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 redef fun name
do return to_s
591 # The model of the type
592 fun model
: Model is abstract
594 # Return true if `self` is an subtype of `sup`.
595 # The typing is done using the standard typing policy of Nit.
597 # REQUIRE: `anchor == null implies not self.need_anchor and not sup.need_anchor`
598 # REQUIRE: `anchor != null implies self.can_resolve_for(anchor, null, mmodule) and sup.can_resolve_for(anchor, null, mmodule)`
599 fun is_subtype
(mmodule
: MModule, anchor
: nullable MClassType, sup
: MType): Bool
602 if sub
== sup
then return true
603 if anchor
== null then
604 assert not sub
.need_anchor
605 assert not sup
.need_anchor
607 assert sub
.can_resolve_for
(anchor
, null, mmodule
)
608 assert sup
.can_resolve_for
(anchor
, null, mmodule
)
611 # First, resolve the formal types to a common version in the receiver
612 # The trick here is that fixed formal type will be associed to the bound
613 # And unfixed formal types will be associed to a canonical formal type.
614 if sub
isa MParameterType or sub
isa MVirtualType then
615 assert anchor
!= null
616 sub
= sub
.resolve_for
(anchor
.mclass
.mclass_type
, anchor
, mmodule
, false)
618 if sup
isa MParameterType or sup
isa MVirtualType then
619 assert anchor
!= null
620 sup
= sup
.resolve_for
(anchor
.mclass
.mclass_type
, anchor
, mmodule
, false)
623 # Does `sup` accept null or not?
624 # Discard the nullable marker if it exists
625 var sup_accept_null
= false
626 if sup
isa MNullableType then
627 sup_accept_null
= true
629 else if sup
isa MNullType then
630 sup_accept_null
= true
633 # Can `sub` provide null or not?
634 # Thus we can match with `sup_accept_null`
635 # Also discard the nullable marker if it exists
636 if sub
isa MNullableType then
637 if not sup_accept_null
then return false
639 else if sub
isa MNullType then
640 return sup_accept_null
642 # Now the case of direct null and nullable is over.
644 # A unfixed formal type can only accept itself
645 if sup
isa MParameterType or sup
isa MVirtualType then
649 # If `sub` is a formal type, then it is accepted if its bound is accepted
650 if sub
isa MParameterType or sub
isa MVirtualType then
651 assert anchor
!= null
652 sub
= sub
.anchor_to
(mmodule
, anchor
)
654 # Manage the second layer of null/nullable
655 if sub
isa MNullableType then
656 if not sup_accept_null
then return false
658 else if sub
isa MNullType then
659 return sup_accept_null
663 assert sub
isa MClassType # It is the only remaining type
665 if sup
isa MNullType then
666 # `sup` accepts only null
670 assert sup
isa MClassType # It is the only remaining type
672 # Now both are MClassType, we need to dig
674 if sub
== sup
then return true
676 if anchor
== null then anchor
= sub
# UGLY: any anchor will work
677 var resolved_sub
= sub
.anchor_to
(mmodule
, anchor
)
678 var res
= resolved_sub
.collect_mclasses
(mmodule
).has
(sup
.mclass
)
679 if res
== false then return false
680 if not sup
isa MGenericType then return true
681 var sub2
= sub
.supertype_to
(mmodule
, anchor
, sup
.mclass
)
682 assert sub2
.mclass
== sup
.mclass
683 for i
in [0..sup
.mclass
.arity
[ do
684 var sub_arg
= sub2
.arguments
[i
]
685 var sup_arg
= sup
.arguments
[i
]
686 res
= sub_arg
.is_subtype
(mmodule
, anchor
, sup_arg
)
687 if res
== false then return false
692 # The base class type on which self is based
694 # This base type is used to get property (an internally to perform
695 # unsafe type comparison).
697 # Beware: some types (like null) are not based on a class thus this
700 # Basically, this function transform the virtual types and parameter
701 # types to their bounds.
705 # class B super A end
707 # class Y super X end
715 # Map[T,U] anchor_to H #-> Map[B,Y]
717 # Explanation of the example:
718 # In H, T is set to B, because "H super G[B]", and U is bound to Y,
719 # because "redef type U: Y". Therefore, Map[T, U] is bound to
722 # ENSURE: `not self.need_anchor implies result == self`
723 # ENSURE: `not result.need_anchor`
724 fun anchor_to
(mmodule
: MModule, anchor
: MClassType): MType
726 if not need_anchor
then return self
727 assert not anchor
.need_anchor
728 # Just resolve to the anchor and clear all the virtual types
729 var res
= self.resolve_for
(anchor
, null, mmodule
, true)
730 assert not res
.need_anchor
734 # Does `self` contain a virtual type or a formal generic parameter type?
735 # In order to remove those types, you usually want to use `anchor_to`.
736 fun need_anchor
: Bool do return true
738 # Return the supertype when adapted to a class.
740 # In Nit, for each super-class of a type, there is a equivalent super-type.
744 # class H[V] super G[V, Bool] end
745 # H[Int] supertype_to G #-> G[Int, Bool]
747 # REQUIRE: `super_mclass` is a super-class of `self`
748 # REQUIRE: `self.need_anchor implies anchor != null and self.can_resolve_for(anchor, null, mmodule)`
749 # ENSURE: `result.mclass = super_mclass`
750 fun supertype_to
(mmodule
: MModule, anchor
: nullable MClassType, super_mclass
: MClass): MClassType
752 if super_mclass
.arity
== 0 then return super_mclass
.mclass_type
753 if self isa MClassType and self.mclass
== super_mclass
then return self
755 if self.need_anchor
then
756 assert anchor
!= null
757 resolved_self
= self.anchor_to
(mmodule
, anchor
)
761 var supertypes
= resolved_self
.collect_mtypes
(mmodule
)
762 for supertype
in supertypes
do
763 if supertype
.mclass
== super_mclass
then
764 # FIXME: Here, we stop on the first goal. Should we check others and detect inconsistencies?
765 return supertype
.resolve_for
(self, anchor
, mmodule
, false)
771 # Replace formals generic types in self with resolved values in `mtype`
772 # If `cleanup_virtual` is true, then virtual types are also replaced
775 # This function returns self if `need_anchor` is false.
780 # class H[F] super G[F] end
783 # * Array[E].resolve_for(H[Int]) #-> Array[Int]
784 # * Array[E].resolve_for(G[Z], X[Int]) #-> Array[Z]
786 # Explanation of the example:
787 # * Array[E].need_anchor is true because there is a formal generic parameter type E
788 # * E makes sense for H[Int] because E is a formal parameter of G and H specialize G
789 # * Since "H[F] super G[F]", E is in fact F for H
790 # * More specifically, in H[Int], E is Int
791 # * So, in H[Int], Array[E] is Array[Int]
793 # This function is mainly used to inherit a signature.
794 # Because, unlike `anchor_to`, we do not want a full resolution of
795 # a type but only an adapted version of it.
800 # fun foo(e:E):E is abstract
802 # class B super A[Int] end
804 # The signature on foo is (e: E): E
805 # If we resolve the signature for B, we get (e:Int):Int
810 # fun foo(e:E) is abstract
814 # fun bar do a.foo(x) # <- x is here
817 # The first question is: is foo available on `a`?
819 # The static type of a is `A[Array[F]]`, that is an open type.
820 # in order to find a method `foo`, whe must look at a resolved type.
822 # A[Array[F]].anchor_to(B[nullable Object]) #-> A[Array[nullable Object]]
824 # the method `foo` exists in `A[Array[nullable Object]]`, therefore `foo` exists for `a`.
826 # The next question is: what is the accepted types for `x`?
828 # the signature of `foo` is `foo(e:E)`, thus we must resolve the type E
830 # E.resolve_for(A[Array[F]],B[nullable Object]) #-> Array[F]
832 # The resolution can be done because `E` make sense for the class A (see `can_resolve_for`)
834 # TODO: Explain the cleanup_virtual
836 # FIXME: the parameter `cleanup_virtual` is just a bad idea, but having
837 # two function instead of one seems also to be a bad idea.
839 # REQUIRE: `can_resolve_for(mtype, anchor, mmodule)`
840 # ENSURE: `not self.need_anchor implies result == self`
841 fun resolve_for
(mtype
: MType, anchor
: nullable MClassType, mmodule
: MModule, cleanup_virtual
: Bool): MType is abstract
843 # Can the type be resolved?
845 # In order to resolve open types, the formal types must make sence.
854 # * E.can_resolve_for(A[Int]) #-> true, E make sense in A
855 # * E.can_resolve_for(B[Int]) #-> false, E does not make sense in B
856 # * B[E].can_resolve_for(A[F], B[Object]) #-> true,
857 # B[E] is a red hearing only the E is important,
860 # REQUIRE: `anchor != null implies not anchor.need_anchor`
861 # REQUIRE: `mtype.need_anchor implies anchor != null and mtype.can_resolve_for(anchor, null, mmodule)`
862 # ENSURE: `not self.need_anchor implies result == true`
863 fun can_resolve_for
(mtype
: MType, anchor
: nullable MClassType, mmodule
: MModule): Bool is abstract
865 # Return the nullable version of the type
866 # If the type is already nullable then self is returned
867 fun as_nullable
: MType
869 var res
= self.as_nullable_cache
870 if res
!= null then return res
871 res
= new MNullableType(self)
872 self.as_nullable_cache
= res
876 private var as_nullable_cache
: nullable MType = null
879 # The deph of the type seen as a tree.
886 # Formal types have a depth of 1.
892 # The length of the type seen as a tree.
899 # Formal types have a length of 1.
905 # Compute all the classdefs inherited/imported.
906 # The returned set contains:
907 # * the class definitions from `mmodule` and its imported modules
908 # * the class definitions of this type and its super-types
910 # This function is used mainly internally.
912 # REQUIRE: `not self.need_anchor`
913 fun collect_mclassdefs
(mmodule
: MModule): Set[MClassDef] is abstract
915 # Compute all the super-classes.
916 # This function is used mainly internally.
918 # REQUIRE: `not self.need_anchor`
919 fun collect_mclasses
(mmodule
: MModule): Set[MClass] is abstract
921 # Compute all the declared super-types.
922 # Super-types are returned as declared in the classdefs (verbatim).
923 # This function is used mainly internally.
925 # REQUIRE: `not self.need_anchor`
926 fun collect_mtypes
(mmodule
: MModule): Set[MClassType] is abstract
928 # Is the property in self for a given module
929 # This method does not filter visibility or whatever
931 # REQUIRE: `not self.need_anchor`
932 fun has_mproperty
(mmodule
: MModule, mproperty
: MProperty): Bool
934 assert not self.need_anchor
935 return self.collect_mclassdefs
(mmodule
).has
(mproperty
.intro_mclassdef
)
939 # A type based on a class.
941 # `MClassType` have properties (see `has_mproperty`).
945 # The associated class
948 redef fun model
do return self.mclass
.intro_mmodule
.model
950 private init(mclass
: MClass)
955 # The formal arguments of the type
956 # ENSURE: `result.length == self.mclass.arity`
957 var arguments
: Array[MType] = new Array[MType]
959 redef fun to_s
do return mclass
.to_s
961 redef fun need_anchor
do return false
963 redef fun anchor_to
(mmodule
: MModule, anchor
: MClassType): MClassType
965 return super.as(MClassType)
968 redef fun resolve_for
(mtype
: MType, anchor
: nullable MClassType, mmodule
: MModule, cleanup_virtual
: Bool): MClassType do return self
970 redef fun can_resolve_for
(mtype
, anchor
, mmodule
) do return true
972 redef fun collect_mclassdefs
(mmodule
)
974 assert not self.need_anchor
975 var cache
= self.collect_mclassdefs_cache
976 if not cache
.has_key
(mmodule
) then
977 self.collect_things
(mmodule
)
979 return cache
[mmodule
]
982 redef fun collect_mclasses
(mmodule
)
984 assert not self.need_anchor
985 var cache
= self.collect_mclasses_cache
986 if not cache
.has_key
(mmodule
) then
987 self.collect_things
(mmodule
)
989 return cache
[mmodule
]
992 redef fun collect_mtypes
(mmodule
)
994 assert not self.need_anchor
995 var cache
= self.collect_mtypes_cache
996 if not cache
.has_key
(mmodule
) then
997 self.collect_things
(mmodule
)
999 return cache
[mmodule
]
1002 # common implementation for `collect_mclassdefs`, `collect_mclasses`, and `collect_mtypes`.
1003 private fun collect_things
(mmodule
: MModule)
1005 var res
= new HashSet[MClassDef]
1006 var seen
= new HashSet[MClass]
1007 var types
= new HashSet[MClassType]
1008 seen
.add
(self.mclass
)
1009 var todo
= [self.mclass
]
1010 while not todo
.is_empty
do
1011 var mclass
= todo
.pop
1012 #print "process {mclass}"
1013 for mclassdef
in mclass
.mclassdefs
do
1014 if not mmodule
.in_importation
<= mclassdef
.mmodule
then continue
1015 #print " process {mclassdef}"
1017 for supertype
in mclassdef
.supertypes
do
1018 types
.add
(supertype
)
1019 var superclass
= supertype
.mclass
1020 if seen
.has
(superclass
) then continue
1021 #print " add {superclass}"
1022 seen
.add
(superclass
)
1023 todo
.add
(superclass
)
1027 collect_mclassdefs_cache
[mmodule
] = res
1028 collect_mclasses_cache
[mmodule
] = seen
1029 collect_mtypes_cache
[mmodule
] = types
1032 private var collect_mclassdefs_cache
: HashMap[MModule, Set[MClassDef]] = new HashMap[MModule, Set[MClassDef]]
1033 private var collect_mclasses_cache
: HashMap[MModule, Set[MClass]] = new HashMap[MModule, Set[MClass]]
1034 private var collect_mtypes_cache
: HashMap[MModule, Set[MClassType]] = new HashMap[MModule, Set[MClassType]]
1038 # A type based on a generic class.
1039 # A generic type a just a class with additional formal generic arguments.
1043 private init(mclass
: MClass, arguments
: Array[MType])
1046 assert self.mclass
.arity
== arguments
.length
1047 self.arguments
= arguments
1049 self.need_anchor
= false
1050 for t
in arguments
do
1051 if t
.need_anchor
then
1052 self.need_anchor
= true
1057 self.to_s
= "{mclass}[{arguments.join(", ")}]"
1060 # Recursively print the type of the arguments within brackets.
1061 # Example: `"Map[String, List[Int]]"`
1062 redef var to_s
: String
1064 redef var need_anchor
: Bool
1066 redef fun resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1068 if not need_anchor
then return self
1069 assert can_resolve_for
(mtype
, anchor
, mmodule
)
1070 var types
= new Array[MType]
1071 for t
in arguments
do
1072 types
.add
(t
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
))
1074 return mclass
.get_mtype
(types
)
1077 redef fun can_resolve_for
(mtype
, anchor
, mmodule
)
1079 if not need_anchor
then return true
1080 for t
in arguments
do
1081 if not t
.can_resolve_for
(mtype
, anchor
, mmodule
) then return false
1090 for a
in self.arguments
do
1092 if d
> dmax
then dmax
= d
1100 for a
in self.arguments
do
1107 # A virtual formal type.
1111 # The property associated with the type.
1112 # Its the definitions of this property that determine the bound or the virtual type.
1113 var mproperty
: MProperty
1115 redef fun model
do return self.mproperty
.intro_mclassdef
.mmodule
.model
1117 # Lookup the bound for a given resolved_receiver
1118 # The result may be a other virtual type (or a parameter type)
1120 # The result is returned exactly as declared in the "type" property (verbatim).
1122 # In case of conflict, the method aborts.
1123 fun lookup_bound
(mmodule
: MModule, resolved_receiver
: MType): MType
1125 assert not resolved_receiver
.need_anchor
1126 var props
= self.mproperty
.lookup_definitions
(mmodule
, resolved_receiver
)
1127 if props
.is_empty
then
1129 else if props
.length
== 1 then
1130 return props
.first
.as(MVirtualTypeDef).bound
.as(not null)
1132 var types
= new ArraySet[MType]
1134 types
.add
(p
.as(MVirtualTypeDef).bound
.as(not null))
1136 if types
.length
== 1 then
1142 redef fun resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1144 assert can_resolve_for
(mtype
, anchor
, mmodule
)
1145 # self is a virtual type declared (or inherited) in mtype
1146 # The point of the function it to get the bound of the virtual type that make sense for mtype
1147 # But because mtype is maybe a virtual/formal type, we need to get a real receiver first
1148 #print "{class_name}: {self}/{mtype}/{anchor}?"
1149 var resolved_reciever
1150 if mtype
.need_anchor
then
1151 assert anchor
!= null
1152 resolved_reciever
= mtype
.resolve_for
(anchor
, null, mmodule
, true)
1154 resolved_reciever
= mtype
1156 # Now, we can get the bound
1157 var verbatim_bound
= lookup_bound
(mmodule
, resolved_reciever
)
1158 # The bound is exactly as declared in the "type" property, so we must resolve it again
1159 var res
= verbatim_bound
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1160 #print "{class_name}: {self}/{mtype}/{anchor} -> {self}/{resolved_reciever}/{anchor} -> {verbatim_bound}/{mtype}/{anchor} -> {res}"
1162 # What to return here? There is a bunch a special cases:
1163 # If 'cleanup_virtual' we must return the resolved type, since we cannot return self
1164 if cleanup_virtual
then return res
1165 # 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
1166 if resolved_reciever
isa MNullableType then resolved_reciever
= resolved_reciever
.mtype
1167 if resolved_reciever
.as(MClassType).mclass
.kind
== enum_kind
then return res
1168 # 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.
1169 if res
isa MVirtualType then return res
1170 # 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
1171 if res
isa MClassType and res
.mclass
.kind
== enum_kind
then return res
1172 # TODO: Add 'fixed' virtual type in the specification.
1173 # TODO: What if bound to a MParameterType?
1174 # Note that Nullable types can always be redefined by the non nullable version, so there is no specific case on it.
1176 # If anything apply, then `self' cannot be resolved, so return self
1180 redef fun can_resolve_for
(mtype
, anchor
, mmodule
)
1182 if mtype
.need_anchor
then
1183 assert anchor
!= null
1184 mtype
= mtype
.anchor_to
(mmodule
, anchor
)
1186 return mtype
.has_mproperty
(mmodule
, mproperty
)
1189 redef fun to_s
do return self.mproperty
.to_s
1191 init(mproperty
: MProperty)
1193 self.mproperty
= mproperty
1197 # The type associated the a formal parameter generic type of a class
1199 # Each parameter type is associated to a specific class.
1200 # It's mean that all refinements of a same class "share" the parameter type,
1201 # but that a generic subclass has its on parameter types.
1203 # However, in the sense of the meta-model, the a parameter type of a class is
1204 # a valid types in a subclass. The "in the sense of the meta-model" is
1205 # important because, in the Nit language, the programmer cannot refers
1206 # directly to the parameter types of the super-classes.
1210 # fun e: E is abstract
1215 # In the class definition B[F], `F` is a valid type but `E` is not.
1216 # However, `self.e` is a valid method call, and the signature of `e` is
1219 # Note that parameter types are shared among class refinements.
1220 # Therefore parameter only have an internal name (see `to_s` for details).
1221 # TODO: Add a `name_for` to get better messages.
1222 class MParameterType
1225 # The generic class where the parameter belong
1228 redef fun model
do return self.mclass
.intro_mmodule
.model
1230 # The position of the parameter (0 for the first parameter)
1231 # FIXME: is `position` a better name?
1234 # Internal name of the parameter type
1235 # Names of parameter types changes in each class definition
1236 # Therefore, this method return an internal name.
1237 # Example: return "G#1" for the second parameter of the class G
1238 # FIXME: add a way to get the real name in a classdef
1239 redef fun to_s
do return "{mclass}#{rank}"
1241 # Resolve the bound for a given resolved_receiver
1242 # The result may be a other virtual type (or a parameter type)
1243 fun lookup_bound
(mmodule
: MModule, resolved_receiver
: MType): MType
1245 assert not resolved_receiver
.need_anchor
1246 var goalclass
= self.mclass
1247 var supertypes
= resolved_receiver
.collect_mtypes
(mmodule
)
1248 for t
in supertypes
do
1249 if t
.mclass
== goalclass
then
1250 # Yeah! c specialize goalclass with a "super `t'". So the question is what is the argument of f
1251 # FIXME: Here, we stop on the first goal. Should we check others and detect inconsistencies?
1252 var res
= t
.arguments
[self.rank
]
1259 redef fun resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1261 assert can_resolve_for
(mtype
, anchor
, mmodule
)
1262 #print "{class_name}: {self}/{mtype}/{anchor}?"
1264 if mtype
isa MGenericType and mtype
.mclass
== self.mclass
then
1265 return mtype
.arguments
[self.rank
]
1268 # self is a parameter type of mtype (or of a super-class of mtype)
1269 # The point of the function it to get the bound of the virtual type that make sense for mtype
1270 # But because mtype is maybe a virtual/formal type, we need to get a real receiver first
1271 # FIXME: What happend here is far from clear. Thus this part must be validated and clarified
1272 var resolved_receiver
1273 if mtype
.need_anchor
then
1274 assert anchor
!= null
1275 resolved_receiver
= mtype
.resolve_for
(anchor
.mclass
.mclass_type
, anchor
, mmodule
, true)
1277 resolved_receiver
= mtype
1279 if resolved_receiver
isa MNullableType then resolved_receiver
= resolved_receiver
.mtype
1280 if resolved_receiver
isa MParameterType then
1281 assert resolved_receiver
.mclass
== anchor
.mclass
1282 resolved_receiver
= anchor
.arguments
[resolved_receiver
.rank
]
1283 if resolved_receiver
isa MNullableType then resolved_receiver
= resolved_receiver
.mtype
1285 assert resolved_receiver
isa MClassType
1287 # Eh! The parameter is in the current class.
1288 # So we return the corresponding argument, no mater what!
1289 if resolved_receiver
.mclass
== self.mclass
then
1290 var res
= resolved_receiver
.arguments
[self.rank
]
1291 #print "{class_name}: {self}/{mtype}/{anchor} -> direct {res}"
1295 if resolved_receiver
.need_anchor
then
1296 assert anchor
!= null
1297 resolved_receiver
= resolved_receiver
.resolve_for
(anchor
, null, mmodule
, false)
1299 # Now, we can get the bound
1300 var verbatim_bound
= lookup_bound
(mmodule
, resolved_receiver
)
1301 # The bound is exactly as declared in the "type" property, so we must resolve it again
1302 var res
= verbatim_bound
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1304 #print "{class_name}: {self}/{mtype}/{anchor} -> indirect {res}"
1309 redef fun can_resolve_for
(mtype
, anchor
, mmodule
)
1311 if mtype
.need_anchor
then
1312 assert anchor
!= null
1313 mtype
= mtype
.anchor_to
(mmodule
, anchor
)
1315 return mtype
.collect_mclassdefs
(mmodule
).has
(mclass
.intro
)
1318 init(mclass
: MClass, rank
: Int)
1320 self.mclass
= mclass
1325 # A type prefixed with "nullable"
1329 # The base type of the nullable type
1332 redef fun model
do return self.mtype
.model
1337 self.to_s
= "nullable {mtype}"
1340 redef var to_s
: String
1342 redef fun need_anchor
do return mtype
.need_anchor
1343 redef fun as_nullable
do return self
1344 redef fun resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1346 var res
= self.mtype
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1347 return res
.as_nullable
1350 redef fun can_resolve_for
(mtype
, anchor
, mmodule
)
1352 return self.mtype
.can_resolve_for
(mtype
, anchor
, mmodule
)
1355 redef fun depth
do return self.mtype
.depth
1357 redef fun length
do return self.mtype
.length
1359 redef fun collect_mclassdefs
(mmodule
)
1361 assert not self.need_anchor
1362 return self.mtype
.collect_mclassdefs
(mmodule
)
1365 redef fun collect_mclasses
(mmodule
)
1367 assert not self.need_anchor
1368 return self.mtype
.collect_mclasses
(mmodule
)
1371 redef fun collect_mtypes
(mmodule
)
1373 assert not self.need_anchor
1374 return self.mtype
.collect_mtypes
(mmodule
)
1378 # The type of the only value null
1380 # The is only one null type per model, see `MModel::null_type`.
1383 redef var model
: Model
1384 protected init(model
: Model)
1388 redef fun to_s
do return "null"
1389 redef fun as_nullable
do return self
1390 redef fun need_anchor
do return false
1391 redef fun resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
) do return self
1392 redef fun can_resolve_for
(mtype
, anchor
, mmodule
) do return true
1394 redef fun collect_mclassdefs
(mmodule
) do return new HashSet[MClassDef]
1396 redef fun collect_mclasses
(mmodule
) do return new HashSet[MClass]
1398 redef fun collect_mtypes
(mmodule
) do return new HashSet[MClassType]
1401 # A signature of a method
1405 # The each parameter (in order)
1406 var mparameters
: Array[MParameter]
1408 # The return type (null for a procedure)
1409 var return_mtype
: nullable MType
1414 var t
= self.return_mtype
1415 if t
!= null then dmax
= t
.depth
1416 for p
in mparameters
do
1417 var d
= p
.mtype
.depth
1418 if d
> dmax
then dmax
= d
1426 var t
= self.return_mtype
1427 if t
!= null then res
+= t
.length
1428 for p
in mparameters
do
1429 res
+= p
.mtype
.length
1434 # REQUIRE: 1 <= mparameters.count p -> p.is_vararg
1435 init(mparameters
: Array[MParameter], return_mtype
: nullable MType)
1437 var vararg_rank
= -1
1438 for i
in [0..mparameters
.length
[ do
1439 var parameter
= mparameters
[i
]
1440 if parameter
.is_vararg
then
1441 assert vararg_rank
== -1
1445 self.mparameters
= mparameters
1446 self.return_mtype
= return_mtype
1447 self.vararg_rank
= vararg_rank
1450 # The rank of the ellipsis (`...`) for vararg (starting from 0).
1451 # value is -1 if there is no vararg.
1452 # Example: for "(a: Int, b: Bool..., c: Char)" #-> vararg_rank=1
1453 var vararg_rank
: Int
1455 # The number or parameters
1456 fun arity
: Int do return mparameters
.length
1460 var b
= new FlatBuffer
1461 if not mparameters
.is_empty
then
1463 for i
in [0..mparameters
.length
[ do
1464 var mparameter
= mparameters
[i
]
1465 if i
> 0 then b
.append
(", ")
1466 b
.append
(mparameter
.name
)
1468 b
.append
(mparameter
.mtype
.to_s
)
1469 if mparameter
.is_vararg
then
1475 var ret
= self.return_mtype
1483 redef fun resolve_for
(mtype
: MType, anchor
: nullable MClassType, mmodule
: MModule, cleanup_virtual
: Bool): MSignature
1485 var params
= new Array[MParameter]
1486 for p
in self.mparameters
do
1487 params
.add
(p
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
))
1489 var ret
= self.return_mtype
1491 ret
= ret
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1493 var res
= new MSignature(params
, ret
)
1498 # A parameter in a signature
1502 # The name of the parameter
1503 redef var name
: String
1505 # The static type of the parameter
1508 # Is the parameter a vararg?
1511 init(name
: String, mtype
: MType, is_vararg
: Bool) do
1514 self.is_vararg
= is_vararg
1520 return "{name}: {mtype}..."
1522 return "{name}: {mtype}"
1526 fun resolve_for
(mtype
: MType, anchor
: nullable MClassType, mmodule
: MModule, cleanup_virtual
: Bool): MParameter
1528 if not self.mtype
.need_anchor
then return self
1529 var newtype
= self.mtype
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1530 var res
= new MParameter(self.name
, newtype
, self.is_vararg
)
1535 # A service (global property) that generalize method, attribute, etc.
1537 # `MProperty` are global to the model; it means that a `MProperty` is not bound
1538 # to a specific `MModule` nor a specific `MClass`.
1540 # A MProperty gather definitions (see `mpropdefs`) ; one for the introduction
1541 # and the other in subclasses and in refinements.
1543 # A `MProperty` is used to denotes services in polymorphic way (ie. independent
1544 # of any dynamic type).
1545 # For instance, a call site "x.foo" is associated to a `MProperty`.
1546 abstract class MProperty
1549 # The associated MPropDef subclass.
1550 # The two specialization hierarchy are symmetric.
1551 type MPROPDEF: MPropDef
1553 # The classdef that introduce the property
1554 # While a property is not bound to a specific module, or class,
1555 # the introducing mclassdef is used for naming and visibility
1556 var intro_mclassdef
: MClassDef
1558 # The (short) name of the property
1559 redef var name
: String
1561 # The canonical name of the property
1562 # Example: "owner::my_module::MyClass::my_method"
1563 fun full_name
: String
1565 return "{self.intro_mclassdef.mmodule.full_name}::{self.intro_mclassdef.mclass.name}::{name}"
1568 # The visibility of the property
1569 var visibility
: MVisibility
1571 init(intro_mclassdef
: MClassDef, name
: String, visibility
: MVisibility)
1573 self.intro_mclassdef
= intro_mclassdef
1575 self.visibility
= visibility
1576 intro_mclassdef
.intro_mproperties
.add
(self)
1577 var model
= intro_mclassdef
.mmodule
.model
1578 model
.mproperties_by_name
.add_one
(name
, self)
1579 model
.mproperties
.add
(self)
1582 # All definitions of the property.
1583 # The first is the introduction,
1584 # The other are redefinitions (in refinements and in subclasses)
1585 var mpropdefs
: Array[MPROPDEF] = new Array[MPROPDEF]
1587 # The definition that introduced the property
1588 # Warning: the introduction is the first `MPropDef` object
1589 # associated to self. If self is just created without having any
1590 # associated definition, this method will abort
1591 fun intro
: MPROPDEF do return mpropdefs
.first
1594 redef fun to_s
do return name
1596 # Return the most specific property definitions defined or inherited by a type.
1597 # The selection knows that refinement is stronger than specialization;
1598 # however, in case of conflict more than one property are returned.
1599 # If mtype does not know mproperty then an empty array is returned.
1601 # If you want the really most specific property, then look at `lookup_first_definition`
1602 fun lookup_definitions
(mmodule
: MModule, mtype
: MType): Array[MPROPDEF]
1604 assert not mtype
.need_anchor
1605 if mtype
isa MNullableType then mtype
= mtype
.mtype
1607 var cache
= self.lookup_definitions_cache
[mmodule
, mtype
]
1608 if cache
!= null then return cache
1610 #print "select prop {mproperty} for {mtype} in {self}"
1611 # First, select all candidates
1612 var candidates
= new Array[MPROPDEF]
1613 for mpropdef
in self.mpropdefs
do
1614 # If the definition is not imported by the module, then skip
1615 if not mmodule
.in_importation
<= mpropdef
.mclassdef
.mmodule
then continue
1616 # If the definition is not inherited by the type, then skip
1617 if not mtype
.is_subtype
(mmodule
, null, mpropdef
.mclassdef
.bound_mtype
) then continue
1619 candidates
.add
(mpropdef
)
1621 # Fast track for only one candidate
1622 if candidates
.length
<= 1 then
1623 self.lookup_definitions_cache
[mmodule
, mtype
] = candidates
1627 # Second, filter the most specific ones
1628 return select_most_specific
(mmodule
, candidates
)
1631 private var lookup_definitions_cache
: HashMap2[MModule, MType, Array[MPROPDEF]] = new HashMap2[MModule, MType, Array[MPROPDEF]]
1633 # Return the most specific property definitions inherited by a type.
1634 # The selection knows that refinement is stronger than specialization;
1635 # however, in case of conflict more than one property are returned.
1636 # If mtype does not know mproperty then an empty array is returned.
1638 # If you want the really most specific property, then look at `lookup_next_definition`
1640 # FIXME: Move to `MPropDef`?
1641 fun lookup_super_definitions
(mmodule
: MModule, mtype
: MType): Array[MPROPDEF]
1643 assert not mtype
.need_anchor
1644 if mtype
isa MNullableType then mtype
= mtype
.mtype
1646 # First, select all candidates
1647 var candidates
= new Array[MPROPDEF]
1648 for mpropdef
in self.mpropdefs
do
1649 # If the definition is not imported by the module, then skip
1650 if not mmodule
.in_importation
<= mpropdef
.mclassdef
.mmodule
then continue
1651 # If the definition is not inherited by the type, then skip
1652 if not mtype
.is_subtype
(mmodule
, null, mpropdef
.mclassdef
.bound_mtype
) then continue
1653 # If the definition is defined by the type, then skip (we want the super, so e skip the current)
1654 if mtype
== mpropdef
.mclassdef
.bound_mtype
and mmodule
== mpropdef
.mclassdef
.mmodule
then continue
1656 candidates
.add
(mpropdef
)
1658 # Fast track for only one candidate
1659 if candidates
.length
<= 1 then return candidates
1661 # Second, filter the most specific ones
1662 return select_most_specific
(mmodule
, candidates
)
1665 # Return an array containing olny the most specific property definitions
1666 # This is an helper function for `lookup_definitions` and `lookup_super_definitions`
1667 private fun select_most_specific
(mmodule
: MModule, candidates
: Array[MPROPDEF]): Array[MPROPDEF]
1669 var res
= new Array[MPROPDEF]
1670 for pd1
in candidates
do
1671 var cd1
= pd1
.mclassdef
1674 for pd2
in candidates
do
1675 if pd2
== pd1
then continue # do not compare with self!
1676 var cd2
= pd2
.mclassdef
1678 if c2
.mclass_type
== c1
.mclass_type
then
1679 if cd2
.mmodule
.in_importation
< cd1
.mmodule
then
1680 # cd2 refines cd1; therefore we skip pd1
1684 else if cd2
.bound_mtype
.is_subtype
(mmodule
, null, cd1
.bound_mtype
) and cd2
.bound_mtype
!= cd1
.bound_mtype
then
1685 # cd2 < cd1; therefore we skip pd1
1694 if res
.is_empty
then
1695 print
"All lost! {candidates.join(", ")}"
1696 # FIXME: should be abort!
1701 # Return the most specific definition in the linearization of `mtype`.
1703 # If you want to know the next properties in the linearization,
1704 # look at `MPropDef::lookup_next_definition`.
1706 # FIXME: the linearisation is still unspecified
1708 # REQUIRE: `not mtype.need_anchor`
1709 # REQUIRE: `mtype.has_mproperty(mmodule, self)`
1710 fun lookup_first_definition
(mmodule
: MModule, mtype
: MType): MPROPDEF
1712 assert mtype
.has_mproperty
(mmodule
, self)
1713 return lookup_all_definitions
(mmodule
, mtype
).first
1716 # Return all definitions in a linearisation order
1717 # Most speficic first, most general last
1718 fun lookup_all_definitions
(mmodule
: MModule, mtype
: MType): Array[MPROPDEF]
1720 assert not mtype
.need_anchor
1721 if mtype
isa MNullableType then mtype
= mtype
.mtype
1723 var cache
= self.lookup_all_definitions_cache
[mmodule
, mtype
]
1724 if cache
!= null then return cache
1726 #print "select prop {mproperty} for {mtype} in {self}"
1727 # First, select all candidates
1728 var candidates
= new Array[MPROPDEF]
1729 for mpropdef
in self.mpropdefs
do
1730 # If the definition is not imported by the module, then skip
1731 if not mmodule
.in_importation
<= mpropdef
.mclassdef
.mmodule
then continue
1732 # If the definition is not inherited by the type, then skip
1733 if not mtype
.is_subtype
(mmodule
, null, mpropdef
.mclassdef
.bound_mtype
) then continue
1735 candidates
.add
(mpropdef
)
1737 # Fast track for only one candidate
1738 if candidates
.length
<= 1 then
1739 self.lookup_all_definitions_cache
[mmodule
, mtype
] = candidates
1743 mmodule
.linearize_mpropdefs
(candidates
)
1744 candidates
= candidates
.reversed
1745 self.lookup_all_definitions_cache
[mmodule
, mtype
] = candidates
1749 private var lookup_all_definitions_cache
: HashMap2[MModule, MType, Array[MPROPDEF]] = new HashMap2[MModule, MType, Array[MPROPDEF]]
1756 redef type MPROPDEF: MMethodDef
1758 init(intro_mclassdef
: MClassDef, name
: String, visibility
: MVisibility)
1763 # Is the property defined at the top_level of the module?
1764 # Currently such a property are stored in `Object`
1765 var is_toplevel
: Bool writable = false
1767 # Is the property a constructor?
1768 # Warning, this property can be inherited by subclasses with or without being a constructor
1769 # therefore, you should use `is_init_for` the verify if the property is a legal constructor for a given class
1770 var is_init
: Bool writable = false
1772 # The the property a 'new' contructor?
1773 var is_new
: Bool writable = false
1775 # Is the property a legal constructor for a given class?
1776 # As usual, visibility is not considered.
1777 # FIXME not implemented
1778 fun is_init_for
(mclass
: MClass): Bool
1784 # A global attribute
1788 redef type MPROPDEF: MAttributeDef
1790 init(intro_mclassdef
: MClassDef, name
: String, visibility
: MVisibility)
1796 # A global virtual type
1797 class MVirtualTypeProp
1800 redef type MPROPDEF: MVirtualTypeDef
1802 init(intro_mclassdef
: MClassDef, name
: String, visibility
: MVisibility)
1807 # The formal type associated to the virtual type property
1808 var mvirtualtype
: MVirtualType = new MVirtualType(self)
1811 # A definition of a property (local property)
1813 # Unlike `MProperty`, a `MPropDef` is a local definition that belong to a
1814 # specific class definition (which belong to a specific module)
1815 abstract class MPropDef
1818 # The associated `MProperty` subclass.
1819 # the two specialization hierarchy are symmetric
1820 type MPROPERTY: MProperty
1823 type MPROPDEF: MPropDef
1825 # The origin of the definition
1826 var location
: Location
1828 # The class definition where the property definition is
1829 var mclassdef
: MClassDef
1831 # The associated global property
1832 var mproperty
: MPROPERTY
1834 init(mclassdef
: MClassDef, mproperty
: MPROPERTY, location
: Location)
1836 self.mclassdef
= mclassdef
1837 self.mproperty
= mproperty
1838 self.location
= location
1839 mclassdef
.mpropdefs
.add
(self)
1840 mproperty
.mpropdefs
.add
(self)
1841 self.to_s
= "{mclassdef}#{mproperty}"
1844 # Actually the name of the `mproperty`
1845 redef fun name
do return mproperty
.name
1847 # Internal name combining the module, the class and the property
1848 # Example: "mymodule#MyClass#mymethod"
1849 redef var to_s
: String
1851 # Is self the definition that introduce the property?
1852 fun is_intro
: Bool do return mproperty
.intro
== self
1854 # Return the next definition in linearization of `mtype`.
1856 # This method is used to determine what method is called by a super.
1858 # REQUIRE: `not mtype.need_anchor`
1859 fun lookup_next_definition
(mmodule
: MModule, mtype
: MType): MPROPDEF
1861 assert not mtype
.need_anchor
1863 var mpropdefs
= self.mproperty
.lookup_all_definitions
(mmodule
, mtype
)
1864 var i
= mpropdefs
.iterator
1865 while i
.is_ok
and i
.item
!= self do i
.next
1866 assert has_property
: i
.is_ok
1868 assert has_next_property
: i
.is_ok
1873 # A local definition of a method
1877 redef type MPROPERTY: MMethod
1878 redef type MPROPDEF: MMethodDef
1880 init(mclassdef
: MClassDef, mproperty
: MPROPERTY, location
: Location)
1885 # The signature attached to the property definition
1886 var msignature
: nullable MSignature writable = null
1888 # Is the method definition abstract?
1889 var is_abstract
: Bool writable = false
1891 # Is the method definition intern?
1892 var is_intern
writable = false
1894 # Is the method definition extern?
1895 var is_extern
writable = false
1898 # A local definition of an attribute
1902 redef type MPROPERTY: MAttribute
1903 redef type MPROPDEF: MAttributeDef
1905 init(mclassdef
: MClassDef, mproperty
: MPROPERTY, location
: Location)
1910 # The static type of the attribute
1911 var static_mtype
: nullable MType writable = null
1914 # A local definition of a virtual type
1915 class MVirtualTypeDef
1918 redef type MPROPERTY: MVirtualTypeProp
1919 redef type MPROPDEF: MVirtualTypeDef
1921 init(mclassdef
: MClassDef, mproperty
: MPROPERTY, location
: Location)
1926 # The bound of the virtual type
1927 var bound
: nullable MType writable = null
1934 # * `interface_kind`
1938 # Note this class is basically an enum.
1939 # FIXME: use a real enum once user-defined enums are available
1941 redef var to_s
: String
1943 # Is a constructor required?
1945 private init(s
: String, need_init
: Bool)
1948 self.need_init
= need_init
1951 # Can a class of kind `self` specializes a class of kine `other`?
1952 fun can_specialize
(other
: MClassKind): Bool
1954 if other
== interface_kind
then return true # everybody can specialize interfaces
1955 if self == interface_kind
or self == enum_kind
then
1956 # no other case for interfaces
1958 else if self == extern_kind
then
1959 # only compatible with themselve
1960 return self == other
1961 else if other
== enum_kind
or other
== extern_kind
then
1962 # abstract_kind and concrete_kind are incompatible
1965 # remain only abstract_kind and concrete_kind
1970 fun abstract_kind
: MClassKind do return once
new MClassKind("abstract class", true)
1971 fun concrete_kind
: MClassKind do return once
new MClassKind("class", true)
1972 fun interface_kind
: MClassKind do return once
new MClassKind("interface", false)
1973 fun enum_kind
: MClassKind do return once
new MClassKind("enum", false)
1974 fun extern_kind
: MClassKind do return once
new MClassKind("extern class", false)