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
: MProperty
1161 redef fun model
do return self.mproperty
.intro_mclassdef
.mmodule
.model
1163 redef fun lookup_bound
(mmodule
: MModule, resolved_receiver
: MType): MType
1165 assert not resolved_receiver
.need_anchor
1166 var props
= self.mproperty
.lookup_definitions
(mmodule
, resolved_receiver
)
1167 if props
.is_empty
then
1169 else if props
.length
== 1 then
1170 return props
.first
.as(MVirtualTypeDef).bound
.as(not null)
1172 var types
= new ArraySet[MType]
1174 types
.add
(p
.as(MVirtualTypeDef).bound
.as(not null))
1176 if types
.length
== 1 then
1182 # Is the virtual type fixed for a given resolved_receiver?
1183 fun is_fixed
(mmodule
: MModule, resolved_receiver
: MType): Bool
1185 assert not resolved_receiver
.need_anchor
1186 var props
= self.mproperty
.lookup_definitions
(mmodule
, resolved_receiver
)
1187 if props
.is_empty
then
1191 if p
.as(MVirtualTypeDef).is_fixed
then return true
1196 redef fun resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1198 assert can_resolve_for
(mtype
, anchor
, mmodule
)
1199 # self is a virtual type declared (or inherited) in mtype
1200 # The point of the function it to get the bound of the virtual type that make sense for mtype
1201 # But because mtype is maybe a virtual/formal type, we need to get a real receiver first
1202 #print "{class_name}: {self}/{mtype}/{anchor}?"
1203 var resolved_reciever
1204 if mtype
.need_anchor
then
1205 assert anchor
!= null
1206 resolved_reciever
= mtype
.resolve_for
(anchor
, null, mmodule
, true)
1208 resolved_reciever
= mtype
1210 # Now, we can get the bound
1211 var verbatim_bound
= lookup_bound
(mmodule
, resolved_reciever
)
1212 # The bound is exactly as declared in the "type" property, so we must resolve it again
1213 var res
= verbatim_bound
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1214 #print "{class_name}: {self}/{mtype}/{anchor} -> {self}/{resolved_receiver}/{anchor} -> {verbatim_bound}/{mtype}/{anchor} -> {res}"
1216 # What to return here? There is a bunch a special cases:
1217 # If 'cleanup_virtual' we must return the resolved type, since we cannot return self
1218 if cleanup_virtual
then return res
1219 # 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
1220 if resolved_reciever
isa MNullableType then resolved_reciever
= resolved_reciever
.mtype
1221 if resolved_reciever
.as(MClassType).mclass
.kind
== enum_kind
then return res
1222 # 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.
1223 if res
isa MVirtualType then return res
1224 # If we are final, just return the resolution
1225 if is_fixed
(mmodule
, resolved_reciever
) then return res
1226 # 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
1227 if res
isa MClassType and res
.mclass
.kind
== enum_kind
then return res
1228 # TODO: What if bound to a MParameterType?
1229 # Note that Nullable types can always be redefined by the non nullable version, so there is no specific case on it.
1231 # If anything apply, then `self' cannot be resolved, so return self
1235 redef fun can_resolve_for
(mtype
, anchor
, mmodule
)
1237 if mtype
.need_anchor
then
1238 assert anchor
!= null
1239 mtype
= mtype
.anchor_to
(mmodule
, anchor
)
1241 return mtype
.has_mproperty
(mmodule
, mproperty
)
1244 redef fun to_s
do return self.mproperty
.to_s
1247 # The type associated to a formal parameter generic type of a class
1249 # Each parameter type is associated to a specific class.
1250 # It means that all refinements of a same class "share" the parameter type,
1251 # but that a generic subclass has its own parameter types.
1253 # However, in the sense of the meta-model, a parameter type of a class is
1254 # a valid type in a subclass. The "in the sense of the meta-model" is
1255 # important because, in the Nit language, the programmer cannot refers
1256 # directly to the parameter types of the super-classes.
1260 # fun e: E is abstract
1265 # In the class definition B[F], `F` is a valid type but `E` is not.
1266 # However, `self.e` is a valid method call, and the signature of `e` is
1269 # Note that parameter types are shared among class refinements.
1270 # Therefore parameter only have an internal name (see `to_s` for details).
1271 class MParameterType
1274 # The generic class where the parameter belong
1277 redef fun model
do return self.mclass
.intro_mmodule
.model
1279 # The position of the parameter (0 for the first parameter)
1280 # FIXME: is `position` a better name?
1285 redef fun to_s
do return name
1287 redef fun lookup_bound
(mmodule
: MModule, resolved_receiver
: MType): MType
1289 assert not resolved_receiver
.need_anchor
1290 var goalclass
= self.mclass
1291 var supertypes
= resolved_receiver
.collect_mtypes
(mmodule
)
1292 for t
in supertypes
do
1293 if t
.mclass
== goalclass
then
1294 # Yeah! c specialize goalclass with a "super `t'". So the question is what is the argument of f
1295 # FIXME: Here, we stop on the first goal. Should we check others and detect inconsistencies?
1296 var res
= t
.arguments
[self.rank
]
1303 redef fun resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1305 assert can_resolve_for
(mtype
, anchor
, mmodule
)
1306 #print "{class_name}: {self}/{mtype}/{anchor}?"
1308 if mtype
isa MGenericType and mtype
.mclass
== self.mclass
then
1309 var res
= mtype
.arguments
[self.rank
]
1310 if anchor
!= null and res
.need_anchor
then
1311 # Maybe the result can be resolved more if are bound to a final class
1312 var r2
= res
.anchor_to
(mmodule
, anchor
)
1313 if r2
isa MClassType and r2
.mclass
.kind
== enum_kind
then return r2
1318 # self is a parameter type of mtype (or of a super-class of mtype)
1319 # The point of the function it to get the bound of the virtual type that make sense for mtype
1320 # But because mtype is maybe a virtual/formal type, we need to get a real receiver first
1321 # FIXME: What happens here is far from clear. Thus this part must be validated and clarified
1322 var resolved_receiver
1323 if mtype
.need_anchor
then
1324 assert anchor
!= null
1325 resolved_receiver
= mtype
.resolve_for
(anchor
.mclass
.mclass_type
, anchor
, mmodule
, true)
1327 resolved_receiver
= mtype
1329 if resolved_receiver
isa MNullableType then resolved_receiver
= resolved_receiver
.mtype
1330 if resolved_receiver
isa MParameterType then
1331 assert resolved_receiver
.mclass
== anchor
.mclass
1332 resolved_receiver
= anchor
.arguments
[resolved_receiver
.rank
]
1333 if resolved_receiver
isa MNullableType then resolved_receiver
= resolved_receiver
.mtype
1335 assert resolved_receiver
isa MClassType
1337 # Eh! The parameter is in the current class.
1338 # So we return the corresponding argument, no mater what!
1339 if resolved_receiver
.mclass
== self.mclass
then
1340 var res
= resolved_receiver
.arguments
[self.rank
]
1341 #print "{class_name}: {self}/{mtype}/{anchor} -> direct {res}"
1345 if resolved_receiver
.need_anchor
then
1346 assert anchor
!= null
1347 resolved_receiver
= resolved_receiver
.resolve_for
(anchor
, null, mmodule
, false)
1349 # Now, we can get the bound
1350 var verbatim_bound
= lookup_bound
(mmodule
, resolved_receiver
)
1351 # The bound is exactly as declared in the "type" property, so we must resolve it again
1352 var res
= verbatim_bound
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1354 #print "{class_name}: {self}/{mtype}/{anchor} -> indirect {res}"
1359 redef fun can_resolve_for
(mtype
, anchor
, mmodule
)
1361 if mtype
.need_anchor
then
1362 assert anchor
!= null
1363 mtype
= mtype
.anchor_to
(mmodule
, anchor
)
1365 return mtype
.collect_mclassdefs
(mmodule
).has
(mclass
.intro
)
1369 # A type prefixed with "nullable"
1373 # The base type of the nullable type
1376 redef fun model
do return self.mtype
.model
1380 self.to_s
= "nullable {mtype}"
1383 redef var to_s
: String is noinit
1385 redef fun need_anchor
do return mtype
.need_anchor
1386 redef fun as_nullable
do return self
1387 redef fun as_notnullable
do return mtype
1388 redef fun resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1390 var res
= self.mtype
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1391 return res
.as_nullable
1394 redef fun can_resolve_for
(mtype
, anchor
, mmodule
)
1396 return self.mtype
.can_resolve_for
(mtype
, anchor
, mmodule
)
1399 redef fun depth
do return self.mtype
.depth
1401 redef fun length
do return self.mtype
.length
1403 redef fun collect_mclassdefs
(mmodule
)
1405 assert not self.need_anchor
1406 return self.mtype
.collect_mclassdefs
(mmodule
)
1409 redef fun collect_mclasses
(mmodule
)
1411 assert not self.need_anchor
1412 return self.mtype
.collect_mclasses
(mmodule
)
1415 redef fun collect_mtypes
(mmodule
)
1417 assert not self.need_anchor
1418 return self.mtype
.collect_mtypes
(mmodule
)
1422 # The type of the only value null
1424 # The is only one null type per model, see `MModel::null_type`.
1427 redef var model
: Model
1428 redef fun to_s
do return "null"
1429 redef fun as_nullable
do return self
1430 redef fun need_anchor
do return false
1431 redef fun resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
) do return self
1432 redef fun can_resolve_for
(mtype
, anchor
, mmodule
) do return true
1434 redef fun collect_mclassdefs
(mmodule
) do return new HashSet[MClassDef]
1436 redef fun collect_mclasses
(mmodule
) do return new HashSet[MClass]
1438 redef fun collect_mtypes
(mmodule
) do return new HashSet[MClassType]
1441 # A signature of a method
1445 # The each parameter (in order)
1446 var mparameters
: Array[MParameter]
1448 # The return type (null for a procedure)
1449 var return_mtype
: nullable MType
1454 var t
= self.return_mtype
1455 if t
!= null then dmax
= t
.depth
1456 for p
in mparameters
do
1457 var d
= p
.mtype
.depth
1458 if d
> dmax
then dmax
= d
1466 var t
= self.return_mtype
1467 if t
!= null then res
+= t
.length
1468 for p
in mparameters
do
1469 res
+= p
.mtype
.length
1474 # REQUIRE: 1 <= mparameters.count p -> p.is_vararg
1477 var vararg_rank
= -1
1478 for i
in [0..mparameters
.length
[ do
1479 var parameter
= mparameters
[i
]
1480 if parameter
.is_vararg
then
1481 assert vararg_rank
== -1
1485 self.vararg_rank
= vararg_rank
1488 # The rank of the ellipsis (`...`) for vararg (starting from 0).
1489 # value is -1 if there is no vararg.
1490 # Example: for "(a: Int, b: Bool..., c: Char)" #-> vararg_rank=1
1491 var vararg_rank
: Int is noinit
1493 # The number or parameters
1494 fun arity
: Int do return mparameters
.length
1498 var b
= new FlatBuffer
1499 if not mparameters
.is_empty
then
1501 for i
in [0..mparameters
.length
[ do
1502 var mparameter
= mparameters
[i
]
1503 if i
> 0 then b
.append
(", ")
1504 b
.append
(mparameter
.name
)
1506 b
.append
(mparameter
.mtype
.to_s
)
1507 if mparameter
.is_vararg
then
1513 var ret
= self.return_mtype
1521 redef fun resolve_for
(mtype
: MType, anchor
: nullable MClassType, mmodule
: MModule, cleanup_virtual
: Bool): MSignature
1523 var params
= new Array[MParameter]
1524 for p
in self.mparameters
do
1525 params
.add
(p
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
))
1527 var ret
= self.return_mtype
1529 ret
= ret
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1531 var res
= new MSignature(params
, ret
)
1536 # A parameter in a signature
1540 # The name of the parameter
1541 redef var name
: String
1543 # The static type of the parameter
1546 # Is the parameter a vararg?
1552 return "{name}: {mtype}..."
1554 return "{name}: {mtype}"
1558 fun resolve_for
(mtype
: MType, anchor
: nullable MClassType, mmodule
: MModule, cleanup_virtual
: Bool): MParameter
1560 if not self.mtype
.need_anchor
then return self
1561 var newtype
= self.mtype
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1562 var res
= new MParameter(self.name
, newtype
, self.is_vararg
)
1566 redef fun model
do return mtype
.model
1569 # A service (global property) that generalize method, attribute, etc.
1571 # `MProperty` are global to the model; it means that a `MProperty` is not bound
1572 # to a specific `MModule` nor a specific `MClass`.
1574 # A MProperty gather definitions (see `mpropdefs`) ; one for the introduction
1575 # and the other in subclasses and in refinements.
1577 # A `MProperty` is used to denotes services in polymorphic way (ie. independent
1578 # of any dynamic type).
1579 # For instance, a call site "x.foo" is associated to a `MProperty`.
1580 abstract class MProperty
1583 # The associated MPropDef subclass.
1584 # The two specialization hierarchy are symmetric.
1585 type MPROPDEF: MPropDef
1587 # The classdef that introduce the property
1588 # While a property is not bound to a specific module, or class,
1589 # the introducing mclassdef is used for naming and visibility
1590 var intro_mclassdef
: MClassDef
1592 # The (short) name of the property
1593 redef var name
: String
1595 # The canonical name of the property
1596 # Example: "owner::my_module::MyClass::my_method"
1597 fun full_name
: String
1599 return "{self.intro_mclassdef.mmodule.full_name}::{self.intro_mclassdef.mclass.name}::{name}"
1602 # The visibility of the property
1603 var visibility
: MVisibility
1607 intro_mclassdef
.intro_mproperties
.add
(self)
1608 var model
= intro_mclassdef
.mmodule
.model
1609 model
.mproperties_by_name
.add_one
(name
, self)
1610 model
.mproperties
.add
(self)
1613 # All definitions of the property.
1614 # The first is the introduction,
1615 # The other are redefinitions (in refinements and in subclasses)
1616 var mpropdefs
= new Array[MPROPDEF]
1618 # The definition that introduces the property.
1620 # Warning: such a definition may not exist in the early life of the object.
1621 # In this case, the method will abort.
1622 var intro
: MPROPDEF is noinit
1624 redef fun model
do return intro
.model
1627 redef fun to_s
do return name
1629 # Return the most specific property definitions defined or inherited by a type.
1630 # The selection knows that refinement is stronger than specialization;
1631 # however, in case of conflict more than one property are returned.
1632 # If mtype does not know mproperty then an empty array is returned.
1634 # If you want the really most specific property, then look at `lookup_first_definition`
1635 fun lookup_definitions
(mmodule
: MModule, mtype
: MType): Array[MPROPDEF]
1637 assert not mtype
.need_anchor
1638 mtype
= mtype
.as_notnullable
1640 var cache
= self.lookup_definitions_cache
[mmodule
, mtype
]
1641 if cache
!= null then return cache
1643 #print "select prop {mproperty} for {mtype} in {self}"
1644 # First, select all candidates
1645 var candidates
= new Array[MPROPDEF]
1646 for mpropdef
in self.mpropdefs
do
1647 # If the definition is not imported by the module, then skip
1648 if not mmodule
.in_importation
<= mpropdef
.mclassdef
.mmodule
then continue
1649 # If the definition is not inherited by the type, then skip
1650 if not mtype
.is_subtype
(mmodule
, null, mpropdef
.mclassdef
.bound_mtype
) then continue
1652 candidates
.add
(mpropdef
)
1654 # Fast track for only one candidate
1655 if candidates
.length
<= 1 then
1656 self.lookup_definitions_cache
[mmodule
, mtype
] = candidates
1660 # Second, filter the most specific ones
1661 return select_most_specific
(mmodule
, candidates
)
1664 private var lookup_definitions_cache
= new HashMap2[MModule, MType, Array[MPROPDEF]]
1666 # Return the most specific property definitions inherited by a type.
1667 # The selection knows that refinement is stronger than specialization;
1668 # however, in case of conflict more than one property are returned.
1669 # If mtype does not know mproperty then an empty array is returned.
1671 # If you want the really most specific property, then look at `lookup_next_definition`
1673 # FIXME: Move to `MPropDef`?
1674 fun lookup_super_definitions
(mmodule
: MModule, mtype
: MType): Array[MPROPDEF]
1676 assert not mtype
.need_anchor
1677 mtype
= mtype
.as_notnullable
1679 # First, select all candidates
1680 var candidates
= new Array[MPROPDEF]
1681 for mpropdef
in self.mpropdefs
do
1682 # If the definition is not imported by the module, then skip
1683 if not mmodule
.in_importation
<= mpropdef
.mclassdef
.mmodule
then continue
1684 # If the definition is not inherited by the type, then skip
1685 if not mtype
.is_subtype
(mmodule
, null, mpropdef
.mclassdef
.bound_mtype
) then continue
1686 # If the definition is defined by the type, then skip (we want the super, so e skip the current)
1687 if mtype
== mpropdef
.mclassdef
.bound_mtype
and mmodule
== mpropdef
.mclassdef
.mmodule
then continue
1689 candidates
.add
(mpropdef
)
1691 # Fast track for only one candidate
1692 if candidates
.length
<= 1 then return candidates
1694 # Second, filter the most specific ones
1695 return select_most_specific
(mmodule
, candidates
)
1698 # Return an array containing olny the most specific property definitions
1699 # This is an helper function for `lookup_definitions` and `lookup_super_definitions`
1700 private fun select_most_specific
(mmodule
: MModule, candidates
: Array[MPROPDEF]): Array[MPROPDEF]
1702 var res
= new Array[MPROPDEF]
1703 for pd1
in candidates
do
1704 var cd1
= pd1
.mclassdef
1707 for pd2
in candidates
do
1708 if pd2
== pd1
then continue # do not compare with self!
1709 var cd2
= pd2
.mclassdef
1711 if c2
.mclass_type
== c1
.mclass_type
then
1712 if cd2
.mmodule
.in_importation
< cd1
.mmodule
then
1713 # cd2 refines cd1; therefore we skip pd1
1717 else if cd2
.bound_mtype
.is_subtype
(mmodule
, null, cd1
.bound_mtype
) and cd2
.bound_mtype
!= cd1
.bound_mtype
then
1718 # cd2 < cd1; therefore we skip pd1
1727 if res
.is_empty
then
1728 print
"All lost! {candidates.join(", ")}"
1729 # FIXME: should be abort!
1734 # Return the most specific definition in the linearization of `mtype`.
1736 # If you want to know the next properties in the linearization,
1737 # look at `MPropDef::lookup_next_definition`.
1739 # FIXME: the linearization is still unspecified
1741 # REQUIRE: `not mtype.need_anchor`
1742 # REQUIRE: `mtype.has_mproperty(mmodule, self)`
1743 fun lookup_first_definition
(mmodule
: MModule, mtype
: MType): MPROPDEF
1745 assert mtype
.has_mproperty
(mmodule
, self)
1746 return lookup_all_definitions
(mmodule
, mtype
).first
1749 # Return all definitions in a linearization order
1750 # Most specific first, most general last
1751 fun lookup_all_definitions
(mmodule
: MModule, mtype
: MType): Array[MPROPDEF]
1753 assert not mtype
.need_anchor
1754 mtype
= mtype
.as_notnullable
1756 var cache
= self.lookup_all_definitions_cache
[mmodule
, mtype
]
1757 if cache
!= null then return cache
1759 #print "select prop {mproperty} for {mtype} in {self}"
1760 # First, select all candidates
1761 var candidates
= new Array[MPROPDEF]
1762 for mpropdef
in self.mpropdefs
do
1763 # If the definition is not imported by the module, then skip
1764 if not mmodule
.in_importation
<= mpropdef
.mclassdef
.mmodule
then continue
1765 # If the definition is not inherited by the type, then skip
1766 if not mtype
.is_subtype
(mmodule
, null, mpropdef
.mclassdef
.bound_mtype
) then continue
1768 candidates
.add
(mpropdef
)
1770 # Fast track for only one candidate
1771 if candidates
.length
<= 1 then
1772 self.lookup_all_definitions_cache
[mmodule
, mtype
] = candidates
1776 mmodule
.linearize_mpropdefs
(candidates
)
1777 candidates
= candidates
.reversed
1778 self.lookup_all_definitions_cache
[mmodule
, mtype
] = candidates
1782 private var lookup_all_definitions_cache
= new HashMap2[MModule, MType, Array[MPROPDEF]]
1789 redef type MPROPDEF: MMethodDef
1791 # Is the property defined at the top_level of the module?
1792 # Currently such a property are stored in `Object`
1793 var is_toplevel
: Bool = false is writable
1795 # Is the property a constructor?
1796 # Warning, this property can be inherited by subclasses with or without being a constructor
1797 # therefore, you should use `is_init_for` the verify if the property is a legal constructor for a given class
1798 var is_init
: Bool = false is writable
1800 # The constructor is a (the) root init with empty signature but a set of initializers
1801 var is_root_init
: Bool = false is writable
1803 # Is the property a 'new' constructor?
1804 var is_new
: Bool = false is writable
1806 # Is the property a legal constructor for a given class?
1807 # As usual, visibility is not considered.
1808 # FIXME not implemented
1809 fun is_init_for
(mclass
: MClass): Bool
1815 # A global attribute
1819 redef type MPROPDEF: MAttributeDef
1823 # A global virtual type
1824 class MVirtualTypeProp
1827 redef type MPROPDEF: MVirtualTypeDef
1829 # The formal type associated to the virtual type property
1830 var mvirtualtype
= new MVirtualType(self)
1833 # A definition of a property (local property)
1835 # Unlike `MProperty`, a `MPropDef` is a local definition that belong to a
1836 # specific class definition (which belong to a specific module)
1837 abstract class MPropDef
1840 # The associated `MProperty` subclass.
1841 # the two specialization hierarchy are symmetric
1842 type MPROPERTY: MProperty
1845 type MPROPDEF: MPropDef
1847 # The class definition where the property definition is
1848 var mclassdef
: MClassDef
1850 # The associated global property
1851 var mproperty
: MPROPERTY
1853 # The origin of the definition
1854 var location
: Location
1858 mclassdef
.mpropdefs
.add
(self)
1859 mproperty
.mpropdefs
.add
(self)
1860 if mproperty
.intro_mclassdef
== mclassdef
then
1861 assert not isset mproperty
._intro
1862 mproperty
.intro
= self
1864 self.to_s
= "{mclassdef}#{mproperty}"
1867 # Actually the name of the `mproperty`
1868 redef fun name
do return mproperty
.name
1870 redef fun model
do return mclassdef
.model
1872 # Internal name combining the module, the class and the property
1873 # Example: "mymodule#MyClass#mymethod"
1874 redef var to_s
: String is noinit
1876 # Is self the definition that introduce the property?
1877 fun is_intro
: Bool do return mproperty
.intro
== self
1879 # Return the next definition in linearization of `mtype`.
1881 # This method is used to determine what method is called by a super.
1883 # REQUIRE: `not mtype.need_anchor`
1884 fun lookup_next_definition
(mmodule
: MModule, mtype
: MType): MPROPDEF
1886 assert not mtype
.need_anchor
1888 var mpropdefs
= self.mproperty
.lookup_all_definitions
(mmodule
, mtype
)
1889 var i
= mpropdefs
.iterator
1890 while i
.is_ok
and i
.item
!= self do i
.next
1891 assert has_property
: i
.is_ok
1893 assert has_next_property
: i
.is_ok
1898 # A local definition of a method
1902 redef type MPROPERTY: MMethod
1903 redef type MPROPDEF: MMethodDef
1905 # The signature attached to the property definition
1906 var msignature
: nullable MSignature = null is writable
1908 # The signature attached to the `new` call on a root-init
1909 # This is a concatenation of the signatures of the initializers
1911 # REQUIRE `mproperty.is_root_init == (new_msignature != null)`
1912 var new_msignature
: nullable MSignature = null is writable
1914 # List of initialisers to call in root-inits
1916 # They could be setters or attributes
1918 # REQUIRE `mproperty.is_root_init == (new_msignature != null)`
1919 var initializers
= new Array[MProperty]
1921 # Is the method definition abstract?
1922 var is_abstract
: Bool = false is writable
1924 # Is the method definition intern?
1925 var is_intern
= false is writable
1927 # Is the method definition extern?
1928 var is_extern
= false is writable
1930 # An optional constant value returned in functions.
1932 # Only some specific primitife value are accepted by engines.
1933 # Is used when there is no better implementation available.
1935 # Currently used only for the implementation of the `--define`
1936 # command-line option.
1937 # SEE: module `mixin`.
1938 var constant_value
: nullable Object = null is writable
1941 # A local definition of an attribute
1945 redef type MPROPERTY: MAttribute
1946 redef type MPROPDEF: MAttributeDef
1948 # The static type of the attribute
1949 var static_mtype
: nullable MType = null is writable
1952 # A local definition of a virtual type
1953 class MVirtualTypeDef
1956 redef type MPROPERTY: MVirtualTypeProp
1957 redef type MPROPDEF: MVirtualTypeDef
1959 # The bound of the virtual type
1960 var bound
: nullable MType = null is writable
1962 # Is the bound fixed?
1963 var is_fixed
= false is writable
1970 # * `interface_kind`
1974 # Note this class is basically an enum.
1975 # FIXME: use a real enum once user-defined enums are available
1977 redef var to_s
: String
1979 # Is a constructor required?
1982 # TODO: private init because enumeration.
1984 # Can a class of kind `self` specializes a class of kine `other`?
1985 fun can_specialize
(other
: MClassKind): Bool
1987 if other
== interface_kind
then return true # everybody can specialize interfaces
1988 if self == interface_kind
or self == enum_kind
then
1989 # no other case for interfaces
1991 else if self == extern_kind
then
1992 # only compatible with themselves
1993 return self == other
1994 else if other
== enum_kind
or other
== extern_kind
then
1995 # abstract_kind and concrete_kind are incompatible
1998 # remain only abstract_kind and concrete_kind
2003 # The class kind `abstract`
2004 fun abstract_kind
: MClassKind do return once
new MClassKind("abstract class", true)
2005 # The class kind `concrete`
2006 fun concrete_kind
: MClassKind do return once
new MClassKind("class", true)
2007 # The class kind `interface`
2008 fun interface_kind
: MClassKind do return once
new MClassKind("interface", false)
2009 # The class kind `enum`
2010 fun enum_kind
: MClassKind do return once
new MClassKind("enum", false)
2011 # The class kind `extern`
2012 fun extern_kind
: MClassKind do return once
new MClassKind("extern class", false)