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 # Classes, types and properties
19 # All three concepts are defined in this same module because these are strongly connected:
20 # * types are based on classes
21 # * classes contains properties
22 # * some properties are types (virtual types)
24 # TODO: liearization, extern stuff
25 # FIXME: better handling of the types
33 private import more_collections
37 var mclasses
: Array[MClass] = new Array[MClass]
39 # All known properties
40 var mproperties
: Array[MProperty] = new Array[MProperty]
42 # Hierarchy of class definition.
44 # Each classdef is associated with its super-classdefs in regard to
45 # its module of definition.
46 var mclassdef_hierarchy
: POSet[MClassDef] = new POSet[MClassDef]
48 # Class-type hierarchy restricted to the introduction.
50 # The idea is that what is true on introduction is always true whatever
51 # the module considered.
52 # Therefore, this hierarchy is used for a fast positive subtype check.
54 # This poset will evolve in a monotonous way:
55 # * Two non connected nodes will remain unconnected
56 # * New nodes can appear with new edges
57 private var intro_mtype_specialization_hierarchy
: POSet[MClassType] = new POSet[MClassType]
59 # Global overlapped class-type hierarchy.
60 # The hierarchy when all modules are combined.
61 # Therefore, this hierarchy is used for a fast negative subtype check.
63 # This poset will evolve in an anarchic way. Loops can even be created.
65 # FIXME decide what to do on loops
66 private var full_mtype_specialization_hierarchy
: POSet[MClassType] = new POSet[MClassType]
68 # Collections of classes grouped by their short name
69 private var mclasses_by_name
: MultiHashMap[String, MClass] = new MultiHashMap[String, MClass]
71 # Return all class named `name`.
73 # If such a class does not exist, null is returned
74 # (instead of an empty array)
76 # Visibility or modules are not considered
77 fun get_mclasses_by_name
(name
: String): nullable Array[MClass]
79 if mclasses_by_name
.has_key
(name
) then
80 return mclasses_by_name
[name
]
86 # Collections of properties grouped by their short name
87 private var mproperties_by_name
: MultiHashMap[String, MProperty] = new MultiHashMap[String, MProperty]
89 # Return all properties named `name`.
91 # If such a property does not exist, null is returned
92 # (instead of an empty array)
94 # Visibility or modules are not considered
95 fun get_mproperties_by_name
(name
: String): nullable Array[MProperty]
97 if not mproperties_by_name
.has_key
(name
) then
100 return mproperties_by_name
[name
]
105 var null_type
: MNullType = new MNullType(self)
107 # Build an ordered tree with from `concerns`
108 fun concerns_tree
(mconcerns
: Collection[MConcern]): ConcernsTree do
109 var seen
= new HashSet[MConcern]
110 var res
= new ConcernsTree
112 var todo
= new Array[MConcern]
113 todo
.add_all mconcerns
115 while not todo
.is_empty
do
117 if seen
.has
(c
) then continue
118 var pc
= c
.parent_concern
132 # An OrderedTree that can be easily refined for display purposes
134 super OrderedTree[MConcern]
138 # All the classes introduced in the module
139 var intro_mclasses
: Array[MClass] = new Array[MClass]
141 # All the class definitions of the module
142 # (introduction and refinement)
143 var mclassdefs
: Array[MClassDef] = new Array[MClassDef]
145 # Does the current module has a given class `mclass`?
146 # Return true if the mmodule introduces, refines or imports a class.
147 # Visibility is not considered.
148 fun has_mclass
(mclass
: MClass): Bool
150 return self.in_importation
<= mclass
.intro_mmodule
153 # Full hierarchy of introduced ans imported classes.
155 # Create a new hierarchy got by flattening the classes for the module
156 # and its imported modules.
157 # Visibility is not considered.
159 # Note: this function is expensive and is usually used for the main
160 # module of a program only. Do not use it to do you own subtype
162 fun flatten_mclass_hierarchy
: POSet[MClass]
164 var res
= self.flatten_mclass_hierarchy_cache
165 if res
!= null then return res
166 res
= new POSet[MClass]
167 for m
in self.in_importation
.greaters
do
168 for cd
in m
.mclassdefs
do
171 for s
in cd
.supertypes
do
172 res
.add_edge
(c
, s
.mclass
)
176 self.flatten_mclass_hierarchy_cache
= res
180 # Sort a given array of classes using the linerarization order of the module
181 # The most general is first, the most specific is last
182 fun linearize_mclasses
(mclasses
: Array[MClass])
184 self.flatten_mclass_hierarchy
.sort
(mclasses
)
187 # Sort a given array of class definitions using the linerarization order of the module
188 # the refinement link is stronger than the specialisation link
189 # The most general is first, the most specific is last
190 fun linearize_mclassdefs
(mclassdefs
: Array[MClassDef])
192 var sorter
= new MClassDefSorter(self)
193 sorter
.sort
(mclassdefs
)
196 # Sort a given array of property definitions using the linerarization order of the module
197 # the refinement link is stronger than the specialisation link
198 # The most general is first, the most specific is last
199 fun linearize_mpropdefs
(mpropdefs
: Array[MPropDef])
201 var sorter
= new MPropDefSorter(self)
202 sorter
.sort
(mpropdefs
)
205 private var flatten_mclass_hierarchy_cache
: nullable POSet[MClass] = null
207 # The primitive type `Object`, the root of the class hierarchy
208 fun object_type
: MClassType
210 var res
= self.object_type_cache
211 if res
!= null then return res
212 res
= self.get_primitive_class
("Object").mclass_type
213 self.object_type_cache
= res
217 private var object_type_cache
: nullable MClassType
219 # The primitive type `Bool`
220 fun bool_type
: MClassType
222 var res
= self.bool_type_cache
223 if res
!= null then return res
224 res
= self.get_primitive_class
("Bool").mclass_type
225 self.bool_type_cache
= res
229 private var bool_type_cache
: nullable MClassType
231 # The primitive type `Sys`, the main type of the program, if any
232 fun sys_type
: nullable MClassType
234 var clas
= self.model
.get_mclasses_by_name
("Sys")
235 if clas
== null then return null
236 return get_primitive_class
("Sys").mclass_type
239 # Force to get the primitive class named `name` or abort
240 fun get_primitive_class
(name
: String): MClass
242 var cla
= self.model
.get_mclasses_by_name
(name
)
244 if name
== "Bool" then
245 var c
= new MClass(self, name
, 0, enum_kind
, public_visibility
)
246 var cladef
= new MClassDef(self, c
.mclass_type
, new Location(null, 0,0,0,0), new Array[String])
249 print
("Fatal Error: no primitive class {name}")
252 if cla
.length
!= 1 then
253 var msg
= "Fatal Error: more than one primitive class {name}:"
254 for c
in cla
do msg
+= " {c.full_name}"
261 # Try to get the primitive method named `name` on the type `recv`
262 fun try_get_primitive_method
(name
: String, recv
: MClass): nullable MMethod
264 var props
= self.model
.get_mproperties_by_name
(name
)
265 if props
== null then return null
266 var res
: nullable MMethod = null
267 for mprop
in props
do
268 assert mprop
isa MMethod
269 var intro
= mprop
.intro_mclassdef
270 for mclassdef
in recv
.mclassdefs
do
271 if not self.in_importation
.greaters
.has
(mclassdef
.mmodule
) then continue
272 if not mclassdef
.in_hierarchy
.greaters
.has
(intro
) then continue
275 else if res
!= mprop
then
276 print
("Fatal Error: ambigous property name '{name}'; conflict between {mprop.full_name} and {res.full_name}")
285 private class MClassDefSorter
286 super AbstractSorter[MClassDef]
288 redef fun compare
(a
, b
)
292 if ca
!= cb
then return mmodule
.flatten_mclass_hierarchy
.compare
(ca
, cb
)
293 return mmodule
.model
.mclassdef_hierarchy
.compare
(a
, b
)
297 private class MPropDefSorter
298 super AbstractSorter[MPropDef]
300 redef fun compare
(pa
, pb
)
306 if ca
!= cb
then return mmodule
.flatten_mclass_hierarchy
.compare
(ca
, cb
)
307 return mmodule
.model
.mclassdef_hierarchy
.compare
(a
, b
)
313 # `MClass` are global to the model; it means that a `MClass` is not bound to a
314 # specific `MModule`.
316 # This characteristic helps the reasoning about classes in a program since a
317 # single `MClass` object always denote the same class.
319 # The drawback is that classes (`MClass`) contain almost nothing by themselves.
320 # These do not really have properties nor belong to a hierarchy since the property and the
321 # hierarchy of a class depends of the refinement in the modules.
323 # Most services on classes require the precision of a module, and no one can asks what are
324 # the super-classes of a class nor what are properties of a class without precising what is
325 # the module considered.
327 # For instance, during the typing of a source-file, the module considered is the module of the file.
328 # eg. the question *is the method `foo` exists in the class `Bar`?* must be reformulated into
329 # *is the method `foo` exists in the class `Bar` in the current module?*
331 # During some global analysis, the module considered may be the main module of the program.
335 # The module that introduce the class
336 # While classes are not bound to a specific module,
337 # the introducing module is used for naming an visibility
338 var intro_mmodule
: MModule
340 # The short name of the class
341 # In Nit, the name of a class cannot evolve in refinements
342 redef var name
: String
344 # The canonical name of the class
345 # Example: `"owner::module::MyClass"`
346 fun full_name
: String
348 return "{self.intro_mmodule.full_name}::{name}"
351 # The number of generic formal parameters
352 # 0 if the class is not generic
355 # The kind of the class (interface, abstract class, etc.)
356 # In Nit, the kind of a class cannot evolve in refinements
359 # The visibility of the class
360 # In Nit, the visibility of a class cannot evolve in refinements
361 var visibility
: MVisibility
363 init(intro_mmodule
: MModule, name
: String, arity
: Int, kind
: MClassKind, visibility
: MVisibility)
365 self.intro_mmodule
= intro_mmodule
369 self.visibility
= visibility
370 intro_mmodule
.intro_mclasses
.add
(self)
371 var model
= intro_mmodule
.model
372 model
.mclasses_by_name
.add_one
(name
, self)
373 model
.mclasses
.add
(self)
375 # Create the formal parameter types
377 var mparametertypes
= new Array[MParameterType]
378 for i
in [0..arity
[ do
379 var mparametertype
= new MParameterType(self, i
)
380 mparametertypes
.add
(mparametertype
)
382 var mclass_type
= new MGenericType(self, mparametertypes
)
383 self.mclass_type
= mclass_type
384 self.get_mtype_cache
.add
(mclass_type
)
386 self.mclass_type
= new MClassType(self)
390 redef fun model
do return intro_mmodule
.model
392 # All class definitions (introduction and refinements)
393 var mclassdefs
: Array[MClassDef] = new Array[MClassDef]
396 redef fun to_s
do return self.name
398 # The definition that introduced the class
399 # Warning: the introduction is the first `MClassDef` object associated
400 # to self. If self is just created without having any associated
401 # definition, this method will abort
404 assert has_a_first_definition
: not mclassdefs
.is_empty
405 return mclassdefs
.first
408 # Return the class `self` in the class hierarchy of the module `mmodule`.
410 # SEE: `MModule::flatten_mclass_hierarchy`
411 # REQUIRE: `mmodule.has_mclass(self)`
412 fun in_hierarchy
(mmodule
: MModule): POSetElement[MClass]
414 return mmodule
.flatten_mclass_hierarchy
[self]
417 # The principal static type of the class.
419 # For non-generic class, mclass_type is the only `MClassType` based
422 # For a generic class, the arguments are the formal parameters.
423 # i.e.: for the class Array[E:Object], the `mclass_type` is Array[E].
424 # If you want Array[Object] the see `MClassDef::bound_mtype`
426 # For generic classes, the mclass_type is also the way to get a formal
427 # generic parameter type.
429 # To get other types based on a generic class, see `get_mtype`.
431 # ENSURE: `mclass_type.mclass == self`
432 var mclass_type
: MClassType
434 # Return a generic type based on the class
435 # Is the class is not generic, then the result is `mclass_type`
437 # REQUIRE: `mtype_arguments.length == self.arity`
438 fun get_mtype
(mtype_arguments
: Array[MType]): MClassType
440 assert mtype_arguments
.length
== self.arity
441 if self.arity
== 0 then return self.mclass_type
442 for t
in self.get_mtype_cache
do
443 if t
.arguments
== mtype_arguments
then
447 var res
= new MGenericType(self, mtype_arguments
)
448 self.get_mtype_cache
.add res
452 private var get_mtype_cache
: Array[MGenericType] = new Array[MGenericType]
456 # A definition (an introduction or a refinement) of a class in a module
458 # A `MClassDef` is associated with an explicit (or almost) definition of a
459 # class. Unlike `MClass`, a `MClassDef` is a local definition that belong to
460 # a specific class and a specific module, and contains declarations like super-classes
463 # It is the class definitions that are the backbone of most things in the model:
464 # ClassDefs are defined with regard with other classdefs.
465 # Refinement and specialization are combined to produce a big poset called the `Model::mclassdef_hierarchy`.
467 # Moreover, the extension and the intention of types is defined by looking at the MClassDefs.
471 # The module where the definition is
474 # The associated `MClass`
477 # The bounded type associated to the mclassdef
479 # For a non-generic class, `bound_mtype` and `mclass.mclass_type`
483 # For the classdef Array[E: Object], the bound_mtype is Array[Object].
484 # If you want Array[E], then see `mclass.mclass_type`
486 # ENSURE: `bound_mtype.mclass == self.mclass`
487 var bound_mtype
: MClassType
489 # Name of each formal generic parameter (in order of declaration)
490 var parameter_names
: Array[String]
492 # The origin of the definition
493 var location
: Location
495 # Internal name combining the module and the class
496 # Example: "mymodule#MyClass"
497 redef var to_s
: String
499 init(mmodule
: MModule, bound_mtype
: MClassType, location
: Location, parameter_names
: Array[String])
501 assert bound_mtype
.mclass
.arity
== parameter_names
.length
502 self.bound_mtype
= bound_mtype
503 self.mmodule
= mmodule
504 self.mclass
= bound_mtype
.mclass
505 self.location
= location
506 mmodule
.mclassdefs
.add
(self)
507 mclass
.mclassdefs
.add
(self)
508 self.parameter_names
= parameter_names
509 self.to_s
= "{mmodule}#{mclass}"
512 # Actually the name of the `mclass`
513 redef fun name
do return mclass
.name
515 redef fun model
do return mmodule
.model
517 # All declared super-types
518 # FIXME: quite ugly but not better idea yet
519 var supertypes
: Array[MClassType] = new Array[MClassType]
521 # Register some super-types for the class (ie "super SomeType")
523 # The hierarchy must not already be set
524 # REQUIRE: `self.in_hierarchy == null`
525 fun set_supertypes
(supertypes
: Array[MClassType])
527 assert unique_invocation
: self.in_hierarchy
== null
528 var mmodule
= self.mmodule
529 var model
= mmodule
.model
530 var mtype
= self.bound_mtype
532 for supertype
in supertypes
do
533 self.supertypes
.add
(supertype
)
535 # Register in full_type_specialization_hierarchy
536 model
.full_mtype_specialization_hierarchy
.add_edge
(mtype
, supertype
)
537 # Register in intro_type_specialization_hierarchy
538 if mclass
.intro_mmodule
== mmodule
and supertype
.mclass
.intro_mmodule
== mmodule
then
539 model
.intro_mtype_specialization_hierarchy
.add_edge
(mtype
, supertype
)
545 # Collect the super-types (set by set_supertypes) to build the hierarchy
547 # This function can only invoked once by class
548 # REQUIRE: `self.in_hierarchy == null`
549 # ENSURE: `self.in_hierarchy != null`
552 assert unique_invocation
: self.in_hierarchy
== null
553 var model
= mmodule
.model
554 var res
= model
.mclassdef_hierarchy
.add_node
(self)
555 self.in_hierarchy
= res
556 var mtype
= self.bound_mtype
558 # Here we need to connect the mclassdef to its pairs in the mclassdef_hierarchy
559 # The simpliest way is to attach it to collect_mclassdefs
560 for mclassdef
in mtype
.collect_mclassdefs
(mmodule
) do
561 res
.poset
.add_edge
(self, mclassdef
)
565 # The view of the class definition in `mclassdef_hierarchy`
566 var in_hierarchy
: nullable POSetElement[MClassDef] = null
568 # Is the definition the one that introduced `mclass`?
569 fun is_intro
: Bool do return mclass
.intro
== self
571 # All properties introduced by the classdef
572 var intro_mproperties
: Array[MProperty] = new Array[MProperty]
574 # All property definitions in the class (introductions and redefinitions)
575 var mpropdefs
: Array[MPropDef] = new Array[MPropDef]
578 # A global static type
580 # MType are global to the model; it means that a `MType` is not bound to a
581 # specific `MModule`.
582 # This characteristic helps the reasoning about static types in a program
583 # since a single `MType` object always denote the same type.
585 # However, because a `MType` is global, it does not really have properties
586 # nor have subtypes to a hierarchy since the property and the class hierarchy
587 # depends of a module.
588 # Moreover, virtual types an formal generic parameter types also depends on
589 # a receiver to have sense.
591 # Therefore, most method of the types require a module and an anchor.
592 # The module is used to know what are the classes and the specialization
594 # The anchor is used to know what is the bound of the virtual types and formal
595 # generic parameter types.
597 # MType are not directly usable to get properties. See the `anchor_to` method
598 # and the `MClassType` class.
600 # FIXME: the order of the parameters is not the best. We mus pick on from:
601 # * foo(mmodule, anchor, othertype)
602 # * foo(othertype, anchor, mmodule)
603 # * foo(anchor, mmodule, othertype)
604 # * foo(othertype, mmodule, anchor)
608 redef fun name
do return to_s
610 # Return true if `self` is an subtype of `sup`.
611 # The typing is done using the standard typing policy of Nit.
613 # REQUIRE: `anchor == null implies not self.need_anchor and not sup.need_anchor`
614 # REQUIRE: `anchor != null implies self.can_resolve_for(anchor, null, mmodule) and sup.can_resolve_for(anchor, null, mmodule)`
615 fun is_subtype
(mmodule
: MModule, anchor
: nullable MClassType, sup
: MType): Bool
618 if sub
== sup
then return true
619 if anchor
== null then
620 assert not sub
.need_anchor
621 assert not sup
.need_anchor
623 assert sub
.can_resolve_for
(anchor
, null, mmodule
)
624 assert sup
.can_resolve_for
(anchor
, null, mmodule
)
627 # First, resolve the formal types to a common version in the receiver
628 # The trick here is that fixed formal type will be associed to the bound
629 # And unfixed formal types will be associed to a canonical formal type.
630 if sub
isa MParameterType or sub
isa MVirtualType then
631 assert anchor
!= null
632 sub
= sub
.resolve_for
(anchor
.mclass
.mclass_type
, anchor
, mmodule
, false)
634 if sup
isa MParameterType or sup
isa MVirtualType then
635 assert anchor
!= null
636 sup
= sup
.resolve_for
(anchor
.mclass
.mclass_type
, anchor
, mmodule
, false)
639 # Does `sup` accept null or not?
640 # Discard the nullable marker if it exists
641 var sup_accept_null
= false
642 if sup
isa MNullableType then
643 sup_accept_null
= true
645 else if sup
isa MNullType then
646 sup_accept_null
= true
649 # Can `sub` provide null or not?
650 # Thus we can match with `sup_accept_null`
651 # Also discard the nullable marker if it exists
652 if sub
isa MNullableType then
653 if not sup_accept_null
then return false
655 else if sub
isa MNullType then
656 return sup_accept_null
658 # Now the case of direct null and nullable is over.
660 # A unfixed formal type can only accept itself
661 if sup
isa MParameterType or sup
isa MVirtualType then
665 # If `sub` is a formal type, then it is accepted if its bound is accepted
666 if sub
isa MParameterType or sub
isa MVirtualType then
667 assert anchor
!= null
668 sub
= sub
.anchor_to
(mmodule
, anchor
)
670 # Manage the second layer of null/nullable
671 if sub
isa MNullableType then
672 if not sup_accept_null
then return false
674 else if sub
isa MNullType then
675 return sup_accept_null
679 assert sub
isa MClassType # It is the only remaining type
681 if sup
isa MNullType then
682 # `sup` accepts only null
686 assert sup
isa MClassType # It is the only remaining type
688 # Now both are MClassType, we need to dig
690 if sub
== sup
then return true
692 if anchor
== null then anchor
= sub
# UGLY: any anchor will work
693 var resolved_sub
= sub
.anchor_to
(mmodule
, anchor
)
694 var res
= resolved_sub
.collect_mclasses
(mmodule
).has
(sup
.mclass
)
695 if res
== false then return false
696 if not sup
isa MGenericType then return true
697 var sub2
= sub
.supertype_to
(mmodule
, anchor
, sup
.mclass
)
698 assert sub2
.mclass
== sup
.mclass
699 for i
in [0..sup
.mclass
.arity
[ do
700 var sub_arg
= sub2
.arguments
[i
]
701 var sup_arg
= sup
.arguments
[i
]
702 res
= sub_arg
.is_subtype
(mmodule
, anchor
, sup_arg
)
703 if res
== false then return false
708 # The base class type on which self is based
710 # This base type is used to get property (an internally to perform
711 # unsafe type comparison).
713 # Beware: some types (like null) are not based on a class thus this
716 # Basically, this function transform the virtual types and parameter
717 # types to their bounds.
721 # class B super A end
723 # class Y super X end
731 # Map[T,U] anchor_to H #-> Map[B,Y]
733 # Explanation of the example:
734 # In H, T is set to B, because "H super G[B]", and U is bound to Y,
735 # because "redef type U: Y". Therefore, Map[T, U] is bound to
738 # ENSURE: `not self.need_anchor implies result == self`
739 # ENSURE: `not result.need_anchor`
740 fun anchor_to
(mmodule
: MModule, anchor
: MClassType): MType
742 if not need_anchor
then return self
743 assert not anchor
.need_anchor
744 # Just resolve to the anchor and clear all the virtual types
745 var res
= self.resolve_for
(anchor
, null, mmodule
, true)
746 assert not res
.need_anchor
750 # Does `self` contain a virtual type or a formal generic parameter type?
751 # In order to remove those types, you usually want to use `anchor_to`.
752 fun need_anchor
: Bool do return true
754 # Return the supertype when adapted to a class.
756 # In Nit, for each super-class of a type, there is a equivalent super-type.
760 # class H[V] super G[V, Bool] end
761 # H[Int] supertype_to G #-> G[Int, Bool]
763 # REQUIRE: `super_mclass` is a super-class of `self`
764 # REQUIRE: `self.need_anchor implies anchor != null and self.can_resolve_for(anchor, null, mmodule)`
765 # ENSURE: `result.mclass = super_mclass`
766 fun supertype_to
(mmodule
: MModule, anchor
: nullable MClassType, super_mclass
: MClass): MClassType
768 if super_mclass
.arity
== 0 then return super_mclass
.mclass_type
769 if self isa MClassType and self.mclass
== super_mclass
then return self
771 if self.need_anchor
then
772 assert anchor
!= null
773 resolved_self
= self.anchor_to
(mmodule
, anchor
)
777 var supertypes
= resolved_self
.collect_mtypes
(mmodule
)
778 for supertype
in supertypes
do
779 if supertype
.mclass
== super_mclass
then
780 # FIXME: Here, we stop on the first goal. Should we check others and detect inconsistencies?
781 return supertype
.resolve_for
(self, anchor
, mmodule
, false)
787 # Replace formals generic types in self with resolved values in `mtype`
788 # If `cleanup_virtual` is true, then virtual types are also replaced
791 # This function returns self if `need_anchor` is false.
796 # class H[F] super G[F] end
799 # * Array[E].resolve_for(H[Int]) #-> Array[Int]
800 # * Array[E].resolve_for(G[Z], X[Int]) #-> Array[Z]
802 # Explanation of the example:
803 # * Array[E].need_anchor is true because there is a formal generic parameter type E
804 # * E makes sense for H[Int] because E is a formal parameter of G and H specialize G
805 # * Since "H[F] super G[F]", E is in fact F for H
806 # * More specifically, in H[Int], E is Int
807 # * So, in H[Int], Array[E] is Array[Int]
809 # This function is mainly used to inherit a signature.
810 # Because, unlike `anchor_to`, we do not want a full resolution of
811 # a type but only an adapted version of it.
816 # fun foo(e:E):E is abstract
818 # class B super A[Int] end
820 # The signature on foo is (e: E): E
821 # If we resolve the signature for B, we get (e:Int):Int
826 # fun foo(e:E) is abstract
830 # fun bar do a.foo(x) # <- x is here
833 # The first question is: is foo available on `a`?
835 # The static type of a is `A[Array[F]]`, that is an open type.
836 # in order to find a method `foo`, whe must look at a resolved type.
838 # A[Array[F]].anchor_to(B[nullable Object]) #-> A[Array[nullable Object]]
840 # the method `foo` exists in `A[Array[nullable Object]]`, therefore `foo` exists for `a`.
842 # The next question is: what is the accepted types for `x`?
844 # the signature of `foo` is `foo(e:E)`, thus we must resolve the type E
846 # E.resolve_for(A[Array[F]],B[nullable Object]) #-> Array[F]
848 # The resolution can be done because `E` make sense for the class A (see `can_resolve_for`)
850 # FIXME: the parameter `cleanup_virtual` is just a bad idea, but having
851 # two function instead of one seems also to be a bad idea.
853 # REQUIRE: `can_resolve_for(mtype, anchor, mmodule)`
854 # ENSURE: `not self.need_anchor implies result == self`
855 fun resolve_for
(mtype
: MType, anchor
: nullable MClassType, mmodule
: MModule, cleanup_virtual
: Bool): MType is abstract
857 # Can the type be resolved?
859 # In order to resolve open types, the formal types must make sence.
868 # * E.can_resolve_for(A[Int]) #-> true, E make sense in A
869 # * E.can_resolve_for(B[Int]) #-> false, E does not make sense in B
870 # * B[E].can_resolve_for(A[F], B[Object]) #-> true,
871 # B[E] is a red hearing only the E is important,
874 # REQUIRE: `anchor != null implies not anchor.need_anchor`
875 # REQUIRE: `mtype.need_anchor implies anchor != null and mtype.can_resolve_for(anchor, null, mmodule)`
876 # ENSURE: `not self.need_anchor implies result == true`
877 fun can_resolve_for
(mtype
: MType, anchor
: nullable MClassType, mmodule
: MModule): Bool is abstract
879 # Return the nullable version of the type
880 # If the type is already nullable then self is returned
881 fun as_nullable
: MType
883 var res
= self.as_nullable_cache
884 if res
!= null then return res
885 res
= new MNullableType(self)
886 self.as_nullable_cache
= res
890 private var as_nullable_cache
: nullable MType = null
893 # The deph of the type seen as a tree.
900 # Formal types have a depth of 1.
906 # The length of the type seen as a tree.
913 # Formal types have a length of 1.
919 # Compute all the classdefs inherited/imported.
920 # The returned set contains:
921 # * the class definitions from `mmodule` and its imported modules
922 # * the class definitions of this type and its super-types
924 # This function is used mainly internally.
926 # REQUIRE: `not self.need_anchor`
927 fun collect_mclassdefs
(mmodule
: MModule): Set[MClassDef] is abstract
929 # Compute all the super-classes.
930 # This function is used mainly internally.
932 # REQUIRE: `not self.need_anchor`
933 fun collect_mclasses
(mmodule
: MModule): Set[MClass] is abstract
935 # Compute all the declared super-types.
936 # Super-types are returned as declared in the classdefs (verbatim).
937 # This function is used mainly internally.
939 # REQUIRE: `not self.need_anchor`
940 fun collect_mtypes
(mmodule
: MModule): Set[MClassType] is abstract
942 # Is the property in self for a given module
943 # This method does not filter visibility or whatever
945 # REQUIRE: `not self.need_anchor`
946 fun has_mproperty
(mmodule
: MModule, mproperty
: MProperty): Bool
948 assert not self.need_anchor
949 return self.collect_mclassdefs
(mmodule
).has
(mproperty
.intro_mclassdef
)
953 # A type based on a class.
955 # `MClassType` have properties (see `has_mproperty`).
959 # The associated class
962 redef fun model
do return self.mclass
.intro_mmodule
.model
964 private init(mclass
: MClass)
969 # The formal arguments of the type
970 # ENSURE: `result.length == self.mclass.arity`
971 var arguments
: Array[MType] = new Array[MType]
973 redef fun to_s
do return mclass
.to_s
975 redef fun need_anchor
do return false
977 redef fun anchor_to
(mmodule
: MModule, anchor
: MClassType): MClassType
979 return super.as(MClassType)
982 redef fun resolve_for
(mtype
: MType, anchor
: nullable MClassType, mmodule
: MModule, cleanup_virtual
: Bool): MClassType do return self
984 redef fun can_resolve_for
(mtype
, anchor
, mmodule
) do return true
986 redef fun collect_mclassdefs
(mmodule
)
988 assert not self.need_anchor
989 var cache
= self.collect_mclassdefs_cache
990 if not cache
.has_key
(mmodule
) then
991 self.collect_things
(mmodule
)
993 return cache
[mmodule
]
996 redef fun collect_mclasses
(mmodule
)
998 assert not self.need_anchor
999 var cache
= self.collect_mclasses_cache
1000 if not cache
.has_key
(mmodule
) then
1001 self.collect_things
(mmodule
)
1003 return cache
[mmodule
]
1006 redef fun collect_mtypes
(mmodule
)
1008 assert not self.need_anchor
1009 var cache
= self.collect_mtypes_cache
1010 if not cache
.has_key
(mmodule
) then
1011 self.collect_things
(mmodule
)
1013 return cache
[mmodule
]
1016 # common implementation for `collect_mclassdefs`, `collect_mclasses`, and `collect_mtypes`.
1017 private fun collect_things
(mmodule
: MModule)
1019 var res
= new HashSet[MClassDef]
1020 var seen
= new HashSet[MClass]
1021 var types
= new HashSet[MClassType]
1022 seen
.add
(self.mclass
)
1023 var todo
= [self.mclass
]
1024 while not todo
.is_empty
do
1025 var mclass
= todo
.pop
1026 #print "process {mclass}"
1027 for mclassdef
in mclass
.mclassdefs
do
1028 if not mmodule
.in_importation
<= mclassdef
.mmodule
then continue
1029 #print " process {mclassdef}"
1031 for supertype
in mclassdef
.supertypes
do
1032 types
.add
(supertype
)
1033 var superclass
= supertype
.mclass
1034 if seen
.has
(superclass
) then continue
1035 #print " add {superclass}"
1036 seen
.add
(superclass
)
1037 todo
.add
(superclass
)
1041 collect_mclassdefs_cache
[mmodule
] = res
1042 collect_mclasses_cache
[mmodule
] = seen
1043 collect_mtypes_cache
[mmodule
] = types
1046 private var collect_mclassdefs_cache
: HashMap[MModule, Set[MClassDef]] = new HashMap[MModule, Set[MClassDef]]
1047 private var collect_mclasses_cache
: HashMap[MModule, Set[MClass]] = new HashMap[MModule, Set[MClass]]
1048 private var collect_mtypes_cache
: HashMap[MModule, Set[MClassType]] = new HashMap[MModule, Set[MClassType]]
1052 # A type based on a generic class.
1053 # A generic type a just a class with additional formal generic arguments.
1057 private init(mclass
: MClass, arguments
: Array[MType])
1060 assert self.mclass
.arity
== arguments
.length
1061 self.arguments
= arguments
1063 self.need_anchor
= false
1064 for t
in arguments
do
1065 if t
.need_anchor
then
1066 self.need_anchor
= true
1071 self.to_s
= "{mclass}[{arguments.join(", ")}]"
1074 # Recursively print the type of the arguments within brackets.
1075 # Example: `"Map[String, List[Int]]"`
1076 redef var to_s
: String
1078 redef var need_anchor
: Bool
1080 redef fun resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1082 if not need_anchor
then return self
1083 assert can_resolve_for
(mtype
, anchor
, mmodule
)
1084 var types
= new Array[MType]
1085 for t
in arguments
do
1086 types
.add
(t
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
))
1088 return mclass
.get_mtype
(types
)
1091 redef fun can_resolve_for
(mtype
, anchor
, mmodule
)
1093 if not need_anchor
then return true
1094 for t
in arguments
do
1095 if not t
.can_resolve_for
(mtype
, anchor
, mmodule
) then return false
1104 for a
in self.arguments
do
1106 if d
> dmax
then dmax
= d
1114 for a
in self.arguments
do
1121 # A virtual formal type.
1125 # The property associated with the type.
1126 # Its the definitions of this property that determine the bound or the virtual type.
1127 var mproperty
: MProperty
1129 redef fun model
do return self.mproperty
.intro_mclassdef
.mmodule
.model
1131 # Lookup the bound for a given resolved_receiver
1132 # The result may be a other virtual type (or a parameter type)
1134 # The result is returned exactly as declared in the "type" property (verbatim).
1136 # In case of conflict, the method aborts.
1137 fun lookup_bound
(mmodule
: MModule, resolved_receiver
: MType): MType
1139 assert not resolved_receiver
.need_anchor
1140 var props
= self.mproperty
.lookup_definitions
(mmodule
, resolved_receiver
)
1141 if props
.is_empty
then
1143 else if props
.length
== 1 then
1144 return props
.first
.as(MVirtualTypeDef).bound
.as(not null)
1146 var types
= new ArraySet[MType]
1148 types
.add
(p
.as(MVirtualTypeDef).bound
.as(not null))
1150 if types
.length
== 1 then
1156 # Is the virtual type fixed for a given resolved_receiver?
1157 fun is_fixed
(mmodule
: MModule, resolved_receiver
: MType): Bool
1159 assert not resolved_receiver
.need_anchor
1160 var props
= self.mproperty
.lookup_definitions
(mmodule
, resolved_receiver
)
1161 if props
.is_empty
then
1165 if p
.as(MVirtualTypeDef).is_fixed
then return true
1170 redef fun resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1172 assert can_resolve_for
(mtype
, anchor
, mmodule
)
1173 # self is a virtual type declared (or inherited) in mtype
1174 # The point of the function it to get the bound of the virtual type that make sense for mtype
1175 # But because mtype is maybe a virtual/formal type, we need to get a real receiver first
1176 #print "{class_name}: {self}/{mtype}/{anchor}?"
1177 var resolved_reciever
1178 if mtype
.need_anchor
then
1179 assert anchor
!= null
1180 resolved_reciever
= mtype
.resolve_for
(anchor
, null, mmodule
, true)
1182 resolved_reciever
= mtype
1184 # Now, we can get the bound
1185 var verbatim_bound
= lookup_bound
(mmodule
, resolved_reciever
)
1186 # The bound is exactly as declared in the "type" property, so we must resolve it again
1187 var res
= verbatim_bound
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1188 #print "{class_name}: {self}/{mtype}/{anchor} -> {self}/{resolved_reciever}/{anchor} -> {verbatim_bound}/{mtype}/{anchor} -> {res}"
1190 # What to return here? There is a bunch a special cases:
1191 # If 'cleanup_virtual' we must return the resolved type, since we cannot return self
1192 if cleanup_virtual
then return res
1193 # 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
1194 if resolved_reciever
isa MNullableType then resolved_reciever
= resolved_reciever
.mtype
1195 if resolved_reciever
.as(MClassType).mclass
.kind
== enum_kind
then return res
1196 # 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.
1197 if res
isa MVirtualType then return res
1198 # If we are final, just return the resolution
1199 if is_fixed
(mmodule
, resolved_reciever
) then return res
1200 # 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
1201 if res
isa MClassType and res
.mclass
.kind
== enum_kind
then return res
1202 # TODO: Add 'fixed' virtual type in the specification.
1203 # TODO: What if bound to a MParameterType?
1204 # Note that Nullable types can always be redefined by the non nullable version, so there is no specific case on it.
1206 # If anything apply, then `self' cannot be resolved, so return self
1210 redef fun can_resolve_for
(mtype
, anchor
, mmodule
)
1212 if mtype
.need_anchor
then
1213 assert anchor
!= null
1214 mtype
= mtype
.anchor_to
(mmodule
, anchor
)
1216 return mtype
.has_mproperty
(mmodule
, mproperty
)
1219 redef fun to_s
do return self.mproperty
.to_s
1221 init(mproperty
: MProperty)
1223 self.mproperty
= mproperty
1227 # The type associated the a formal parameter generic type of a class
1229 # Each parameter type is associated to a specific class.
1230 # It's mean that all refinements of a same class "share" the parameter type,
1231 # but that a generic subclass has its on parameter types.
1233 # However, in the sense of the meta-model, a parameter type of a class is
1234 # a valid type in a subclass. The "in the sense of the meta-model" is
1235 # important because, in the Nit language, the programmer cannot refers
1236 # directly to the parameter types of the super-classes.
1240 # fun e: E is abstract
1245 # In the class definition B[F], `F` is a valid type but `E` is not.
1246 # However, `self.e` is a valid method call, and the signature of `e` is
1249 # Note that parameter types are shared among class refinements.
1250 # Therefore parameter only have an internal name (see `to_s` for details).
1251 # TODO: Add a `name_for` to get better messages.
1252 class MParameterType
1255 # The generic class where the parameter belong
1258 redef fun model
do return self.mclass
.intro_mmodule
.model
1260 # The position of the parameter (0 for the first parameter)
1261 # FIXME: is `position` a better name?
1264 # Internal name of the parameter type
1265 # Names of parameter types changes in each class definition
1266 # Therefore, this method return an internal name.
1267 # Example: return "G#1" for the second parameter of the class G
1268 # FIXME: add a way to get the real name in a classdef
1269 redef fun to_s
do return "{mclass}#{rank}"
1271 # Resolve the bound for a given resolved_receiver
1272 # The result may be a other virtual type (or a parameter type)
1273 fun lookup_bound
(mmodule
: MModule, resolved_receiver
: MType): MType
1275 assert not resolved_receiver
.need_anchor
1276 var goalclass
= self.mclass
1277 var supertypes
= resolved_receiver
.collect_mtypes
(mmodule
)
1278 for t
in supertypes
do
1279 if t
.mclass
== goalclass
then
1280 # Yeah! c specialize goalclass with a "super `t'". So the question is what is the argument of f
1281 # FIXME: Here, we stop on the first goal. Should we check others and detect inconsistencies?
1282 var res
= t
.arguments
[self.rank
]
1289 redef fun resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1291 assert can_resolve_for
(mtype
, anchor
, mmodule
)
1292 #print "{class_name}: {self}/{mtype}/{anchor}?"
1294 if mtype
isa MGenericType and mtype
.mclass
== self.mclass
then
1295 var res
= mtype
.arguments
[self.rank
]
1296 if anchor
!= null and res
.need_anchor
then
1297 # Maybe the result can be resolved more if are bound to a final class
1298 var r2
= res
.anchor_to
(mmodule
, anchor
)
1299 if r2
isa MClassType and r2
.mclass
.kind
== enum_kind
then return r2
1304 # self is a parameter type of mtype (or of a super-class of mtype)
1305 # The point of the function it to get the bound of the virtual type that make sense for mtype
1306 # But because mtype is maybe a virtual/formal type, we need to get a real receiver first
1307 # FIXME: What happend here is far from clear. Thus this part must be validated and clarified
1308 var resolved_receiver
1309 if mtype
.need_anchor
then
1310 assert anchor
!= null
1311 resolved_receiver
= mtype
.resolve_for
(anchor
.mclass
.mclass_type
, anchor
, mmodule
, true)
1313 resolved_receiver
= mtype
1315 if resolved_receiver
isa MNullableType then resolved_receiver
= resolved_receiver
.mtype
1316 if resolved_receiver
isa MParameterType then
1317 assert resolved_receiver
.mclass
== anchor
.mclass
1318 resolved_receiver
= anchor
.arguments
[resolved_receiver
.rank
]
1319 if resolved_receiver
isa MNullableType then resolved_receiver
= resolved_receiver
.mtype
1321 assert resolved_receiver
isa MClassType
1323 # Eh! The parameter is in the current class.
1324 # So we return the corresponding argument, no mater what!
1325 if resolved_receiver
.mclass
== self.mclass
then
1326 var res
= resolved_receiver
.arguments
[self.rank
]
1327 #print "{class_name}: {self}/{mtype}/{anchor} -> direct {res}"
1331 if resolved_receiver
.need_anchor
then
1332 assert anchor
!= null
1333 resolved_receiver
= resolved_receiver
.resolve_for
(anchor
, null, mmodule
, false)
1335 # Now, we can get the bound
1336 var verbatim_bound
= lookup_bound
(mmodule
, resolved_receiver
)
1337 # The bound is exactly as declared in the "type" property, so we must resolve it again
1338 var res
= verbatim_bound
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1340 #print "{class_name}: {self}/{mtype}/{anchor} -> indirect {res}"
1345 redef fun can_resolve_for
(mtype
, anchor
, mmodule
)
1347 if mtype
.need_anchor
then
1348 assert anchor
!= null
1349 mtype
= mtype
.anchor_to
(mmodule
, anchor
)
1351 return mtype
.collect_mclassdefs
(mmodule
).has
(mclass
.intro
)
1354 init(mclass
: MClass, rank
: Int)
1356 self.mclass
= mclass
1361 # A type prefixed with "nullable"
1365 # The base type of the nullable type
1368 redef fun model
do return self.mtype
.model
1373 self.to_s
= "nullable {mtype}"
1376 redef var to_s
: String
1378 redef fun need_anchor
do return mtype
.need_anchor
1379 redef fun as_nullable
do return self
1380 redef fun resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1382 var res
= self.mtype
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1383 return res
.as_nullable
1386 redef fun can_resolve_for
(mtype
, anchor
, mmodule
)
1388 return self.mtype
.can_resolve_for
(mtype
, anchor
, mmodule
)
1391 redef fun depth
do return self.mtype
.depth
1393 redef fun length
do return self.mtype
.length
1395 redef fun collect_mclassdefs
(mmodule
)
1397 assert not self.need_anchor
1398 return self.mtype
.collect_mclassdefs
(mmodule
)
1401 redef fun collect_mclasses
(mmodule
)
1403 assert not self.need_anchor
1404 return self.mtype
.collect_mclasses
(mmodule
)
1407 redef fun collect_mtypes
(mmodule
)
1409 assert not self.need_anchor
1410 return self.mtype
.collect_mtypes
(mmodule
)
1414 # The type of the only value null
1416 # The is only one null type per model, see `MModel::null_type`.
1419 redef var model
: Model
1420 protected init(model
: Model)
1424 redef fun to_s
do return "null"
1425 redef fun as_nullable
do return self
1426 redef fun need_anchor
do return false
1427 redef fun resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
) do return self
1428 redef fun can_resolve_for
(mtype
, anchor
, mmodule
) do return true
1430 redef fun collect_mclassdefs
(mmodule
) do return new HashSet[MClassDef]
1432 redef fun collect_mclasses
(mmodule
) do return new HashSet[MClass]
1434 redef fun collect_mtypes
(mmodule
) do return new HashSet[MClassType]
1437 # A signature of a method
1441 # The each parameter (in order)
1442 var mparameters
: Array[MParameter]
1444 # The return type (null for a procedure)
1445 var return_mtype
: nullable MType
1450 var t
= self.return_mtype
1451 if t
!= null then dmax
= t
.depth
1452 for p
in mparameters
do
1453 var d
= p
.mtype
.depth
1454 if d
> dmax
then dmax
= d
1462 var t
= self.return_mtype
1463 if t
!= null then res
+= t
.length
1464 for p
in mparameters
do
1465 res
+= p
.mtype
.length
1470 # REQUIRE: 1 <= mparameters.count p -> p.is_vararg
1471 init(mparameters
: Array[MParameter], return_mtype
: nullable MType)
1473 var vararg_rank
= -1
1474 for i
in [0..mparameters
.length
[ do
1475 var parameter
= mparameters
[i
]
1476 if parameter
.is_vararg
then
1477 assert vararg_rank
== -1
1481 self.mparameters
= mparameters
1482 self.return_mtype
= return_mtype
1483 self.vararg_rank
= vararg_rank
1486 # The rank of the ellipsis (`...`) for vararg (starting from 0).
1487 # value is -1 if there is no vararg.
1488 # Example: for "(a: Int, b: Bool..., c: Char)" #-> vararg_rank=1
1489 var vararg_rank
: Int
1491 # The number or parameters
1492 fun arity
: Int do return mparameters
.length
1496 var b
= new FlatBuffer
1497 if not mparameters
.is_empty
then
1499 for i
in [0..mparameters
.length
[ do
1500 var mparameter
= mparameters
[i
]
1501 if i
> 0 then b
.append
(", ")
1502 b
.append
(mparameter
.name
)
1504 b
.append
(mparameter
.mtype
.to_s
)
1505 if mparameter
.is_vararg
then
1511 var ret
= self.return_mtype
1519 redef fun resolve_for
(mtype
: MType, anchor
: nullable MClassType, mmodule
: MModule, cleanup_virtual
: Bool): MSignature
1521 var params
= new Array[MParameter]
1522 for p
in self.mparameters
do
1523 params
.add
(p
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
))
1525 var ret
= self.return_mtype
1527 ret
= ret
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1529 var res
= new MSignature(params
, ret
)
1534 # A parameter in a signature
1538 # The name of the parameter
1539 redef var name
: String
1541 # The static type of the parameter
1544 # Is the parameter a vararg?
1547 init(name
: String, mtype
: MType, is_vararg
: Bool) do
1550 self.is_vararg
= is_vararg
1556 return "{name}: {mtype}..."
1558 return "{name}: {mtype}"
1562 fun resolve_for
(mtype
: MType, anchor
: nullable MClassType, mmodule
: MModule, cleanup_virtual
: Bool): MParameter
1564 if not self.mtype
.need_anchor
then return self
1565 var newtype
= self.mtype
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1566 var res
= new MParameter(self.name
, newtype
, self.is_vararg
)
1570 redef fun model
do return mtype
.model
1573 # A service (global property) that generalize method, attribute, etc.
1575 # `MProperty` are global to the model; it means that a `MProperty` is not bound
1576 # to a specific `MModule` nor a specific `MClass`.
1578 # A MProperty gather definitions (see `mpropdefs`) ; one for the introduction
1579 # and the other in subclasses and in refinements.
1581 # A `MProperty` is used to denotes services in polymorphic way (ie. independent
1582 # of any dynamic type).
1583 # For instance, a call site "x.foo" is associated to a `MProperty`.
1584 abstract class MProperty
1587 # The associated MPropDef subclass.
1588 # The two specialization hierarchy are symmetric.
1589 type MPROPDEF: MPropDef
1591 # The classdef that introduce the property
1592 # While a property is not bound to a specific module, or class,
1593 # the introducing mclassdef is used for naming and visibility
1594 var intro_mclassdef
: MClassDef
1596 # The (short) name of the property
1597 redef var name
: String
1599 # The canonical name of the property
1600 # Example: "owner::my_module::MyClass::my_method"
1601 fun full_name
: String
1603 return "{self.intro_mclassdef.mmodule.full_name}::{self.intro_mclassdef.mclass.name}::{name}"
1606 # The visibility of the property
1607 var visibility
: MVisibility
1609 init(intro_mclassdef
: MClassDef, name
: String, visibility
: MVisibility)
1611 self.intro_mclassdef
= intro_mclassdef
1613 self.visibility
= visibility
1614 intro_mclassdef
.intro_mproperties
.add
(self)
1615 var model
= intro_mclassdef
.mmodule
.model
1616 model
.mproperties_by_name
.add_one
(name
, self)
1617 model
.mproperties
.add
(self)
1620 # All definitions of the property.
1621 # The first is the introduction,
1622 # The other are redefinitions (in refinements and in subclasses)
1623 var mpropdefs
: Array[MPROPDEF] = new Array[MPROPDEF]
1625 # The definition that introduced the property
1626 # Warning: the introduction is the first `MPropDef` object
1627 # associated to self. If self is just created without having any
1628 # associated definition, this method will abort
1629 fun intro
: MPROPDEF do return mpropdefs
.first
1631 redef fun model
do return intro
.model
1634 redef fun to_s
do return name
1636 # Return the most specific property definitions defined or inherited by a type.
1637 # The selection knows that refinement is stronger than specialization;
1638 # however, in case of conflict more than one property are returned.
1639 # If mtype does not know mproperty then an empty array is returned.
1641 # If you want the really most specific property, then look at `lookup_first_definition`
1642 fun lookup_definitions
(mmodule
: MModule, mtype
: MType): Array[MPROPDEF]
1644 assert not mtype
.need_anchor
1645 if mtype
isa MNullableType then mtype
= mtype
.mtype
1647 var cache
= self.lookup_definitions_cache
[mmodule
, mtype
]
1648 if cache
!= null then return cache
1650 #print "select prop {mproperty} for {mtype} in {self}"
1651 # First, select all candidates
1652 var candidates
= new Array[MPROPDEF]
1653 for mpropdef
in self.mpropdefs
do
1654 # If the definition is not imported by the module, then skip
1655 if not mmodule
.in_importation
<= mpropdef
.mclassdef
.mmodule
then continue
1656 # If the definition is not inherited by the type, then skip
1657 if not mtype
.is_subtype
(mmodule
, null, mpropdef
.mclassdef
.bound_mtype
) then continue
1659 candidates
.add
(mpropdef
)
1661 # Fast track for only one candidate
1662 if candidates
.length
<= 1 then
1663 self.lookup_definitions_cache
[mmodule
, mtype
] = candidates
1667 # Second, filter the most specific ones
1668 return select_most_specific
(mmodule
, candidates
)
1671 private var lookup_definitions_cache
: HashMap2[MModule, MType, Array[MPROPDEF]] = new HashMap2[MModule, MType, Array[MPROPDEF]]
1673 # Return the most specific property definitions inherited by a type.
1674 # The selection knows that refinement is stronger than specialization;
1675 # however, in case of conflict more than one property are returned.
1676 # If mtype does not know mproperty then an empty array is returned.
1678 # If you want the really most specific property, then look at `lookup_next_definition`
1680 # FIXME: Move to `MPropDef`?
1681 fun lookup_super_definitions
(mmodule
: MModule, mtype
: MType): Array[MPROPDEF]
1683 assert not mtype
.need_anchor
1684 if mtype
isa MNullableType then mtype
= mtype
.mtype
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
1693 # If the definition is defined by the type, then skip (we want the super, so e skip the current)
1694 if mtype
== mpropdef
.mclassdef
.bound_mtype
and mmodule
== mpropdef
.mclassdef
.mmodule
then continue
1696 candidates
.add
(mpropdef
)
1698 # Fast track for only one candidate
1699 if candidates
.length
<= 1 then return candidates
1701 # Second, filter the most specific ones
1702 return select_most_specific
(mmodule
, candidates
)
1705 # Return an array containing olny the most specific property definitions
1706 # This is an helper function for `lookup_definitions` and `lookup_super_definitions`
1707 private fun select_most_specific
(mmodule
: MModule, candidates
: Array[MPROPDEF]): Array[MPROPDEF]
1709 var res
= new Array[MPROPDEF]
1710 for pd1
in candidates
do
1711 var cd1
= pd1
.mclassdef
1714 for pd2
in candidates
do
1715 if pd2
== pd1
then continue # do not compare with self!
1716 var cd2
= pd2
.mclassdef
1718 if c2
.mclass_type
== c1
.mclass_type
then
1719 if cd2
.mmodule
.in_importation
< cd1
.mmodule
then
1720 # cd2 refines cd1; therefore we skip pd1
1724 else if cd2
.bound_mtype
.is_subtype
(mmodule
, null, cd1
.bound_mtype
) and cd2
.bound_mtype
!= cd1
.bound_mtype
then
1725 # cd2 < cd1; therefore we skip pd1
1734 if res
.is_empty
then
1735 print
"All lost! {candidates.join(", ")}"
1736 # FIXME: should be abort!
1741 # Return the most specific definition in the linearization of `mtype`.
1743 # If you want to know the next properties in the linearization,
1744 # look at `MPropDef::lookup_next_definition`.
1746 # FIXME: the linearisation is still unspecified
1748 # REQUIRE: `not mtype.need_anchor`
1749 # REQUIRE: `mtype.has_mproperty(mmodule, self)`
1750 fun lookup_first_definition
(mmodule
: MModule, mtype
: MType): MPROPDEF
1752 assert mtype
.has_mproperty
(mmodule
, self)
1753 return lookup_all_definitions
(mmodule
, mtype
).first
1756 # Return all definitions in a linearisation order
1757 # Most speficic first, most general last
1758 fun lookup_all_definitions
(mmodule
: MModule, mtype
: MType): Array[MPROPDEF]
1760 assert not mtype
.need_anchor
1761 if mtype
isa MNullableType then mtype
= mtype
.mtype
1763 var cache
= self.lookup_all_definitions_cache
[mmodule
, mtype
]
1764 if cache
!= null then return cache
1766 #print "select prop {mproperty} for {mtype} in {self}"
1767 # First, select all candidates
1768 var candidates
= new Array[MPROPDEF]
1769 for mpropdef
in self.mpropdefs
do
1770 # If the definition is not imported by the module, then skip
1771 if not mmodule
.in_importation
<= mpropdef
.mclassdef
.mmodule
then continue
1772 # If the definition is not inherited by the type, then skip
1773 if not mtype
.is_subtype
(mmodule
, null, mpropdef
.mclassdef
.bound_mtype
) then continue
1775 candidates
.add
(mpropdef
)
1777 # Fast track for only one candidate
1778 if candidates
.length
<= 1 then
1779 self.lookup_all_definitions_cache
[mmodule
, mtype
] = candidates
1783 mmodule
.linearize_mpropdefs
(candidates
)
1784 candidates
= candidates
.reversed
1785 self.lookup_all_definitions_cache
[mmodule
, mtype
] = candidates
1789 private var lookup_all_definitions_cache
: HashMap2[MModule, MType, Array[MPROPDEF]] = new HashMap2[MModule, MType, Array[MPROPDEF]]
1796 redef type MPROPDEF: MMethodDef
1798 init(intro_mclassdef
: MClassDef, name
: String, visibility
: MVisibility)
1803 # Is the property defined at the top_level of the module?
1804 # Currently such a property are stored in `Object`
1805 var is_toplevel
: Bool writable = false
1807 # Is the property a constructor?
1808 # Warning, this property can be inherited by subclasses with or without being a constructor
1809 # therefore, you should use `is_init_for` the verify if the property is a legal constructor for a given class
1810 var is_init
: Bool writable = false
1812 # The the property a 'new' contructor?
1813 var is_new
: Bool writable = false
1815 # Is the property a legal constructor for a given class?
1816 # As usual, visibility is not considered.
1817 # FIXME not implemented
1818 fun is_init_for
(mclass
: MClass): Bool
1824 # A global attribute
1828 redef type MPROPDEF: MAttributeDef
1830 init(intro_mclassdef
: MClassDef, name
: String, visibility
: MVisibility)
1836 # A global virtual type
1837 class MVirtualTypeProp
1840 redef type MPROPDEF: MVirtualTypeDef
1842 init(intro_mclassdef
: MClassDef, name
: String, visibility
: MVisibility)
1847 # The formal type associated to the virtual type property
1848 var mvirtualtype
: MVirtualType = new MVirtualType(self)
1851 # A definition of a property (local property)
1853 # Unlike `MProperty`, a `MPropDef` is a local definition that belong to a
1854 # specific class definition (which belong to a specific module)
1855 abstract class MPropDef
1858 # The associated `MProperty` subclass.
1859 # the two specialization hierarchy are symmetric
1860 type MPROPERTY: MProperty
1863 type MPROPDEF: MPropDef
1865 # The origin of the definition
1866 var location
: Location
1868 # The class definition where the property definition is
1869 var mclassdef
: MClassDef
1871 # The associated global property
1872 var mproperty
: MPROPERTY
1874 init(mclassdef
: MClassDef, mproperty
: MPROPERTY, location
: Location)
1876 self.mclassdef
= mclassdef
1877 self.mproperty
= mproperty
1878 self.location
= location
1879 mclassdef
.mpropdefs
.add
(self)
1880 mproperty
.mpropdefs
.add
(self)
1881 self.to_s
= "{mclassdef}#{mproperty}"
1884 # Actually the name of the `mproperty`
1885 redef fun name
do return mproperty
.name
1887 redef fun model
do return mclassdef
.model
1889 # Internal name combining the module, the class and the property
1890 # Example: "mymodule#MyClass#mymethod"
1891 redef var to_s
: String
1893 # Is self the definition that introduce the property?
1894 fun is_intro
: Bool do return mproperty
.intro
== self
1896 # Return the next definition in linearization of `mtype`.
1898 # This method is used to determine what method is called by a super.
1900 # REQUIRE: `not mtype.need_anchor`
1901 fun lookup_next_definition
(mmodule
: MModule, mtype
: MType): MPROPDEF
1903 assert not mtype
.need_anchor
1905 var mpropdefs
= self.mproperty
.lookup_all_definitions
(mmodule
, mtype
)
1906 var i
= mpropdefs
.iterator
1907 while i
.is_ok
and i
.item
!= self do i
.next
1908 assert has_property
: i
.is_ok
1910 assert has_next_property
: i
.is_ok
1915 # A local definition of a method
1919 redef type MPROPERTY: MMethod
1920 redef type MPROPDEF: MMethodDef
1922 init(mclassdef
: MClassDef, mproperty
: MPROPERTY, location
: Location)
1927 # The signature attached to the property definition
1928 var msignature
: nullable MSignature writable = null
1930 # Is the method definition abstract?
1931 var is_abstract
: Bool writable = false
1933 # Is the method definition intern?
1934 var is_intern
writable = false
1936 # Is the method definition extern?
1937 var is_extern
writable = false
1940 # A local definition of an attribute
1944 redef type MPROPERTY: MAttribute
1945 redef type MPROPDEF: MAttributeDef
1947 init(mclassdef
: MClassDef, mproperty
: MPROPERTY, location
: Location)
1952 # The static type of the attribute
1953 var static_mtype
: nullable MType writable = null
1956 # A local definition of a virtual type
1957 class MVirtualTypeDef
1960 redef type MPROPERTY: MVirtualTypeProp
1961 redef type MPROPDEF: MVirtualTypeDef
1963 init(mclassdef
: MClassDef, mproperty
: MPROPERTY, location
: Location)
1968 # The bound of the virtual type
1969 var bound
: nullable MType writable = null
1971 # Is the bound fixed?
1972 var is_fixed
writable = false
1979 # * `interface_kind`
1983 # Note this class is basically an enum.
1984 # FIXME: use a real enum once user-defined enums are available
1986 redef var to_s
: String
1988 # Is a constructor required?
1990 private init(s
: String, need_init
: Bool)
1993 self.need_init
= need_init
1996 # Can a class of kind `self` specializes a class of kine `other`?
1997 fun can_specialize
(other
: MClassKind): Bool
1999 if other
== interface_kind
then return true # everybody can specialize interfaces
2000 if self == interface_kind
or self == enum_kind
then
2001 # no other case for interfaces
2003 else if self == extern_kind
then
2004 # only compatible with themselve
2005 return self == other
2006 else if other
== enum_kind
or other
== extern_kind
then
2007 # abstract_kind and concrete_kind are incompatible
2010 # remain only abstract_kind and concrete_kind
2015 fun abstract_kind
: MClassKind do return once
new MClassKind("abstract class", true)
2016 fun concrete_kind
: MClassKind do return once
new MClassKind("class", true)
2017 fun interface_kind
: MClassKind do return once
new MClassKind("interface", false)
2018 fun enum_kind
: MClassKind do return once
new MClassKind("enum", false)
2019 fun extern_kind
: MClassKind do return once
new MClassKind("extern class", false)