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
31 private import more_collections
35 var mclasses
= new Array[MClass]
37 # All known properties
38 var mproperties
= new Array[MProperty]
40 # Hierarchy of class definition.
42 # Each classdef is associated with its super-classdefs in regard to
43 # its module of definition.
44 var mclassdef_hierarchy
= new POSet[MClassDef]
46 # Class-type hierarchy restricted to the introduction.
48 # The idea is that what is true on introduction is always true whatever
49 # the module considered.
50 # Therefore, this hierarchy is used for a fast positive subtype check.
52 # This poset will evolve in a monotonous way:
53 # * Two non connected nodes will remain unconnected
54 # * New nodes can appear with new edges
55 private var intro_mtype_specialization_hierarchy
= new POSet[MClassType]
57 # Global overlapped class-type hierarchy.
58 # The hierarchy when all modules are combined.
59 # Therefore, this hierarchy is used for a fast negative subtype check.
61 # This poset will evolve in an anarchic way. Loops can even be created.
63 # FIXME decide what to do on loops
64 private var full_mtype_specialization_hierarchy
= new POSet[MClassType]
66 # Collections of classes grouped by their short name
67 private var mclasses_by_name
= new MultiHashMap[String, MClass]
69 # Return all class named `name`.
71 # If such a class does not exist, null is returned
72 # (instead of an empty array)
74 # Visibility or modules are not considered
75 fun get_mclasses_by_name
(name
: String): nullable Array[MClass]
77 if mclasses_by_name
.has_key
(name
) then
78 return mclasses_by_name
[name
]
84 # Collections of properties grouped by their short name
85 private var mproperties_by_name
= new MultiHashMap[String, MProperty]
87 # Return all properties named `name`.
89 # If such a property does not exist, null is returned
90 # (instead of an empty array)
92 # Visibility or modules are not considered
93 fun get_mproperties_by_name
(name
: String): nullable Array[MProperty]
95 if not mproperties_by_name
.has_key
(name
) then
98 return mproperties_by_name
[name
]
103 var null_type
= new MNullType(self)
105 # Build an ordered tree with from `concerns`
106 fun concerns_tree
(mconcerns
: Collection[MConcern]): ConcernsTree do
107 var seen
= new HashSet[MConcern]
108 var res
= new ConcernsTree
110 var todo
= new Array[MConcern]
111 todo
.add_all mconcerns
113 while not todo
.is_empty
do
115 if seen
.has
(c
) then continue
116 var pc
= c
.parent_concern
130 # An OrderedTree that can be easily refined for display purposes
132 super OrderedTree[MConcern]
136 # All the classes introduced in the module
137 var intro_mclasses
= new Array[MClass]
139 # All the class definitions of the module
140 # (introduction and refinement)
141 var mclassdefs
= new Array[MClassDef]
143 # Does the current module has a given class `mclass`?
144 # Return true if the mmodule introduces, refines or imports a class.
145 # Visibility is not considered.
146 fun has_mclass
(mclass
: MClass): Bool
148 return self.in_importation
<= mclass
.intro_mmodule
151 # Full hierarchy of introduced ans imported classes.
153 # Create a new hierarchy got by flattening the classes for the module
154 # and its imported modules.
155 # Visibility is not considered.
157 # Note: this function is expensive and is usually used for the main
158 # module of a program only. Do not use it to do you own subtype
160 fun flatten_mclass_hierarchy
: POSet[MClass]
162 var res
= self.flatten_mclass_hierarchy_cache
163 if res
!= null then return res
164 res
= new POSet[MClass]
165 for m
in self.in_importation
.greaters
do
166 for cd
in m
.mclassdefs
do
169 for s
in cd
.supertypes
do
170 res
.add_edge
(c
, s
.mclass
)
174 self.flatten_mclass_hierarchy_cache
= res
178 # Sort a given array of classes using the linearization order of the module
179 # The most general is first, the most specific is last
180 fun linearize_mclasses
(mclasses
: Array[MClass])
182 self.flatten_mclass_hierarchy
.sort
(mclasses
)
185 # Sort a given array of class definitions using the linearization order of the module
186 # the refinement link is stronger than the specialisation link
187 # The most general is first, the most specific is last
188 fun linearize_mclassdefs
(mclassdefs
: Array[MClassDef])
190 var sorter
= new MClassDefSorter(self)
191 sorter
.sort
(mclassdefs
)
194 # Sort a given array of property definitions using the linearization order of the module
195 # the refinement link is stronger than the specialisation link
196 # The most general is first, the most specific is last
197 fun linearize_mpropdefs
(mpropdefs
: Array[MPropDef])
199 var sorter
= new MPropDefSorter(self)
200 sorter
.sort
(mpropdefs
)
203 private var flatten_mclass_hierarchy_cache
: nullable POSet[MClass] = null
205 # The primitive type `Object`, the root of the class hierarchy
206 fun object_type
: MClassType
208 var res
= self.object_type_cache
209 if res
!= null then return res
210 res
= self.get_primitive_class
("Object").mclass_type
211 self.object_type_cache
= res
215 private var object_type_cache
: nullable MClassType
217 # The type `Pointer`, super class to all extern classes
218 var pointer_type
: MClassType = self.get_primitive_class
("Pointer").mclass_type
is lazy
220 # The primitive type `Bool`
221 fun bool_type
: MClassType
223 var res
= self.bool_type_cache
224 if res
!= null then return res
225 res
= self.get_primitive_class
("Bool").mclass_type
226 self.bool_type_cache
= res
230 private var bool_type_cache
: nullable MClassType
232 # The primitive type `Sys`, the main type of the program, if any
233 fun sys_type
: nullable MClassType
235 var clas
= self.model
.get_mclasses_by_name
("Sys")
236 if clas
== null then return null
237 return get_primitive_class
("Sys").mclass_type
240 # The primitive type `Finalizable`
241 # Used to tag classes that need to be finalized.
242 fun finalizable_type
: nullable MClassType
244 var clas
= self.model
.get_mclasses_by_name
("Finalizable")
245 if clas
== null then return null
246 return get_primitive_class
("Finalizable").mclass_type
249 # Force to get the primitive class named `name` or abort
250 fun get_primitive_class
(name
: String): MClass
252 var cla
= self.model
.get_mclasses_by_name
(name
)
254 if name
== "Bool" then
255 var c
= new MClass(self, name
, null, enum_kind
, public_visibility
)
256 var cladef
= new MClassDef(self, c
.mclass_type
, new Location(null, 0,0,0,0))
259 print
("Fatal Error: no primitive class {name}")
262 if cla
.length
!= 1 then
263 var msg
= "Fatal Error: more than one primitive class {name}:"
264 for c
in cla
do msg
+= " {c.full_name}"
271 # Try to get the primitive method named `name` on the type `recv`
272 fun try_get_primitive_method
(name
: String, recv
: MClass): nullable MMethod
274 var props
= self.model
.get_mproperties_by_name
(name
)
275 if props
== null then return null
276 var res
: nullable MMethod = null
277 for mprop
in props
do
278 assert mprop
isa MMethod
279 var intro
= mprop
.intro_mclassdef
280 for mclassdef
in recv
.mclassdefs
do
281 if not self.in_importation
.greaters
.has
(mclassdef
.mmodule
) then continue
282 if not mclassdef
.in_hierarchy
.greaters
.has
(intro
) then continue
285 else if res
!= mprop
then
286 print
("Fatal Error: ambigous property name '{name}'; conflict between {mprop.full_name} and {res.full_name}")
295 private class MClassDefSorter
297 redef type COMPARED: MClassDef
299 redef fun compare
(a
, b
)
303 if ca
!= cb
then return mmodule
.flatten_mclass_hierarchy
.compare
(ca
, cb
)
304 return mmodule
.model
.mclassdef_hierarchy
.compare
(a
, b
)
308 private class MPropDefSorter
310 redef type COMPARED: MPropDef
312 redef fun compare
(pa
, pb
)
318 if ca
!= cb
then return mmodule
.flatten_mclass_hierarchy
.compare
(ca
, cb
)
319 return mmodule
.model
.mclassdef_hierarchy
.compare
(a
, b
)
325 # `MClass` are global to the model; it means that a `MClass` is not bound to a
326 # specific `MModule`.
328 # This characteristic helps the reasoning about classes in a program since a
329 # single `MClass` object always denote the same class.
331 # The drawback is that classes (`MClass`) contain almost nothing by themselves.
332 # These do not really have properties nor belong to a hierarchy since the property and the
333 # hierarchy of a class depends of the refinement in the modules.
335 # Most services on classes require the precision of a module, and no one can asks what are
336 # the super-classes of a class nor what are properties of a class without precising what is
337 # the module considered.
339 # For instance, during the typing of a source-file, the module considered is the module of the file.
340 # eg. the question *is the method `foo` exists in the class `Bar`?* must be reformulated into
341 # *is the method `foo` exists in the class `Bar` in the current module?*
343 # During some global analysis, the module considered may be the main module of the program.
347 # The module that introduce the class
348 # While classes are not bound to a specific module,
349 # the introducing module is used for naming an visibility
350 var intro_mmodule
: MModule
352 # The short name of the class
353 # In Nit, the name of a class cannot evolve in refinements
354 redef var name
: String
356 # The canonical name of the class
357 # Example: `"owner::module::MyClass"`
358 fun full_name
: String
360 return "{self.intro_mmodule.full_name}::{name}"
363 # The number of generic formal parameters
364 # 0 if the class is not generic
365 var arity
: Int is noinit
367 # Each generic formal parameters in order.
368 # is empty if the class is not generic
369 var mparameters
= new Array[MParameterType]
371 protected fun setup_parameter_names
(parameter_names
: nullable Array[String]) is
374 if parameter_names
== null then
377 self.arity
= parameter_names
.length
380 # Create the formal parameter types
382 assert parameter_names
!= null
383 var mparametertypes
= new Array[MParameterType]
384 for i
in [0..arity
[ do
385 var mparametertype
= new MParameterType(self, i
, parameter_names
[i
])
386 mparametertypes
.add
(mparametertype
)
388 self.mparameters
= mparametertypes
389 var mclass_type
= new MGenericType(self, mparametertypes
)
390 self.mclass_type
= mclass_type
391 self.get_mtype_cache
.add
(mclass_type
)
393 self.mclass_type
= new MClassType(self)
397 # The kind of the class (interface, abstract class, etc.)
398 # In Nit, the kind of a class cannot evolve in refinements
401 # The visibility of the class
402 # In Nit, the visibility of a class cannot evolve in refinements
403 var visibility
: MVisibility
407 intro_mmodule
.intro_mclasses
.add
(self)
408 var model
= intro_mmodule
.model
409 model
.mclasses_by_name
.add_one
(name
, self)
410 model
.mclasses
.add
(self)
413 redef fun model
do return intro_mmodule
.model
415 # All class definitions (introduction and refinements)
416 var mclassdefs
= new Array[MClassDef]
419 redef fun to_s
do return self.name
421 # The definition that introduces the class.
423 # Warning: such a definition may not exist in the early life of the object.
424 # In this case, the method will abort.
425 var intro
: MClassDef is noinit
427 # Return the class `self` in the class hierarchy of the module `mmodule`.
429 # SEE: `MModule::flatten_mclass_hierarchy`
430 # REQUIRE: `mmodule.has_mclass(self)`
431 fun in_hierarchy
(mmodule
: MModule): POSetElement[MClass]
433 return mmodule
.flatten_mclass_hierarchy
[self]
436 # The principal static type of the class.
438 # For non-generic class, mclass_type is the only `MClassType` based
441 # For a generic class, the arguments are the formal parameters.
442 # i.e.: for the class Array[E:Object], the `mclass_type` is Array[E].
443 # If you want Array[Object] the see `MClassDef::bound_mtype`
445 # For generic classes, the mclass_type is also the way to get a formal
446 # generic parameter type.
448 # To get other types based on a generic class, see `get_mtype`.
450 # ENSURE: `mclass_type.mclass == self`
451 var mclass_type
: MClassType is noinit
453 # Return a generic type based on the class
454 # Is the class is not generic, then the result is `mclass_type`
456 # REQUIRE: `mtype_arguments.length == self.arity`
457 fun get_mtype
(mtype_arguments
: Array[MType]): MClassType
459 assert mtype_arguments
.length
== self.arity
460 if self.arity
== 0 then return self.mclass_type
461 for t
in self.get_mtype_cache
do
462 if t
.arguments
== mtype_arguments
then
466 var res
= new MGenericType(self, mtype_arguments
)
467 self.get_mtype_cache
.add res
471 private var get_mtype_cache
= new Array[MGenericType]
475 # A definition (an introduction or a refinement) of a class in a module
477 # A `MClassDef` is associated with an explicit (or almost) definition of a
478 # class. Unlike `MClass`, a `MClassDef` is a local definition that belong to
479 # a specific class and a specific module, and contains declarations like super-classes
482 # It is the class definitions that are the backbone of most things in the model:
483 # ClassDefs are defined with regard with other classdefs.
484 # Refinement and specialization are combined to produce a big poset called the `Model::mclassdef_hierarchy`.
486 # Moreover, the extension and the intention of types is defined by looking at the MClassDefs.
490 # The module where the definition is
493 # The associated `MClass`
494 var mclass
: MClass is noinit
496 # The bounded type associated to the mclassdef
498 # For a non-generic class, `bound_mtype` and `mclass.mclass_type`
502 # For the classdef Array[E: Object], the bound_mtype is Array[Object].
503 # If you want Array[E], then see `mclass.mclass_type`
505 # ENSURE: `bound_mtype.mclass == self.mclass`
506 var bound_mtype
: MClassType
508 # The origin of the definition
509 var location
: Location
511 # Internal name combining the module and the class
512 # Example: "mymodule#MyClass"
513 redef var to_s
: String is noinit
517 self.mclass
= bound_mtype
.mclass
518 mmodule
.mclassdefs
.add
(self)
519 mclass
.mclassdefs
.add
(self)
520 if mclass
.intro_mmodule
== mmodule
then
521 assert not isset mclass
._intro
524 self.to_s
= "{mmodule}#{mclass}"
527 # Actually the name of the `mclass`
528 redef fun name
do return mclass
.name
530 redef fun model
do return mmodule
.model
532 # All declared super-types
533 # FIXME: quite ugly but not better idea yet
534 var supertypes
= new Array[MClassType]
536 # Register some super-types for the class (ie "super SomeType")
538 # The hierarchy must not already be set
539 # REQUIRE: `self.in_hierarchy == null`
540 fun set_supertypes
(supertypes
: Array[MClassType])
542 assert unique_invocation
: self.in_hierarchy
== null
543 var mmodule
= self.mmodule
544 var model
= mmodule
.model
545 var mtype
= self.bound_mtype
547 for supertype
in supertypes
do
548 self.supertypes
.add
(supertype
)
550 # Register in full_type_specialization_hierarchy
551 model
.full_mtype_specialization_hierarchy
.add_edge
(mtype
, supertype
)
552 # Register in intro_type_specialization_hierarchy
553 if mclass
.intro_mmodule
== mmodule
and supertype
.mclass
.intro_mmodule
== mmodule
then
554 model
.intro_mtype_specialization_hierarchy
.add_edge
(mtype
, supertype
)
560 # Collect the super-types (set by set_supertypes) to build the hierarchy
562 # This function can only invoked once by class
563 # REQUIRE: `self.in_hierarchy == null`
564 # ENSURE: `self.in_hierarchy != null`
567 assert unique_invocation
: self.in_hierarchy
== null
568 var model
= mmodule
.model
569 var res
= model
.mclassdef_hierarchy
.add_node
(self)
570 self.in_hierarchy
= res
571 var mtype
= self.bound_mtype
573 # Here we need to connect the mclassdef to its pairs in the mclassdef_hierarchy
574 # The simpliest way is to attach it to collect_mclassdefs
575 for mclassdef
in mtype
.collect_mclassdefs
(mmodule
) do
576 res
.poset
.add_edge
(self, mclassdef
)
580 # The view of the class definition in `mclassdef_hierarchy`
581 var in_hierarchy
: nullable POSetElement[MClassDef] = null
583 # Is the definition the one that introduced `mclass`?
584 fun is_intro
: Bool do return mclass
.intro
== self
586 # All properties introduced by the classdef
587 var intro_mproperties
= new Array[MProperty]
589 # All property definitions in the class (introductions and redefinitions)
590 var mpropdefs
= new Array[MPropDef]
593 # A global static type
595 # MType are global to the model; it means that a `MType` is not bound to a
596 # specific `MModule`.
597 # This characteristic helps the reasoning about static types in a program
598 # since a single `MType` object always denote the same type.
600 # However, because a `MType` is global, it does not really have properties
601 # nor have subtypes to a hierarchy since the property and the class hierarchy
602 # depends of a module.
603 # Moreover, virtual types an formal generic parameter types also depends on
604 # a receiver to have sense.
606 # Therefore, most method of the types require a module and an anchor.
607 # The module is used to know what are the classes and the specialization
609 # The anchor is used to know what is the bound of the virtual types and formal
610 # generic parameter types.
612 # MType are not directly usable to get properties. See the `anchor_to` method
613 # and the `MClassType` class.
615 # FIXME: the order of the parameters is not the best. We mus pick on from:
616 # * foo(mmodule, anchor, othertype)
617 # * foo(othertype, anchor, mmodule)
618 # * foo(anchor, mmodule, othertype)
619 # * foo(othertype, mmodule, anchor)
623 redef fun name
do return to_s
625 # Return true if `self` is an subtype of `sup`.
626 # The typing is done using the standard typing policy of Nit.
628 # REQUIRE: `anchor == null implies not self.need_anchor and not sup.need_anchor`
629 # REQUIRE: `anchor != null implies self.can_resolve_for(anchor, null, mmodule) and sup.can_resolve_for(anchor, null, mmodule)`
630 fun is_subtype
(mmodule
: MModule, anchor
: nullable MClassType, sup
: MType): Bool
633 if sub
== sup
then return true
634 if anchor
== null then
635 assert not sub
.need_anchor
636 assert not sup
.need_anchor
638 assert sub
.can_resolve_for
(anchor
, null, mmodule
)
639 assert sup
.can_resolve_for
(anchor
, null, mmodule
)
642 # First, resolve the formal types to a common version in the receiver
643 # The trick here is that fixed formal type will be associated to the bound
644 # And unfixed formal types will be associated to a canonical formal type.
645 if sub
isa MParameterType or sub
isa MVirtualType then
646 assert anchor
!= null
647 sub
= sub
.resolve_for
(anchor
.mclass
.mclass_type
, anchor
, mmodule
, false)
649 if sup
isa MParameterType or sup
isa MVirtualType then
650 assert anchor
!= null
651 sup
= sup
.resolve_for
(anchor
.mclass
.mclass_type
, anchor
, mmodule
, false)
654 # Does `sup` accept null or not?
655 # Discard the nullable marker if it exists
656 var sup_accept_null
= false
657 if sup
isa MNullableType then
658 sup_accept_null
= true
660 else if sup
isa MNullType then
661 sup_accept_null
= true
664 # Can `sub` provide null or not?
665 # Thus we can match with `sup_accept_null`
666 # Also discard the nullable marker if it exists
667 if sub
isa MNullableType then
668 if not sup_accept_null
then return false
670 else if sub
isa MNullType then
671 return sup_accept_null
673 # Now the case of direct null and nullable is over.
675 # A unfixed formal type can only accept itself
676 if sup
isa MParameterType or sup
isa MVirtualType then
680 # If `sub` is a formal type, then it is accepted if its bound is accepted
681 if sub
isa MParameterType or sub
isa MVirtualType then
682 assert anchor
!= null
683 sub
= sub
.anchor_to
(mmodule
, anchor
)
685 # Manage the second layer of null/nullable
686 if sub
isa MNullableType then
687 if not sup_accept_null
then return false
689 else if sub
isa MNullType then
690 return sup_accept_null
694 assert sub
isa MClassType # It is the only remaining type
696 if sup
isa MNullType then
697 # `sup` accepts only null
701 assert sup
isa MClassType # It is the only remaining type
703 # Now both are MClassType, we need to dig
705 if sub
== sup
then return true
707 if anchor
== null then anchor
= sub
# UGLY: any anchor will work
708 var resolved_sub
= sub
.anchor_to
(mmodule
, anchor
)
709 var res
= resolved_sub
.collect_mclasses
(mmodule
).has
(sup
.mclass
)
710 if res
== false then return false
711 if not sup
isa MGenericType then return true
712 var sub2
= sub
.supertype_to
(mmodule
, anchor
, sup
.mclass
)
713 assert sub2
.mclass
== sup
.mclass
714 for i
in [0..sup
.mclass
.arity
[ do
715 var sub_arg
= sub2
.arguments
[i
]
716 var sup_arg
= sup
.arguments
[i
]
717 res
= sub_arg
.is_subtype
(mmodule
, anchor
, sup_arg
)
718 if res
== false then return false
723 # The base class type on which self is based
725 # This base type is used to get property (an internally to perform
726 # unsafe type comparison).
728 # Beware: some types (like null) are not based on a class thus this
731 # Basically, this function transform the virtual types and parameter
732 # types to their bounds.
736 # class B super A end
738 # class Y super X end
746 # Map[T,U] anchor_to H #-> Map[B,Y]
748 # Explanation of the example:
749 # In H, T is set to B, because "H super G[B]", and U is bound to Y,
750 # because "redef type U: Y". Therefore, Map[T, U] is bound to
753 # ENSURE: `not self.need_anchor implies result == self`
754 # ENSURE: `not result.need_anchor`
755 fun anchor_to
(mmodule
: MModule, anchor
: MClassType): MType
757 if not need_anchor
then return self
758 assert not anchor
.need_anchor
759 # Just resolve to the anchor and clear all the virtual types
760 var res
= self.resolve_for
(anchor
, null, mmodule
, true)
761 assert not res
.need_anchor
765 # Does `self` contain a virtual type or a formal generic parameter type?
766 # In order to remove those types, you usually want to use `anchor_to`.
767 fun need_anchor
: Bool do return true
769 # Return the supertype when adapted to a class.
771 # In Nit, for each super-class of a type, there is a equivalent super-type.
775 # class H[V] super G[V, Bool] end
776 # H[Int] supertype_to G #-> G[Int, Bool]
778 # REQUIRE: `super_mclass` is a super-class of `self`
779 # REQUIRE: `self.need_anchor implies anchor != null and self.can_resolve_for(anchor, null, mmodule)`
780 # ENSURE: `result.mclass = super_mclass`
781 fun supertype_to
(mmodule
: MModule, anchor
: nullable MClassType, super_mclass
: MClass): MClassType
783 if super_mclass
.arity
== 0 then return super_mclass
.mclass_type
784 if self isa MClassType and self.mclass
== super_mclass
then return self
786 if self.need_anchor
then
787 assert anchor
!= null
788 resolved_self
= self.anchor_to
(mmodule
, anchor
)
792 var supertypes
= resolved_self
.collect_mtypes
(mmodule
)
793 for supertype
in supertypes
do
794 if supertype
.mclass
== super_mclass
then
795 # FIXME: Here, we stop on the first goal. Should we check others and detect inconsistencies?
796 return supertype
.resolve_for
(self, anchor
, mmodule
, false)
802 # Replace formals generic types in self with resolved values in `mtype`
803 # If `cleanup_virtual` is true, then virtual types are also replaced
806 # This function returns self if `need_anchor` is false.
811 # class H[F] super G[F] end
814 # * Array[E].resolve_for(H[Int]) #-> Array[Int]
815 # * Array[E].resolve_for(G[Z], X[Int]) #-> Array[Z]
817 # Explanation of the example:
818 # * Array[E].need_anchor is true because there is a formal generic parameter type E
819 # * E makes sense for H[Int] because E is a formal parameter of G and H specialize G
820 # * Since "H[F] super G[F]", E is in fact F for H
821 # * More specifically, in H[Int], E is Int
822 # * So, in H[Int], Array[E] is Array[Int]
824 # This function is mainly used to inherit a signature.
825 # Because, unlike `anchor_to`, we do not want a full resolution of
826 # a type but only an adapted version of it.
831 # fun foo(e:E):E is abstract
833 # class B super A[Int] end
835 # The signature on foo is (e: E): E
836 # If we resolve the signature for B, we get (e:Int):Int
841 # fun foo(e:E) is abstract
845 # fun bar do a.foo(x) # <- x is here
848 # The first question is: is foo available on `a`?
850 # The static type of a is `A[Array[F]]`, that is an open type.
851 # in order to find a method `foo`, whe must look at a resolved type.
853 # A[Array[F]].anchor_to(B[nullable Object]) #-> A[Array[nullable Object]]
855 # the method `foo` exists in `A[Array[nullable Object]]`, therefore `foo` exists for `a`.
857 # The next question is: what is the accepted types for `x`?
859 # the signature of `foo` is `foo(e:E)`, thus we must resolve the type E
861 # E.resolve_for(A[Array[F]],B[nullable Object]) #-> Array[F]
863 # The resolution can be done because `E` make sense for the class A (see `can_resolve_for`)
865 # FIXME: the parameter `cleanup_virtual` is just a bad idea, but having
866 # two function instead of one seems also to be a bad idea.
868 # REQUIRE: `can_resolve_for(mtype, anchor, mmodule)`
869 # ENSURE: `not self.need_anchor implies result == self`
870 fun resolve_for
(mtype
: MType, anchor
: nullable MClassType, mmodule
: MModule, cleanup_virtual
: Bool): MType is abstract
872 # Resolve formal type to its verbatim bound.
873 # If the type is not formal, just return self
875 # The result is returned exactly as declared in the "type" property (verbatim).
876 # So it could be another formal type.
878 # In case of conflict, the method aborts.
879 fun lookup_bound
(mmodule
: MModule, resolved_receiver
: MType): MType do return self
880 # Can the type be resolved?
882 # In order to resolve open types, the formal types must make sence.
891 # * E.can_resolve_for(A[Int]) #-> true, E make sense in A
892 # * E.can_resolve_for(B[Int]) #-> false, E does not make sense in B
893 # * B[E].can_resolve_for(A[F], B[Object]) #-> true,
894 # B[E] is a red hearing only the E is important,
897 # REQUIRE: `anchor != null implies not anchor.need_anchor`
898 # REQUIRE: `mtype.need_anchor implies anchor != null and mtype.can_resolve_for(anchor, null, mmodule)`
899 # ENSURE: `not self.need_anchor implies result == true`
900 fun can_resolve_for
(mtype
: MType, anchor
: nullable MClassType, mmodule
: MModule): Bool is abstract
902 # Return the nullable version of the type
903 # If the type is already nullable then self is returned
904 fun as_nullable
: MType
906 var res
= self.as_nullable_cache
907 if res
!= null then return res
908 res
= new MNullableType(self)
909 self.as_nullable_cache
= res
913 # Return the not nullable version of the type
914 # Is the type is already not nullable, then self is returned.
916 # Note: this just remove the `nullable` notation, but the result can still contains null.
917 # For instance if `self isa MNullType` or self is a formal type bounded by a nullable type.
918 fun as_notnullable
: MType
923 private var as_nullable_cache
: nullable MType = null
926 # The depth of the type seen as a tree.
933 # Formal types have a depth of 1.
939 # The length of the type seen as a tree.
946 # Formal types have a length of 1.
952 # Compute all the classdefs inherited/imported.
953 # The returned set contains:
954 # * the class definitions from `mmodule` and its imported modules
955 # * the class definitions of this type and its super-types
957 # This function is used mainly internally.
959 # REQUIRE: `not self.need_anchor`
960 fun collect_mclassdefs
(mmodule
: MModule): Set[MClassDef] is abstract
962 # Compute all the super-classes.
963 # This function is used mainly internally.
965 # REQUIRE: `not self.need_anchor`
966 fun collect_mclasses
(mmodule
: MModule): Set[MClass] is abstract
968 # Compute all the declared super-types.
969 # Super-types are returned as declared in the classdefs (verbatim).
970 # This function is used mainly internally.
972 # REQUIRE: `not self.need_anchor`
973 fun collect_mtypes
(mmodule
: MModule): Set[MClassType] is abstract
975 # Is the property in self for a given module
976 # This method does not filter visibility or whatever
978 # REQUIRE: `not self.need_anchor`
979 fun has_mproperty
(mmodule
: MModule, mproperty
: MProperty): Bool
981 assert not self.need_anchor
982 return self.collect_mclassdefs
(mmodule
).has
(mproperty
.intro_mclassdef
)
986 # A type based on a class.
988 # `MClassType` have properties (see `has_mproperty`).
992 # The associated class
995 redef fun model
do return self.mclass
.intro_mmodule
.model
997 # TODO: private init because strongly bounded to its mclass. see `mclass.mclass_type`
999 # The formal arguments of the type
1000 # ENSURE: `result.length == self.mclass.arity`
1001 var arguments
= new Array[MType]
1003 redef fun to_s
do return mclass
.to_s
1005 redef fun need_anchor
do return false
1007 redef fun anchor_to
(mmodule
: MModule, anchor
: MClassType): MClassType
1009 return super.as(MClassType)
1012 redef fun resolve_for
(mtype
: MType, anchor
: nullable MClassType, mmodule
: MModule, cleanup_virtual
: Bool): MClassType do return self
1014 redef fun can_resolve_for
(mtype
, anchor
, mmodule
) do return true
1016 redef fun collect_mclassdefs
(mmodule
)
1018 assert not self.need_anchor
1019 var cache
= self.collect_mclassdefs_cache
1020 if not cache
.has_key
(mmodule
) then
1021 self.collect_things
(mmodule
)
1023 return cache
[mmodule
]
1026 redef fun collect_mclasses
(mmodule
)
1028 assert not self.need_anchor
1029 var cache
= self.collect_mclasses_cache
1030 if not cache
.has_key
(mmodule
) then
1031 self.collect_things
(mmodule
)
1033 return cache
[mmodule
]
1036 redef fun collect_mtypes
(mmodule
)
1038 assert not self.need_anchor
1039 var cache
= self.collect_mtypes_cache
1040 if not cache
.has_key
(mmodule
) then
1041 self.collect_things
(mmodule
)
1043 return cache
[mmodule
]
1046 # common implementation for `collect_mclassdefs`, `collect_mclasses`, and `collect_mtypes`.
1047 private fun collect_things
(mmodule
: MModule)
1049 var res
= new HashSet[MClassDef]
1050 var seen
= new HashSet[MClass]
1051 var types
= new HashSet[MClassType]
1052 seen
.add
(self.mclass
)
1053 var todo
= [self.mclass
]
1054 while not todo
.is_empty
do
1055 var mclass
= todo
.pop
1056 #print "process {mclass}"
1057 for mclassdef
in mclass
.mclassdefs
do
1058 if not mmodule
.in_importation
<= mclassdef
.mmodule
then continue
1059 #print " process {mclassdef}"
1061 for supertype
in mclassdef
.supertypes
do
1062 types
.add
(supertype
)
1063 var superclass
= supertype
.mclass
1064 if seen
.has
(superclass
) then continue
1065 #print " add {superclass}"
1066 seen
.add
(superclass
)
1067 todo
.add
(superclass
)
1071 collect_mclassdefs_cache
[mmodule
] = res
1072 collect_mclasses_cache
[mmodule
] = seen
1073 collect_mtypes_cache
[mmodule
] = types
1076 private var collect_mclassdefs_cache
= new HashMap[MModule, Set[MClassDef]]
1077 private var collect_mclasses_cache
= new HashMap[MModule, Set[MClass]]
1078 private var collect_mtypes_cache
= new HashMap[MModule, Set[MClassType]]
1082 # A type based on a generic class.
1083 # A generic type a just a class with additional formal generic arguments.
1089 # TODO: private init because strongly bounded to its mclass. see `mclass.get_mtype`
1093 assert self.mclass
.arity
== arguments
.length
1095 self.need_anchor
= false
1096 for t
in arguments
do
1097 if t
.need_anchor
then
1098 self.need_anchor
= true
1103 self.to_s
= "{mclass}[{arguments.join(", ")}]"
1106 # Recursively print the type of the arguments within brackets.
1107 # Example: `"Map[String, List[Int]]"`
1108 redef var to_s
: String is noinit
1110 redef var need_anchor
: Bool is noinit
1112 redef fun resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1114 if not need_anchor
then return self
1115 assert can_resolve_for
(mtype
, anchor
, mmodule
)
1116 var types
= new Array[MType]
1117 for t
in arguments
do
1118 types
.add
(t
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
))
1120 return mclass
.get_mtype
(types
)
1123 redef fun can_resolve_for
(mtype
, anchor
, mmodule
)
1125 if not need_anchor
then return true
1126 for t
in arguments
do
1127 if not t
.can_resolve_for
(mtype
, anchor
, mmodule
) then return false
1136 for a
in self.arguments
do
1138 if d
> dmax
then dmax
= d
1146 for a
in self.arguments
do
1153 # A virtual formal type.
1157 # The property associated with the type.
1158 # Its the definitions of this property that determine the bound or the virtual type.
1159 var mproperty
: MVirtualTypeProp
1161 redef fun model
do return self.mproperty
.intro_mclassdef
.mmodule
.model
1163 redef fun lookup_bound
(mmodule
: MModule, resolved_receiver
: MType): MType
1165 return lookup_single_definition
(mmodule
, resolved_receiver
).bound
.as(not null)
1168 private fun lookup_single_definition
(mmodule
: MModule, resolved_receiver
: MType): MVirtualTypeDef
1170 assert not resolved_receiver
.need_anchor
1171 var props
= self.mproperty
.lookup_definitions
(mmodule
, resolved_receiver
)
1172 if props
.is_empty
then
1174 else if props
.length
== 1 then
1177 var types
= new ArraySet[MType]
1178 var res
= props
.first
1180 types
.add
(p
.bound
.as(not null))
1182 if types
.length
== 1 then
1188 # Is the virtual type fixed for a given resolved_receiver?
1189 fun is_fixed
(mmodule
: MModule, resolved_receiver
: MType): Bool
1191 assert not resolved_receiver
.need_anchor
1192 var props
= self.mproperty
.lookup_definitions
(mmodule
, resolved_receiver
)
1193 if props
.is_empty
then
1197 if p
.as(MVirtualTypeDef).is_fixed
then return true
1202 redef fun resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1204 if not cleanup_virtual
then return self
1205 assert can_resolve_for
(mtype
, anchor
, mmodule
)
1206 # self is a virtual type declared (or inherited) in mtype
1207 # The point of the function it to get the bound of the virtual type that make sense for mtype
1208 # But because mtype is maybe a virtual/formal type, we need to get a real receiver first
1209 #print "{class_name}: {self}/{mtype}/{anchor}?"
1210 var resolved_reciever
1211 if mtype
.need_anchor
then
1212 assert anchor
!= null
1213 resolved_reciever
= mtype
.resolve_for
(anchor
, null, mmodule
, true)
1215 resolved_reciever
= mtype
1217 # Now, we can get the bound
1218 var verbatim_bound
= lookup_bound
(mmodule
, resolved_reciever
)
1219 # The bound is exactly as declared in the "type" property, so we must resolve it again
1220 var res
= verbatim_bound
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1221 #print "{class_name}: {self}/{mtype}/{anchor} -> {self}/{resolved_receiver}/{anchor} -> {verbatim_bound}/{mtype}/{anchor} -> {res}"
1223 # What to return here? There is a bunch a special cases:
1224 # If 'cleanup_virtual' we must return the resolved type, since we cannot return self
1225 if cleanup_virtual
then return res
1226 # If the receiver 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
1227 if resolved_reciever
isa MNullableType then resolved_reciever
= resolved_reciever
.mtype
1228 if resolved_reciever
.as(MClassType).mclass
.kind
== enum_kind
then return res
1229 # 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.
1230 if res
isa MVirtualType then return res
1231 # If we are final, just return the resolution
1232 if is_fixed
(mmodule
, resolved_reciever
) then return res
1233 # If the resolved type isa intern class, then there is no possible valid redefinition in any potential subclass. self is just fixed. so simply return the resolution
1234 if res
isa MClassType and res
.mclass
.kind
== enum_kind
then return res
1235 # TODO: What if bound to a MParameterType?
1236 # Note that Nullable types can always be redefined by the non nullable version, so there is no specific case on it.
1238 # If anything apply, then `self' cannot be resolved, so return self
1242 redef fun can_resolve_for
(mtype
, anchor
, mmodule
)
1244 if mtype
.need_anchor
then
1245 assert anchor
!= null
1246 mtype
= mtype
.anchor_to
(mmodule
, anchor
)
1248 return mtype
.has_mproperty
(mmodule
, mproperty
)
1251 redef fun to_s
do return self.mproperty
.to_s
1254 # The type associated to a formal parameter generic type of a class
1256 # Each parameter type is associated to a specific class.
1257 # It means that all refinements of a same class "share" the parameter type,
1258 # but that a generic subclass has its own parameter types.
1260 # However, in the sense of the meta-model, a parameter type of a class is
1261 # a valid type in a subclass. The "in the sense of the meta-model" is
1262 # important because, in the Nit language, the programmer cannot refers
1263 # directly to the parameter types of the super-classes.
1267 # fun e: E is abstract
1272 # In the class definition B[F], `F` is a valid type but `E` is not.
1273 # However, `self.e` is a valid method call, and the signature of `e` is
1276 # Note that parameter types are shared among class refinements.
1277 # Therefore parameter only have an internal name (see `to_s` for details).
1278 class MParameterType
1281 # The generic class where the parameter belong
1284 redef fun model
do return self.mclass
.intro_mmodule
.model
1286 # The position of the parameter (0 for the first parameter)
1287 # FIXME: is `position` a better name?
1292 redef fun to_s
do return name
1294 redef fun lookup_bound
(mmodule
: MModule, resolved_receiver
: MType): MType
1296 assert not resolved_receiver
.need_anchor
1297 assert resolved_receiver
isa MClassType
1298 var goalclass
= self.mclass
1299 if resolved_receiver
.mclass
== goalclass
then
1300 return resolved_receiver
.arguments
[self.rank
]
1302 var supertypes
= resolved_receiver
.collect_mtypes
(mmodule
)
1303 for t
in supertypes
do
1304 if t
.mclass
== goalclass
then
1305 # Yeah! c specialize goalclass with a "super `t'". So the question is what is the argument of f
1306 # FIXME: Here, we stop on the first goal. Should we check others and detect inconsistencies?
1307 var res
= t
.arguments
[self.rank
]
1314 redef fun resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1316 assert can_resolve_for
(mtype
, anchor
, mmodule
)
1317 #print "{class_name}: {self}/{mtype}/{anchor}?"
1319 if mtype
isa MGenericType and mtype
.mclass
== self.mclass
then
1320 var res
= mtype
.arguments
[self.rank
]
1321 if anchor
!= null and res
.need_anchor
then
1322 # Maybe the result can be resolved more if are bound to a final class
1323 var r2
= res
.anchor_to
(mmodule
, anchor
)
1324 if r2
isa MClassType and r2
.mclass
.kind
== enum_kind
then return r2
1329 # self is a parameter type of mtype (or of a super-class of mtype)
1330 # The point of the function it to get the bound of the virtual type that make sense for mtype
1331 # But because mtype is maybe a virtual/formal type, we need to get a real receiver first
1332 # FIXME: What happens here is far from clear. Thus this part must be validated and clarified
1333 var resolved_receiver
1334 if mtype
.need_anchor
then
1335 assert anchor
!= null
1336 resolved_receiver
= mtype
.resolve_for
(anchor
.mclass
.mclass_type
, anchor
, mmodule
, true)
1338 resolved_receiver
= mtype
1340 if resolved_receiver
isa MNullableType then resolved_receiver
= resolved_receiver
.mtype
1341 if resolved_receiver
isa MParameterType then
1342 assert resolved_receiver
.mclass
== anchor
.mclass
1343 resolved_receiver
= anchor
.arguments
[resolved_receiver
.rank
]
1344 if resolved_receiver
isa MNullableType then resolved_receiver
= resolved_receiver
.mtype
1346 assert resolved_receiver
isa MClassType
1348 # Eh! The parameter is in the current class.
1349 # So we return the corresponding argument, no mater what!
1350 if resolved_receiver
.mclass
== self.mclass
then
1351 var res
= resolved_receiver
.arguments
[self.rank
]
1352 #print "{class_name}: {self}/{mtype}/{anchor} -> direct {res}"
1356 if resolved_receiver
.need_anchor
then
1357 assert anchor
!= null
1358 resolved_receiver
= resolved_receiver
.resolve_for
(anchor
, null, mmodule
, false)
1360 # Now, we can get the bound
1361 var verbatim_bound
= lookup_bound
(mmodule
, resolved_receiver
)
1362 # The bound is exactly as declared in the "type" property, so we must resolve it again
1363 var res
= verbatim_bound
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1365 #print "{class_name}: {self}/{mtype}/{anchor} -> indirect {res}"
1370 redef fun can_resolve_for
(mtype
, anchor
, mmodule
)
1372 if mtype
.need_anchor
then
1373 assert anchor
!= null
1374 mtype
= mtype
.anchor_to
(mmodule
, anchor
)
1376 return mtype
.collect_mclassdefs
(mmodule
).has
(mclass
.intro
)
1380 # A type prefixed with "nullable"
1384 # The base type of the nullable type
1387 redef fun model
do return self.mtype
.model
1391 self.to_s
= "nullable {mtype}"
1394 redef var to_s
: String is noinit
1396 redef fun need_anchor
do return mtype
.need_anchor
1397 redef fun as_nullable
do return self
1398 redef fun as_notnullable
do return mtype
1399 redef fun resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1401 var res
= self.mtype
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1402 return res
.as_nullable
1405 redef fun can_resolve_for
(mtype
, anchor
, mmodule
)
1407 return self.mtype
.can_resolve_for
(mtype
, anchor
, mmodule
)
1410 redef fun depth
do return self.mtype
.depth
1412 redef fun length
do return self.mtype
.length
1414 redef fun collect_mclassdefs
(mmodule
)
1416 assert not self.need_anchor
1417 return self.mtype
.collect_mclassdefs
(mmodule
)
1420 redef fun collect_mclasses
(mmodule
)
1422 assert not self.need_anchor
1423 return self.mtype
.collect_mclasses
(mmodule
)
1426 redef fun collect_mtypes
(mmodule
)
1428 assert not self.need_anchor
1429 return self.mtype
.collect_mtypes
(mmodule
)
1433 # The type of the only value null
1435 # The is only one null type per model, see `MModel::null_type`.
1438 redef var model
: Model
1439 redef fun to_s
do return "null"
1440 redef fun as_nullable
do return self
1441 redef fun need_anchor
do return false
1442 redef fun resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
) do return self
1443 redef fun can_resolve_for
(mtype
, anchor
, mmodule
) do return true
1445 redef fun collect_mclassdefs
(mmodule
) do return new HashSet[MClassDef]
1447 redef fun collect_mclasses
(mmodule
) do return new HashSet[MClass]
1449 redef fun collect_mtypes
(mmodule
) do return new HashSet[MClassType]
1452 # A signature of a method
1456 # The each parameter (in order)
1457 var mparameters
: Array[MParameter]
1459 # The return type (null for a procedure)
1460 var return_mtype
: nullable MType
1465 var t
= self.return_mtype
1466 if t
!= null then dmax
= t
.depth
1467 for p
in mparameters
do
1468 var d
= p
.mtype
.depth
1469 if d
> dmax
then dmax
= d
1477 var t
= self.return_mtype
1478 if t
!= null then res
+= t
.length
1479 for p
in mparameters
do
1480 res
+= p
.mtype
.length
1485 # REQUIRE: 1 <= mparameters.count p -> p.is_vararg
1488 var vararg_rank
= -1
1489 for i
in [0..mparameters
.length
[ do
1490 var parameter
= mparameters
[i
]
1491 if parameter
.is_vararg
then
1492 assert vararg_rank
== -1
1496 self.vararg_rank
= vararg_rank
1499 # The rank of the ellipsis (`...`) for vararg (starting from 0).
1500 # value is -1 if there is no vararg.
1501 # Example: for "(a: Int, b: Bool..., c: Char)" #-> vararg_rank=1
1502 var vararg_rank
: Int is noinit
1504 # The number or parameters
1505 fun arity
: Int do return mparameters
.length
1509 var b
= new FlatBuffer
1510 if not mparameters
.is_empty
then
1512 for i
in [0..mparameters
.length
[ do
1513 var mparameter
= mparameters
[i
]
1514 if i
> 0 then b
.append
(", ")
1515 b
.append
(mparameter
.name
)
1517 b
.append
(mparameter
.mtype
.to_s
)
1518 if mparameter
.is_vararg
then
1524 var ret
= self.return_mtype
1532 redef fun resolve_for
(mtype
: MType, anchor
: nullable MClassType, mmodule
: MModule, cleanup_virtual
: Bool): MSignature
1534 var params
= new Array[MParameter]
1535 for p
in self.mparameters
do
1536 params
.add
(p
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
))
1538 var ret
= self.return_mtype
1540 ret
= ret
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1542 var res
= new MSignature(params
, ret
)
1547 # A parameter in a signature
1551 # The name of the parameter
1552 redef var name
: String
1554 # The static type of the parameter
1557 # Is the parameter a vararg?
1563 return "{name}: {mtype}..."
1565 return "{name}: {mtype}"
1569 fun resolve_for
(mtype
: MType, anchor
: nullable MClassType, mmodule
: MModule, cleanup_virtual
: Bool): MParameter
1571 if not self.mtype
.need_anchor
then return self
1572 var newtype
= self.mtype
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1573 var res
= new MParameter(self.name
, newtype
, self.is_vararg
)
1577 redef fun model
do return mtype
.model
1580 # A service (global property) that generalize method, attribute, etc.
1582 # `MProperty` are global to the model; it means that a `MProperty` is not bound
1583 # to a specific `MModule` nor a specific `MClass`.
1585 # A MProperty gather definitions (see `mpropdefs`) ; one for the introduction
1586 # and the other in subclasses and in refinements.
1588 # A `MProperty` is used to denotes services in polymorphic way (ie. independent
1589 # of any dynamic type).
1590 # For instance, a call site "x.foo" is associated to a `MProperty`.
1591 abstract class MProperty
1594 # The associated MPropDef subclass.
1595 # The two specialization hierarchy are symmetric.
1596 type MPROPDEF: MPropDef
1598 # The classdef that introduce the property
1599 # While a property is not bound to a specific module, or class,
1600 # the introducing mclassdef is used for naming and visibility
1601 var intro_mclassdef
: MClassDef
1603 # The (short) name of the property
1604 redef var name
: String
1606 # The canonical name of the property
1607 # Example: "owner::my_module::MyClass::my_method"
1608 fun full_name
: String
1610 return "{self.intro_mclassdef.mmodule.full_name}::{self.intro_mclassdef.mclass.name}::{name}"
1613 # The visibility of the property
1614 var visibility
: MVisibility
1618 intro_mclassdef
.intro_mproperties
.add
(self)
1619 var model
= intro_mclassdef
.mmodule
.model
1620 model
.mproperties_by_name
.add_one
(name
, self)
1621 model
.mproperties
.add
(self)
1624 # All definitions of the property.
1625 # The first is the introduction,
1626 # The other are redefinitions (in refinements and in subclasses)
1627 var mpropdefs
= new Array[MPROPDEF]
1629 # The definition that introduces the property.
1631 # Warning: such a definition may not exist in the early life of the object.
1632 # In this case, the method will abort.
1633 var intro
: MPROPDEF is noinit
1635 redef fun model
do return intro
.model
1638 redef fun to_s
do return name
1640 # Return the most specific property definitions defined or inherited by a type.
1641 # The selection knows that refinement is stronger than specialization;
1642 # however, in case of conflict more than one property are returned.
1643 # If mtype does not know mproperty then an empty array is returned.
1645 # If you want the really most specific property, then look at `lookup_first_definition`
1646 fun lookup_definitions
(mmodule
: MModule, mtype
: MType): Array[MPROPDEF]
1648 assert not mtype
.need_anchor
1649 mtype
= mtype
.as_notnullable
1651 var cache
= self.lookup_definitions_cache
[mmodule
, mtype
]
1652 if cache
!= null then return cache
1654 #print "select prop {mproperty} for {mtype} in {self}"
1655 # First, select all candidates
1656 var candidates
= new Array[MPROPDEF]
1657 for mpropdef
in self.mpropdefs
do
1658 # If the definition is not imported by the module, then skip
1659 if not mmodule
.in_importation
<= mpropdef
.mclassdef
.mmodule
then continue
1660 # If the definition is not inherited by the type, then skip
1661 if not mtype
.is_subtype
(mmodule
, null, mpropdef
.mclassdef
.bound_mtype
) then continue
1663 candidates
.add
(mpropdef
)
1665 # Fast track for only one candidate
1666 if candidates
.length
<= 1 then
1667 self.lookup_definitions_cache
[mmodule
, mtype
] = candidates
1671 # Second, filter the most specific ones
1672 return select_most_specific
(mmodule
, candidates
)
1675 private var lookup_definitions_cache
= new HashMap2[MModule, MType, Array[MPROPDEF]]
1677 # Return the most specific property definitions inherited by a type.
1678 # The selection knows that refinement is stronger than specialization;
1679 # however, in case of conflict more than one property are returned.
1680 # If mtype does not know mproperty then an empty array is returned.
1682 # If you want the really most specific property, then look at `lookup_next_definition`
1684 # FIXME: Move to `MPropDef`?
1685 fun lookup_super_definitions
(mmodule
: MModule, mtype
: MType): Array[MPROPDEF]
1687 assert not mtype
.need_anchor
1688 mtype
= mtype
.as_notnullable
1690 # First, select all candidates
1691 var candidates
= new Array[MPROPDEF]
1692 for mpropdef
in self.mpropdefs
do
1693 # If the definition is not imported by the module, then skip
1694 if not mmodule
.in_importation
<= mpropdef
.mclassdef
.mmodule
then continue
1695 # If the definition is not inherited by the type, then skip
1696 if not mtype
.is_subtype
(mmodule
, null, mpropdef
.mclassdef
.bound_mtype
) then continue
1697 # If the definition is defined by the type, then skip (we want the super, so e skip the current)
1698 if mtype
== mpropdef
.mclassdef
.bound_mtype
and mmodule
== mpropdef
.mclassdef
.mmodule
then continue
1700 candidates
.add
(mpropdef
)
1702 # Fast track for only one candidate
1703 if candidates
.length
<= 1 then return candidates
1705 # Second, filter the most specific ones
1706 return select_most_specific
(mmodule
, candidates
)
1709 # Return an array containing olny the most specific property definitions
1710 # This is an helper function for `lookup_definitions` and `lookup_super_definitions`
1711 private fun select_most_specific
(mmodule
: MModule, candidates
: Array[MPROPDEF]): Array[MPROPDEF]
1713 var res
= new Array[MPROPDEF]
1714 for pd1
in candidates
do
1715 var cd1
= pd1
.mclassdef
1718 for pd2
in candidates
do
1719 if pd2
== pd1
then continue # do not compare with self!
1720 var cd2
= pd2
.mclassdef
1722 if c2
.mclass_type
== c1
.mclass_type
then
1723 if cd2
.mmodule
.in_importation
< cd1
.mmodule
then
1724 # cd2 refines cd1; therefore we skip pd1
1728 else if cd2
.bound_mtype
.is_subtype
(mmodule
, null, cd1
.bound_mtype
) and cd2
.bound_mtype
!= cd1
.bound_mtype
then
1729 # cd2 < cd1; therefore we skip pd1
1738 if res
.is_empty
then
1739 print
"All lost! {candidates.join(", ")}"
1740 # FIXME: should be abort!
1745 # Return the most specific definition in the linearization of `mtype`.
1747 # If you want to know the next properties in the linearization,
1748 # look at `MPropDef::lookup_next_definition`.
1750 # FIXME: the linearization is still unspecified
1752 # REQUIRE: `not mtype.need_anchor`
1753 # REQUIRE: `mtype.has_mproperty(mmodule, self)`
1754 fun lookup_first_definition
(mmodule
: MModule, mtype
: MType): MPROPDEF
1756 assert mtype
.has_mproperty
(mmodule
, self)
1757 return lookup_all_definitions
(mmodule
, mtype
).first
1760 # Return all definitions in a linearization order
1761 # Most specific first, most general last
1762 fun lookup_all_definitions
(mmodule
: MModule, mtype
: MType): Array[MPROPDEF]
1764 assert not mtype
.need_anchor
1765 mtype
= mtype
.as_notnullable
1767 var cache
= self.lookup_all_definitions_cache
[mmodule
, mtype
]
1768 if cache
!= null then return cache
1770 #print "select prop {mproperty} for {mtype} in {self}"
1771 # First, select all candidates
1772 var candidates
= new Array[MPROPDEF]
1773 for mpropdef
in self.mpropdefs
do
1774 # If the definition is not imported by the module, then skip
1775 if not mmodule
.in_importation
<= mpropdef
.mclassdef
.mmodule
then continue
1776 # If the definition is not inherited by the type, then skip
1777 if not mtype
.is_subtype
(mmodule
, null, mpropdef
.mclassdef
.bound_mtype
) then continue
1779 candidates
.add
(mpropdef
)
1781 # Fast track for only one candidate
1782 if candidates
.length
<= 1 then
1783 self.lookup_all_definitions_cache
[mmodule
, mtype
] = candidates
1787 mmodule
.linearize_mpropdefs
(candidates
)
1788 candidates
= candidates
.reversed
1789 self.lookup_all_definitions_cache
[mmodule
, mtype
] = candidates
1793 private var lookup_all_definitions_cache
= new HashMap2[MModule, MType, Array[MPROPDEF]]
1800 redef type MPROPDEF: MMethodDef
1802 # Is the property defined at the top_level of the module?
1803 # Currently such a property are stored in `Object`
1804 var is_toplevel
: Bool = false is writable
1806 # Is the property a constructor?
1807 # Warning, this property can be inherited by subclasses with or without being a constructor
1808 # therefore, you should use `is_init_for` the verify if the property is a legal constructor for a given class
1809 var is_init
: Bool = false is writable
1811 # The constructor is a (the) root init with empty signature but a set of initializers
1812 var is_root_init
: Bool = false is writable
1814 # Is the property a 'new' constructor?
1815 var is_new
: Bool = false is writable
1817 # Is the property a legal constructor for a given class?
1818 # As usual, visibility is not considered.
1819 # FIXME not implemented
1820 fun is_init_for
(mclass
: MClass): Bool
1826 # A global attribute
1830 redef type MPROPDEF: MAttributeDef
1834 # A global virtual type
1835 class MVirtualTypeProp
1838 redef type MPROPDEF: MVirtualTypeDef
1840 # The formal type associated to the virtual type property
1841 var mvirtualtype
= new MVirtualType(self)
1844 # A definition of a property (local property)
1846 # Unlike `MProperty`, a `MPropDef` is a local definition that belong to a
1847 # specific class definition (which belong to a specific module)
1848 abstract class MPropDef
1851 # The associated `MProperty` subclass.
1852 # the two specialization hierarchy are symmetric
1853 type MPROPERTY: MProperty
1856 type MPROPDEF: MPropDef
1858 # The class definition where the property definition is
1859 var mclassdef
: MClassDef
1861 # The associated global property
1862 var mproperty
: MPROPERTY
1864 # The origin of the definition
1865 var location
: Location
1869 mclassdef
.mpropdefs
.add
(self)
1870 mproperty
.mpropdefs
.add
(self)
1871 if mproperty
.intro_mclassdef
== mclassdef
then
1872 assert not isset mproperty
._intro
1873 mproperty
.intro
= self
1875 self.to_s
= "{mclassdef}#{mproperty}"
1878 # Actually the name of the `mproperty`
1879 redef fun name
do return mproperty
.name
1881 redef fun model
do return mclassdef
.model
1883 # Internal name combining the module, the class and the property
1884 # Example: "mymodule#MyClass#mymethod"
1885 redef var to_s
: String is noinit
1887 # Is self the definition that introduce the property?
1888 fun is_intro
: Bool do return mproperty
.intro
== self
1890 # Return the next definition in linearization of `mtype`.
1892 # This method is used to determine what method is called by a super.
1894 # REQUIRE: `not mtype.need_anchor`
1895 fun lookup_next_definition
(mmodule
: MModule, mtype
: MType): MPROPDEF
1897 assert not mtype
.need_anchor
1899 var mpropdefs
= self.mproperty
.lookup_all_definitions
(mmodule
, mtype
)
1900 var i
= mpropdefs
.iterator
1901 while i
.is_ok
and i
.item
!= self do i
.next
1902 assert has_property
: i
.is_ok
1904 assert has_next_property
: i
.is_ok
1909 # A local definition of a method
1913 redef type MPROPERTY: MMethod
1914 redef type MPROPDEF: MMethodDef
1916 # The signature attached to the property definition
1917 var msignature
: nullable MSignature = null is writable
1919 # The signature attached to the `new` call on a root-init
1920 # This is a concatenation of the signatures of the initializers
1922 # REQUIRE `mproperty.is_root_init == (new_msignature != null)`
1923 var new_msignature
: nullable MSignature = null is writable
1925 # List of initialisers to call in root-inits
1927 # They could be setters or attributes
1929 # REQUIRE `mproperty.is_root_init == (new_msignature != null)`
1930 var initializers
= new Array[MProperty]
1932 # Is the method definition abstract?
1933 var is_abstract
: Bool = false is writable
1935 # Is the method definition intern?
1936 var is_intern
= false is writable
1938 # Is the method definition extern?
1939 var is_extern
= false is writable
1941 # An optional constant value returned in functions.
1943 # Only some specific primitife value are accepted by engines.
1944 # Is used when there is no better implementation available.
1946 # Currently used only for the implementation of the `--define`
1947 # command-line option.
1948 # SEE: module `mixin`.
1949 var constant_value
: nullable Object = null is writable
1952 # A local definition of an attribute
1956 redef type MPROPERTY: MAttribute
1957 redef type MPROPDEF: MAttributeDef
1959 # The static type of the attribute
1960 var static_mtype
: nullable MType = null is writable
1963 # A local definition of a virtual type
1964 class MVirtualTypeDef
1967 redef type MPROPERTY: MVirtualTypeProp
1968 redef type MPROPDEF: MVirtualTypeDef
1970 # The bound of the virtual type
1971 var bound
: nullable MType = null is writable
1973 # Is the bound fixed?
1974 var is_fixed
= false is writable
1981 # * `interface_kind`
1985 # Note this class is basically an enum.
1986 # FIXME: use a real enum once user-defined enums are available
1988 redef var to_s
: String
1990 # Is a constructor required?
1993 # TODO: private init because enumeration.
1995 # Can a class of kind `self` specializes a class of kine `other`?
1996 fun can_specialize
(other
: MClassKind): Bool
1998 if other
== interface_kind
then return true # everybody can specialize interfaces
1999 if self == interface_kind
or self == enum_kind
then
2000 # no other case for interfaces
2002 else if self == extern_kind
then
2003 # only compatible with themselves
2004 return self == other
2005 else if other
== enum_kind
or other
== extern_kind
then
2006 # abstract_kind and concrete_kind are incompatible
2009 # remain only abstract_kind and concrete_kind
2014 # The class kind `abstract`
2015 fun abstract_kind
: MClassKind do return once
new MClassKind("abstract class", true)
2016 # The class kind `concrete`
2017 fun concrete_kind
: MClassKind do return once
new MClassKind("class", true)
2018 # The class kind `interface`
2019 fun interface_kind
: MClassKind do return once
new MClassKind("interface", false)
2020 # The class kind `enum`
2021 fun enum_kind
: MClassKind do return once
new MClassKind("enum", false)
2022 # The class kind `extern`
2023 fun extern_kind
: MClassKind do return once
new MClassKind("extern class", false)