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.
737 # class B super A end
739 # class Y super X end
748 # Map[T,U] anchor_to H #-> Map[B,Y]
750 # Explanation of the example:
751 # In H, T is set to B, because "H super G[B]", and U is bound to Y,
752 # because "redef type U: Y". Therefore, Map[T, U] is bound to
755 # ENSURE: `not self.need_anchor implies result == self`
756 # ENSURE: `not result.need_anchor`
757 fun anchor_to
(mmodule
: MModule, anchor
: MClassType): MType
759 if not need_anchor
then return self
760 assert not anchor
.need_anchor
761 # Just resolve to the anchor and clear all the virtual types
762 var res
= self.resolve_for
(anchor
, null, mmodule
, true)
763 assert not res
.need_anchor
767 # Does `self` contain a virtual type or a formal generic parameter type?
768 # In order to remove those types, you usually want to use `anchor_to`.
769 fun need_anchor
: Bool do return true
771 # Return the supertype when adapted to a class.
773 # In Nit, for each super-class of a type, there is a equivalent super-type.
777 # class H[V] super G[V, Bool] end
778 # H[Int] supertype_to G #-> G[Int, Bool]
780 # REQUIRE: `super_mclass` is a super-class of `self`
781 # REQUIRE: `self.need_anchor implies anchor != null and self.can_resolve_for(anchor, null, mmodule)`
782 # ENSURE: `result.mclass = super_mclass`
783 fun supertype_to
(mmodule
: MModule, anchor
: nullable MClassType, super_mclass
: MClass): MClassType
785 if super_mclass
.arity
== 0 then return super_mclass
.mclass_type
786 if self isa MClassType and self.mclass
== super_mclass
then return self
788 if self.need_anchor
then
789 assert anchor
!= null
790 resolved_self
= self.anchor_to
(mmodule
, anchor
)
794 var supertypes
= resolved_self
.collect_mtypes
(mmodule
)
795 for supertype
in supertypes
do
796 if supertype
.mclass
== super_mclass
then
797 # FIXME: Here, we stop on the first goal. Should we check others and detect inconsistencies?
798 return supertype
.resolve_for
(self, anchor
, mmodule
, false)
804 # Replace formals generic types in self with resolved values in `mtype`
805 # If `cleanup_virtual` is true, then virtual types are also replaced
808 # This function returns self if `need_anchor` is false.
813 # class H[F] super G[F] end
816 # * Array[E].resolve_for(H[Int]) #-> Array[Int]
817 # * Array[E].resolve_for(G[Z], X[Int]) #-> Array[Z]
819 # Explanation of the example:
820 # * Array[E].need_anchor is true because there is a formal generic parameter type E
821 # * E makes sense for H[Int] because E is a formal parameter of G and H specialize G
822 # * Since "H[F] super G[F]", E is in fact F for H
823 # * More specifically, in H[Int], E is Int
824 # * So, in H[Int], Array[E] is Array[Int]
826 # This function is mainly used to inherit a signature.
827 # Because, unlike `anchor_to`, we do not want a full resolution of
828 # a type but only an adapted version of it.
833 # fun foo(e:E):E is abstract
835 # class B super A[Int] end
837 # The signature on foo is (e: E): E
838 # If we resolve the signature for B, we get (e:Int):Int
843 # fun foo(e:E) is abstract
847 # fun bar do a.foo(x) # <- x is here
850 # The first question is: is foo available on `a`?
852 # The static type of a is `A[Array[F]]`, that is an open type.
853 # in order to find a method `foo`, whe must look at a resolved type.
855 # A[Array[F]].anchor_to(B[nullable Object]) #-> A[Array[nullable Object]]
857 # the method `foo` exists in `A[Array[nullable Object]]`, therefore `foo` exists for `a`.
859 # The next question is: what is the accepted types for `x`?
861 # the signature of `foo` is `foo(e:E)`, thus we must resolve the type E
863 # E.resolve_for(A[Array[F]],B[nullable Object]) #-> Array[F]
865 # The resolution can be done because `E` make sense for the class A (see `can_resolve_for`)
867 # FIXME: the parameter `cleanup_virtual` is just a bad idea, but having
868 # two function instead of one seems also to be a bad idea.
870 # REQUIRE: `can_resolve_for(mtype, anchor, mmodule)`
871 # ENSURE: `not self.need_anchor implies result == self`
872 fun resolve_for
(mtype
: MType, anchor
: nullable MClassType, mmodule
: MModule, cleanup_virtual
: Bool): MType is abstract
874 # Can the type be resolved?
876 # In order to resolve open types, the formal types must make sence.
886 # E.can_resolve_for(A[Int]) #-> true, E make sense in A
888 # E.can_resolve_for(B[Int]) #-> false, E does not make sense in B
890 # B[E].can_resolve_for(A[F], B[Object]) #-> true,
891 # # B[E] is a red hearing only the E is important,
892 # # E make sense in A
895 # REQUIRE: `anchor != null implies not anchor.need_anchor`
896 # REQUIRE: `mtype.need_anchor implies anchor != null and mtype.can_resolve_for(anchor, null, mmodule)`
897 # ENSURE: `not self.need_anchor implies result == true`
898 fun can_resolve_for
(mtype
: MType, anchor
: nullable MClassType, mmodule
: MModule): Bool is abstract
900 # Return the nullable version of the type
901 # If the type is already nullable then self is returned
902 fun as_nullable
: MType
904 var res
= self.as_nullable_cache
905 if res
!= null then return res
906 res
= new MNullableType(self)
907 self.as_nullable_cache
= res
911 # Return the not nullable version of the type
912 # Is the type is already not nullable, then self is returned.
914 # Note: this just remove the `nullable` notation, but the result can still contains null.
915 # For instance if `self isa MNullType` or self is a formal type bounded by a nullable type.
916 fun as_notnullable
: MType
921 private var as_nullable_cache
: nullable MType = null
924 # The depth of the type seen as a tree.
931 # Formal types have a depth of 1.
937 # The length of the type seen as a tree.
944 # Formal types have a length of 1.
950 # Compute all the classdefs inherited/imported.
951 # The returned set contains:
952 # * the class definitions from `mmodule` and its imported modules
953 # * the class definitions of this type and its super-types
955 # This function is used mainly internally.
957 # REQUIRE: `not self.need_anchor`
958 fun collect_mclassdefs
(mmodule
: MModule): Set[MClassDef] is abstract
960 # Compute all the super-classes.
961 # This function is used mainly internally.
963 # REQUIRE: `not self.need_anchor`
964 fun collect_mclasses
(mmodule
: MModule): Set[MClass] is abstract
966 # Compute all the declared super-types.
967 # Super-types are returned as declared in the classdefs (verbatim).
968 # This function is used mainly internally.
970 # REQUIRE: `not self.need_anchor`
971 fun collect_mtypes
(mmodule
: MModule): Set[MClassType] is abstract
973 # Is the property in self for a given module
974 # This method does not filter visibility or whatever
976 # REQUIRE: `not self.need_anchor`
977 fun has_mproperty
(mmodule
: MModule, mproperty
: MProperty): Bool
979 assert not self.need_anchor
980 return self.collect_mclassdefs
(mmodule
).has
(mproperty
.intro_mclassdef
)
984 # A type based on a class.
986 # `MClassType` have properties (see `has_mproperty`).
990 # The associated class
993 redef fun model
do return self.mclass
.intro_mmodule
.model
995 # TODO: private init because strongly bounded to its mclass. see `mclass.mclass_type`
997 # The formal arguments of the type
998 # ENSURE: `result.length == self.mclass.arity`
999 var arguments
= new Array[MType]
1001 redef fun to_s
do return mclass
.to_s
1003 redef fun need_anchor
do return false
1005 redef fun anchor_to
(mmodule
: MModule, anchor
: MClassType): MClassType
1007 return super.as(MClassType)
1010 redef fun resolve_for
(mtype
: MType, anchor
: nullable MClassType, mmodule
: MModule, cleanup_virtual
: Bool): MClassType do return self
1012 redef fun can_resolve_for
(mtype
, anchor
, mmodule
) do return true
1014 redef fun collect_mclassdefs
(mmodule
)
1016 assert not self.need_anchor
1017 var cache
= self.collect_mclassdefs_cache
1018 if not cache
.has_key
(mmodule
) then
1019 self.collect_things
(mmodule
)
1021 return cache
[mmodule
]
1024 redef fun collect_mclasses
(mmodule
)
1026 assert not self.need_anchor
1027 var cache
= self.collect_mclasses_cache
1028 if not cache
.has_key
(mmodule
) then
1029 self.collect_things
(mmodule
)
1031 return cache
[mmodule
]
1034 redef fun collect_mtypes
(mmodule
)
1036 assert not self.need_anchor
1037 var cache
= self.collect_mtypes_cache
1038 if not cache
.has_key
(mmodule
) then
1039 self.collect_things
(mmodule
)
1041 return cache
[mmodule
]
1044 # common implementation for `collect_mclassdefs`, `collect_mclasses`, and `collect_mtypes`.
1045 private fun collect_things
(mmodule
: MModule)
1047 var res
= new HashSet[MClassDef]
1048 var seen
= new HashSet[MClass]
1049 var types
= new HashSet[MClassType]
1050 seen
.add
(self.mclass
)
1051 var todo
= [self.mclass
]
1052 while not todo
.is_empty
do
1053 var mclass
= todo
.pop
1054 #print "process {mclass}"
1055 for mclassdef
in mclass
.mclassdefs
do
1056 if not mmodule
.in_importation
<= mclassdef
.mmodule
then continue
1057 #print " process {mclassdef}"
1059 for supertype
in mclassdef
.supertypes
do
1060 types
.add
(supertype
)
1061 var superclass
= supertype
.mclass
1062 if seen
.has
(superclass
) then continue
1063 #print " add {superclass}"
1064 seen
.add
(superclass
)
1065 todo
.add
(superclass
)
1069 collect_mclassdefs_cache
[mmodule
] = res
1070 collect_mclasses_cache
[mmodule
] = seen
1071 collect_mtypes_cache
[mmodule
] = types
1074 private var collect_mclassdefs_cache
= new HashMap[MModule, Set[MClassDef]]
1075 private var collect_mclasses_cache
= new HashMap[MModule, Set[MClass]]
1076 private var collect_mtypes_cache
= new HashMap[MModule, Set[MClassType]]
1080 # A type based on a generic class.
1081 # A generic type a just a class with additional formal generic arguments.
1087 # TODO: private init because strongly bounded to its mclass. see `mclass.get_mtype`
1091 assert self.mclass
.arity
== arguments
.length
1093 self.need_anchor
= false
1094 for t
in arguments
do
1095 if t
.need_anchor
then
1096 self.need_anchor
= true
1101 self.to_s
= "{mclass}[{arguments.join(", ")}]"
1104 # Recursively print the type of the arguments within brackets.
1105 # Example: `"Map[String, List[Int]]"`
1106 redef var to_s
: String is noinit
1108 redef var need_anchor
: Bool is noinit
1110 redef fun resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1112 if not need_anchor
then return self
1113 assert can_resolve_for
(mtype
, anchor
, mmodule
)
1114 var types
= new Array[MType]
1115 for t
in arguments
do
1116 types
.add
(t
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
))
1118 return mclass
.get_mtype
(types
)
1121 redef fun can_resolve_for
(mtype
, anchor
, mmodule
)
1123 if not need_anchor
then return true
1124 for t
in arguments
do
1125 if not t
.can_resolve_for
(mtype
, anchor
, mmodule
) then return false
1134 for a
in self.arguments
do
1136 if d
> dmax
then dmax
= d
1144 for a
in self.arguments
do
1151 # A virtual formal type.
1155 # The property associated with the type.
1156 # Its the definitions of this property that determine the bound or the virtual type.
1157 var mproperty
: MProperty
1159 redef fun model
do return self.mproperty
.intro_mclassdef
.mmodule
.model
1161 # Lookup the bound for a given resolved_receiver
1162 # The result may be a other virtual type (or a parameter type)
1164 # The result is returned exactly as declared in the "type" property (verbatim).
1166 # In case of conflict, the method aborts.
1167 fun lookup_bound
(mmodule
: MModule, resolved_receiver
: MType): MType
1169 assert not resolved_receiver
.need_anchor
1170 var props
= self.mproperty
.lookup_definitions
(mmodule
, resolved_receiver
)
1171 if props
.is_empty
then
1173 else if props
.length
== 1 then
1174 return props
.first
.as(MVirtualTypeDef).bound
.as(not null)
1176 var types
= new ArraySet[MType]
1178 types
.add
(p
.as(MVirtualTypeDef).bound
.as(not null))
1180 if types
.length
== 1 then
1186 # Is the virtual type fixed for a given resolved_receiver?
1187 fun is_fixed
(mmodule
: MModule, resolved_receiver
: MType): Bool
1189 assert not resolved_receiver
.need_anchor
1190 var props
= self.mproperty
.lookup_definitions
(mmodule
, resolved_receiver
)
1191 if props
.is_empty
then
1195 if p
.as(MVirtualTypeDef).is_fixed
then return true
1200 redef fun resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1202 assert can_resolve_for
(mtype
, anchor
, mmodule
)
1203 # self is a virtual type declared (or inherited) in mtype
1204 # The point of the function it to get the bound of the virtual type that make sense for mtype
1205 # But because mtype is maybe a virtual/formal type, we need to get a real receiver first
1206 #print "{class_name}: {self}/{mtype}/{anchor}?"
1207 var resolved_reciever
1208 if mtype
.need_anchor
then
1209 assert anchor
!= null
1210 resolved_reciever
= mtype
.resolve_for
(anchor
, null, mmodule
, true)
1212 resolved_reciever
= mtype
1214 # Now, we can get the bound
1215 var verbatim_bound
= lookup_bound
(mmodule
, resolved_reciever
)
1216 # The bound is exactly as declared in the "type" property, so we must resolve it again
1217 var res
= verbatim_bound
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1218 #print "{class_name}: {self}/{mtype}/{anchor} -> {self}/{resolved_receiver}/{anchor} -> {verbatim_bound}/{mtype}/{anchor} -> {res}"
1220 # What to return here? There is a bunch a special cases:
1221 # If 'cleanup_virtual' we must return the resolved type, since we cannot return self
1222 if cleanup_virtual
then return res
1223 # 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
1224 if resolved_reciever
isa MNullableType then resolved_reciever
= resolved_reciever
.mtype
1225 if resolved_reciever
.as(MClassType).mclass
.kind
== enum_kind
then return res
1226 # 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.
1227 if res
isa MVirtualType then return res
1228 # If we are final, just return the resolution
1229 if is_fixed
(mmodule
, resolved_reciever
) then return res
1230 # 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
1231 if res
isa MClassType and res
.mclass
.kind
== enum_kind
then return res
1232 # TODO: What if bound to a MParameterType?
1233 # Note that Nullable types can always be redefined by the non nullable version, so there is no specific case on it.
1235 # If anything apply, then `self' cannot be resolved, so return self
1239 redef fun can_resolve_for
(mtype
, anchor
, mmodule
)
1241 if mtype
.need_anchor
then
1242 assert anchor
!= null
1243 mtype
= mtype
.anchor_to
(mmodule
, anchor
)
1245 return mtype
.has_mproperty
(mmodule
, mproperty
)
1248 redef fun to_s
do return self.mproperty
.to_s
1251 # The type associated to a formal parameter generic type of a class
1253 # Each parameter type is associated to a specific class.
1254 # It means that all refinements of a same class "share" the parameter type,
1255 # but that a generic subclass has its own parameter types.
1257 # However, in the sense of the meta-model, a parameter type of a class is
1258 # a valid type in a subclass. The "in the sense of the meta-model" is
1259 # important because, in the Nit language, the programmer cannot refers
1260 # directly to the parameter types of the super-classes.
1265 # fun e: E is abstract
1271 # In the class definition B[F], `F` is a valid type but `E` is not.
1272 # However, `self.e` is a valid method call, and the signature of `e` is
1275 # Note that parameter types are shared among class refinements.
1276 # Therefore parameter only have an internal name (see `to_s` for details).
1277 class MParameterType
1280 # The generic class where the parameter belong
1283 redef fun model
do return self.mclass
.intro_mmodule
.model
1285 # The position of the parameter (0 for the first parameter)
1286 # FIXME: is `position` a better name?
1291 redef fun to_s
do return name
1293 # Resolve the bound for a given resolved_receiver
1294 # The result may be a other virtual type (or a parameter type)
1295 fun lookup_bound
(mmodule
: MModule, resolved_receiver
: MType): MType
1297 assert not resolved_receiver
.need_anchor
1298 var goalclass
= self.mclass
1299 var supertypes
= resolved_receiver
.collect_mtypes
(mmodule
)
1300 for t
in supertypes
do
1301 if t
.mclass
== goalclass
then
1302 # Yeah! c specialize goalclass with a "super `t'". So the question is what is the argument of f
1303 # FIXME: Here, we stop on the first goal. Should we check others and detect inconsistencies?
1304 var res
= t
.arguments
[self.rank
]
1311 redef fun resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1313 assert can_resolve_for
(mtype
, anchor
, mmodule
)
1314 #print "{class_name}: {self}/{mtype}/{anchor}?"
1316 if mtype
isa MGenericType and mtype
.mclass
== self.mclass
then
1317 var res
= mtype
.arguments
[self.rank
]
1318 if anchor
!= null and res
.need_anchor
then
1319 # Maybe the result can be resolved more if are bound to a final class
1320 var r2
= res
.anchor_to
(mmodule
, anchor
)
1321 if r2
isa MClassType and r2
.mclass
.kind
== enum_kind
then return r2
1326 # self is a parameter type of mtype (or of a super-class of mtype)
1327 # The point of the function it to get the bound of the virtual type that make sense for mtype
1328 # But because mtype is maybe a virtual/formal type, we need to get a real receiver first
1329 # FIXME: What happens here is far from clear. Thus this part must be validated and clarified
1330 var resolved_receiver
1331 if mtype
.need_anchor
then
1332 assert anchor
!= null
1333 resolved_receiver
= mtype
.resolve_for
(anchor
.mclass
.mclass_type
, anchor
, mmodule
, true)
1335 resolved_receiver
= mtype
1337 if resolved_receiver
isa MNullableType then resolved_receiver
= resolved_receiver
.mtype
1338 if resolved_receiver
isa MParameterType then
1339 assert resolved_receiver
.mclass
== anchor
.mclass
1340 resolved_receiver
= anchor
.arguments
[resolved_receiver
.rank
]
1341 if resolved_receiver
isa MNullableType then resolved_receiver
= resolved_receiver
.mtype
1343 assert resolved_receiver
isa MClassType
1345 # Eh! The parameter is in the current class.
1346 # So we return the corresponding argument, no mater what!
1347 if resolved_receiver
.mclass
== self.mclass
then
1348 var res
= resolved_receiver
.arguments
[self.rank
]
1349 #print "{class_name}: {self}/{mtype}/{anchor} -> direct {res}"
1353 if resolved_receiver
.need_anchor
then
1354 assert anchor
!= null
1355 resolved_receiver
= resolved_receiver
.resolve_for
(anchor
, null, mmodule
, false)
1357 # Now, we can get the bound
1358 var verbatim_bound
= lookup_bound
(mmodule
, resolved_receiver
)
1359 # The bound is exactly as declared in the "type" property, so we must resolve it again
1360 var res
= verbatim_bound
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1362 #print "{class_name}: {self}/{mtype}/{anchor} -> indirect {res}"
1367 redef fun can_resolve_for
(mtype
, anchor
, mmodule
)
1369 if mtype
.need_anchor
then
1370 assert anchor
!= null
1371 mtype
= mtype
.anchor_to
(mmodule
, anchor
)
1373 return mtype
.collect_mclassdefs
(mmodule
).has
(mclass
.intro
)
1377 # A type prefixed with "nullable"
1381 # The base type of the nullable type
1384 redef fun model
do return self.mtype
.model
1388 self.to_s
= "nullable {mtype}"
1391 redef var to_s
: String is noinit
1393 redef fun need_anchor
do return mtype
.need_anchor
1394 redef fun as_nullable
do return self
1395 redef fun as_notnullable
do return mtype
1396 redef fun resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1398 var res
= self.mtype
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1399 return res
.as_nullable
1402 redef fun can_resolve_for
(mtype
, anchor
, mmodule
)
1404 return self.mtype
.can_resolve_for
(mtype
, anchor
, mmodule
)
1407 redef fun depth
do return self.mtype
.depth
1409 redef fun length
do return self.mtype
.length
1411 redef fun collect_mclassdefs
(mmodule
)
1413 assert not self.need_anchor
1414 return self.mtype
.collect_mclassdefs
(mmodule
)
1417 redef fun collect_mclasses
(mmodule
)
1419 assert not self.need_anchor
1420 return self.mtype
.collect_mclasses
(mmodule
)
1423 redef fun collect_mtypes
(mmodule
)
1425 assert not self.need_anchor
1426 return self.mtype
.collect_mtypes
(mmodule
)
1430 # The type of the only value null
1432 # The is only one null type per model, see `MModel::null_type`.
1435 redef var model
: Model
1436 redef fun to_s
do return "null"
1437 redef fun as_nullable
do return self
1438 redef fun need_anchor
do return false
1439 redef fun resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
) do return self
1440 redef fun can_resolve_for
(mtype
, anchor
, mmodule
) do return true
1442 redef fun collect_mclassdefs
(mmodule
) do return new HashSet[MClassDef]
1444 redef fun collect_mclasses
(mmodule
) do return new HashSet[MClass]
1446 redef fun collect_mtypes
(mmodule
) do return new HashSet[MClassType]
1449 # A signature of a method
1453 # The each parameter (in order)
1454 var mparameters
: Array[MParameter]
1456 # The return type (null for a procedure)
1457 var return_mtype
: nullable MType
1462 var t
= self.return_mtype
1463 if t
!= null then dmax
= t
.depth
1464 for p
in mparameters
do
1465 var d
= p
.mtype
.depth
1466 if d
> dmax
then dmax
= d
1474 var t
= self.return_mtype
1475 if t
!= null then res
+= t
.length
1476 for p
in mparameters
do
1477 res
+= p
.mtype
.length
1482 # REQUIRE: 1 <= mparameters.count p -> p.is_vararg
1485 var vararg_rank
= -1
1486 for i
in [0..mparameters
.length
[ do
1487 var parameter
= mparameters
[i
]
1488 if parameter
.is_vararg
then
1489 assert vararg_rank
== -1
1493 self.vararg_rank
= vararg_rank
1496 # The rank of the ellipsis (`...`) for vararg (starting from 0).
1497 # value is -1 if there is no vararg.
1498 # Example: for "(a: Int, b: Bool..., c: Char)" #-> vararg_rank=1
1499 var vararg_rank
: Int is noinit
1501 # The number or parameters
1502 fun arity
: Int do return mparameters
.length
1506 var b
= new FlatBuffer
1507 if not mparameters
.is_empty
then
1509 for i
in [0..mparameters
.length
[ do
1510 var mparameter
= mparameters
[i
]
1511 if i
> 0 then b
.append
(", ")
1512 b
.append
(mparameter
.name
)
1514 b
.append
(mparameter
.mtype
.to_s
)
1515 if mparameter
.is_vararg
then
1521 var ret
= self.return_mtype
1529 redef fun resolve_for
(mtype
: MType, anchor
: nullable MClassType, mmodule
: MModule, cleanup_virtual
: Bool): MSignature
1531 var params
= new Array[MParameter]
1532 for p
in self.mparameters
do
1533 params
.add
(p
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
))
1535 var ret
= self.return_mtype
1537 ret
= ret
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1539 var res
= new MSignature(params
, ret
)
1544 # A parameter in a signature
1548 # The name of the parameter
1549 redef var name
: String
1551 # The static type of the parameter
1554 # Is the parameter a vararg?
1560 return "{name}: {mtype}..."
1562 return "{name}: {mtype}"
1566 fun resolve_for
(mtype
: MType, anchor
: nullable MClassType, mmodule
: MModule, cleanup_virtual
: Bool): MParameter
1568 if not self.mtype
.need_anchor
then return self
1569 var newtype
= self.mtype
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1570 var res
= new MParameter(self.name
, newtype
, self.is_vararg
)
1574 redef fun model
do return mtype
.model
1577 # A service (global property) that generalize method, attribute, etc.
1579 # `MProperty` are global to the model; it means that a `MProperty` is not bound
1580 # to a specific `MModule` nor a specific `MClass`.
1582 # A MProperty gather definitions (see `mpropdefs`) ; one for the introduction
1583 # and the other in subclasses and in refinements.
1585 # A `MProperty` is used to denotes services in polymorphic way (ie. independent
1586 # of any dynamic type).
1587 # For instance, a call site "x.foo" is associated to a `MProperty`.
1588 abstract class MProperty
1591 # The associated MPropDef subclass.
1592 # The two specialization hierarchy are symmetric.
1593 type MPROPDEF: MPropDef
1595 # The classdef that introduce the property
1596 # While a property is not bound to a specific module, or class,
1597 # the introducing mclassdef is used for naming and visibility
1598 var intro_mclassdef
: MClassDef
1600 # The (short) name of the property
1601 redef var name
: String
1603 # The canonical name of the property
1604 # Example: "owner::my_module::MyClass::my_method"
1605 fun full_name
: String
1607 return "{self.intro_mclassdef.mmodule.full_name}::{self.intro_mclassdef.mclass.name}::{name}"
1610 # The visibility of the property
1611 var visibility
: MVisibility
1615 intro_mclassdef
.intro_mproperties
.add
(self)
1616 var model
= intro_mclassdef
.mmodule
.model
1617 model
.mproperties_by_name
.add_one
(name
, self)
1618 model
.mproperties
.add
(self)
1621 # All definitions of the property.
1622 # The first is the introduction,
1623 # The other are redefinitions (in refinements and in subclasses)
1624 var mpropdefs
= new Array[MPROPDEF]
1626 # The definition that introduces the property.
1628 # Warning: such a definition may not exist in the early life of the object.
1629 # In this case, the method will abort.
1630 var intro
: MPROPDEF is noinit
1632 redef fun model
do return intro
.model
1635 redef fun to_s
do return name
1637 # Return the most specific property definitions defined or inherited by a type.
1638 # The selection knows that refinement is stronger than specialization;
1639 # however, in case of conflict more than one property are returned.
1640 # If mtype does not know mproperty then an empty array is returned.
1642 # If you want the really most specific property, then look at `lookup_first_definition`
1643 fun lookup_definitions
(mmodule
: MModule, mtype
: MType): Array[MPROPDEF]
1645 assert not mtype
.need_anchor
1646 mtype
= mtype
.as_notnullable
1648 var cache
= self.lookup_definitions_cache
[mmodule
, mtype
]
1649 if cache
!= null then return cache
1651 #print "select prop {mproperty} for {mtype} in {self}"
1652 # First, select all candidates
1653 var candidates
= new Array[MPROPDEF]
1654 for mpropdef
in self.mpropdefs
do
1655 # If the definition is not imported by the module, then skip
1656 if not mmodule
.in_importation
<= mpropdef
.mclassdef
.mmodule
then continue
1657 # If the definition is not inherited by the type, then skip
1658 if not mtype
.is_subtype
(mmodule
, null, mpropdef
.mclassdef
.bound_mtype
) then continue
1660 candidates
.add
(mpropdef
)
1662 # Fast track for only one candidate
1663 if candidates
.length
<= 1 then
1664 self.lookup_definitions_cache
[mmodule
, mtype
] = candidates
1668 # Second, filter the most specific ones
1669 return select_most_specific
(mmodule
, candidates
)
1672 private var lookup_definitions_cache
= new HashMap2[MModule, MType, Array[MPROPDEF]]
1674 # Return the most specific property definitions inherited by a type.
1675 # The selection knows that refinement is stronger than specialization;
1676 # however, in case of conflict more than one property are returned.
1677 # If mtype does not know mproperty then an empty array is returned.
1679 # If you want the really most specific property, then look at `lookup_next_definition`
1681 # FIXME: Move to `MPropDef`?
1682 fun lookup_super_definitions
(mmodule
: MModule, mtype
: MType): Array[MPROPDEF]
1684 assert not mtype
.need_anchor
1685 mtype
= mtype
.as_notnullable
1687 # First, select all candidates
1688 var candidates
= new Array[MPROPDEF]
1689 for mpropdef
in self.mpropdefs
do
1690 # If the definition is not imported by the module, then skip
1691 if not mmodule
.in_importation
<= mpropdef
.mclassdef
.mmodule
then continue
1692 # If the definition is not inherited by the type, then skip
1693 if not mtype
.is_subtype
(mmodule
, null, mpropdef
.mclassdef
.bound_mtype
) then continue
1694 # If the definition is defined by the type, then skip (we want the super, so e skip the current)
1695 if mtype
== mpropdef
.mclassdef
.bound_mtype
and mmodule
== mpropdef
.mclassdef
.mmodule
then continue
1697 candidates
.add
(mpropdef
)
1699 # Fast track for only one candidate
1700 if candidates
.length
<= 1 then return candidates
1702 # Second, filter the most specific ones
1703 return select_most_specific
(mmodule
, candidates
)
1706 # Return an array containing olny the most specific property definitions
1707 # This is an helper function for `lookup_definitions` and `lookup_super_definitions`
1708 private fun select_most_specific
(mmodule
: MModule, candidates
: Array[MPROPDEF]): Array[MPROPDEF]
1710 var res
= new Array[MPROPDEF]
1711 for pd1
in candidates
do
1712 var cd1
= pd1
.mclassdef
1715 for pd2
in candidates
do
1716 if pd2
== pd1
then continue # do not compare with self!
1717 var cd2
= pd2
.mclassdef
1719 if c2
.mclass_type
== c1
.mclass_type
then
1720 if cd2
.mmodule
.in_importation
< cd1
.mmodule
then
1721 # cd2 refines cd1; therefore we skip pd1
1725 else if cd2
.bound_mtype
.is_subtype
(mmodule
, null, cd1
.bound_mtype
) and cd2
.bound_mtype
!= cd1
.bound_mtype
then
1726 # cd2 < cd1; therefore we skip pd1
1735 if res
.is_empty
then
1736 print
"All lost! {candidates.join(", ")}"
1737 # FIXME: should be abort!
1742 # Return the most specific definition in the linearization of `mtype`.
1744 # If you want to know the next properties in the linearization,
1745 # look at `MPropDef::lookup_next_definition`.
1747 # FIXME: the linearization is still unspecified
1749 # REQUIRE: `not mtype.need_anchor`
1750 # REQUIRE: `mtype.has_mproperty(mmodule, self)`
1751 fun lookup_first_definition
(mmodule
: MModule, mtype
: MType): MPROPDEF
1753 assert mtype
.has_mproperty
(mmodule
, self)
1754 return lookup_all_definitions
(mmodule
, mtype
).first
1757 # Return all definitions in a linearization order
1758 # Most specific first, most general last
1759 fun lookup_all_definitions
(mmodule
: MModule, mtype
: MType): Array[MPROPDEF]
1761 assert not mtype
.need_anchor
1762 mtype
= mtype
.as_notnullable
1764 var cache
= self.lookup_all_definitions_cache
[mmodule
, mtype
]
1765 if cache
!= null then return cache
1767 #print "select prop {mproperty} for {mtype} in {self}"
1768 # First, select all candidates
1769 var candidates
= new Array[MPROPDEF]
1770 for mpropdef
in self.mpropdefs
do
1771 # If the definition is not imported by the module, then skip
1772 if not mmodule
.in_importation
<= mpropdef
.mclassdef
.mmodule
then continue
1773 # If the definition is not inherited by the type, then skip
1774 if not mtype
.is_subtype
(mmodule
, null, mpropdef
.mclassdef
.bound_mtype
) then continue
1776 candidates
.add
(mpropdef
)
1778 # Fast track for only one candidate
1779 if candidates
.length
<= 1 then
1780 self.lookup_all_definitions_cache
[mmodule
, mtype
] = candidates
1784 mmodule
.linearize_mpropdefs
(candidates
)
1785 candidates
= candidates
.reversed
1786 self.lookup_all_definitions_cache
[mmodule
, mtype
] = candidates
1790 private var lookup_all_definitions_cache
= new HashMap2[MModule, MType, Array[MPROPDEF]]
1797 redef type MPROPDEF: MMethodDef
1799 # Is the property defined at the top_level of the module?
1800 # Currently such a property are stored in `Object`
1801 var is_toplevel
: Bool = false is writable
1803 # Is the property a constructor?
1804 # Warning, this property can be inherited by subclasses with or without being a constructor
1805 # therefore, you should use `is_init_for` the verify if the property is a legal constructor for a given class
1806 var is_init
: Bool = false is writable
1808 # The constructor is a (the) root init with empty signature but a set of initializers
1809 var is_root_init
: Bool = false is writable
1811 # Is the property a 'new' constructor?
1812 var is_new
: Bool = false is writable
1814 # Is the property a legal constructor for a given class?
1815 # As usual, visibility is not considered.
1816 # FIXME not implemented
1817 fun is_init_for
(mclass
: MClass): Bool
1823 # A global attribute
1827 redef type MPROPDEF: MAttributeDef
1831 # A global virtual type
1832 class MVirtualTypeProp
1835 redef type MPROPDEF: MVirtualTypeDef
1837 # The formal type associated to the virtual type property
1838 var mvirtualtype
= new MVirtualType(self)
1841 # A definition of a property (local property)
1843 # Unlike `MProperty`, a `MPropDef` is a local definition that belong to a
1844 # specific class definition (which belong to a specific module)
1845 abstract class MPropDef
1848 # The associated `MProperty` subclass.
1849 # the two specialization hierarchy are symmetric
1850 type MPROPERTY: MProperty
1853 type MPROPDEF: MPropDef
1855 # The class definition where the property definition is
1856 var mclassdef
: MClassDef
1858 # The associated global property
1859 var mproperty
: MPROPERTY
1861 # The origin of the definition
1862 var location
: Location
1866 mclassdef
.mpropdefs
.add
(self)
1867 mproperty
.mpropdefs
.add
(self)
1868 if mproperty
.intro_mclassdef
== mclassdef
then
1869 assert not isset mproperty
._intro
1870 mproperty
.intro
= self
1872 self.to_s
= "{mclassdef}#{mproperty}"
1875 # Actually the name of the `mproperty`
1876 redef fun name
do return mproperty
.name
1878 redef fun model
do return mclassdef
.model
1880 # Internal name combining the module, the class and the property
1881 # Example: "mymodule#MyClass#mymethod"
1882 redef var to_s
: String is noinit
1884 # Is self the definition that introduce the property?
1885 fun is_intro
: Bool do return mproperty
.intro
== self
1887 # Return the next definition in linearization of `mtype`.
1889 # This method is used to determine what method is called by a super.
1891 # REQUIRE: `not mtype.need_anchor`
1892 fun lookup_next_definition
(mmodule
: MModule, mtype
: MType): MPROPDEF
1894 assert not mtype
.need_anchor
1896 var mpropdefs
= self.mproperty
.lookup_all_definitions
(mmodule
, mtype
)
1897 var i
= mpropdefs
.iterator
1898 while i
.is_ok
and i
.item
!= self do i
.next
1899 assert has_property
: i
.is_ok
1901 assert has_next_property
: i
.is_ok
1906 # A local definition of a method
1910 redef type MPROPERTY: MMethod
1911 redef type MPROPDEF: MMethodDef
1913 # The signature attached to the property definition
1914 var msignature
: nullable MSignature = null is writable
1916 # The signature attached to the `new` call on a root-init
1917 # This is a concatenation of the signatures of the initializers
1919 # REQUIRE `mproperty.is_root_init == (new_msignature != null)`
1920 var new_msignature
: nullable MSignature = null is writable
1922 # List of initialisers to call in root-inits
1924 # They could be setters or attributes
1926 # REQUIRE `mproperty.is_root_init == (new_msignature != null)`
1927 var initializers
= new Array[MProperty]
1929 # Is the method definition abstract?
1930 var is_abstract
: Bool = false is writable
1932 # Is the method definition intern?
1933 var is_intern
= false is writable
1935 # Is the method definition extern?
1936 var is_extern
= false is writable
1938 # An optional constant value returned in functions.
1940 # Only some specific primitife value are accepted by engines.
1941 # Is used when there is no better implementation available.
1943 # Currently used only for the implementation of the `--define`
1944 # command-line option.
1945 # SEE: module `mixin`.
1946 var constant_value
: nullable Object = null is writable
1949 # A local definition of an attribute
1953 redef type MPROPERTY: MAttribute
1954 redef type MPROPDEF: MAttributeDef
1956 # The static type of the attribute
1957 var static_mtype
: nullable MType = null is writable
1960 # A local definition of a virtual type
1961 class MVirtualTypeDef
1964 redef type MPROPERTY: MVirtualTypeProp
1965 redef type MPROPDEF: MVirtualTypeDef
1967 # The bound of the virtual type
1968 var bound
: nullable MType = null is writable
1970 # Is the bound fixed?
1971 var is_fixed
= false is writable
1978 # * `interface_kind`
1982 # Note this class is basically an enum.
1983 # FIXME: use a real enum once user-defined enums are available
1985 redef var to_s
: String
1987 # Is a constructor required?
1990 # TODO: private init because enumeration.
1992 # Can a class of kind `self` specializes a class of kine `other`?
1993 fun can_specialize
(other
: MClassKind): Bool
1995 if other
== interface_kind
then return true # everybody can specialize interfaces
1996 if self == interface_kind
or self == enum_kind
then
1997 # no other case for interfaces
1999 else if self == extern_kind
then
2000 # only compatible with themselves
2001 return self == other
2002 else if other
== enum_kind
or other
== extern_kind
then
2003 # abstract_kind and concrete_kind are incompatible
2006 # remain only abstract_kind and concrete_kind
2011 # The class kind `abstract`
2012 fun abstract_kind
: MClassKind do return once
new MClassKind("abstract class", true)
2013 # The class kind `concrete`
2014 fun concrete_kind
: MClassKind do return once
new MClassKind("class", true)
2015 # The class kind `interface`
2016 fun interface_kind
: MClassKind do return once
new MClassKind("interface", false)
2017 # The class kind `enum`
2018 fun enum_kind
: MClassKind do return once
new MClassKind("enum", false)
2019 # The class kind `extern`
2020 fun extern_kind
: MClassKind do return once
new MClassKind("extern class", false)