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.
779 # class H[V] super G[V, Bool] end
781 # H[Int] supertype_to G #-> G[Int, Bool]
784 # REQUIRE: `super_mclass` is a super-class of `self`
785 # REQUIRE: `self.need_anchor implies anchor != null and self.can_resolve_for(anchor, null, mmodule)`
786 # ENSURE: `result.mclass = super_mclass`
787 fun supertype_to
(mmodule
: MModule, anchor
: nullable MClassType, super_mclass
: MClass): MClassType
789 if super_mclass
.arity
== 0 then return super_mclass
.mclass_type
790 if self isa MClassType and self.mclass
== super_mclass
then return self
792 if self.need_anchor
then
793 assert anchor
!= null
794 resolved_self
= self.anchor_to
(mmodule
, anchor
)
798 var supertypes
= resolved_self
.collect_mtypes
(mmodule
)
799 for supertype
in supertypes
do
800 if supertype
.mclass
== super_mclass
then
801 # FIXME: Here, we stop on the first goal. Should we check others and detect inconsistencies?
802 return supertype
.resolve_for
(self, anchor
, mmodule
, false)
808 # Replace formals generic types in self with resolved values in `mtype`
809 # If `cleanup_virtual` is true, then virtual types are also replaced
812 # This function returns self if `need_anchor` is false.
818 # class H[F] super G[F] end
822 # * Array[E].resolve_for(H[Int]) #-> Array[Int]
823 # * Array[E].resolve_for(G[Z], X[Int]) #-> Array[Z]
825 # Explanation of the example:
826 # * Array[E].need_anchor is true because there is a formal generic parameter type E
827 # * E makes sense for H[Int] because E is a formal parameter of G and H specialize G
828 # * Since "H[F] super G[F]", E is in fact F for H
829 # * More specifically, in H[Int], E is Int
830 # * So, in H[Int], Array[E] is Array[Int]
832 # This function is mainly used to inherit a signature.
833 # Because, unlike `anchor_to`, we do not want a full resolution of
834 # a type but only an adapted version of it.
840 # fun foo(e:E):E is abstract
842 # class B super A[Int] end
845 # The signature on foo is (e: E): E
846 # If we resolve the signature for B, we get (e:Int):Int
852 # fun foo(e:E):E is abstract
856 # fun bar do a.foo(x) # <- x is here
860 # The first question is: is foo available on `a`?
862 # The static type of a is `A[Array[F]]`, that is an open type.
863 # in order to find a method `foo`, whe must look at a resolved type.
865 # A[Array[F]].anchor_to(C[nullable Object]) #-> A[Array[nullable Object]]
867 # the method `foo` exists in `A[Array[nullable Object]]`, therefore `foo` exists for `a`.
869 # The next question is: what is the accepted types for `x`?
871 # the signature of `foo` is `foo(e:E)`, thus we must resolve the type E
873 # E.resolve_for(A[Array[F]],C[nullable Object]) #-> Array[F]
875 # The resolution can be done because `E` make sense for the class A (see `can_resolve_for`)
877 # FIXME: the parameter `cleanup_virtual` is just a bad idea, but having
878 # two function instead of one seems also to be a bad idea.
880 # REQUIRE: `can_resolve_for(mtype, anchor, mmodule)`
881 # ENSURE: `not self.need_anchor implies result == self`
882 fun resolve_for
(mtype
: MType, anchor
: nullable MClassType, mmodule
: MModule, cleanup_virtual
: Bool): MType is abstract
884 # Can the type be resolved?
886 # In order to resolve open types, the formal types must make sence.
896 # E.can_resolve_for(A[Int]) #-> true, E make sense in A
898 # E.can_resolve_for(B[Int]) #-> false, E does not make sense in B
900 # B[E].can_resolve_for(A[F], B[Object]) #-> true,
901 # # B[E] is a red hearing only the E is important,
902 # # E make sense in A
905 # REQUIRE: `anchor != null implies not anchor.need_anchor`
906 # REQUIRE: `mtype.need_anchor implies anchor != null and mtype.can_resolve_for(anchor, null, mmodule)`
907 # ENSURE: `not self.need_anchor implies result == true`
908 fun can_resolve_for
(mtype
: MType, anchor
: nullable MClassType, mmodule
: MModule): Bool is abstract
910 # Return the nullable version of the type
911 # If the type is already nullable then self is returned
912 fun as_nullable
: MType
914 var res
= self.as_nullable_cache
915 if res
!= null then return res
916 res
= new MNullableType(self)
917 self.as_nullable_cache
= res
921 # Return the not nullable version of the type
922 # Is the type is already not nullable, then self is returned.
924 # Note: this just remove the `nullable` notation, but the result can still contains null.
925 # For instance if `self isa MNullType` or self is a formal type bounded by a nullable type.
926 fun as_notnullable
: MType
931 private var as_nullable_cache
: nullable MType = null
934 # The depth of the type seen as a tree.
941 # Formal types have a depth of 1.
947 # The length of the type seen as a tree.
954 # Formal types have a length of 1.
960 # Compute all the classdefs inherited/imported.
961 # The returned set contains:
962 # * the class definitions from `mmodule` and its imported modules
963 # * the class definitions of this type and its super-types
965 # This function is used mainly internally.
967 # REQUIRE: `not self.need_anchor`
968 fun collect_mclassdefs
(mmodule
: MModule): Set[MClassDef] is abstract
970 # Compute all the super-classes.
971 # This function is used mainly internally.
973 # REQUIRE: `not self.need_anchor`
974 fun collect_mclasses
(mmodule
: MModule): Set[MClass] is abstract
976 # Compute all the declared super-types.
977 # Super-types are returned as declared in the classdefs (verbatim).
978 # This function is used mainly internally.
980 # REQUIRE: `not self.need_anchor`
981 fun collect_mtypes
(mmodule
: MModule): Set[MClassType] is abstract
983 # Is the property in self for a given module
984 # This method does not filter visibility or whatever
986 # REQUIRE: `not self.need_anchor`
987 fun has_mproperty
(mmodule
: MModule, mproperty
: MProperty): Bool
989 assert not self.need_anchor
990 return self.collect_mclassdefs
(mmodule
).has
(mproperty
.intro_mclassdef
)
994 # A type based on a class.
996 # `MClassType` have properties (see `has_mproperty`).
1000 # The associated class
1003 redef fun model
do return self.mclass
.intro_mmodule
.model
1005 # TODO: private init because strongly bounded to its mclass. see `mclass.mclass_type`
1007 # The formal arguments of the type
1008 # ENSURE: `result.length == self.mclass.arity`
1009 var arguments
= new Array[MType]
1011 redef fun to_s
do return mclass
.to_s
1013 redef fun need_anchor
do return false
1015 redef fun anchor_to
(mmodule
: MModule, anchor
: MClassType): MClassType
1017 return super.as(MClassType)
1020 redef fun resolve_for
(mtype
: MType, anchor
: nullable MClassType, mmodule
: MModule, cleanup_virtual
: Bool): MClassType do return self
1022 redef fun can_resolve_for
(mtype
, anchor
, mmodule
) do return true
1024 redef fun collect_mclassdefs
(mmodule
)
1026 assert not self.need_anchor
1027 var cache
= self.collect_mclassdefs_cache
1028 if not cache
.has_key
(mmodule
) then
1029 self.collect_things
(mmodule
)
1031 return cache
[mmodule
]
1034 redef fun collect_mclasses
(mmodule
)
1036 assert not self.need_anchor
1037 var cache
= self.collect_mclasses_cache
1038 if not cache
.has_key
(mmodule
) then
1039 self.collect_things
(mmodule
)
1041 return cache
[mmodule
]
1044 redef fun collect_mtypes
(mmodule
)
1046 assert not self.need_anchor
1047 var cache
= self.collect_mtypes_cache
1048 if not cache
.has_key
(mmodule
) then
1049 self.collect_things
(mmodule
)
1051 return cache
[mmodule
]
1054 # common implementation for `collect_mclassdefs`, `collect_mclasses`, and `collect_mtypes`.
1055 private fun collect_things
(mmodule
: MModule)
1057 var res
= new HashSet[MClassDef]
1058 var seen
= new HashSet[MClass]
1059 var types
= new HashSet[MClassType]
1060 seen
.add
(self.mclass
)
1061 var todo
= [self.mclass
]
1062 while not todo
.is_empty
do
1063 var mclass
= todo
.pop
1064 #print "process {mclass}"
1065 for mclassdef
in mclass
.mclassdefs
do
1066 if not mmodule
.in_importation
<= mclassdef
.mmodule
then continue
1067 #print " process {mclassdef}"
1069 for supertype
in mclassdef
.supertypes
do
1070 types
.add
(supertype
)
1071 var superclass
= supertype
.mclass
1072 if seen
.has
(superclass
) then continue
1073 #print " add {superclass}"
1074 seen
.add
(superclass
)
1075 todo
.add
(superclass
)
1079 collect_mclassdefs_cache
[mmodule
] = res
1080 collect_mclasses_cache
[mmodule
] = seen
1081 collect_mtypes_cache
[mmodule
] = types
1084 private var collect_mclassdefs_cache
= new HashMap[MModule, Set[MClassDef]]
1085 private var collect_mclasses_cache
= new HashMap[MModule, Set[MClass]]
1086 private var collect_mtypes_cache
= new HashMap[MModule, Set[MClassType]]
1090 # A type based on a generic class.
1091 # A generic type a just a class with additional formal generic arguments.
1097 # TODO: private init because strongly bounded to its mclass. see `mclass.get_mtype`
1101 assert self.mclass
.arity
== arguments
.length
1103 self.need_anchor
= false
1104 for t
in arguments
do
1105 if t
.need_anchor
then
1106 self.need_anchor
= true
1111 self.to_s
= "{mclass}[{arguments.join(", ")}]"
1114 # Recursively print the type of the arguments within brackets.
1115 # Example: `"Map[String, List[Int]]"`
1116 redef var to_s
: String is noinit
1118 redef var need_anchor
: Bool is noinit
1120 redef fun resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1122 if not need_anchor
then return self
1123 assert can_resolve_for
(mtype
, anchor
, mmodule
)
1124 var types
= new Array[MType]
1125 for t
in arguments
do
1126 types
.add
(t
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
))
1128 return mclass
.get_mtype
(types
)
1131 redef fun can_resolve_for
(mtype
, anchor
, mmodule
)
1133 if not need_anchor
then return true
1134 for t
in arguments
do
1135 if not t
.can_resolve_for
(mtype
, anchor
, mmodule
) then return false
1144 for a
in self.arguments
do
1146 if d
> dmax
then dmax
= d
1154 for a
in self.arguments
do
1161 # A virtual formal type.
1165 # The property associated with the type.
1166 # Its the definitions of this property that determine the bound or the virtual type.
1167 var mproperty
: MProperty
1169 redef fun model
do return self.mproperty
.intro_mclassdef
.mmodule
.model
1171 # Lookup the bound for a given resolved_receiver
1172 # The result may be a other virtual type (or a parameter type)
1174 # The result is returned exactly as declared in the "type" property (verbatim).
1176 # In case of conflict, the method aborts.
1177 fun lookup_bound
(mmodule
: MModule, resolved_receiver
: MType): MType
1179 assert not resolved_receiver
.need_anchor
1180 var props
= self.mproperty
.lookup_definitions
(mmodule
, resolved_receiver
)
1181 if props
.is_empty
then
1183 else if props
.length
== 1 then
1184 return props
.first
.as(MVirtualTypeDef).bound
.as(not null)
1186 var types
= new ArraySet[MType]
1188 types
.add
(p
.as(MVirtualTypeDef).bound
.as(not null))
1190 if types
.length
== 1 then
1196 # Is the virtual type fixed for a given resolved_receiver?
1197 fun is_fixed
(mmodule
: MModule, resolved_receiver
: MType): Bool
1199 assert not resolved_receiver
.need_anchor
1200 var props
= self.mproperty
.lookup_definitions
(mmodule
, resolved_receiver
)
1201 if props
.is_empty
then
1205 if p
.as(MVirtualTypeDef).is_fixed
then return true
1210 redef fun resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1212 assert can_resolve_for
(mtype
, anchor
, mmodule
)
1213 # self is a virtual type declared (or inherited) in mtype
1214 # The point of the function it to get the bound of the virtual type that make sense for mtype
1215 # But because mtype is maybe a virtual/formal type, we need to get a real receiver first
1216 #print "{class_name}: {self}/{mtype}/{anchor}?"
1217 var resolved_reciever
1218 if mtype
.need_anchor
then
1219 assert anchor
!= null
1220 resolved_reciever
= mtype
.resolve_for
(anchor
, null, mmodule
, true)
1222 resolved_reciever
= mtype
1224 # Now, we can get the bound
1225 var verbatim_bound
= lookup_bound
(mmodule
, resolved_reciever
)
1226 # The bound is exactly as declared in the "type" property, so we must resolve it again
1227 var res
= verbatim_bound
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1228 #print "{class_name}: {self}/{mtype}/{anchor} -> {self}/{resolved_receiver}/{anchor} -> {verbatim_bound}/{mtype}/{anchor} -> {res}"
1230 # What to return here? There is a bunch a special cases:
1231 # If 'cleanup_virtual' we must return the resolved type, since we cannot return self
1232 if cleanup_virtual
then return res
1233 # 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
1234 if resolved_reciever
isa MNullableType then resolved_reciever
= resolved_reciever
.mtype
1235 if resolved_reciever
.as(MClassType).mclass
.kind
== enum_kind
then return res
1236 # 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.
1237 if res
isa MVirtualType then return res
1238 # If we are final, just return the resolution
1239 if is_fixed
(mmodule
, resolved_reciever
) then return res
1240 # 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
1241 if res
isa MClassType and res
.mclass
.kind
== enum_kind
then return res
1242 # TODO: What if bound to a MParameterType?
1243 # Note that Nullable types can always be redefined by the non nullable version, so there is no specific case on it.
1245 # If anything apply, then `self' cannot be resolved, so return self
1249 redef fun can_resolve_for
(mtype
, anchor
, mmodule
)
1251 if mtype
.need_anchor
then
1252 assert anchor
!= null
1253 mtype
= mtype
.anchor_to
(mmodule
, anchor
)
1255 return mtype
.has_mproperty
(mmodule
, mproperty
)
1258 redef fun to_s
do return self.mproperty
.to_s
1261 # The type associated to a formal parameter generic type of a class
1263 # Each parameter type is associated to a specific class.
1264 # It means that all refinements of a same class "share" the parameter type,
1265 # but that a generic subclass has its own parameter types.
1267 # However, in the sense of the meta-model, a parameter type of a class is
1268 # a valid type in a subclass. The "in the sense of the meta-model" is
1269 # important because, in the Nit language, the programmer cannot refers
1270 # directly to the parameter types of the super-classes.
1275 # fun e: E is abstract
1281 # In the class definition B[F], `F` is a valid type but `E` is not.
1282 # However, `self.e` is a valid method call, and the signature of `e` is
1285 # Note that parameter types are shared among class refinements.
1286 # Therefore parameter only have an internal name (see `to_s` for details).
1287 class MParameterType
1290 # The generic class where the parameter belong
1293 redef fun model
do return self.mclass
.intro_mmodule
.model
1295 # The position of the parameter (0 for the first parameter)
1296 # FIXME: is `position` a better name?
1301 redef fun to_s
do return name
1303 # Resolve the bound for a given resolved_receiver
1304 # The result may be a other virtual type (or a parameter type)
1305 fun lookup_bound
(mmodule
: MModule, resolved_receiver
: MType): MType
1307 assert not resolved_receiver
.need_anchor
1308 var goalclass
= self.mclass
1309 var supertypes
= resolved_receiver
.collect_mtypes
(mmodule
)
1310 for t
in supertypes
do
1311 if t
.mclass
== goalclass
then
1312 # Yeah! c specialize goalclass with a "super `t'". So the question is what is the argument of f
1313 # FIXME: Here, we stop on the first goal. Should we check others and detect inconsistencies?
1314 var res
= t
.arguments
[self.rank
]
1321 redef fun resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1323 assert can_resolve_for
(mtype
, anchor
, mmodule
)
1324 #print "{class_name}: {self}/{mtype}/{anchor}?"
1326 if mtype
isa MGenericType and mtype
.mclass
== self.mclass
then
1327 var res
= mtype
.arguments
[self.rank
]
1328 if anchor
!= null and res
.need_anchor
then
1329 # Maybe the result can be resolved more if are bound to a final class
1330 var r2
= res
.anchor_to
(mmodule
, anchor
)
1331 if r2
isa MClassType and r2
.mclass
.kind
== enum_kind
then return r2
1336 # self is a parameter type of mtype (or of a super-class of mtype)
1337 # The point of the function it to get the bound of the virtual type that make sense for mtype
1338 # But because mtype is maybe a virtual/formal type, we need to get a real receiver first
1339 # FIXME: What happens here is far from clear. Thus this part must be validated and clarified
1340 var resolved_receiver
1341 if mtype
.need_anchor
then
1342 assert anchor
!= null
1343 resolved_receiver
= mtype
.resolve_for
(anchor
.mclass
.mclass_type
, anchor
, mmodule
, true)
1345 resolved_receiver
= mtype
1347 if resolved_receiver
isa MNullableType then resolved_receiver
= resolved_receiver
.mtype
1348 if resolved_receiver
isa MParameterType then
1349 assert resolved_receiver
.mclass
== anchor
.mclass
1350 resolved_receiver
= anchor
.arguments
[resolved_receiver
.rank
]
1351 if resolved_receiver
isa MNullableType then resolved_receiver
= resolved_receiver
.mtype
1353 assert resolved_receiver
isa MClassType
1355 # Eh! The parameter is in the current class.
1356 # So we return the corresponding argument, no mater what!
1357 if resolved_receiver
.mclass
== self.mclass
then
1358 var res
= resolved_receiver
.arguments
[self.rank
]
1359 #print "{class_name}: {self}/{mtype}/{anchor} -> direct {res}"
1363 if resolved_receiver
.need_anchor
then
1364 assert anchor
!= null
1365 resolved_receiver
= resolved_receiver
.resolve_for
(anchor
, null, mmodule
, false)
1367 # Now, we can get the bound
1368 var verbatim_bound
= lookup_bound
(mmodule
, resolved_receiver
)
1369 # The bound is exactly as declared in the "type" property, so we must resolve it again
1370 var res
= verbatim_bound
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1372 #print "{class_name}: {self}/{mtype}/{anchor} -> indirect {res}"
1377 redef fun can_resolve_for
(mtype
, anchor
, mmodule
)
1379 if mtype
.need_anchor
then
1380 assert anchor
!= null
1381 mtype
= mtype
.anchor_to
(mmodule
, anchor
)
1383 return mtype
.collect_mclassdefs
(mmodule
).has
(mclass
.intro
)
1387 # A type prefixed with "nullable"
1391 # The base type of the nullable type
1394 redef fun model
do return self.mtype
.model
1398 self.to_s
= "nullable {mtype}"
1401 redef var to_s
: String is noinit
1403 redef fun need_anchor
do return mtype
.need_anchor
1404 redef fun as_nullable
do return self
1405 redef fun as_notnullable
do return mtype
1406 redef fun resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1408 var res
= self.mtype
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1409 return res
.as_nullable
1412 redef fun can_resolve_for
(mtype
, anchor
, mmodule
)
1414 return self.mtype
.can_resolve_for
(mtype
, anchor
, mmodule
)
1417 redef fun depth
do return self.mtype
.depth
1419 redef fun length
do return self.mtype
.length
1421 redef fun collect_mclassdefs
(mmodule
)
1423 assert not self.need_anchor
1424 return self.mtype
.collect_mclassdefs
(mmodule
)
1427 redef fun collect_mclasses
(mmodule
)
1429 assert not self.need_anchor
1430 return self.mtype
.collect_mclasses
(mmodule
)
1433 redef fun collect_mtypes
(mmodule
)
1435 assert not self.need_anchor
1436 return self.mtype
.collect_mtypes
(mmodule
)
1440 # The type of the only value null
1442 # The is only one null type per model, see `MModel::null_type`.
1445 redef var model
: Model
1446 redef fun to_s
do return "null"
1447 redef fun as_nullable
do return self
1448 redef fun need_anchor
do return false
1449 redef fun resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
) do return self
1450 redef fun can_resolve_for
(mtype
, anchor
, mmodule
) do return true
1452 redef fun collect_mclassdefs
(mmodule
) do return new HashSet[MClassDef]
1454 redef fun collect_mclasses
(mmodule
) do return new HashSet[MClass]
1456 redef fun collect_mtypes
(mmodule
) do return new HashSet[MClassType]
1459 # A signature of a method
1463 # The each parameter (in order)
1464 var mparameters
: Array[MParameter]
1466 # The return type (null for a procedure)
1467 var return_mtype
: nullable MType
1472 var t
= self.return_mtype
1473 if t
!= null then dmax
= t
.depth
1474 for p
in mparameters
do
1475 var d
= p
.mtype
.depth
1476 if d
> dmax
then dmax
= d
1484 var t
= self.return_mtype
1485 if t
!= null then res
+= t
.length
1486 for p
in mparameters
do
1487 res
+= p
.mtype
.length
1492 # REQUIRE: 1 <= mparameters.count p -> p.is_vararg
1495 var vararg_rank
= -1
1496 for i
in [0..mparameters
.length
[ do
1497 var parameter
= mparameters
[i
]
1498 if parameter
.is_vararg
then
1499 assert vararg_rank
== -1
1503 self.vararg_rank
= vararg_rank
1506 # The rank of the ellipsis (`...`) for vararg (starting from 0).
1507 # value is -1 if there is no vararg.
1508 # Example: for "(a: Int, b: Bool..., c: Char)" #-> vararg_rank=1
1509 var vararg_rank
: Int is noinit
1511 # The number or parameters
1512 fun arity
: Int do return mparameters
.length
1516 var b
= new FlatBuffer
1517 if not mparameters
.is_empty
then
1519 for i
in [0..mparameters
.length
[ do
1520 var mparameter
= mparameters
[i
]
1521 if i
> 0 then b
.append
(", ")
1522 b
.append
(mparameter
.name
)
1524 b
.append
(mparameter
.mtype
.to_s
)
1525 if mparameter
.is_vararg
then
1531 var ret
= self.return_mtype
1539 redef fun resolve_for
(mtype
: MType, anchor
: nullable MClassType, mmodule
: MModule, cleanup_virtual
: Bool): MSignature
1541 var params
= new Array[MParameter]
1542 for p
in self.mparameters
do
1543 params
.add
(p
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
))
1545 var ret
= self.return_mtype
1547 ret
= ret
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1549 var res
= new MSignature(params
, ret
)
1554 # A parameter in a signature
1558 # The name of the parameter
1559 redef var name
: String
1561 # The static type of the parameter
1564 # Is the parameter a vararg?
1570 return "{name}: {mtype}..."
1572 return "{name}: {mtype}"
1576 fun resolve_for
(mtype
: MType, anchor
: nullable MClassType, mmodule
: MModule, cleanup_virtual
: Bool): MParameter
1578 if not self.mtype
.need_anchor
then return self
1579 var newtype
= self.mtype
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1580 var res
= new MParameter(self.name
, newtype
, self.is_vararg
)
1584 redef fun model
do return mtype
.model
1587 # A service (global property) that generalize method, attribute, etc.
1589 # `MProperty` are global to the model; it means that a `MProperty` is not bound
1590 # to a specific `MModule` nor a specific `MClass`.
1592 # A MProperty gather definitions (see `mpropdefs`) ; one for the introduction
1593 # and the other in subclasses and in refinements.
1595 # A `MProperty` is used to denotes services in polymorphic way (ie. independent
1596 # of any dynamic type).
1597 # For instance, a call site "x.foo" is associated to a `MProperty`.
1598 abstract class MProperty
1601 # The associated MPropDef subclass.
1602 # The two specialization hierarchy are symmetric.
1603 type MPROPDEF: MPropDef
1605 # The classdef that introduce the property
1606 # While a property is not bound to a specific module, or class,
1607 # the introducing mclassdef is used for naming and visibility
1608 var intro_mclassdef
: MClassDef
1610 # The (short) name of the property
1611 redef var name
: String
1613 # The canonical name of the property
1614 # Example: "owner::my_module::MyClass::my_method"
1615 fun full_name
: String
1617 return "{self.intro_mclassdef.mmodule.full_name}::{self.intro_mclassdef.mclass.name}::{name}"
1620 # The visibility of the property
1621 var visibility
: MVisibility
1625 intro_mclassdef
.intro_mproperties
.add
(self)
1626 var model
= intro_mclassdef
.mmodule
.model
1627 model
.mproperties_by_name
.add_one
(name
, self)
1628 model
.mproperties
.add
(self)
1631 # All definitions of the property.
1632 # The first is the introduction,
1633 # The other are redefinitions (in refinements and in subclasses)
1634 var mpropdefs
= new Array[MPROPDEF]
1636 # The definition that introduces the property.
1638 # Warning: such a definition may not exist in the early life of the object.
1639 # In this case, the method will abort.
1640 var intro
: MPROPDEF is noinit
1642 redef fun model
do return intro
.model
1645 redef fun to_s
do return name
1647 # Return the most specific property definitions defined or inherited by a type.
1648 # The selection knows that refinement is stronger than specialization;
1649 # however, in case of conflict more than one property are returned.
1650 # If mtype does not know mproperty then an empty array is returned.
1652 # If you want the really most specific property, then look at `lookup_first_definition`
1653 fun lookup_definitions
(mmodule
: MModule, mtype
: MType): Array[MPROPDEF]
1655 assert not mtype
.need_anchor
1656 mtype
= mtype
.as_notnullable
1658 var cache
= self.lookup_definitions_cache
[mmodule
, mtype
]
1659 if cache
!= null then return cache
1661 #print "select prop {mproperty} for {mtype} in {self}"
1662 # First, select all candidates
1663 var candidates
= new Array[MPROPDEF]
1664 for mpropdef
in self.mpropdefs
do
1665 # If the definition is not imported by the module, then skip
1666 if not mmodule
.in_importation
<= mpropdef
.mclassdef
.mmodule
then continue
1667 # If the definition is not inherited by the type, then skip
1668 if not mtype
.is_subtype
(mmodule
, null, mpropdef
.mclassdef
.bound_mtype
) then continue
1670 candidates
.add
(mpropdef
)
1672 # Fast track for only one candidate
1673 if candidates
.length
<= 1 then
1674 self.lookup_definitions_cache
[mmodule
, mtype
] = candidates
1678 # Second, filter the most specific ones
1679 return select_most_specific
(mmodule
, candidates
)
1682 private var lookup_definitions_cache
= new HashMap2[MModule, MType, Array[MPROPDEF]]
1684 # Return the most specific property definitions inherited by a type.
1685 # The selection knows that refinement is stronger than specialization;
1686 # however, in case of conflict more than one property are returned.
1687 # If mtype does not know mproperty then an empty array is returned.
1689 # If you want the really most specific property, then look at `lookup_next_definition`
1691 # FIXME: Move to `MPropDef`?
1692 fun lookup_super_definitions
(mmodule
: MModule, mtype
: MType): Array[MPROPDEF]
1694 assert not mtype
.need_anchor
1695 mtype
= mtype
.as_notnullable
1697 # First, select all candidates
1698 var candidates
= new Array[MPROPDEF]
1699 for mpropdef
in self.mpropdefs
do
1700 # If the definition is not imported by the module, then skip
1701 if not mmodule
.in_importation
<= mpropdef
.mclassdef
.mmodule
then continue
1702 # If the definition is not inherited by the type, then skip
1703 if not mtype
.is_subtype
(mmodule
, null, mpropdef
.mclassdef
.bound_mtype
) then continue
1704 # If the definition is defined by the type, then skip (we want the super, so e skip the current)
1705 if mtype
== mpropdef
.mclassdef
.bound_mtype
and mmodule
== mpropdef
.mclassdef
.mmodule
then continue
1707 candidates
.add
(mpropdef
)
1709 # Fast track for only one candidate
1710 if candidates
.length
<= 1 then return candidates
1712 # Second, filter the most specific ones
1713 return select_most_specific
(mmodule
, candidates
)
1716 # Return an array containing olny the most specific property definitions
1717 # This is an helper function for `lookup_definitions` and `lookup_super_definitions`
1718 private fun select_most_specific
(mmodule
: MModule, candidates
: Array[MPROPDEF]): Array[MPROPDEF]
1720 var res
= new Array[MPROPDEF]
1721 for pd1
in candidates
do
1722 var cd1
= pd1
.mclassdef
1725 for pd2
in candidates
do
1726 if pd2
== pd1
then continue # do not compare with self!
1727 var cd2
= pd2
.mclassdef
1729 if c2
.mclass_type
== c1
.mclass_type
then
1730 if cd2
.mmodule
.in_importation
< cd1
.mmodule
then
1731 # cd2 refines cd1; therefore we skip pd1
1735 else if cd2
.bound_mtype
.is_subtype
(mmodule
, null, cd1
.bound_mtype
) and cd2
.bound_mtype
!= cd1
.bound_mtype
then
1736 # cd2 < cd1; therefore we skip pd1
1745 if res
.is_empty
then
1746 print
"All lost! {candidates.join(", ")}"
1747 # FIXME: should be abort!
1752 # Return the most specific definition in the linearization of `mtype`.
1754 # If you want to know the next properties in the linearization,
1755 # look at `MPropDef::lookup_next_definition`.
1757 # FIXME: the linearization is still unspecified
1759 # REQUIRE: `not mtype.need_anchor`
1760 # REQUIRE: `mtype.has_mproperty(mmodule, self)`
1761 fun lookup_first_definition
(mmodule
: MModule, mtype
: MType): MPROPDEF
1763 assert mtype
.has_mproperty
(mmodule
, self)
1764 return lookup_all_definitions
(mmodule
, mtype
).first
1767 # Return all definitions in a linearization order
1768 # Most specific first, most general last
1769 fun lookup_all_definitions
(mmodule
: MModule, mtype
: MType): Array[MPROPDEF]
1771 assert not mtype
.need_anchor
1772 mtype
= mtype
.as_notnullable
1774 var cache
= self.lookup_all_definitions_cache
[mmodule
, mtype
]
1775 if cache
!= null then return cache
1777 #print "select prop {mproperty} for {mtype} in {self}"
1778 # First, select all candidates
1779 var candidates
= new Array[MPROPDEF]
1780 for mpropdef
in self.mpropdefs
do
1781 # If the definition is not imported by the module, then skip
1782 if not mmodule
.in_importation
<= mpropdef
.mclassdef
.mmodule
then continue
1783 # If the definition is not inherited by the type, then skip
1784 if not mtype
.is_subtype
(mmodule
, null, mpropdef
.mclassdef
.bound_mtype
) then continue
1786 candidates
.add
(mpropdef
)
1788 # Fast track for only one candidate
1789 if candidates
.length
<= 1 then
1790 self.lookup_all_definitions_cache
[mmodule
, mtype
] = candidates
1794 mmodule
.linearize_mpropdefs
(candidates
)
1795 candidates
= candidates
.reversed
1796 self.lookup_all_definitions_cache
[mmodule
, mtype
] = candidates
1800 private var lookup_all_definitions_cache
= new HashMap2[MModule, MType, Array[MPROPDEF]]
1807 redef type MPROPDEF: MMethodDef
1809 # Is the property defined at the top_level of the module?
1810 # Currently such a property are stored in `Object`
1811 var is_toplevel
: Bool = false is writable
1813 # Is the property a constructor?
1814 # Warning, this property can be inherited by subclasses with or without being a constructor
1815 # therefore, you should use `is_init_for` the verify if the property is a legal constructor for a given class
1816 var is_init
: Bool = false is writable
1818 # The constructor is a (the) root init with empty signature but a set of initializers
1819 var is_root_init
: Bool = false is writable
1821 # Is the property a 'new' constructor?
1822 var is_new
: Bool = false is writable
1824 # Is the property a legal constructor for a given class?
1825 # As usual, visibility is not considered.
1826 # FIXME not implemented
1827 fun is_init_for
(mclass
: MClass): Bool
1833 # A global attribute
1837 redef type MPROPDEF: MAttributeDef
1841 # A global virtual type
1842 class MVirtualTypeProp
1845 redef type MPROPDEF: MVirtualTypeDef
1847 # The formal type associated to the virtual type property
1848 var mvirtualtype
= new MVirtualType(self)
1851 # A definition of a property (local property)
1853 # Unlike `MProperty`, a `MPropDef` is a local definition that belong to a
1854 # specific class definition (which belong to a specific module)
1855 abstract class MPropDef
1858 # The associated `MProperty` subclass.
1859 # the two specialization hierarchy are symmetric
1860 type MPROPERTY: MProperty
1863 type MPROPDEF: MPropDef
1865 # The class definition where the property definition is
1866 var mclassdef
: MClassDef
1868 # The associated global property
1869 var mproperty
: MPROPERTY
1871 # The origin of the definition
1872 var location
: Location
1876 mclassdef
.mpropdefs
.add
(self)
1877 mproperty
.mpropdefs
.add
(self)
1878 if mproperty
.intro_mclassdef
== mclassdef
then
1879 assert not isset mproperty
._intro
1880 mproperty
.intro
= self
1882 self.to_s
= "{mclassdef}#{mproperty}"
1885 # Actually the name of the `mproperty`
1886 redef fun name
do return mproperty
.name
1888 redef fun model
do return mclassdef
.model
1890 # Internal name combining the module, the class and the property
1891 # Example: "mymodule#MyClass#mymethod"
1892 redef var to_s
: String is noinit
1894 # Is self the definition that introduce the property?
1895 fun is_intro
: Bool do return mproperty
.intro
== self
1897 # Return the next definition in linearization of `mtype`.
1899 # This method is used to determine what method is called by a super.
1901 # REQUIRE: `not mtype.need_anchor`
1902 fun lookup_next_definition
(mmodule
: MModule, mtype
: MType): MPROPDEF
1904 assert not mtype
.need_anchor
1906 var mpropdefs
= self.mproperty
.lookup_all_definitions
(mmodule
, mtype
)
1907 var i
= mpropdefs
.iterator
1908 while i
.is_ok
and i
.item
!= self do i
.next
1909 assert has_property
: i
.is_ok
1911 assert has_next_property
: i
.is_ok
1916 # A local definition of a method
1920 redef type MPROPERTY: MMethod
1921 redef type MPROPDEF: MMethodDef
1923 # The signature attached to the property definition
1924 var msignature
: nullable MSignature = null is writable
1926 # The signature attached to the `new` call on a root-init
1927 # This is a concatenation of the signatures of the initializers
1929 # REQUIRE `mproperty.is_root_init == (new_msignature != null)`
1930 var new_msignature
: nullable MSignature = null is writable
1932 # List of initialisers to call in root-inits
1934 # They could be setters or attributes
1936 # REQUIRE `mproperty.is_root_init == (new_msignature != null)`
1937 var initializers
= new Array[MProperty]
1939 # Is the method definition abstract?
1940 var is_abstract
: Bool = false is writable
1942 # Is the method definition intern?
1943 var is_intern
= false is writable
1945 # Is the method definition extern?
1946 var is_extern
= false is writable
1948 # An optional constant value returned in functions.
1950 # Only some specific primitife value are accepted by engines.
1951 # Is used when there is no better implementation available.
1953 # Currently used only for the implementation of the `--define`
1954 # command-line option.
1955 # SEE: module `mixin`.
1956 var constant_value
: nullable Object = null is writable
1959 # A local definition of an attribute
1963 redef type MPROPERTY: MAttribute
1964 redef type MPROPDEF: MAttributeDef
1966 # The static type of the attribute
1967 var static_mtype
: nullable MType = null is writable
1970 # A local definition of a virtual type
1971 class MVirtualTypeDef
1974 redef type MPROPERTY: MVirtualTypeProp
1975 redef type MPROPDEF: MVirtualTypeDef
1977 # The bound of the virtual type
1978 var bound
: nullable MType = null is writable
1980 # Is the bound fixed?
1981 var is_fixed
= false is writable
1988 # * `interface_kind`
1992 # Note this class is basically an enum.
1993 # FIXME: use a real enum once user-defined enums are available
1995 redef var to_s
: String
1997 # Is a constructor required?
2000 # TODO: private init because enumeration.
2002 # Can a class of kind `self` specializes a class of kine `other`?
2003 fun can_specialize
(other
: MClassKind): Bool
2005 if other
== interface_kind
then return true # everybody can specialize interfaces
2006 if self == interface_kind
or self == enum_kind
then
2007 # no other case for interfaces
2009 else if self == extern_kind
then
2010 # only compatible with themselves
2011 return self == other
2012 else if other
== enum_kind
or other
== extern_kind
then
2013 # abstract_kind and concrete_kind are incompatible
2016 # remain only abstract_kind and concrete_kind
2021 # The class kind `abstract`
2022 fun abstract_kind
: MClassKind do return once
new MClassKind("abstract class", true)
2023 # The class kind `concrete`
2024 fun concrete_kind
: MClassKind do return once
new MClassKind("class", true)
2025 # The class kind `interface`
2026 fun interface_kind
: MClassKind do return once
new MClassKind("interface", false)
2027 # The class kind `enum`
2028 fun enum_kind
: MClassKind do return once
new MClassKind("enum", false)
2029 # The class kind `extern`
2030 fun extern_kind
: MClassKind do return once
new MClassKind("extern class", false)