.add
(self)
368 # Create the formal parameter types
370 var mparametertypes
= new Array[MParameterType]
371 for i
in [0..arity
[ do
372 var mparametertype
= new MParameterType(self, i
)
373 mparametertypes
.add
(mparametertype
)
375 var mclass_type
= new MGenericType(self, mparametertypes
)
376 self.mclass_type
= mclass_type
377 self.get_mtype_cache
.add
(mclass_type
)
379 self.mclass_type
= new MClassType(self)
383 # All class definitions (introduction and refinements)
384 var mclassdefs
: Array[MClassDef] = new Array[MClassDef]
387 redef fun to_s
do return self.name
389 # The definition that introduced the class
390 # Warning: the introduction is the first `MClassDef` object associated
391 # to self. If self is just created without having any associated
392 # definition, this method will abort
395 assert has_a_first_definition
: not mclassdefs
.is_empty
396 return mclassdefs
.first
399 # Return the class `self` in the class hierarchy of the module `mmodule`.
401 # SEE: `MModule::flatten_mclass_hierarchy`
402 # REQUIRE: `mmodule.has_mclass(self)`
403 fun in_hierarchy
(mmodule
: MModule): POSetElement[MClass]
405 return mmodule
.flatten_mclass_hierarchy
[self]
408 # The principal static type of the class.
410 # For non-generic class, mclass_type is the only `MClassType` based
413 # For a generic class, the arguments are the formal parameters.
414 # i.e.: for the class Array[E:Object], the `mclass_type` is Array[E].
415 # If you want Array[Object] the see `MClassDef::bound_mtype`
417 # For generic classes, the mclass_type is also the way to get a formal
418 # generic parameter type.
420 # To get other types based on a generic class, see `get_mtype`.
422 # ENSURE: `mclass_type.mclass == self`
423 var mclass_type
: MClassType
425 # Return a generic type based on the class
426 # Is the class is not generic, then the result is `mclass_type`
428 # REQUIRE: `mtype_arguments.length == self.arity`
429 fun get_mtype
(mtype_arguments
: Array[MType]): MClassType
431 assert mtype_arguments
.length
== self.arity
432 if self.arity
== 0 then return self.mclass_type
433 for t
in self.get_mtype_cache
do
434 if t
.arguments
== mtype_arguments
then
438 var res
= new MGenericType(self, mtype_arguments
)
439 self.get_mtype_cache
.add res
443 private var get_mtype_cache
: Array[MGenericType] = new Array[MGenericType]
447 # A definition (an introduction or a refinement) of a class in a module
449 # A `MClassDef` is associated with an explicit (or almost) definition of a
450 # class. Unlike `MClass`, a `MClassDef` is a local definition that belong to
455 # The module where the definition is
458 # The associated `MClass`
461 # The bounded type associated to the mclassdef
463 # For a non-generic class, `bound_mtype` and `mclass.mclass_type`
467 # For the classdef Array[E: Object], the bound_mtype is Array[Object].
468 # If you want Array[E], then see `mclass.mclass_type`
470 # ENSURE: `bound_mtype.mclass == self.mclass`
471 var bound_mtype
: MClassType
473 # Name of each formal generic parameter (in order of declaration)
474 var parameter_names
: Array[String]
476 # The origin of the definition
477 var location
: Location
479 # Internal name combining the module and the class
480 # Example: "mymodule#MyClass"
481 redef var to_s
: String
483 init(mmodule
: MModule, bound_mtype
: MClassType, location
: Location, parameter_names
: Array[String])
485 assert bound_mtype
.mclass
.arity
== parameter_names
.length
486 self.bound_mtype
= bound_mtype
487 self.mmodule
= mmodule
488 self.mclass
= bound_mtype
.mclass
489 self.location
= location
490 mmodule
.mclassdefs
.add
(self)
491 mclass
.mclassdefs
.add
(self)
492 self.parameter_names
= parameter_names
493 self.to_s
= "{mmodule}#{mclass}"
496 # Actually the name of the `mclass`
497 redef fun name
do return mclass
.name
499 # All declared super-types
500 # FIXME: quite ugly but not better idea yet
501 var supertypes
: Array[MClassType] = new Array[MClassType]
503 # Register some super-types for the class (ie "super SomeType")
505 # The hierarchy must not already be set
506 # REQUIRE: `self.in_hierarchy == null`
507 fun set_supertypes
(supertypes
: Array[MClassType])
509 assert unique_invocation
: self.in_hierarchy
== null
510 var mmodule
= self.mmodule
511 var model
= mmodule
.model
512 var mtype
= self.bound_mtype
514 for supertype
in supertypes
do
515 self.supertypes
.add
(supertype
)
517 # Register in full_type_specialization_hierarchy
518 model
.full_mtype_specialization_hierarchy
.add_edge
(mtype
, supertype
)
519 # Register in intro_type_specialization_hierarchy
520 if mclass
.intro_mmodule
== mmodule
and supertype
.mclass
.intro_mmodule
== mmodule
then
521 model
.intro_mtype_specialization_hierarchy
.add_edge
(mtype
, supertype
)
527 # Collect the super-types (set by set_supertypes) to build the hierarchy
529 # This function can only invoked once by class
530 # REQUIRE: `self.in_hierarchy == null`
531 # ENSURE: `self.in_hierarchy != null`
534 assert unique_invocation
: self.in_hierarchy
== null
535 var model
= mmodule
.model
536 var res
= model
.mclassdef_hierarchy
.add_node
(self)
537 self.in_hierarchy
= res
538 var mtype
= self.bound_mtype
540 # Here we need to connect the mclassdef to its pairs in the mclassdef_hierarchy
541 # The simpliest way is to attach it to collect_mclassdefs
542 for mclassdef
in mtype
.collect_mclassdefs
(mmodule
) do
543 res
.poset
.add_edge
(self, mclassdef
)
547 # The view of the class definition in `mclassdef_hierarchy`
548 var in_hierarchy
: nullable POSetElement[MClassDef] = null
550 # Is the definition the one that introduced `mclass`?
551 fun is_intro
: Bool do return mclass
.intro
== self
553 # All properties introduced by the classdef
554 var intro_mproperties
: Array[MProperty] = new Array[MProperty]
556 # All property definitions in the class (introductions and redefinitions)
557 var mpropdefs
: Array[MPropDef] = new Array[MPropDef]
560 # A global static type
562 # MType are global to the model; it means that a `MType` is not bound to a
563 # specific `MModule`.
564 # This characteristic helps the reasoning about static types in a program
565 # since a single `MType` object always denote the same type.
567 # However, because a `MType` is global, it does not really have properties
568 # nor have subtypes to a hierarchy since the property and the class hierarchy
569 # depends of a module.
570 # Moreover, virtual types an formal generic parameter types also depends on
571 # a receiver to have sense.
573 # Therefore, most method of the types require a module and an anchor.
574 # The module is used to know what are the classes and the specialization
576 # The anchor is used to know what is the bound of the virtual types and formal
577 # generic parameter types.
579 # MType are not directly usable to get properties. See the `anchor_to` method
580 # and the `MClassType` class.
582 # FIXME: the order of the parameters is not the best. We mus pick on from:
583 # * foo(mmodule, anchor, othertype)
584 # * foo(othertype, anchor, mmodule)
585 # * foo(anchor, mmodule, othertype)
586 # * foo(othertype, mmodule, anchor)
590 # The model of the type
591 fun model
: Model is abstract
593 # Return true if `self` is an subtype of `sup`.
594 # The typing is done using the standard typing policy of Nit.
596 # REQUIRE: `anchor == null implies not self.need_anchor and not sup.need_anchor`
597 # REQUIRE: `anchor != null implies self.can_resolve_for(anchor, null, mmodule) and sup.can_resolve_for(anchor, null, mmodule)`
598 fun is_subtype
(mmodule
: MModule, anchor
: nullable MClassType, sup
: MType): Bool
601 if sub
== sup
then return true
602 if anchor
== null then
603 assert not sub
.need_anchor
604 assert not sup
.need_anchor
606 assert sub
.can_resolve_for
(anchor
, null, mmodule
)
607 assert sup
.can_resolve_for
(anchor
, null, mmodule
)
610 # First, resolve the formal types to a common version in the receiver
611 # The trick here is that fixed formal type will be associed to the bound
612 # And unfixed formal types will be associed to a canonical formal type.
613 if sub
isa MParameterType or sub
isa MVirtualType then
614 assert anchor
!= null
615 sub
= sub
.resolve_for
(anchor
.mclass
.mclass_type
, anchor
, mmodule
, false)
617 if sup
isa MParameterType or sup
isa MVirtualType then
618 assert anchor
!= null
619 sup
= sup
.resolve_for
(anchor
.mclass
.mclass_type
, anchor
, mmodule
, false)
622 # Does `sup` accept null or not?
623 # Discard the nullable marker if it exists
624 var sup_accept_null
= false
625 if sup
isa MNullableType then
626 sup_accept_null
= true
628 else if sup
isa MNullType then
629 sup_accept_null
= true
632 # Can `sub` provide null or not?
633 # Thus we can match with `sup_accept_null`
634 # Also discard the nullable marker if it exists
635 if sub
isa MNullableType then
636 if not sup_accept_null
then return false
638 else if sub
isa MNullType then
639 return sup_accept_null
641 # Now the case of direct null and nullable is over.
643 # A unfixed formal type can only accept itself
644 if sup
isa MParameterType or sup
isa MVirtualType then
648 # If `sub` is a formal type, then it is accepted if its bound is accepted
649 if sub
isa MParameterType or sub
isa MVirtualType then
650 assert anchor
!= null
651 sub
= sub
.anchor_to
(mmodule
, anchor
)
653 # Manage the second layer of null/nullable
654 if sub
isa MNullableType then
655 if not sup_accept_null
then return false
657 else if sub
isa MNullType then
658 return sup_accept_null
662 assert sub
isa MClassType # It is the only remaining type
664 if sup
isa MNullType then
665 # `sup` accepts only null
669 assert sup
isa MClassType # It is the only remaining type
671 # Now both are MClassType, we need to dig
673 if sub
== sup
then return true
675 if anchor
== null then anchor
= sub
# UGLY: any anchor will work
676 var resolved_sub
= sub
.anchor_to
(mmodule
, anchor
)
677 var res
= resolved_sub
.collect_mclasses
(mmodule
).has
(sup
.mclass
)
678 if res
== false then return false
679 if not sup
isa MGenericType then return true
680 var sub2
= sub
.supertype_to
(mmodule
, anchor
, sup
.mclass
)
681 assert sub2
.mclass
== sup
.mclass
682 for i
in [0..sup
.mclass
.arity
[ do
683 var sub_arg
= sub2
.arguments
[i
]
684 var sup_arg
= sup
.arguments
[i
]
685 res
= sub_arg
.is_subtype
(mmodule
, anchor
, sup_arg
)
686 if res
== false then return false
691 # The base class type on which self is based
693 # This base type is used to get property (an internally to perform
694 # unsafe type comparison).
696 # Beware: some types (like null) are not based on a class thus this
699 # Basically, this function transform the virtual types and parameter
700 # types to their bounds.
704 # class B super A end
706 # class Y super X end
714 # Map[T,U] anchor_to H #-> Map[B,Y]
716 # Explanation of the example:
717 # In H, T is set to B, because "H super G[B]", and U is bound to Y,
718 # because "redef type U: Y". Therefore, Map[T, U] is bound to
721 # ENSURE: `not self.need_anchor implies result == self`
722 # ENSURE: `not result.need_anchor`
723 fun anchor_to
(mmodule
: MModule, anchor
: MClassType): MType
725 if not need_anchor
then return self
726 assert not anchor
.need_anchor
727 # Just resolve to the anchor and clear all the virtual types
728 var res
= self.resolve_for
(anchor
, null, mmodule
, true)
729 assert not res
.need_anchor
733 # Does `self` contain a virtual type or a formal generic parameter type?
734 # In order to remove those types, you usually want to use `anchor_to`.
735 fun need_anchor
: Bool do return true
737 # Return the supertype when adapted to a class.
739 # In Nit, for each super-class of a type, there is a equivalent super-type.
743 # class H[V] super G[V, Bool] end
744 # H[Int] supertype_to G #-> G[Int, Bool]
746 # REQUIRE: `super_mclass` is a super-class of `self`
747 # REQUIRE: `self.need_anchor implies anchor != null and self.can_resolve_for(anchor, null, mmodule)`
748 # ENSURE: `result.mclass = super_mclass`
749 fun supertype_to
(mmodule
: MModule, anchor
: nullable MClassType, super_mclass
: MClass): MClassType
751 if super_mclass
.arity
== 0 then return super_mclass
.mclass_type
752 if self isa MClassType and self.mclass
== super_mclass
then return self
754 if self.need_anchor
then
755 assert anchor
!= null
756 resolved_self
= self.anchor_to
(mmodule
, anchor
)
760 var supertypes
= resolved_self
.collect_mtypes
(mmodule
)
761 for supertype
in supertypes
do
762 if supertype
.mclass
== super_mclass
then
763 # FIXME: Here, we stop on the first goal. Should we check others and detect inconsistencies?
764 return supertype
.resolve_for
(self, anchor
, mmodule
, false)
770 # Replace formals generic types in self with resolved values in `mtype`
771 # If `cleanup_virtual` is true, then virtual types are also replaced
774 # This function returns self if `need_anchor` is false.
779 # class H[F] super G[F] end
782 # * Array[E].resolve_for(H[Int]) #-> Array[Int]
783 # * Array[E].resolve_for(G[Z], X[Int]) #-> Array[Z]
785 # Explanation of the example:
786 # * Array[E].need_anchor is true because there is a formal generic parameter type E
787 # * E makes sense for H[Int] because E is a formal parameter of G and H specialize G
788 # * Since "H[F] super G[F]", E is in fact F for H
789 # * More specifically, in H[Int], E is Int
790 # * So, in H[Int], Array[E] is Array[Int]
792 # This function is mainly used to inherit a signature.
793 # Because, unlike `anchor_to`, we do not want a full resolution of
794 # a type but only an adapted version of it.
799 # fun foo(e:E):E is abstract
801 # class B super A[Int] end
803 # The signature on foo is (e: E): E
804 # If we resolve the signature for B, we get (e:Int):Int
809 # fun foo(e:E) is abstract
813 # fun bar do a.foo(x) # <- x is here
816 # The first question is: is foo available on `a`?
818 # The static type of a is `A[Array[F]]`, that is an open type.
819 # in order to find a method `foo`, whe must look at a resolved type.
821 # A[Array[F]].anchor_to(B[nullable Object]) #-> A[Array[nullable Object]]
823 # the method `foo` exists in `A[Array[nullable Object]]`, therefore `foo` exists for `a`.
825 # The next question is: what is the accepted types for `x`?
827 # the signature of `foo` is `foo(e:E)`, thus we must resolve the type E
829 # E.resolve_for(A[Array[F]],B[nullable Object]) #-> Array[F]
831 # The resolution can be done because `E` make sense for the class A (see `can_resolve_for`)
833 # TODO: Explain the cleanup_virtual
835 # FIXME: the parameter `cleanup_virtual` is just a bad idea, but having
836 # two function instead of one seems also to be a bad idea.
838 # REQUIRE: `can_resolve_for(mtype, anchor, mmodule)`
839 # ENSURE: `not self.need_anchor implies result == self`
840 fun resolve_for
(mtype
: MType, anchor
: nullable MClassType, mmodule
: MModule, cleanup_virtual
: Bool): MType is abstract
842 # Can the type be resolved?
844 # In order to resolve open types, the formal types must make sence.
853 # * E.can_resolve_for(A[Int]) #-> true, E make sense in A
854 # * E.can_resolve_for(B[Int]) #-> false, E does not make sense in B
855 # * B[E].can_resolve_for(A[F], B[Object]) #-> true,
856 # B[E] is a red hearing only the E is important,
859 # REQUIRE: `anchor != null implies not anchor.need_anchor`
860 # REQUIRE: `mtype.need_anchor implies anchor != null and mtype.can_resolve_for(anchor, null, mmodule)`
861 # ENSURE: `not self.need_anchor implies result == true`
862 fun can_resolve_for
(mtype
: MType, anchor
: nullable MClassType, mmodule
: MModule): Bool is abstract
864 # Return the nullable version of the type
865 # If the type is already nullable then self is returned
866 fun as_nullable
: MType
868 var res
= self.as_nullable_cache
869 if res
!= null then return res
870 res
= new MNullableType(self)
871 self.as_nullable_cache
= res
875 private var as_nullable_cache
: nullable MType = null
878 # The deph of the type seen as a tree.
885 # Formal types have a depth of 1.
891 # The length of the type seen as a tree.
898 # Formal types have a length of 1.
904 # Compute all the classdefs inherited/imported.
905 # The returned set contains:
906 # * the class definitions from `mmodule` and its imported modules
907 # * the class definitions of this type and its super-types
909 # This function is used mainly internally.
911 # REQUIRE: `not self.need_anchor`
912 fun collect_mclassdefs
(mmodule
: MModule): Set[MClassDef] is abstract
914 # Compute all the super-classes.
915 # This function is used mainly internally.
917 # REQUIRE: `not self.need_anchor`
918 fun collect_mclasses
(mmodule
: MModule): Set[MClass] is abstract
920 # Compute all the declared super-types.
921 # Super-types are returned as declared in the classdefs (verbatim).
922 # This function is used mainly internally.
924 # REQUIRE: `not self.need_anchor`
925 fun collect_mtypes
(mmodule
: MModule): Set[MClassType] is abstract
927 # Is the property in self for a given module
928 # This method does not filter visibility or whatever
930 # REQUIRE: `not self.need_anchor`
931 fun has_mproperty
(mmodule
: MModule, mproperty
: MProperty): Bool
933 assert not self.need_anchor
934 return self.collect_mclassdefs
(mmodule
).has
(mproperty
.intro_mclassdef
)
938 # A type based on a class.
940 # `MClassType` have properties (see `has_mproperty`).
944 # The associated class
947 redef fun model
do return self.mclass
.intro_mmodule
.model
949 private init(mclass
: MClass)
954 # The formal arguments of the type
955 # ENSURE: `result.length == self.mclass.arity`
956 var arguments
: Array[MType] = new Array[MType]
958 redef fun to_s
do return mclass
.to_s
960 redef fun need_anchor
do return false
962 redef fun anchor_to
(mmodule
: MModule, anchor
: MClassType): MClassType
964 return super.as(MClassType)
967 redef fun resolve_for
(mtype
: MType, anchor
: nullable MClassType, mmodule
: MModule, cleanup_virtual
: Bool): MClassType do return self
969 redef fun can_resolve_for
(mtype
, anchor
, mmodule
) do return true
971 redef fun collect_mclassdefs
(mmodule
)
973 assert not self.need_anchor
974 var cache
= self.collect_mclassdefs_cache
975 if not cache
.has_key
(mmodule
) then
976 self.collect_things
(mmodule
)
978 return cache
[mmodule
]
981 redef fun collect_mclasses
(mmodule
)
983 assert not self.need_anchor
984 var cache
= self.collect_mclasses_cache
985 if not cache
.has_key
(mmodule
) then
986 self.collect_things
(mmodule
)
988 return cache
[mmodule
]
991 redef fun collect_mtypes
(mmodule
)
993 assert not self.need_anchor
994 var cache
= self.collect_mtypes_cache
995 if not cache
.has_key
(mmodule
) then
996 self.collect_things
(mmodule
)
998 return cache
[mmodule
]
1001 # common implementation for `collect_mclassdefs`, `collect_mclasses`, and `collect_mtypes`.
1002 private fun collect_things
(mmodule
: MModule)
1004 var res
= new HashSet[MClassDef]
1005 var seen
= new HashSet[MClass]
1006 var types
= new HashSet[MClassType]
1007 seen
.add
(self.mclass
)
1008 var todo
= [self.mclass
]
1009 while not todo
.is_empty
do
1010 var mclass
= todo
.pop
1011 #print "process {mclass}"
1012 for mclassdef
in mclass
.mclassdefs
do
1013 if not mmodule
.in_importation
<= mclassdef
.mmodule
then continue
1014 #print " process {mclassdef}"
1016 for supertype
in mclassdef
.supertypes
do
1017 types
.add
(supertype
)
1018 var superclass
= supertype
.mclass
1019 if seen
.has
(superclass
) then continue
1020 #print " add {superclass}"
1021 seen
.add
(superclass
)
1022 todo
.add
(superclass
)
1026 collect_mclassdefs_cache
[mmodule
] = res
1027 collect_mclasses_cache
[mmodule
] = seen
1028 collect_mtypes_cache
[mmodule
] = types
1031 private var collect_mclassdefs_cache
: HashMap[MModule, Set[MClassDef]] = new HashMap[MModule, Set[MClassDef]]
1032 private var collect_mclasses_cache
: HashMap[MModule, Set[MClass]] = new HashMap[MModule, Set[MClass]]
1033 private var collect_mtypes_cache
: HashMap[MModule, Set[MClassType]] = new HashMap[MModule, Set[MClassType]]
1037 # A type based on a generic class.
1038 # A generic type a just a class with additional formal generic arguments.
1042 private init(mclass
: MClass, arguments
: Array[MType])
1045 assert self.mclass
.arity
== arguments
.length
1046 self.arguments
= arguments
1048 self.need_anchor
= false
1049 for t
in arguments
do
1050 if t
.need_anchor
then
1051 self.need_anchor
= true
1056 self.to_s
= "{mclass}[{arguments.join(", ")}]"
1059 # Recursively print the type of the arguments within brackets.
1060 # Example: `"Map[String, List[Int]]"`
1061 redef var to_s
: String
1063 redef var need_anchor
: Bool
1065 redef fun resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1067 if not need_anchor
then return self
1068 assert can_resolve_for
(mtype
, anchor
, mmodule
)
1069 var types
= new Array[MType]
1070 for t
in arguments
do
1071 types
.add
(t
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
))
1073 return mclass
.get_mtype
(types
)
1076 redef fun can_resolve_for
(mtype
, anchor
, mmodule
)
1078 if not need_anchor
then return true
1079 for t
in arguments
do
1080 if not t
.can_resolve_for
(mtype
, anchor
, mmodule
) then return false
1089 for a
in self.arguments
do
1091 if d
> dmax
then dmax
= d
1099 for a
in self.arguments
do
1106 # A virtual formal type.
1110 # The property associated with the type.
1111 # Its the definitions of this property that determine the bound or the virtual type.
1112 var mproperty
: MProperty
1114 redef fun model
do return self.mproperty
.intro_mclassdef
.mmodule
.model
1116 # Lookup the bound for a given resolved_receiver
1117 # The result may be a other virtual type (or a parameter type)
1119 # The result is returned exactly as declared in the "type" property (verbatim).
1121 # In case of conflict, the method aborts.
1122 fun lookup_bound
(mmodule
: MModule, resolved_receiver
: MType): MType
1124 assert not resolved_receiver
.need_anchor
1125 var props
= self.mproperty
.lookup_definitions
(mmodule
, resolved_receiver
)
1126 if props
.is_empty
then
1128 else if props
.length
== 1 then
1129 return props
.first
.as(MVirtualTypeDef).bound
.as(not null)
1131 var types
= new ArraySet[MType]
1133 types
.add
(p
.as(MVirtualTypeDef).bound
.as(not null))
1135 if types
.length
== 1 then
1141 redef fun resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1143 assert can_resolve_for
(mtype
, anchor
, mmodule
)
1144 # self is a virtual type declared (or inherited) in mtype
1145 # The point of the function it to get the bound of the virtual type that make sense for mtype
1146 # But because mtype is maybe a virtual/formal type, we need to get a real receiver first
1147 #print "{class_name}: {self}/{mtype}/{anchor}?"
1148 var resolved_reciever
1149 if mtype
.need_anchor
then
1150 assert anchor
!= null
1151 resolved_reciever
= mtype
.resolve_for
(anchor
, null, mmodule
, true)
1153 resolved_reciever
= mtype
1155 # Now, we can get the bound
1156 var verbatim_bound
= lookup_bound
(mmodule
, resolved_reciever
)
1157 # The bound is exactly as declared in the "type" property, so we must resolve it again
1158 var res
= verbatim_bound
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1159 #print "{class_name}: {self}/{mtype}/{anchor} -> {self}/{resolved_reciever}/{anchor} -> {verbatim_bound}/{mtype}/{anchor} -> {res}"
1161 # What to return here? There is a bunch a special cases:
1162 # If 'cleanup_virtual' we must return the resolved type, since we cannot return self
1163 if cleanup_virtual
then return res
1164 # 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
1165 if resolved_reciever
isa MNullableType then resolved_reciever
= resolved_reciever
.mtype
1166 if resolved_reciever
.as(MClassType).mclass
.kind
== enum_kind
then return res
1167 # 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.
1168 if res
isa MVirtualType then return res
1169 # 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
1170 if res
isa MClassType and res
.mclass
.kind
== enum_kind
then return res
1171 # TODO: Add 'fixed' virtual type in the specification.
1172 # TODO: What if bound to a MParameterType?
1173 # Note that Nullable types can always be redefined by the non nullable version, so there is no specific case on it.
1175 # If anything apply, then `self' cannot be resolved, so return self
1179 redef fun can_resolve_for
(mtype
, anchor
, mmodule
)
1181 if mtype
.need_anchor
then
1182 assert anchor
!= null
1183 mtype
= mtype
.anchor_to
(mmodule
, anchor
)
1185 return mtype
.has_mproperty
(mmodule
, mproperty
)
1188 redef fun to_s
do return self.mproperty
.to_s
1190 init(mproperty
: MProperty)
1192 self.mproperty
= mproperty
1196 # The type associated the a formal parameter generic type of a class
1198 # Each parameter type is associated to a specific class.
1199 # It's mean that all refinements of a same class "share" the parameter type,
1200 # but that a generic subclass has its on parameter types.
1202 # However, in the sense of the meta-model, the a parameter type of a class is
1203 # a valid types in a subclass. The "in the sense of the meta-model" is
1204 # important because, in the Nit language, the programmer cannot refers
1205 # directly to the parameter types of the super-classes.
1209 # fun e: E is abstract
1214 # In the class definition B[F], `F` is a valid type but `E` is not.
1215 # However, `self.e` is a valid method call, and the signature of `e` is
1218 # Note that parameter types are shared among class refinements.
1219 # Therefore parameter only have an internal name (see `to_s` for details).
1220 # TODO: Add a `name_for` to get better messages.
1221 class MParameterType
1224 # The generic class where the parameter belong
1227 redef fun model
do return self.mclass
.intro_mmodule
.model
1229 # The position of the parameter (0 for the first parameter)
1230 # FIXME: is `position` a better name?
1233 # Internal name of the parameter type
1234 # Names of parameter types changes in each class definition
1235 # Therefore, this method return an internal name.
1236 # Example: return "G#1" for the second parameter of the class G
1237 # FIXME: add a way to get the real name in a classdef
1238 redef fun to_s
do return "{mclass}#{rank}"
1240 # Resolve the bound for a given resolved_receiver
1241 # The result may be a other virtual type (or a parameter type)
1242 fun lookup_bound
(mmodule
: MModule, resolved_receiver
: MType): MType
1244 assert not resolved_receiver
.need_anchor
1245 var goalclass
= self.mclass
1246 var supertypes
= resolved_receiver
.collect_mtypes
(mmodule
)
1247 for t
in supertypes
do
1248 if t
.mclass
== goalclass
then
1249 # Yeah! c specialize goalclass with a "super `t'". So the question is what is the argument of f
1250 # FIXME: Here, we stop on the first goal. Should we check others and detect inconsistencies?
1251 var res
= t
.arguments
[self.rank
]
1258 redef fun resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1260 assert can_resolve_for
(mtype
, anchor
, mmodule
)
1261 #print "{class_name}: {self}/{mtype}/{anchor}?"
1263 if mtype
isa MGenericType and mtype
.mclass
== self.mclass
then
1264 return mtype
.arguments
[self.rank
]
1267 # self is a parameter type of mtype (or of a super-class of mtype)
1268 # The point of the function it to get the bound of the virtual type that make sense for mtype
1269 # But because mtype is maybe a virtual/formal type, we need to get a real receiver first
1270 # FIXME: What happend here is far from clear. Thus this part must be validated and clarified
1271 var resolved_receiver
1272 if mtype
.need_anchor
then
1273 assert anchor
!= null
1274 resolved_receiver
= mtype
.resolve_for
(anchor
.mclass
.mclass_type
, anchor
, mmodule
, true)
1276 resolved_receiver
= mtype
1278 if resolved_receiver
isa MNullableType then resolved_receiver
= resolved_receiver
.mtype
1279 if resolved_receiver
isa MParameterType then
1280 assert resolved_receiver
.mclass
== anchor
.mclass
1281 resolved_receiver
= anchor
.arguments
[resolved_receiver
.rank
]
1282 if resolved_receiver
isa MNullableType then resolved_receiver
= resolved_receiver
.mtype
1284 assert resolved_receiver
isa MClassType
1286 # Eh! The parameter is in the current class.
1287 # So we return the corresponding argument, no mater what!
1288 if resolved_receiver
.mclass
== self.mclass
then
1289 var res
= resolved_receiver
.arguments
[self.rank
]
1290 #print "{class_name}: {self}/{mtype}/{anchor} -> direct {res}"
1294 if resolved_receiver
.need_anchor
then
1295 assert anchor
!= null
1296 resolved_receiver
= resolved_receiver
.resolve_for
(anchor
, null, mmodule
, false)
1298 # Now, we can get the bound
1299 var verbatim_bound
= lookup_bound
(mmodule
, resolved_receiver
)
1300 # The bound is exactly as declared in the "type" property, so we must resolve it again
1301 var res
= verbatim_bound
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1303 #print "{class_name}: {self}/{mtype}/{anchor} -> indirect {res}"
1308 redef fun can_resolve_for
(mtype
, anchor
, mmodule
)
1310 if mtype
.need_anchor
then
1311 assert anchor
!= null
1312 mtype
= mtype
.anchor_to
(mmodule
, anchor
)
1314 return mtype
.collect_mclassdefs
(mmodule
).has
(mclass
.intro
)
1317 init(mclass
: MClass, rank
: Int)
1319 self.mclass
= mclass
1324 # A type prefixed with "nullable"
1328 # The base type of the nullable type
1331 redef fun model
do return self.mtype
.model
1336 self.to_s
= "nullable {mtype}"
1339 redef var to_s
: String
1341 redef fun need_anchor
do return mtype
.need_anchor
1342 redef fun as_nullable
do return self
1343 redef fun resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1345 var res
= self.mtype
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1346 return res
.as_nullable
1349 redef fun can_resolve_for
(mtype
, anchor
, mmodule
)
1351 return self.mtype
.can_resolve_for
(mtype
, anchor
, mmodule
)
1354 redef fun depth
do return self.mtype
.depth
1356 redef fun length
do return self.mtype
.length
1358 redef fun collect_mclassdefs
(mmodule
)
1360 assert not self.need_anchor
1361 return self.mtype
.collect_mclassdefs
(mmodule
)
1364 redef fun collect_mclasses
(mmodule
)
1366 assert not self.need_anchor
1367 return self.mtype
.collect_mclasses
(mmodule
)
1370 redef fun collect_mtypes
(mmodule
)
1372 assert not self.need_anchor
1373 return self.mtype
.collect_mtypes
(mmodule
)
1377 # The type of the only value null
1379 # The is only one null type per model, see `MModel::null_type`.
1382 redef var model
: Model
1383 protected init(model
: Model)
1387 redef fun to_s
do return "null"
1388 redef fun as_nullable
do return self
1389 redef fun need_anchor
do return false
1390 redef fun resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
) do return self
1391 redef fun can_resolve_for
(mtype
, anchor
, mmodule
) do return true
1393 redef fun collect_mclassdefs
(mmodule
) do return new HashSet[MClassDef]
1395 redef fun collect_mclasses
(mmodule
) do return new HashSet[MClass]
1397 redef fun collect_mtypes
(mmodule
) do return new HashSet[MClassType]
1400 # A signature of a method
1404 # The each parameter (in order)
1405 var mparameters
: Array[MParameter]
1407 # The return type (null for a procedure)
1408 var return_mtype
: nullable MType
1413 var t
= self.return_mtype
1414 if t
!= null then dmax
= t
.depth
1415 for p
in mparameters
do
1416 var d
= p
.mtype
.depth
1417 if d
> dmax
then dmax
= d
1425 var t
= self.return_mtype
1426 if t
!= null then res
+= t
.length
1427 for p
in mparameters
do
1428 res
+= p
.mtype
.length
1433 # REQUIRE: 1 <= mparameters.count p -> p.is_vararg
1434 init(mparameters
: Array[MParameter], return_mtype
: nullable MType)
1436 var vararg_rank
= -1
1437 for i
in [0..mparameters
.length
[ do
1438 var parameter
= mparameters
[i
]
1439 if parameter
.is_vararg
then
1440 assert vararg_rank
== -1
1444 self.mparameters
= mparameters
1445 self.return_mtype
= return_mtype
1446 self.vararg_rank
= vararg_rank
1449 # The rank of the ellipsis (`...`) for vararg (starting from 0).
1450 # value is -1 if there is no vararg.
1451 # Example: for "(a: Int, b: Bool..., c: Char)" #-> vararg_rank=1
1452 var vararg_rank
: Int
1454 # The number or parameters
1455 fun arity
: Int do return mparameters
.length
1459 var b
= new FlatBuffer
1460 if not mparameters
.is_empty
then
1462 for i
in [0..mparameters
.length
[ do
1463 var mparameter
= mparameters
[i
]
1464 if i
> 0 then b
.append
(", ")
1465 b
.append
(mparameter
.name
)
1467 b
.append
(mparameter
.mtype
.to_s
)
1468 if mparameter
.is_vararg
then
1474 var ret
= self.return_mtype
1482 redef fun resolve_for
(mtype
: MType, anchor
: nullable MClassType, mmodule
: MModule, cleanup_virtual
: Bool): MSignature
1484 var params
= new Array[MParameter]
1485 for p
in self.mparameters
do
1486 params
.add
(p
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
))
1488 var ret
= self.return_mtype
1490 ret
= ret
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1492 var res
= new MSignature(params
, ret
)
1497 # A parameter in a signature
1499 # The name of the parameter
1502 # The static type of the parameter
1505 # Is the parameter a vararg?
1511 return "{name}: {mtype}..."
1513 return "{name}: {mtype}"
1517 fun resolve_for
(mtype
: MType, anchor
: nullable MClassType, mmodule
: MModule, cleanup_virtual
: Bool): MParameter
1519 if not self.mtype
.need_anchor
then return self
1520 var newtype
= self.mtype
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1521 var res
= new MParameter(self.name
, newtype
, self.is_vararg
)
1526 # A service (global property) that generalize method, attribute, etc.
1528 # `MProperty` are global to the model; it means that a `MProperty` is not bound
1529 # to a specific `MModule` nor a specific `MClass`.
1531 # A MProperty gather definitions (see `mpropdefs`) ; one for the introduction
1532 # and the other in subclasses and in refinements.
1534 # A `MProperty` is used to denotes services in polymorphic way (ie. independent
1535 # of any dynamic type).
1536 # For instance, a call site "x.foo" is associated to a `MProperty`.
1537 abstract class MProperty
1540 # The associated MPropDef subclass.
1541 # The two specialization hierarchy are symmetric.
1542 type MPROPDEF: MPropDef
1544 # The classdef that introduce the property
1545 # While a property is not bound to a specific module, or class,
1546 # the introducing mclassdef is used for naming and visibility
1547 var intro_mclassdef
: MClassDef
1549 # The (short) name of the property
1550 redef var name
: String
1552 # The canonical name of the property
1553 # Example: "owner::my_module::MyClass::my_method"
1554 fun full_name
: String
1556 return "{self.intro_mclassdef.mmodule.full_name}::{self.intro_mclassdef.mclass.name}::{name}"
1559 # The visibility of the property
1560 var visibility
: MVisibility
1562 init(intro_mclassdef
: MClassDef, name
: String, visibility
: MVisibility)
1564 self.intro_mclassdef
= intro_mclassdef
1566 self.visibility
= visibility
1567 intro_mclassdef
.intro_mproperties
.add
(self)
1568 var model
= intro_mclassdef
.mmodule
.model
1569 model
.mproperties_by_name
.add_one
(name
, self)
1570 model
.mproperties
.add
(self)
1573 # All definitions of the property.
1574 # The first is the introduction,
1575 # The other are redefinitions (in refinements and in subclasses)
1576 var mpropdefs
: Array[MPROPDEF] = new Array[MPROPDEF]
1578 # The definition that introduced the property
1579 # Warning: the introduction is the first `MPropDef` object
1580 # associated to self. If self is just created without having any
1581 # associated definition, this method will abort
1582 fun intro
: MPROPDEF do return mpropdefs
.first
1585 redef fun to_s
do return name
1587 # Return the most specific property definitions defined or inherited by a type.
1588 # The selection knows that refinement is stronger than specialization;
1589 # however, in case of conflict more than one property are returned.
1590 # If mtype does not know mproperty then an empty array is returned.
1592 # If you want the really most specific property, then look at `lookup_first_definition`
1593 fun lookup_definitions
(mmodule
: MModule, mtype
: MType): Array[MPROPDEF]
1595 assert not mtype
.need_anchor
1596 if mtype
isa MNullableType then mtype
= mtype
.mtype
1598 var cache
= self.lookup_definitions_cache
[mmodule
, mtype
]
1599 if cache
!= null then return cache
1601 #print "select prop {mproperty} for {mtype} in {self}"
1602 # First, select all candidates
1603 var candidates
= new Array[MPROPDEF]
1604 for mpropdef
in self.mpropdefs
do
1605 # If the definition is not imported by the module, then skip
1606 if not mmodule
.in_importation
<= mpropdef
.mclassdef
.mmodule
then continue
1607 # If the definition is not inherited by the type, then skip
1608 if not mtype
.is_subtype
(mmodule
, null, mpropdef
.mclassdef
.bound_mtype
) then continue
1610 candidates
.add
(mpropdef
)
1612 # Fast track for only one candidate
1613 if candidates
.length
<= 1 then
1614 self.lookup_definitions_cache
[mmodule
, mtype
] = candidates
1618 # Second, filter the most specific ones
1619 return select_most_specific
(mmodule
, candidates
)
1622 private var lookup_definitions_cache
: HashMap2[MModule, MType, Array[MPROPDEF]] = new HashMap2[MModule, MType, Array[MPROPDEF]]
1624 # Return the most specific property definitions inherited by a type.
1625 # The selection knows that refinement is stronger than specialization;
1626 # however, in case of conflict more than one property are returned.
1627 # If mtype does not know mproperty then an empty array is returned.
1629 # If you want the really most specific property, then look at `lookup_next_definition`
1631 # FIXME: Move to `MPropDef`?
1632 fun lookup_super_definitions
(mmodule
: MModule, mtype
: MType): Array[MPROPDEF]
1634 assert not mtype
.need_anchor
1635 if mtype
isa MNullableType then mtype
= mtype
.mtype
1637 # First, select all candidates
1638 var candidates
= new Array[MPROPDEF]
1639 for mpropdef
in self.mpropdefs
do
1640 # If the definition is not imported by the module, then skip
1641 if not mmodule
.in_importation
<= mpropdef
.mclassdef
.mmodule
then continue
1642 # If the definition is not inherited by the type, then skip
1643 if not mtype
.is_subtype
(mmodule
, null, mpropdef
.mclassdef
.bound_mtype
) then continue
1644 # If the definition is defined by the type, then skip (we want the super, so e skip the current)
1645 if mtype
== mpropdef
.mclassdef
.bound_mtype
and mmodule
== mpropdef
.mclassdef
.mmodule
then continue
1647 candidates
.add
(mpropdef
)
1649 # Fast track for only one candidate
1650 if candidates
.length
<= 1 then return candidates
1652 # Second, filter the most specific ones
1653 return select_most_specific
(mmodule
, candidates
)
1656 # Return an array containing olny the most specific property definitions
1657 # This is an helper function for `lookup_definitions` and `lookup_super_definitions`
1658 private fun select_most_specific
(mmodule
: MModule, candidates
: Array[MPROPDEF]): Array[MPROPDEF]
1660 var res
= new Array[MPROPDEF]
1661 for pd1
in candidates
do
1662 var cd1
= pd1
.mclassdef
1665 for pd2
in candidates
do
1666 if pd2
== pd1
then continue # do not compare with self!
1667 var cd2
= pd2
.mclassdef
1669 if c2
.mclass_type
== c1
.mclass_type
then
1670 if cd2
.mmodule
.in_importation
< cd1
.mmodule
then
1671 # cd2 refines cd1; therefore we skip pd1
1675 else if cd2
.bound_mtype
.is_subtype
(mmodule
, null, cd1
.bound_mtype
) and cd2
.bound_mtype
!= cd1
.bound_mtype
then
1676 # cd2 < cd1; therefore we skip pd1
1685 if res
.is_empty
then
1686 print
"All lost! {candidates.join(", ")}"
1687 # FIXME: should be abort!
1692 # Return the most specific definition in the linearization of `mtype`.
1694 # If you want to know the next properties in the linearization,
1695 # look at `MPropDef::lookup_next_definition`.
1697 # FIXME: the linearisation is still unspecified
1699 # REQUIRE: `not mtype.need_anchor`
1700 # REQUIRE: `mtype.has_mproperty(mmodule, self)`
1701 fun lookup_first_definition
(mmodule
: MModule, mtype
: MType): MPROPDEF
1703 assert mtype
.has_mproperty
(mmodule
, self)
1704 return lookup_all_definitions
(mmodule
, mtype
).first
1707 # Return all definitions in a linearisation order
1708 # Most speficic first, most general last
1709 fun lookup_all_definitions
(mmodule
: MModule, mtype
: MType): Array[MPROPDEF]
1711 assert not mtype
.need_anchor
1712 if mtype
isa MNullableType then mtype
= mtype
.mtype
1714 var cache
= self.lookup_all_definitions_cache
[mmodule
, mtype
]
1715 if cache
!= null then return cache
1717 #print "select prop {mproperty} for {mtype} in {self}"
1718 # First, select all candidates
1719 var candidates
= new Array[MPROPDEF]
1720 for mpropdef
in self.mpropdefs
do
1721 # If the definition is not imported by the module, then skip
1722 if not mmodule
.in_importation
<= mpropdef
.mclassdef
.mmodule
then continue
1723 # If the definition is not inherited by the type, then skip
1724 if not mtype
.is_subtype
(mmodule
, null, mpropdef
.mclassdef
.bound_mtype
) then continue
1726 candidates
.add
(mpropdef
)
1728 # Fast track for only one candidate
1729 if candidates
.length
<= 1 then
1730 self.lookup_all_definitions_cache
[mmodule
, mtype
] = candidates
1734 mmodule
.linearize_mpropdefs
(candidates
)
1735 candidates
= candidates
.reversed
1736 self.lookup_all_definitions_cache
[mmodule
, mtype
] = candidates
1740 private var lookup_all_definitions_cache
: HashMap2[MModule, MType, Array[MPROPDEF]] = new HashMap2[MModule, MType, Array[MPROPDEF]]
1747 redef type MPROPDEF: MMethodDef
1749 init(intro_mclassdef
: MClassDef, name
: String, visibility
: MVisibility)
1754 # Is the property defined at the top_level of the module?
1755 # Currently such a property are stored in `Object`
1756 var is_toplevel
: Bool writable = false
1758 # Is the property a constructor?
1759 # Warning, this property can be inherited by subclasses with or without being a constructor
1760 # therefore, you should use `is_init_for` the verify if the property is a legal constructor for a given class
1761 var is_init
: Bool writable = false
1763 # The the property a 'new' contructor?
1764 var is_new
: Bool writable = false
1766 # Is the property a legal constructor for a given class?
1767 # As usual, visibility is not considered.
1768 # FIXME not implemented
1769 fun is_init_for
(mclass
: MClass): Bool
1775 # A global attribute
1779 redef type MPROPDEF: MAttributeDef
1781 init(intro_mclassdef
: MClassDef, name
: String, visibility
: MVisibility)
1787 # A global virtual type
1788 class MVirtualTypeProp
1791 redef type MPROPDEF: MVirtualTypeDef
1793 init(intro_mclassdef
: MClassDef, name
: String, visibility
: MVisibility)
1798 # The formal type associated to the virtual type property
1799 var mvirtualtype
: MVirtualType = new MVirtualType(self)
1802 # A definition of a property (local property)
1804 # Unlike `MProperty`, a `MPropDef` is a local definition that belong to a
1805 # specific class definition (which belong to a specific module)
1806 abstract class MPropDef
1809 # The associated `MProperty` subclass.
1810 # the two specialization hierarchy are symmetric
1811 type MPROPERTY: MProperty
1814 type MPROPDEF: MPropDef
1816 # The origin of the definition
1817 var location
: Location
1819 # The class definition where the property definition is
1820 var mclassdef
: MClassDef
1822 # The associated global property
1823 var mproperty
: MPROPERTY
1825 init(mclassdef
: MClassDef, mproperty
: MPROPERTY, location
: Location)
1827 self.mclassdef
= mclassdef
1828 self.mproperty
= mproperty
1829 self.location
= location
1830 mclassdef
.mpropdefs
.add
(self)
1831 mproperty
.mpropdefs
.add
(self)
1832 self.to_s
= "{mclassdef}#{mproperty}"
1835 # Actually the name of the `mproperty`
1836 redef fun name
do return mproperty
.name
1838 # Internal name combining the module, the class and the property
1839 # Example: "mymodule#MyClass#mymethod"
1840 redef var to_s
: String
1842 # Is self the definition that introduce the property?
1843 fun is_intro
: Bool do return mproperty
.intro
== self
1845 # Return the next definition in linearization of `mtype`.
1847 # This method is used to determine what method is called by a super.
1849 # REQUIRE: `not mtype.need_anchor`
1850 fun lookup_next_definition
(mmodule
: MModule, mtype
: MType): MPROPDEF
1852 assert not mtype
.need_anchor
1854 var mpropdefs
= self.mproperty
.lookup_all_definitions
(mmodule
, mtype
)
1855 var i
= mpropdefs
.iterator
1856 while i
.is_ok
and i
.item
!= self do i
.next
1857 assert has_property
: i
.is_ok
1859 assert has_next_property
: i
.is_ok
1864 # A local definition of a method
1868 redef type MPROPERTY: MMethod
1869 redef type MPROPDEF: MMethodDef
1871 init(mclassdef
: MClassDef, mproperty
: MPROPERTY, location
: Location)
1876 # The signature attached to the property definition
1877 var msignature
: nullable MSignature writable = null
1879 # Is the method definition abstract?
1880 var is_abstract
: Bool writable = false
1882 # Is the method definition intern?
1883 var is_intern
writable = false
1885 # Is the method definition extern?
1886 var is_extern
writable = false
1889 # A local definition of an attribute
1893 redef type MPROPERTY: MAttribute
1894 redef type MPROPDEF: MAttributeDef
1896 init(mclassdef
: MClassDef, mproperty
: MPROPERTY, location
: Location)
1901 # The static type of the attribute
1902 var static_mtype
: nullable MType writable = null
1905 # A local definition of a virtual type
1906 class MVirtualTypeDef
1909 redef type MPROPERTY: MVirtualTypeProp
1910 redef type MPROPDEF: MVirtualTypeDef
1912 init(mclassdef
: MClassDef, mproperty
: MPROPERTY, location
: Location)
1917 # The bound of the virtual type
1918 var bound
: nullable MType writable = null
1925 # * `interface_kind`
1929 # Note this class is basically an enum.
1930 # FIXME: use a real enum once user-defined enums are available
1932 redef var to_s
: String
1934 # Is a constructor required?
1936 private init(s
: String, need_init
: Bool)
1939 self.need_init
= need_init
1942 # Can a class of kind `self` specializes a class of kine `other`?
1943 fun can_specialize
(other
: MClassKind): Bool
1945 if other
== interface_kind
then return true # everybody can specialize interfaces
1946 if self == interface_kind
or self == enum_kind
then
1947 # no other case for interfaces
1949 else if self == extern_kind
then
1950 # only compatible with themselve
1951 return self == other
1952 else if other
== enum_kind
or other
== extern_kind
then
1953 # abstract_kind and concrete_kind are incompatible
1956 # remain only abstract_kind and concrete_kind
1961 fun abstract_kind
: MClassKind do return once
new MClassKind("abstract class", true)
1962 fun concrete_kind
: MClassKind do return once
new MClassKind("class", true)
1963 fun interface_kind
: MClassKind do return once
new MClassKind("interface", false)
1964 fun enum_kind
: MClassKind do return once
new MClassKind("enum", false)
1965 fun extern_kind
: MClassKind do return once
new MClassKind("extern class", false)