1 # This file is part of NIT ( http://www.nitlanguage.org ).
3 # Copyright 2012 Jean Privat <jean@pryen.org>
5 # Licensed under the Apache License, Version 2.0 (the "License");
6 # you may not use this file except in compliance with the License.
7 # You may obtain a copy of the License at
9 # http://www.apache.org/licenses/LICENSE-2.0
11 # Unless required by applicable law or agreed to in writing, software
12 # distributed under the License is distributed on an "AS IS" BASIS,
13 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 # See the License for the specific language governing permissions and
15 # limitations under the License.
17 # Classes, types and properties
19 # All three concepts are defined in this same module because these are strongly connected:
20 # * types are based on classes
21 # * classes contains properties
22 # * some properties are types (virtual types)
24 # TODO: liearization, extern stuff
25 # FIXME: better handling of the types
33 private import more_collections
37 var mclasses
: Array[MClass] = new Array[MClass]
39 # All known properties
40 var mproperties
: Array[MProperty] = new Array[MProperty]
42 # Hierarchy of class definition.
44 # Each classdef is associated with its super-classdefs in regard to
45 # its module of definition.
46 var mclassdef_hierarchy
: POSet[MClassDef] = new POSet[MClassDef]
48 # Class-type hierarchy restricted to the introduction.
50 # The idea is that what is true on introduction is always true whatever
51 # the module considered.
52 # Therefore, this hierarchy is used for a fast positive subtype check.
54 # This poset will evolve in a monotonous way:
55 # * Two non connected nodes will remain unconnected
56 # * New nodes can appear with new edges
57 private var intro_mtype_specialization_hierarchy
: POSet[MClassType] = new POSet[MClassType]
59 # Global overlapped class-type hierarchy.
60 # The hierarchy when all modules are combined.
61 # Therefore, this hierarchy is used for a fast negative subtype check.
63 # This poset will evolve in an anarchic way. Loops can even be created.
65 # FIXME decide what to do on loops
66 private var full_mtype_specialization_hierarchy
: POSet[MClassType] = new POSet[MClassType]
68 # Collections of classes grouped by their short name
69 private var mclasses_by_name
: MultiHashMap[String, MClass] = new MultiHashMap[String, MClass]
71 # Return all class named `name`.
73 # If such a class does not exist, null is returned
74 # (instead of an empty array)
76 # Visibility or modules are not considered
77 fun get_mclasses_by_name
(name
: String): nullable Array[MClass]
79 if mclasses_by_name
.has_key
(name
) then
80 return mclasses_by_name
[name
]
86 # Collections of properties grouped by their short name
87 private var mproperties_by_name
: MultiHashMap[String, MProperty] = new MultiHashMap[String, MProperty]
89 # Return all properties named `name`.
91 # If such a property does not exist, null is returned
92 # (instead of an empty array)
94 # Visibility or modules are not considered
95 fun get_mproperties_by_name
(name
: String): nullable Array[MProperty]
97 if not mproperties_by_name
.has_key
(name
) then
100 return mproperties_by_name
[name
]
105 var null_type
: MNullType = new MNullType(self)
107 # Build an ordered tree with from `concerns`
108 fun concerns_tree
(mconcerns
: Collection[MConcern]): ConcernsTree do
109 var seen
= new HashSet[MConcern]
110 var res
= new ConcernsTree
112 var todo
= new Array[MConcern]
113 todo
.add_all mconcerns
115 while not todo
.is_empty
do
117 if seen
.has
(c
) then continue
118 var pc
= c
.parent_concern
132 # An OrderedTree that can be easily refined for display purposes
134 super OrderedTree[MConcern]
138 # All the classes introduced in the module
139 var intro_mclasses
: Array[MClass] = new Array[MClass]
141 # All the class definitions of the module
142 # (introduction and refinement)
143 var mclassdefs
: Array[MClassDef] = new Array[MClassDef]
145 # Does the current module has a given class `mclass`?
146 # Return true if the mmodule introduces, refines or imports a class.
147 # Visibility is not considered.
148 fun has_mclass
(mclass
: MClass): Bool
150 return self.in_importation
<= mclass
.intro_mmodule
153 # Full hierarchy of introduced ans imported classes.
155 # Create a new hierarchy got by flattening the classes for the module
156 # and its imported modules.
157 # Visibility is not considered.
159 # Note: this function is expensive and is usually used for the main
160 # module of a program only. Do not use it to do you own subtype
162 fun flatten_mclass_hierarchy
: POSet[MClass]
164 var res
= self.flatten_mclass_hierarchy_cache
165 if res
!= null then return res
166 res
= new POSet[MClass]
167 for m
in self.in_importation
.greaters
do
168 for cd
in m
.mclassdefs
do
171 for s
in cd
.supertypes
do
172 res
.add_edge
(c
, s
.mclass
)
176 self.flatten_mclass_hierarchy_cache
= res
180 # Sort a given array of classes using the linerarization order of the module
181 # The most general is first, the most specific is last
182 fun linearize_mclasses
(mclasses
: Array[MClass])
184 self.flatten_mclass_hierarchy
.sort
(mclasses
)
187 # Sort a given array of class definitions using the linerarization order of the module
188 # the refinement link is stronger than the specialisation link
189 # The most general is first, the most specific is last
190 fun linearize_mclassdefs
(mclassdefs
: Array[MClassDef])
192 var sorter
= new MClassDefSorter(self)
193 sorter
.sort
(mclassdefs
)
196 # Sort a given array of property definitions using the linerarization order of the module
197 # the refinement link is stronger than the specialisation link
198 # The most general is first, the most specific is last
199 fun linearize_mpropdefs
(mpropdefs
: Array[MPropDef])
201 var sorter
= new MPropDefSorter(self)
202 sorter
.sort
(mpropdefs
)
205 private var flatten_mclass_hierarchy_cache
: nullable POSet[MClass] = null
207 # The primitive type `Object`, the root of the class hierarchy
208 fun object_type
: MClassType
210 var res
= self.object_type_cache
211 if res
!= null then return res
212 res
= self.get_primitive_class
("Object").mclass_type
213 self.object_type_cache
= res
217 private var object_type_cache
: nullable MClassType
219 # The primitive type `Bool`
220 fun bool_type
: MClassType
222 var res
= self.bool_type_cache
223 if res
!= null then return res
224 res
= self.get_primitive_class
("Bool").mclass_type
225 self.bool_type_cache
= res
229 private var bool_type_cache
: nullable MClassType
231 # The primitive type `Sys`, the main type of the program, if any
232 fun sys_type
: nullable MClassType
234 var clas
= self.model
.get_mclasses_by_name
("Sys")
235 if clas
== null then return null
236 return get_primitive_class
("Sys").mclass_type
239 # Force to get the primitive class named `name` or abort
240 fun get_primitive_class
(name
: String): MClass
242 var cla
= self.model
.get_mclasses_by_name
(name
)
244 if name
== "Bool" then
245 var c
= new MClass(self, name
, 0, enum_kind
, public_visibility
)
246 var cladef
= new MClassDef(self, c
.mclass_type
, new Location(null, 0,0,0,0), new Array[String])
249 print
("Fatal Error: no primitive class {name}")
252 if cla
.length
!= 1 then
253 var msg
= "Fatal Error: more than one primitive class {name}:"
254 for c
in cla
do msg
+= " {c.full_name}"
261 # Try to get the primitive method named `name` on the type `recv`
262 fun try_get_primitive_method
(name
: String, recv
: MClass): nullable MMethod
264 var props
= self.model
.get_mproperties_by_name
(name
)
265 if props
== null then return null
266 var res
: nullable MMethod = null
267 for mprop
in props
do
268 assert mprop
isa MMethod
269 var intro
= mprop
.intro_mclassdef
270 for mclassdef
in recv
.mclassdefs
do
271 if not self.in_importation
.greaters
.has
(mclassdef
.mmodule
) then continue
272 if not mclassdef
.in_hierarchy
.greaters
.has
(intro
) then continue
275 else if res
!= mprop
then
276 print
("Fatal Error: ambigous property name '{name}'; conflict between {mprop.full_name} and {res.full_name}")
285 private class MClassDefSorter
286 super AbstractSorter[MClassDef]
288 redef fun compare
(a
, b
)
292 if ca
!= cb
then return mmodule
.flatten_mclass_hierarchy
.compare
(ca
, cb
)
293 return mmodule
.model
.mclassdef_hierarchy
.compare
(a
, b
)
297 private class MPropDefSorter
298 super AbstractSorter[MPropDef]
300 redef fun compare
(pa
, pb
)
306 if ca
!= cb
then return mmodule
.flatten_mclass_hierarchy
.compare
(ca
, cb
)
307 return mmodule
.model
.mclassdef_hierarchy
.compare
(a
, b
)
313 # `MClass` are global to the model; it means that a `MClass` is not bound to a
314 # specific `MModule`.
316 # This characteristic helps the reasoning about classes in a program since a
317 # single `MClass` object always denote the same class.
319 # The drawback is that classes (`MClass`) contain almost nothing by themselves.
320 # These do not really have properties nor belong to a hierarchy since the property and the
321 # hierarchy of a class depends of the refinement in the modules.
323 # Most services on classes require the precision of a module, and no one can asks what are
324 # the super-classes of a class nor what are properties of a class without precising what is
325 # the module considered.
327 # For instance, during the typing of a source-file, the module considered is the module of the file.
328 # eg. the question *is the method `foo` exists in the class `Bar`?* must be reformulated into
329 # *is the method `foo` exists in the class `Bar` in the current module?*
331 # During some global analysis, the module considered may be the main module of the program.
335 # The module that introduce the class
336 # While classes are not bound to a specific module,
337 # the introducing module is used for naming an visibility
338 var intro_mmodule
: MModule
340 # The short name of the class
341 # In Nit, the name of a class cannot evolve in refinements
342 redef var name
: String
344 # The canonical name of the class
345 # Example: `"owner::module::MyClass"`
346 fun full_name
: String
348 return "{self.intro_mmodule.full_name}::{name}"
351 # The number of generic formal parameters
352 # 0 if the class is not generic
355 # The kind of the class (interface, abstract class, etc.)
356 # In Nit, the kind of a class cannot evolve in refinements
359 # The visibility of the class
360 # In Nit, the visibility of a class cannot evolve in refinements
361 var visibility
: MVisibility
363 init(intro_mmodule
: MModule, name
: String, arity
: Int, kind
: MClassKind, visibility
: MVisibility)
365 self.intro_mmodule
= intro_mmodule
369 self.visibility
= visibility
370 intro_mmodule
.intro_mclasses
.add
(self)
371 var model
= intro_mmodule
.model
372 model
.mclasses_by_name
.add_one
(name
, self)
373 model
.mclasses
.add
(self)
375 # Create the formal parameter types
377 var mparametertypes
= new Array[MParameterType]
378 for i
in [0..arity
[ do
379 var mparametertype
= new MParameterType(self, i
)
380 mparametertypes
.add
(mparametertype
)
382 var mclass_type
= new MGenericType(self, mparametertypes
)
383 self.mclass_type
= mclass_type
384 self.get_mtype_cache
.add
(mclass_type
)
386 self.mclass_type
= new MClassType(self)
390 # All class definitions (introduction and refinements)
391 var mclassdefs
: Array[MClassDef] = new Array[MClassDef]
394 redef fun to_s
do return self.name
396 # The definition that introduced the class
397 # Warning: the introduction is the first `MClassDef` object associated
398 # to self. If self is just created without having any associated
399 # definition, this method will abort
402 assert has_a_first_definition
: not mclassdefs
.is_empty
403 return mclassdefs
.first
406 # Return the class `self` in the class hierarchy of the module `mmodule`.
408 # SEE: `MModule::flatten_mclass_hierarchy`
409 # REQUIRE: `mmodule.has_mclass(self)`
410 fun in_hierarchy
(mmodule
: MModule): POSetElement[MClass]
412 return mmodule
.flatten_mclass_hierarchy
[self]
415 # The principal static type of the class.
417 # For non-generic class, mclass_type is the only `MClassType` based
420 # For a generic class, the arguments are the formal parameters.
421 # i.e.: for the class Array[E:Object], the `mclass_type` is Array[E].
422 # If you want Array[Object] the see `MClassDef::bound_mtype`
424 # For generic classes, the mclass_type is also the way to get a formal
425 # generic parameter type.
427 # To get other types based on a generic class, see `get_mtype`.
429 # ENSURE: `mclass_type.mclass == self`
430 var mclass_type
: MClassType
432 # Return a generic type based on the class
433 # Is the class is not generic, then the result is `mclass_type`
435 # REQUIRE: `mtype_arguments.length == self.arity`
436 fun get_mtype
(mtype_arguments
: Array[MType]): MClassType
438 assert mtype_arguments
.length
== self.arity
439 if self.arity
== 0 then return self.mclass_type
440 for t
in self.get_mtype_cache
do
441 if t
.arguments
== mtype_arguments
then
445 var res
= new MGenericType(self, mtype_arguments
)
446 self.get_mtype_cache
.add res
450 private var get_mtype_cache
: Array[MGenericType] = new Array[MGenericType]
454 # A definition (an introduction or a refinement) of a class in a module
456 # A `MClassDef` is associated with an explicit (or almost) definition of a
457 # class. Unlike `MClass`, a `MClassDef` is a local definition that belong to
458 # a specific class and a specific module, and contains declarations like super-classes
461 # It is the class definitions that are the backbone of most things in the model:
462 # ClassDefs are defined with regard with other classdefs.
463 # Refinement and specialization are combined to produce a big poset called the `Model::mclassdef_hierarchy`.
465 # Moreover, the extension and the intention of types is defined by looking at the MClassDefs.
469 # The module where the definition is
472 # The associated `MClass`
475 # The bounded type associated to the mclassdef
477 # For a non-generic class, `bound_mtype` and `mclass.mclass_type`
481 # For the classdef Array[E: Object], the bound_mtype is Array[Object].
482 # If you want Array[E], then see `mclass.mclass_type`
484 # ENSURE: `bound_mtype.mclass == self.mclass`
485 var bound_mtype
: MClassType
487 # Name of each formal generic parameter (in order of declaration)
488 var parameter_names
: Array[String]
490 # The origin of the definition
491 var location
: Location
493 # Internal name combining the module and the class
494 # Example: "mymodule#MyClass"
495 redef var to_s
: String
497 init(mmodule
: MModule, bound_mtype
: MClassType, location
: Location, parameter_names
: Array[String])
499 assert bound_mtype
.mclass
.arity
== parameter_names
.length
500 self.bound_mtype
= bound_mtype
501 self.mmodule
= mmodule
502 self.mclass
= bound_mtype
.mclass
503 self.location
= location
504 mmodule
.mclassdefs
.add
(self)
505 mclass
.mclassdefs
.add
(self)
506 self.parameter_names
= parameter_names
507 self.to_s
= "{mmodule}#{mclass}"
510 # Actually the name of the `mclass`
511 redef fun name
do return mclass
.name
513 # All declared super-types
514 # FIXME: quite ugly but not better idea yet
515 var supertypes
: Array[MClassType] = new Array[MClassType]
517 # Register some super-types for the class (ie "super SomeType")
519 # The hierarchy must not already be set
520 # REQUIRE: `self.in_hierarchy == null`
521 fun set_supertypes
(supertypes
: Array[MClassType])
523 assert unique_invocation
: self.in_hierarchy
== null
524 var mmodule
= self.mmodule
525 var model
= mmodule
.model
526 var mtype
= self.bound_mtype
528 for supertype
in supertypes
do
529 self.supertypes
.add
(supertype
)
531 # Register in full_type_specialization_hierarchy
532 model
.full_mtype_specialization_hierarchy
.add_edge
(mtype
, supertype
)
533 # Register in intro_type_specialization_hierarchy
534 if mclass
.intro_mmodule
== mmodule
and supertype
.mclass
.intro_mmodule
== mmodule
then
535 model
.intro_mtype_specialization_hierarchy
.add_edge
(mtype
, supertype
)
541 # Collect the super-types (set by set_supertypes) to build the hierarchy
543 # This function can only invoked once by class
544 # REQUIRE: `self.in_hierarchy == null`
545 # ENSURE: `self.in_hierarchy != null`
548 assert unique_invocation
: self.in_hierarchy
== null
549 var model
= mmodule
.model
550 var res
= model
.mclassdef_hierarchy
.add_node
(self)
551 self.in_hierarchy
= res
552 var mtype
= self.bound_mtype
554 # Here we need to connect the mclassdef to its pairs in the mclassdef_hierarchy
555 # The simpliest way is to attach it to collect_mclassdefs
556 for mclassdef
in mtype
.collect_mclassdefs
(mmodule
) do
557 res
.poset
.add_edge
(self, mclassdef
)
561 # The view of the class definition in `mclassdef_hierarchy`
562 var in_hierarchy
: nullable POSetElement[MClassDef] = null
564 # Is the definition the one that introduced `mclass`?
565 fun is_intro
: Bool do return mclass
.intro
== self
567 # All properties introduced by the classdef
568 var intro_mproperties
: Array[MProperty] = new Array[MProperty]
570 # All property definitions in the class (introductions and redefinitions)
571 var mpropdefs
: Array[MPropDef] = new Array[MPropDef]
574 # A global static type
576 # MType are global to the model; it means that a `MType` is not bound to a
577 # specific `MModule`.
578 # This characteristic helps the reasoning about static types in a program
579 # since a single `MType` object always denote the same type.
581 # However, because a `MType` is global, it does not really have properties
582 # nor have subtypes to a hierarchy since the property and the class hierarchy
583 # depends of a module.
584 # Moreover, virtual types an formal generic parameter types also depends on
585 # a receiver to have sense.
587 # Therefore, most method of the types require a module and an anchor.
588 # The module is used to know what are the classes and the specialization
590 # The anchor is used to know what is the bound of the virtual types and formal
591 # generic parameter types.
593 # MType are not directly usable to get properties. See the `anchor_to` method
594 # and the `MClassType` class.
596 # FIXME: the order of the parameters is not the best. We mus pick on from:
597 # * foo(mmodule, anchor, othertype)
598 # * foo(othertype, anchor, mmodule)
599 # * foo(anchor, mmodule, othertype)
600 # * foo(othertype, mmodule, anchor)
604 # The model of the type
605 fun model
: Model is abstract
607 # Return true if `self` is an subtype of `sup`.
608 # The typing is done using the standard typing policy of Nit.
610 # REQUIRE: `anchor == null implies not self.need_anchor and not sup.need_anchor`
611 # REQUIRE: `anchor != null implies self.can_resolve_for(anchor, null, mmodule) and sup.can_resolve_for(anchor, null, mmodule)`
612 fun is_subtype
(mmodule
: MModule, anchor
: nullable MClassType, sup
: MType): Bool
615 if sub
== sup
then return true
616 if anchor
== null then
617 assert not sub
.need_anchor
618 assert not sup
.need_anchor
620 assert sub
.can_resolve_for
(anchor
, null, mmodule
)
621 assert sup
.can_resolve_for
(anchor
, null, mmodule
)
624 # First, resolve the formal types to a common version in the receiver
625 # The trick here is that fixed formal type will be associed to the bound
626 # And unfixed formal types will be associed to a canonical formal type.
627 if sub
isa MParameterType or sub
isa MVirtualType then
628 assert anchor
!= null
629 sub
= sub
.resolve_for
(anchor
.mclass
.mclass_type
, anchor
, mmodule
, false)
631 if sup
isa MParameterType or sup
isa MVirtualType then
632 assert anchor
!= null
633 sup
= sup
.resolve_for
(anchor
.mclass
.mclass_type
, anchor
, mmodule
, false)
636 # Does `sup` accept null or not?
637 # Discard the nullable marker if it exists
638 var sup_accept_null
= false
639 if sup
isa MNullableType then
640 sup_accept_null
= true
642 else if sup
isa MNullType then
643 sup_accept_null
= true
646 # Can `sub` provide null or not?
647 # Thus we can match with `sup_accept_null`
648 # Also discard the nullable marker if it exists
649 if sub
isa MNullableType then
650 if not sup_accept_null
then return false
652 else if sub
isa MNullType then
653 return sup_accept_null
655 # Now the case of direct null and nullable is over.
657 # A unfixed formal type can only accept itself
658 if sup
isa MParameterType or sup
isa MVirtualType then
662 # If `sub` is a formal type, then it is accepted if its bound is accepted
663 if sub
isa MParameterType or sub
isa MVirtualType then
664 assert anchor
!= null
665 sub
= sub
.anchor_to
(mmodule
, anchor
)
667 # Manage the second layer of null/nullable
668 if sub
isa MNullableType then
669 if not sup_accept_null
then return false
671 else if sub
isa MNullType then
672 return sup_accept_null
676 assert sub
isa MClassType # It is the only remaining type
678 if sup
isa MNullType then
679 # `sup` accepts only null
683 assert sup
isa MClassType # It is the only remaining type
685 # Now both are MClassType, we need to dig
687 if sub
== sup
then return true
689 if anchor
== null then anchor
= sub
# UGLY: any anchor will work
690 var resolved_sub
= sub
.anchor_to
(mmodule
, anchor
)
691 var res
= resolved_sub
.collect_mclasses
(mmodule
).has
(sup
.mclass
)
692 if res
== false then return false
693 if not sup
isa MGenericType then return true
694 var sub2
= sub
.supertype_to
(mmodule
, anchor
, sup
.mclass
)
695 assert sub2
.mclass
== sup
.mclass
696 for i
in [0..sup
.mclass
.arity
[ do
697 var sub_arg
= sub2
.arguments
[i
]
698 var sup_arg
= sup
.arguments
[i
]
699 res
= sub_arg
.is_subtype
(mmodule
, anchor
, sup_arg
)
700 if res
== false then return false
705 # The base class type on which self is based
707 # This base type is used to get property (an internally to perform
708 # unsafe type comparison).
710 # Beware: some types (like null) are not based on a class thus this
713 # Basically, this function transform the virtual types and parameter
714 # types to their bounds.
718 # class B super A end
720 # class Y super X end
728 # Map[T,U] anchor_to H #-> Map[B,Y]
730 # Explanation of the example:
731 # In H, T is set to B, because "H super G[B]", and U is bound to Y,
732 # because "redef type U: Y". Therefore, Map[T, U] is bound to
735 # ENSURE: `not self.need_anchor implies result == self`
736 # ENSURE: `not result.need_anchor`
737 fun anchor_to
(mmodule
: MModule, anchor
: MClassType): MType
739 if not need_anchor
then return self
740 assert not anchor
.need_anchor
741 # Just resolve to the anchor and clear all the virtual types
742 var res
= self.resolve_for
(anchor
, null, mmodule
, true)
743 assert not res
.need_anchor
747 # Does `self` contain a virtual type or a formal generic parameter type?
748 # In order to remove those types, you usually want to use `anchor_to`.
749 fun need_anchor
: Bool do return true
751 # Return the supertype when adapted to a class.
753 # In Nit, for each super-class of a type, there is a equivalent super-type.
757 # class H[V] super G[V, Bool] end
758 # H[Int] supertype_to G #-> G[Int, Bool]
760 # REQUIRE: `super_mclass` is a super-class of `self`
761 # REQUIRE: `self.need_anchor implies anchor != null and self.can_resolve_for(anchor, null, mmodule)`
762 # ENSURE: `result.mclass = super_mclass`
763 fun supertype_to
(mmodule
: MModule, anchor
: nullable MClassType, super_mclass
: MClass): MClassType
765 if super_mclass
.arity
== 0 then return super_mclass
.mclass_type
766 if self isa MClassType and self.mclass
== super_mclass
then return self
768 if self.need_anchor
then
769 assert anchor
!= null
770 resolved_self
= self.anchor_to
(mmodule
, anchor
)
774 var supertypes
= resolved_self
.collect_mtypes
(mmodule
)
775 for supertype
in supertypes
do
776 if supertype
.mclass
== super_mclass
then
777 # FIXME: Here, we stop on the first goal. Should we check others and detect inconsistencies?
778 return supertype
.resolve_for
(self, anchor
, mmodule
, false)
784 # Replace formals generic types in self with resolved values in `mtype`
785 # If `cleanup_virtual` is true, then virtual types are also replaced
788 # This function returns self if `need_anchor` is false.
793 # class H[F] super G[F] end
796 # * Array[E].resolve_for(H[Int]) #-> Array[Int]
797 # * Array[E].resolve_for(G[Z], X[Int]) #-> Array[Z]
799 # Explanation of the example:
800 # * Array[E].need_anchor is true because there is a formal generic parameter type E
801 # * E makes sense for H[Int] because E is a formal parameter of G and H specialize G
802 # * Since "H[F] super G[F]", E is in fact F for H
803 # * More specifically, in H[Int], E is Int
804 # * So, in H[Int], Array[E] is Array[Int]
806 # This function is mainly used to inherit a signature.
807 # Because, unlike `anchor_to`, we do not want a full resolution of
808 # a type but only an adapted version of it.
813 # fun foo(e:E):E is abstract
815 # class B super A[Int] end
817 # The signature on foo is (e: E): E
818 # If we resolve the signature for B, we get (e:Int):Int
823 # fun foo(e:E) is abstract
827 # fun bar do a.foo(x) # <- x is here
830 # The first question is: is foo available on `a`?
832 # The static type of a is `A[Array[F]]`, that is an open type.
833 # in order to find a method `foo`, whe must look at a resolved type.
835 # A[Array[F]].anchor_to(B[nullable Object]) #-> A[Array[nullable Object]]
837 # the method `foo` exists in `A[Array[nullable Object]]`, therefore `foo` exists for `a`.
839 # The next question is: what is the accepted types for `x`?
841 # the signature of `foo` is `foo(e:E)`, thus we must resolve the type E
843 # E.resolve_for(A[Array[F]],B[nullable Object]) #-> Array[F]
845 # The resolution can be done because `E` make sense for the class A (see `can_resolve_for`)
847 # FIXME: the parameter `cleanup_virtual` is just a bad idea, but having
848 # two function instead of one seems also to be a bad idea.
850 # REQUIRE: `can_resolve_for(mtype, anchor, mmodule)`
851 # ENSURE: `not self.need_anchor implies result == self`
852 fun resolve_for
(mtype
: MType, anchor
: nullable MClassType, mmodule
: MModule, cleanup_virtual
: Bool): MType is abstract
854 # Can the type be resolved?
856 # In order to resolve open types, the formal types must make sence.
865 # * E.can_resolve_for(A[Int]) #-> true, E make sense in A
866 # * E.can_resolve_for(B[Int]) #-> false, E does not make sense in B
867 # * B[E].can_resolve_for(A[F], B[Object]) #-> true,
868 # B[E] is a red hearing only the E is important,
871 # REQUIRE: `anchor != null implies not anchor.need_anchor`
872 # REQUIRE: `mtype.need_anchor implies anchor != null and mtype.can_resolve_for(anchor, null, mmodule)`
873 # ENSURE: `not self.need_anchor implies result == true`
874 fun can_resolve_for
(mtype
: MType, anchor
: nullable MClassType, mmodule
: MModule): Bool is abstract
876 # Return the nullable version of the type
877 # If the type is already nullable then self is returned
878 fun as_nullable
: MType
880 var res
= self.as_nullable_cache
881 if res
!= null then return res
882 res
= new MNullableType(self)
883 self.as_nullable_cache
= res
887 private var as_nullable_cache
: nullable MType = null
890 # The deph of the type seen as a tree.
897 # Formal types have a depth of 1.
903 # The length of the type seen as a tree.
910 # Formal types have a length of 1.
916 # Compute all the classdefs inherited/imported.
917 # The returned set contains:
918 # * the class definitions from `mmodule` and its imported modules
919 # * the class definitions of this type and its super-types
921 # This function is used mainly internally.
923 # REQUIRE: `not self.need_anchor`
924 fun collect_mclassdefs
(mmodule
: MModule): Set[MClassDef] is abstract
926 # Compute all the super-classes.
927 # This function is used mainly internally.
929 # REQUIRE: `not self.need_anchor`
930 fun collect_mclasses
(mmodule
: MModule): Set[MClass] is abstract
932 # Compute all the declared super-types.
933 # Super-types are returned as declared in the classdefs (verbatim).
934 # This function is used mainly internally.
936 # REQUIRE: `not self.need_anchor`
937 fun collect_mtypes
(mmodule
: MModule): Set[MClassType] is abstract
939 # Is the property in self for a given module
940 # This method does not filter visibility or whatever
942 # REQUIRE: `not self.need_anchor`
943 fun has_mproperty
(mmodule
: MModule, mproperty
: MProperty): Bool
945 assert not self.need_anchor
946 return self.collect_mclassdefs
(mmodule
).has
(mproperty
.intro_mclassdef
)
950 # A type based on a class.
952 # `MClassType` have properties (see `has_mproperty`).
956 # The associated class
959 redef fun model
do return self.mclass
.intro_mmodule
.model
961 private init(mclass
: MClass)
966 # The formal arguments of the type
967 # ENSURE: `result.length == self.mclass.arity`
968 var arguments
: Array[MType] = new Array[MType]
970 redef fun to_s
do return mclass
.to_s
972 redef fun need_anchor
do return false
974 redef fun anchor_to
(mmodule
: MModule, anchor
: MClassType): MClassType
976 return super.as(MClassType)
979 redef fun resolve_for
(mtype
: MType, anchor
: nullable MClassType, mmodule
: MModule, cleanup_virtual
: Bool): MClassType do return self
981 redef fun can_resolve_for
(mtype
, anchor
, mmodule
) do return true
983 redef fun collect_mclassdefs
(mmodule
)
985 assert not self.need_anchor
986 var cache
= self.collect_mclassdefs_cache
987 if not cache
.has_key
(mmodule
) then
988 self.collect_things
(mmodule
)
990 return cache
[mmodule
]
993 redef fun collect_mclasses
(mmodule
)
995 assert not self.need_anchor
996 var cache
= self.collect_mclasses_cache
997 if not cache
.has_key
(mmodule
) then
998 self.collect_things
(mmodule
)
1000 return cache
[mmodule
]
1003 redef fun collect_mtypes
(mmodule
)
1005 assert not self.need_anchor
1006 var cache
= self.collect_mtypes_cache
1007 if not cache
.has_key
(mmodule
) then
1008 self.collect_things
(mmodule
)
1010 return cache
[mmodule
]
1013 # common implementation for `collect_mclassdefs`, `collect_mclasses`, and `collect_mtypes`.
1014 private fun collect_things
(mmodule
: MModule)
1016 var res
= new HashSet[MClassDef]
1017 var seen
= new HashSet[MClass]
1018 var types
= new HashSet[MClassType]
1019 seen
.add
(self.mclass
)
1020 var todo
= [self.mclass
]
1021 while not todo
.is_empty
do
1022 var mclass
= todo
.pop
1023 #print "process {mclass}"
1024 for mclassdef
in mclass
.mclassdefs
do
1025 if not mmodule
.in_importation
<= mclassdef
.mmodule
then continue
1026 #print " process {mclassdef}"
1028 for supertype
in mclassdef
.supertypes
do
1029 types
.add
(supertype
)
1030 var superclass
= supertype
.mclass
1031 if seen
.has
(superclass
) then continue
1032 #print " add {superclass}"
1033 seen
.add
(superclass
)
1034 todo
.add
(superclass
)
1038 collect_mclassdefs_cache
[mmodule
] = res
1039 collect_mclasses_cache
[mmodule
] = seen
1040 collect_mtypes_cache
[mmodule
] = types
1043 private var collect_mclassdefs_cache
: HashMap[MModule, Set[MClassDef]] = new HashMap[MModule, Set[MClassDef]]
1044 private var collect_mclasses_cache
: HashMap[MModule, Set[MClass]] = new HashMap[MModule, Set[MClass]]
1045 private var collect_mtypes_cache
: HashMap[MModule, Set[MClassType]] = new HashMap[MModule, Set[MClassType]]
1049 # A type based on a generic class.
1050 # A generic type a just a class with additional formal generic arguments.
1054 private init(mclass
: MClass, arguments
: Array[MType])
1057 assert self.mclass
.arity
== arguments
.length
1058 self.arguments
= arguments
1060 self.need_anchor
= false
1061 for t
in arguments
do
1062 if t
.need_anchor
then
1063 self.need_anchor
= true
1068 self.to_s
= "{mclass}[{arguments.join(", ")}]"
1071 # Recursively print the type of the arguments within brackets.
1072 # Example: `"Map[String, List[Int]]"`
1073 redef var to_s
: String
1075 redef var need_anchor
: Bool
1077 redef fun resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1079 if not need_anchor
then return self
1080 assert can_resolve_for
(mtype
, anchor
, mmodule
)
1081 var types
= new Array[MType]
1082 for t
in arguments
do
1083 types
.add
(t
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
))
1085 return mclass
.get_mtype
(types
)
1088 redef fun can_resolve_for
(mtype
, anchor
, mmodule
)
1090 if not need_anchor
then return true
1091 for t
in arguments
do
1092 if not t
.can_resolve_for
(mtype
, anchor
, mmodule
) then return false
1101 for a
in self.arguments
do
1103 if d
> dmax
then dmax
= d
1111 for a
in self.arguments
do
1118 # A virtual formal type.
1122 # The property associated with the type.
1123 # Its the definitions of this property that determine the bound or the virtual type.
1124 var mproperty
: MProperty
1126 redef fun model
do return self.mproperty
.intro_mclassdef
.mmodule
.model
1128 # Lookup the bound for a given resolved_receiver
1129 # The result may be a other virtual type (or a parameter type)
1131 # The result is returned exactly as declared in the "type" property (verbatim).
1133 # In case of conflict, the method aborts.
1134 fun lookup_bound
(mmodule
: MModule, resolved_receiver
: MType): MType
1136 assert not resolved_receiver
.need_anchor
1137 var props
= self.mproperty
.lookup_definitions
(mmodule
, resolved_receiver
)
1138 if props
.is_empty
then
1140 else if props
.length
== 1 then
1141 return props
.first
.as(MVirtualTypeDef).bound
.as(not null)
1143 var types
= new ArraySet[MType]
1145 types
.add
(p
.as(MVirtualTypeDef).bound
.as(not null))
1147 if types
.length
== 1 then
1153 redef fun resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1155 assert can_resolve_for
(mtype
, anchor
, mmodule
)
1156 # self is a virtual type declared (or inherited) in mtype
1157 # The point of the function it to get the bound of the virtual type that make sense for mtype
1158 # But because mtype is maybe a virtual/formal type, we need to get a real receiver first
1159 #print "{class_name}: {self}/{mtype}/{anchor}?"
1160 var resolved_reciever
1161 if mtype
.need_anchor
then
1162 assert anchor
!= null
1163 resolved_reciever
= mtype
.resolve_for
(anchor
, null, mmodule
, true)
1165 resolved_reciever
= mtype
1167 # Now, we can get the bound
1168 var verbatim_bound
= lookup_bound
(mmodule
, resolved_reciever
)
1169 # The bound is exactly as declared in the "type" property, so we must resolve it again
1170 var res
= verbatim_bound
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1171 #print "{class_name}: {self}/{mtype}/{anchor} -> {self}/{resolved_reciever}/{anchor} -> {verbatim_bound}/{mtype}/{anchor} -> {res}"
1173 # What to return here? There is a bunch a special cases:
1174 # If 'cleanup_virtual' we must return the resolved type, since we cannot return self
1175 if cleanup_virtual
then return res
1176 # If the reciever is a intern class, then the virtual type cannot be redefined since there is no possible subclass. self is just fixed. so simply return the resolution
1177 if resolved_reciever
isa MNullableType then resolved_reciever
= resolved_reciever
.mtype
1178 if resolved_reciever
.as(MClassType).mclass
.kind
== enum_kind
then return res
1179 # 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.
1180 if res
isa MVirtualType then return res
1181 # It the resolved type isa intern class, then there is no possible valid redefinition is any potentiel subclass. self is just fixed. so simply return the resolution
1182 if res
isa MClassType and res
.mclass
.kind
== enum_kind
then return res
1183 # TODO: Add 'fixed' virtual type in the specification.
1184 # TODO: What if bound to a MParameterType?
1185 # Note that Nullable types can always be redefined by the non nullable version, so there is no specific case on it.
1187 # If anything apply, then `self' cannot be resolved, so return self
1191 redef fun can_resolve_for
(mtype
, anchor
, mmodule
)
1193 if mtype
.need_anchor
then
1194 assert anchor
!= null
1195 mtype
= mtype
.anchor_to
(mmodule
, anchor
)
1197 return mtype
.has_mproperty
(mmodule
, mproperty
)
1200 redef fun to_s
do return self.mproperty
.to_s
1202 init(mproperty
: MProperty)
1204 self.mproperty
= mproperty
1208 # The type associated the a formal parameter generic type of a class
1210 # Each parameter type is associated to a specific class.
1211 # It's mean that all refinements of a same class "share" the parameter type,
1212 # but that a generic subclass has its on parameter types.
1214 # However, in the sense of the meta-model, a parameter type of a class is
1215 # a valid type in a subclass. The "in the sense of the meta-model" is
1216 # important because, in the Nit language, the programmer cannot refers
1217 # directly to the parameter types of the super-classes.
1221 # fun e: E is abstract
1226 # In the class definition B[F], `F` is a valid type but `E` is not.
1227 # However, `self.e` is a valid method call, and the signature of `e` is
1230 # Note that parameter types are shared among class refinements.
1231 # Therefore parameter only have an internal name (see `to_s` for details).
1232 # TODO: Add a `name_for` to get better messages.
1233 class MParameterType
1236 # The generic class where the parameter belong
1239 redef fun model
do return self.mclass
.intro_mmodule
.model
1241 # The position of the parameter (0 for the first parameter)
1242 # FIXME: is `position` a better name?
1245 # Internal name of the parameter type
1246 # Names of parameter types changes in each class definition
1247 # Therefore, this method return an internal name.
1248 # Example: return "G#1" for the second parameter of the class G
1249 # FIXME: add a way to get the real name in a classdef
1250 redef fun to_s
do return "{mclass}#{rank}"
1252 # Resolve the bound for a given resolved_receiver
1253 # The result may be a other virtual type (or a parameter type)
1254 fun lookup_bound
(mmodule
: MModule, resolved_receiver
: MType): MType
1256 assert not resolved_receiver
.need_anchor
1257 var goalclass
= self.mclass
1258 var supertypes
= resolved_receiver
.collect_mtypes
(mmodule
)
1259 for t
in supertypes
do
1260 if t
.mclass
== goalclass
then
1261 # Yeah! c specialize goalclass with a "super `t'". So the question is what is the argument of f
1262 # FIXME: Here, we stop on the first goal. Should we check others and detect inconsistencies?
1263 var res
= t
.arguments
[self.rank
]
1270 redef fun resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1272 assert can_resolve_for
(mtype
, anchor
, mmodule
)
1273 #print "{class_name}: {self}/{mtype}/{anchor}?"
1275 if mtype
isa MGenericType and mtype
.mclass
== self.mclass
then
1276 return mtype
.arguments
[self.rank
]
1279 # self is a parameter type of mtype (or of a super-class of mtype)
1280 # The point of the function it to get the bound of the virtual type that make sense for mtype
1281 # But because mtype is maybe a virtual/formal type, we need to get a real receiver first
1282 # FIXME: What happend here is far from clear. Thus this part must be validated and clarified
1283 var resolved_receiver
1284 if mtype
.need_anchor
then
1285 assert anchor
!= null
1286 resolved_receiver
= mtype
.resolve_for
(anchor
.mclass
.mclass_type
, anchor
, mmodule
, true)
1288 resolved_receiver
= mtype
1290 if resolved_receiver
isa MNullableType then resolved_receiver
= resolved_receiver
.mtype
1291 if resolved_receiver
isa MParameterType then
1292 assert resolved_receiver
.mclass
== anchor
.mclass
1293 resolved_receiver
= anchor
.arguments
[resolved_receiver
.rank
]
1294 if resolved_receiver
isa MNullableType then resolved_receiver
= resolved_receiver
.mtype
1296 assert resolved_receiver
isa MClassType
1298 # Eh! The parameter is in the current class.
1299 # So we return the corresponding argument, no mater what!
1300 if resolved_receiver
.mclass
== self.mclass
then
1301 var res
= resolved_receiver
.arguments
[self.rank
]
1302 #print "{class_name}: {self}/{mtype}/{anchor} -> direct {res}"
1306 if resolved_receiver
.need_anchor
then
1307 assert anchor
!= null
1308 resolved_receiver
= resolved_receiver
.resolve_for
(anchor
, null, mmodule
, false)
1310 # Now, we can get the bound
1311 var verbatim_bound
= lookup_bound
(mmodule
, resolved_receiver
)
1312 # The bound is exactly as declared in the "type" property, so we must resolve it again
1313 var res
= verbatim_bound
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1315 #print "{class_name}: {self}/{mtype}/{anchor} -> indirect {res}"
1320 redef fun can_resolve_for
(mtype
, anchor
, mmodule
)
1322 if mtype
.need_anchor
then
1323 assert anchor
!= null
1324 mtype
= mtype
.anchor_to
(mmodule
, anchor
)
1326 return mtype
.collect_mclassdefs
(mmodule
).has
(mclass
.intro
)
1329 init(mclass
: MClass, rank
: Int)
1331 self.mclass
= mclass
1336 # A type prefixed with "nullable"
1340 # The base type of the nullable type
1343 redef fun model
do return self.mtype
.model
1348 self.to_s
= "nullable {mtype}"
1351 redef var to_s
: String
1353 redef fun need_anchor
do return mtype
.need_anchor
1354 redef fun as_nullable
do return self
1355 redef fun resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1357 var res
= self.mtype
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1358 return res
.as_nullable
1361 redef fun can_resolve_for
(mtype
, anchor
, mmodule
)
1363 return self.mtype
.can_resolve_for
(mtype
, anchor
, mmodule
)
1366 redef fun depth
do return self.mtype
.depth
1368 redef fun length
do return self.mtype
.length
1370 redef fun collect_mclassdefs
(mmodule
)
1372 assert not self.need_anchor
1373 return self.mtype
.collect_mclassdefs
(mmodule
)
1376 redef fun collect_mclasses
(mmodule
)
1378 assert not self.need_anchor
1379 return self.mtype
.collect_mclasses
(mmodule
)
1382 redef fun collect_mtypes
(mmodule
)
1384 assert not self.need_anchor
1385 return self.mtype
.collect_mtypes
(mmodule
)
1389 # The type of the only value null
1391 # The is only one null type per model, see `MModel::null_type`.
1394 redef var model
: Model
1395 protected init(model
: Model)
1399 redef fun to_s
do return "null"
1400 redef fun as_nullable
do return self
1401 redef fun need_anchor
do return false
1402 redef fun resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
) do return self
1403 redef fun can_resolve_for
(mtype
, anchor
, mmodule
) do return true
1405 redef fun collect_mclassdefs
(mmodule
) do return new HashSet[MClassDef]
1407 redef fun collect_mclasses
(mmodule
) do return new HashSet[MClass]
1409 redef fun collect_mtypes
(mmodule
) do return new HashSet[MClassType]
1412 # A signature of a method
1416 # The each parameter (in order)
1417 var mparameters
: Array[MParameter]
1419 # The return type (null for a procedure)
1420 var return_mtype
: nullable MType
1425 var t
= self.return_mtype
1426 if t
!= null then dmax
= t
.depth
1427 for p
in mparameters
do
1428 var d
= p
.mtype
.depth
1429 if d
> dmax
then dmax
= d
1437 var t
= self.return_mtype
1438 if t
!= null then res
+= t
.length
1439 for p
in mparameters
do
1440 res
+= p
.mtype
.length
1445 # REQUIRE: 1 <= mparameters.count p -> p.is_vararg
1446 init(mparameters
: Array[MParameter], return_mtype
: nullable MType)
1448 var vararg_rank
= -1
1449 for i
in [0..mparameters
.length
[ do
1450 var parameter
= mparameters
[i
]
1451 if parameter
.is_vararg
then
1452 assert vararg_rank
== -1
1456 self.mparameters
= mparameters
1457 self.return_mtype
= return_mtype
1458 self.vararg_rank
= vararg_rank
1461 # The rank of the ellipsis (`...`) for vararg (starting from 0).
1462 # value is -1 if there is no vararg.
1463 # Example: for "(a: Int, b: Bool..., c: Char)" #-> vararg_rank=1
1464 var vararg_rank
: Int
1466 # The number or parameters
1467 fun arity
: Int do return mparameters
.length
1471 var b
= new FlatBuffer
1472 if not mparameters
.is_empty
then
1474 for i
in [0..mparameters
.length
[ do
1475 var mparameter
= mparameters
[i
]
1476 if i
> 0 then b
.append
(", ")
1477 b
.append
(mparameter
.name
)
1479 b
.append
(mparameter
.mtype
.to_s
)
1480 if mparameter
.is_vararg
then
1486 var ret
= self.return_mtype
1494 redef fun resolve_for
(mtype
: MType, anchor
: nullable MClassType, mmodule
: MModule, cleanup_virtual
: Bool): MSignature
1496 var params
= new Array[MParameter]
1497 for p
in self.mparameters
do
1498 params
.add
(p
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
))
1500 var ret
= self.return_mtype
1502 ret
= ret
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1504 var res
= new MSignature(params
, ret
)
1509 # A parameter in a signature
1511 # The name of the parameter
1514 # The static type of the parameter
1517 # Is the parameter a vararg?
1523 return "{name}: {mtype}..."
1525 return "{name}: {mtype}"
1529 fun resolve_for
(mtype
: MType, anchor
: nullable MClassType, mmodule
: MModule, cleanup_virtual
: Bool): MParameter
1531 if not self.mtype
.need_anchor
then return self
1532 var newtype
= self.mtype
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1533 var res
= new MParameter(self.name
, newtype
, self.is_vararg
)
1538 # A service (global property) that generalize method, attribute, etc.
1540 # `MProperty` are global to the model; it means that a `MProperty` is not bound
1541 # to a specific `MModule` nor a specific `MClass`.
1543 # A MProperty gather definitions (see `mpropdefs`) ; one for the introduction
1544 # and the other in subclasses and in refinements.
1546 # A `MProperty` is used to denotes services in polymorphic way (ie. independent
1547 # of any dynamic type).
1548 # For instance, a call site "x.foo" is associated to a `MProperty`.
1549 abstract class MProperty
1552 # The associated MPropDef subclass.
1553 # The two specialization hierarchy are symmetric.
1554 type MPROPDEF: MPropDef
1556 # The classdef that introduce the property
1557 # While a property is not bound to a specific module, or class,
1558 # the introducing mclassdef is used for naming and visibility
1559 var intro_mclassdef
: MClassDef
1561 # The (short) name of the property
1562 redef var name
: String
1564 # The canonical name of the property
1565 # Example: "owner::my_module::MyClass::my_method"
1566 fun full_name
: String
1568 return "{self.intro_mclassdef.mmodule.full_name}::{self.intro_mclassdef.mclass.name}::{name}"
1571 # The visibility of the property
1572 var visibility
: MVisibility
1574 init(intro_mclassdef
: MClassDef, name
: String, visibility
: MVisibility)
1576 self.intro_mclassdef
= intro_mclassdef
1578 self.visibility
= visibility
1579 intro_mclassdef
.intro_mproperties
.add
(self)
1580 var model
= intro_mclassdef
.mmodule
.model
1581 model
.mproperties_by_name
.add_one
(name
, self)
1582 model
.mproperties
.add
(self)
1585 # All definitions of the property.
1586 # The first is the introduction,
1587 # The other are redefinitions (in refinements and in subclasses)
1588 var mpropdefs
: Array[MPROPDEF] = new Array[MPROPDEF]
1590 # The definition that introduced the property
1591 # Warning: the introduction is the first `MPropDef` object
1592 # associated to self. If self is just created without having any
1593 # associated definition, this method will abort
1594 fun intro
: MPROPDEF do return mpropdefs
.first
1597 redef fun to_s
do return name
1599 # Return the most specific property definitions defined or inherited by a type.
1600 # The selection knows that refinement is stronger than specialization;
1601 # however, in case of conflict more than one property are returned.
1602 # If mtype does not know mproperty then an empty array is returned.
1604 # If you want the really most specific property, then look at `lookup_first_definition`
1605 fun lookup_definitions
(mmodule
: MModule, mtype
: MType): Array[MPROPDEF]
1607 assert not mtype
.need_anchor
1608 if mtype
isa MNullableType then mtype
= mtype
.mtype
1610 var cache
= self.lookup_definitions_cache
[mmodule
, mtype
]
1611 if cache
!= null then return cache
1613 #print "select prop {mproperty} for {mtype} in {self}"
1614 # First, select all candidates
1615 var candidates
= new Array[MPROPDEF]
1616 for mpropdef
in self.mpropdefs
do
1617 # If the definition is not imported by the module, then skip
1618 if not mmodule
.in_importation
<= mpropdef
.mclassdef
.mmodule
then continue
1619 # If the definition is not inherited by the type, then skip
1620 if not mtype
.is_subtype
(mmodule
, null, mpropdef
.mclassdef
.bound_mtype
) then continue
1622 candidates
.add
(mpropdef
)
1624 # Fast track for only one candidate
1625 if candidates
.length
<= 1 then
1626 self.lookup_definitions_cache
[mmodule
, mtype
] = candidates
1630 # Second, filter the most specific ones
1631 return select_most_specific
(mmodule
, candidates
)
1634 private var lookup_definitions_cache
: HashMap2[MModule, MType, Array[MPROPDEF]] = new HashMap2[MModule, MType, Array[MPROPDEF]]
1636 # Return the most specific property definitions inherited by a type.
1637 # The selection knows that refinement is stronger than specialization;
1638 # however, in case of conflict more than one property are returned.
1639 # If mtype does not know mproperty then an empty array is returned.
1641 # If you want the really most specific property, then look at `lookup_next_definition`
1643 # FIXME: Move to `MPropDef`?
1644 fun lookup_super_definitions
(mmodule
: MModule, mtype
: MType): Array[MPROPDEF]
1646 assert not mtype
.need_anchor
1647 if mtype
isa MNullableType then mtype
= mtype
.mtype
1649 # First, select all candidates
1650 var candidates
= new Array[MPROPDEF]
1651 for mpropdef
in self.mpropdefs
do
1652 # If the definition is not imported by the module, then skip
1653 if not mmodule
.in_importation
<= mpropdef
.mclassdef
.mmodule
then continue
1654 # If the definition is not inherited by the type, then skip
1655 if not mtype
.is_subtype
(mmodule
, null, mpropdef
.mclassdef
.bound_mtype
) then continue
1656 # If the definition is defined by the type, then skip (we want the super, so e skip the current)
1657 if mtype
== mpropdef
.mclassdef
.bound_mtype
and mmodule
== mpropdef
.mclassdef
.mmodule
then continue
1659 candidates
.add
(mpropdef
)
1661 # Fast track for only one candidate
1662 if candidates
.length
<= 1 then return candidates
1664 # Second, filter the most specific ones
1665 return select_most_specific
(mmodule
, candidates
)
1668 # Return an array containing olny the most specific property definitions
1669 # This is an helper function for `lookup_definitions` and `lookup_super_definitions`
1670 private fun select_most_specific
(mmodule
: MModule, candidates
: Array[MPROPDEF]): Array[MPROPDEF]
1672 var res
= new Array[MPROPDEF]
1673 for pd1
in candidates
do
1674 var cd1
= pd1
.mclassdef
1677 for pd2
in candidates
do
1678 if pd2
== pd1
then continue # do not compare with self!
1679 var cd2
= pd2
.mclassdef
1681 if c2
.mclass_type
== c1
.mclass_type
then
1682 if cd2
.mmodule
.in_importation
< cd1
.mmodule
then
1683 # cd2 refines cd1; therefore we skip pd1
1687 else if cd2
.bound_mtype
.is_subtype
(mmodule
, null, cd1
.bound_mtype
) and cd2
.bound_mtype
!= cd1
.bound_mtype
then
1688 # cd2 < cd1; therefore we skip pd1
1697 if res
.is_empty
then
1698 print
"All lost! {candidates.join(", ")}"
1699 # FIXME: should be abort!
1704 # Return the most specific definition in the linearization of `mtype`.
1706 # If you want to know the next properties in the linearization,
1707 # look at `MPropDef::lookup_next_definition`.
1709 # FIXME: the linearisation is still unspecified
1711 # REQUIRE: `not mtype.need_anchor`
1712 # REQUIRE: `mtype.has_mproperty(mmodule, self)`
1713 fun lookup_first_definition
(mmodule
: MModule, mtype
: MType): MPROPDEF
1715 assert mtype
.has_mproperty
(mmodule
, self)
1716 return lookup_all_definitions
(mmodule
, mtype
).first
1719 # Return all definitions in a linearisation order
1720 # Most speficic first, most general last
1721 fun lookup_all_definitions
(mmodule
: MModule, mtype
: MType): Array[MPROPDEF]
1723 assert not mtype
.need_anchor
1724 if mtype
isa MNullableType then mtype
= mtype
.mtype
1726 var cache
= self.lookup_all_definitions_cache
[mmodule
, mtype
]
1727 if cache
!= null then return cache
1729 #print "select prop {mproperty} for {mtype} in {self}"
1730 # First, select all candidates
1731 var candidates
= new Array[MPROPDEF]
1732 for mpropdef
in self.mpropdefs
do
1733 # If the definition is not imported by the module, then skip
1734 if not mmodule
.in_importation
<= mpropdef
.mclassdef
.mmodule
then continue
1735 # If the definition is not inherited by the type, then skip
1736 if not mtype
.is_subtype
(mmodule
, null, mpropdef
.mclassdef
.bound_mtype
) then continue
1738 candidates
.add
(mpropdef
)
1740 # Fast track for only one candidate
1741 if candidates
.length
<= 1 then
1742 self.lookup_all_definitions_cache
[mmodule
, mtype
] = candidates
1746 mmodule
.linearize_mpropdefs
(candidates
)
1747 candidates
= candidates
.reversed
1748 self.lookup_all_definitions_cache
[mmodule
, mtype
] = candidates
1752 private var lookup_all_definitions_cache
: HashMap2[MModule, MType, Array[MPROPDEF]] = new HashMap2[MModule, MType, Array[MPROPDEF]]
1759 redef type MPROPDEF: MMethodDef
1761 init(intro_mclassdef
: MClassDef, name
: String, visibility
: MVisibility)
1766 # Is the property defined at the top_level of the module?
1767 # Currently such a property are stored in `Object`
1768 var is_toplevel
: Bool writable = false
1770 # Is the property a constructor?
1771 # Warning, this property can be inherited by subclasses with or without being a constructor
1772 # therefore, you should use `is_init_for` the verify if the property is a legal constructor for a given class
1773 var is_init
: Bool writable = false
1775 # The the property a 'new' contructor?
1776 var is_new
: Bool writable = false
1778 # Is the property a legal constructor for a given class?
1779 # As usual, visibility is not considered.
1780 # FIXME not implemented
1781 fun is_init_for
(mclass
: MClass): Bool
1787 # A global attribute
1791 redef type MPROPDEF: MAttributeDef
1793 init(intro_mclassdef
: MClassDef, name
: String, visibility
: MVisibility)
1799 # A global virtual type
1800 class MVirtualTypeProp
1803 redef type MPROPDEF: MVirtualTypeDef
1805 init(intro_mclassdef
: MClassDef, name
: String, visibility
: MVisibility)
1810 # The formal type associated to the virtual type property
1811 var mvirtualtype
: MVirtualType = new MVirtualType(self)
1814 # A definition of a property (local property)
1816 # Unlike `MProperty`, a `MPropDef` is a local definition that belong to a
1817 # specific class definition (which belong to a specific module)
1818 abstract class MPropDef
1821 # The associated `MProperty` subclass.
1822 # the two specialization hierarchy are symmetric
1823 type MPROPERTY: MProperty
1826 type MPROPDEF: MPropDef
1828 # The origin of the definition
1829 var location
: Location
1831 # The class definition where the property definition is
1832 var mclassdef
: MClassDef
1834 # The associated global property
1835 var mproperty
: MPROPERTY
1837 init(mclassdef
: MClassDef, mproperty
: MPROPERTY, location
: Location)
1839 self.mclassdef
= mclassdef
1840 self.mproperty
= mproperty
1841 self.location
= location
1842 mclassdef
.mpropdefs
.add
(self)
1843 mproperty
.mpropdefs
.add
(self)
1844 self.to_s
= "{mclassdef}#{mproperty}"
1847 # Actually the name of the `mproperty`
1848 redef fun name
do return mproperty
.name
1850 # Internal name combining the module, the class and the property
1851 # Example: "mymodule#MyClass#mymethod"
1852 redef var to_s
: String
1854 # Is self the definition that introduce the property?
1855 fun is_intro
: Bool do return mproperty
.intro
== self
1857 # Return the next definition in linearization of `mtype`.
1859 # This method is used to determine what method is called by a super.
1861 # REQUIRE: `not mtype.need_anchor`
1862 fun lookup_next_definition
(mmodule
: MModule, mtype
: MType): MPROPDEF
1864 assert not mtype
.need_anchor
1866 var mpropdefs
= self.mproperty
.lookup_all_definitions
(mmodule
, mtype
)
1867 var i
= mpropdefs
.iterator
1868 while i
.is_ok
and i
.item
!= self do i
.next
1869 assert has_property
: i
.is_ok
1871 assert has_next_property
: i
.is_ok
1876 # A local definition of a method
1880 redef type MPROPERTY: MMethod
1881 redef type MPROPDEF: MMethodDef
1883 init(mclassdef
: MClassDef, mproperty
: MPROPERTY, location
: Location)
1888 # The signature attached to the property definition
1889 var msignature
: nullable MSignature writable = null
1891 # Is the method definition abstract?
1892 var is_abstract
: Bool writable = false
1894 # Is the method definition intern?
1895 var is_intern
writable = false
1897 # Is the method definition extern?
1898 var is_extern
writable = false
1901 # A local definition of an attribute
1905 redef type MPROPERTY: MAttribute
1906 redef type MPROPDEF: MAttributeDef
1908 init(mclassdef
: MClassDef, mproperty
: MPROPERTY, location
: Location)
1913 # The static type of the attribute
1914 var static_mtype
: nullable MType writable = null
1917 # A local definition of a virtual type
1918 class MVirtualTypeDef
1921 redef type MPROPERTY: MVirtualTypeProp
1922 redef type MPROPDEF: MVirtualTypeDef
1924 init(mclassdef
: MClassDef, mproperty
: MPROPERTY, location
: Location)
1929 # The bound of the virtual type
1930 var bound
: nullable MType writable = null
1937 # * `interface_kind`
1941 # Note this class is basically an enum.
1942 # FIXME: use a real enum once user-defined enums are available
1944 redef var to_s
: String
1946 # Is a constructor required?
1948 private init(s
: String, need_init
: Bool)
1951 self.need_init
= need_init
1954 # Can a class of kind `self` specializes a class of kine `other`?
1955 fun can_specialize
(other
: MClassKind): Bool
1957 if other
== interface_kind
then return true # everybody can specialize interfaces
1958 if self == interface_kind
or self == enum_kind
then
1959 # no other case for interfaces
1961 else if self == extern_kind
then
1962 # only compatible with themselve
1963 return self == other
1964 else if other
== enum_kind
or other
== extern_kind
then
1965 # abstract_kind and concrete_kind are incompatible
1968 # remain only abstract_kind and concrete_kind
1973 fun abstract_kind
: MClassKind do return once
new MClassKind("abstract class", true)
1974 fun concrete_kind
: MClassKind do return once
new MClassKind("class", true)
1975 fun interface_kind
: MClassKind do return once
new MClassKind("interface", false)
1976 fun enum_kind
: MClassKind do return once
new MClassKind("enum", false)
1977 fun extern_kind
: MClassKind do return once
new MClassKind("extern class", false)