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" and self.model
.get_mclasses_by_name
("Object") != null then
255 # Bool is injected because it is needed by engine to code the result
256 # of the implicit casts.
257 var c
= new MClass(self, name
, null, enum_kind
, public_visibility
)
258 var cladef
= new MClassDef(self, c
.mclass_type
, new Location(null, 0,0,0,0))
259 cladef
.set_supertypes
([object_type
])
260 cladef
.add_in_hierarchy
263 print
("Fatal Error: no primitive class {name}")
266 if cla
.length
!= 1 then
267 var msg
= "Fatal Error: more than one primitive class {name}:"
268 for c
in cla
do msg
+= " {c.full_name}"
275 # Try to get the primitive method named `name` on the type `recv`
276 fun try_get_primitive_method
(name
: String, recv
: MClass): nullable MMethod
278 var props
= self.model
.get_mproperties_by_name
(name
)
279 if props
== null then return null
280 var res
: nullable MMethod = null
281 for mprop
in props
do
282 assert mprop
isa MMethod
283 var intro
= mprop
.intro_mclassdef
284 for mclassdef
in recv
.mclassdefs
do
285 if not self.in_importation
.greaters
.has
(mclassdef
.mmodule
) then continue
286 if not mclassdef
.in_hierarchy
.greaters
.has
(intro
) then continue
289 else if res
!= mprop
then
290 print
("Fatal Error: ambigous property name '{name}'; conflict between {mprop.full_name} and {res.full_name}")
299 private class MClassDefSorter
301 redef type COMPARED: MClassDef
303 redef fun compare
(a
, b
)
307 if ca
!= cb
then return mmodule
.flatten_mclass_hierarchy
.compare
(ca
, cb
)
308 return mmodule
.model
.mclassdef_hierarchy
.compare
(a
, b
)
312 private class MPropDefSorter
314 redef type COMPARED: MPropDef
316 redef fun compare
(pa
, pb
)
322 if ca
!= cb
then return mmodule
.flatten_mclass_hierarchy
.compare
(ca
, cb
)
323 return mmodule
.model
.mclassdef_hierarchy
.compare
(a
, b
)
329 # `MClass` are global to the model; it means that a `MClass` is not bound to a
330 # specific `MModule`.
332 # This characteristic helps the reasoning about classes in a program since a
333 # single `MClass` object always denote the same class.
335 # The drawback is that classes (`MClass`) contain almost nothing by themselves.
336 # These do not really have properties nor belong to a hierarchy since the property and the
337 # hierarchy of a class depends of the refinement in the modules.
339 # Most services on classes require the precision of a module, and no one can asks what are
340 # the super-classes of a class nor what are properties of a class without precising what is
341 # the module considered.
343 # For instance, during the typing of a source-file, the module considered is the module of the file.
344 # eg. the question *is the method `foo` exists in the class `Bar`?* must be reformulated into
345 # *is the method `foo` exists in the class `Bar` in the current module?*
347 # During some global analysis, the module considered may be the main module of the program.
351 # The module that introduce the class
352 # While classes are not bound to a specific module,
353 # the introducing module is used for naming an visibility
354 var intro_mmodule
: MModule
356 # The short name of the class
357 # In Nit, the name of a class cannot evolve in refinements
358 redef var name
: String
360 # The canonical name of the class
362 # It is the name of the class prefixed by the full_name of the `intro_mmodule`
363 # Example: `"owner::module::MyClass"`
364 redef var full_name
is lazy
do return "{self.intro_mmodule.full_name}::{name}"
366 # The number of generic formal parameters
367 # 0 if the class is not generic
368 var arity
: Int is noinit
370 # Each generic formal parameters in order.
371 # is empty if the class is not generic
372 var mparameters
= new Array[MParameterType]
374 protected fun setup_parameter_names
(parameter_names
: nullable Array[String]) is
377 if parameter_names
== null then
380 self.arity
= parameter_names
.length
383 # Create the formal parameter types
385 assert parameter_names
!= null
386 var mparametertypes
= new Array[MParameterType]
387 for i
in [0..arity
[ do
388 var mparametertype
= new MParameterType(self, i
, parameter_names
[i
])
389 mparametertypes
.add
(mparametertype
)
391 self.mparameters
= mparametertypes
392 var mclass_type
= new MGenericType(self, mparametertypes
)
393 self.mclass_type
= mclass_type
394 self.get_mtype_cache
[mparametertypes
] = mclass_type
396 self.mclass_type
= new MClassType(self)
400 # The kind of the class (interface, abstract class, etc.)
401 # In Nit, the kind of a class cannot evolve in refinements
404 # The visibility of the class
405 # In Nit, the visibility of a class cannot evolve in refinements
406 var visibility
: MVisibility
410 intro_mmodule
.intro_mclasses
.add
(self)
411 var model
= intro_mmodule
.model
412 model
.mclasses_by_name
.add_one
(name
, self)
413 model
.mclasses
.add
(self)
416 redef fun model
do return intro_mmodule
.model
418 # All class definitions (introduction and refinements)
419 var mclassdefs
= new Array[MClassDef]
422 redef fun to_s
do return self.name
424 # The definition that introduces the class.
426 # Warning: such a definition may not exist in the early life of the object.
427 # In this case, the method will abort.
428 var intro
: MClassDef is noinit
430 # Return the class `self` in the class hierarchy of the module `mmodule`.
432 # SEE: `MModule::flatten_mclass_hierarchy`
433 # REQUIRE: `mmodule.has_mclass(self)`
434 fun in_hierarchy
(mmodule
: MModule): POSetElement[MClass]
436 return mmodule
.flatten_mclass_hierarchy
[self]
439 # The principal static type of the class.
441 # For non-generic class, mclass_type is the only `MClassType` based
444 # For a generic class, the arguments are the formal parameters.
445 # i.e.: for the class Array[E:Object], the `mclass_type` is Array[E].
446 # If you want Array[Object] the see `MClassDef::bound_mtype`
448 # For generic classes, the mclass_type is also the way to get a formal
449 # generic parameter type.
451 # To get other types based on a generic class, see `get_mtype`.
453 # ENSURE: `mclass_type.mclass == self`
454 var mclass_type
: MClassType is noinit
456 # Return a generic type based on the class
457 # Is the class is not generic, then the result is `mclass_type`
459 # REQUIRE: `mtype_arguments.length == self.arity`
460 fun get_mtype
(mtype_arguments
: Array[MType]): MClassType
462 assert mtype_arguments
.length
== self.arity
463 if self.arity
== 0 then return self.mclass_type
464 var res
= get_mtype_cache
.get_or_null
(mtype_arguments
)
465 if res
!= null then return res
466 res
= new MGenericType(self, mtype_arguments
)
467 self.get_mtype_cache
[mtype_arguments
.to_a
] = res
471 private var get_mtype_cache
= new HashMap[Array[MType], 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
635 #print "1.is {sub} a {sup}? ===="
637 if anchor
== null then
638 assert not sub
.need_anchor
639 assert not sup
.need_anchor
641 # First, resolve the formal types to the simplest equivalent forms in the receiver
642 assert sub
.can_resolve_for
(anchor
, null, mmodule
)
643 sub
= sub
.lookup_fixed
(mmodule
, anchor
)
644 assert sup
.can_resolve_for
(anchor
, null, mmodule
)
645 sup
= sup
.lookup_fixed
(mmodule
, anchor
)
648 # Does `sup` accept null or not?
649 # Discard the nullable marker if it exists
650 var sup_accept_null
= false
651 if sup
isa MNullableType then
652 sup_accept_null
= true
654 else if sup
isa MNullType then
655 sup_accept_null
= true
658 # Can `sub` provide null or not?
659 # Thus we can match with `sup_accept_null`
660 # Also discard the nullable marker if it exists
661 if sub
isa MNullableType then
662 if not sup_accept_null
then return false
664 else if sub
isa MNullType then
665 return sup_accept_null
667 # Now the case of direct null and nullable is over.
669 # If `sub` is a formal type, then it is accepted if its bound is accepted
670 while sub
isa MParameterType or sub
isa MVirtualType do
671 #print "3.is {sub} a {sup}?"
673 # A unfixed formal type can only accept itself
674 if sub
== sup
then return true
676 assert anchor
!= null
677 sub
= sub
.lookup_bound
(mmodule
, anchor
)
679 #print "3.is {sub} a {sup}?"
681 # Manage the second layer of null/nullable
682 if sub
isa MNullableType then
683 if not sup_accept_null
then return false
685 else if sub
isa MNullType then
686 return sup_accept_null
689 #print "4.is {sub} a {sup}? <- no more resolution"
691 assert sub
isa MClassType # It is the only remaining type
693 # A unfixed formal type can only accept itself
694 if sup
isa MParameterType or sup
isa MVirtualType then
698 if sup
isa MNullType then
699 # `sup` accepts only null
703 assert sup
isa MClassType # It is the only remaining type
705 # Now both are MClassType, we need to dig
707 if sub
== sup
then return true
709 if anchor
== null then anchor
= sub
# UGLY: any anchor will work
710 var resolved_sub
= sub
.anchor_to
(mmodule
, anchor
)
711 var res
= resolved_sub
.collect_mclasses
(mmodule
).has
(sup
.mclass
)
712 if res
== false then return false
713 if not sup
isa MGenericType then return true
714 var sub2
= sub
.supertype_to
(mmodule
, anchor
, sup
.mclass
)
715 assert sub2
.mclass
== sup
.mclass
716 for i
in [0..sup
.mclass
.arity
[ do
717 var sub_arg
= sub2
.arguments
[i
]
718 var sup_arg
= sup
.arguments
[i
]
719 res
= sub_arg
.is_subtype
(mmodule
, anchor
, sup_arg
)
720 if res
== false then return false
725 # The base class type on which self is based
727 # This base type is used to get property (an internally to perform
728 # unsafe type comparison).
730 # Beware: some types (like null) are not based on a class thus this
733 # Basically, this function transform the virtual types and parameter
734 # types to their bounds.
739 # class B super A end
741 # class Y super X end
750 # Map[T,U] anchor_to H #-> Map[B,Y]
752 # Explanation of the example:
753 # In H, T is set to B, because "H super G[B]", and U is bound to Y,
754 # because "redef type U: Y". Therefore, Map[T, U] is bound to
757 # ENSURE: `not self.need_anchor implies result == self`
758 # ENSURE: `not result.need_anchor`
759 fun anchor_to
(mmodule
: MModule, anchor
: MClassType): MType
761 if not need_anchor
then return self
762 assert not anchor
.need_anchor
763 # Just resolve to the anchor and clear all the virtual types
764 var res
= self.resolve_for
(anchor
, null, mmodule
, true)
765 assert not res
.need_anchor
769 # Does `self` contain a virtual type or a formal generic parameter type?
770 # In order to remove those types, you usually want to use `anchor_to`.
771 fun need_anchor
: Bool do return true
773 # Return the supertype when adapted to a class.
775 # In Nit, for each super-class of a type, there is a equivalent super-type.
781 # class H[V] super G[V, Bool] end
783 # H[Int] supertype_to G #-> G[Int, Bool]
786 # REQUIRE: `super_mclass` is a super-class of `self`
787 # REQUIRE: `self.need_anchor implies anchor != null and self.can_resolve_for(anchor, null, mmodule)`
788 # ENSURE: `result.mclass = super_mclass`
789 fun supertype_to
(mmodule
: MModule, anchor
: nullable MClassType, super_mclass
: MClass): MClassType
791 if super_mclass
.arity
== 0 then return super_mclass
.mclass_type
792 if self isa MClassType and self.mclass
== super_mclass
then return self
794 if self.need_anchor
then
795 assert anchor
!= null
796 resolved_self
= self.anchor_to
(mmodule
, anchor
)
800 var supertypes
= resolved_self
.collect_mtypes
(mmodule
)
801 for supertype
in supertypes
do
802 if supertype
.mclass
== super_mclass
then
803 # FIXME: Here, we stop on the first goal. Should we check others and detect inconsistencies?
804 return supertype
.resolve_for
(self, anchor
, mmodule
, false)
810 # Replace formals generic types in self with resolved values in `mtype`
811 # If `cleanup_virtual` is true, then virtual types are also replaced
814 # This function returns self if `need_anchor` is false.
820 # class H[F] super G[F] end
824 # * Array[E].resolve_for(H[Int]) #-> Array[Int]
825 # * Array[E].resolve_for(G[Z], X[Int]) #-> Array[Z]
827 # Explanation of the example:
828 # * Array[E].need_anchor is true because there is a formal generic parameter type E
829 # * E makes sense for H[Int] because E is a formal parameter of G and H specialize G
830 # * Since "H[F] super G[F]", E is in fact F for H
831 # * More specifically, in H[Int], E is Int
832 # * So, in H[Int], Array[E] is Array[Int]
834 # This function is mainly used to inherit a signature.
835 # Because, unlike `anchor_to`, we do not want a full resolution of
836 # a type but only an adapted version of it.
842 # fun foo(e:E):E is abstract
844 # class B super A[Int] end
847 # The signature on foo is (e: E): E
848 # If we resolve the signature for B, we get (e:Int):Int
854 # fun foo(e:E):E is abstract
858 # fun bar do a.foo(x) # <- x is here
862 # The first question is: is foo available on `a`?
864 # The static type of a is `A[Array[F]]`, that is an open type.
865 # in order to find a method `foo`, whe must look at a resolved type.
867 # A[Array[F]].anchor_to(C[nullable Object]) #-> A[Array[nullable Object]]
869 # the method `foo` exists in `A[Array[nullable Object]]`, therefore `foo` exists for `a`.
871 # The next question is: what is the accepted types for `x`?
873 # the signature of `foo` is `foo(e:E)`, thus we must resolve the type E
875 # E.resolve_for(A[Array[F]],C[nullable Object]) #-> Array[F]
877 # The resolution can be done because `E` make sense for the class A (see `can_resolve_for`)
879 # FIXME: the parameter `cleanup_virtual` is just a bad idea, but having
880 # two function instead of one seems also to be a bad idea.
882 # REQUIRE: `can_resolve_for(mtype, anchor, mmodule)`
883 # ENSURE: `not self.need_anchor implies result == self`
884 fun resolve_for
(mtype
: MType, anchor
: nullable MClassType, mmodule
: MModule, cleanup_virtual
: Bool): MType is abstract
886 # Resolve formal type to its verbatim bound.
887 # If the type is not formal, just return self
889 # The result is returned exactly as declared in the "type" property (verbatim).
890 # So it could be another formal type.
892 # In case of conflict, the method aborts.
893 fun lookup_bound
(mmodule
: MModule, resolved_receiver
: MType): MType do return self
895 # Resolve the formal type to its simplest equivalent form.
897 # Formal types are either free or fixed.
898 # When it is fixed, it means that it is equivalent with a simpler type.
899 # When a formal type is free, it means that it is only equivalent with itself.
900 # This method return the most simple equivalent type of `self`.
902 # This method is mainly used for subtype test in order to sanely compare fixed.
904 # By default, return self.
905 # See the redefinitions for specific behavior in each kind of type.
906 fun lookup_fixed
(mmodule
: MModule, resolved_receiver
: MType): MType do return self
908 # Can the type be resolved?
910 # In order to resolve open types, the formal types must make sence.
920 # E.can_resolve_for(A[Int]) #-> true, E make sense in A
922 # E.can_resolve_for(B[Int]) #-> false, E does not make sense in B
924 # B[E].can_resolve_for(A[F], B[Object]) #-> true,
925 # # B[E] is a red hearing only the E is important,
926 # # E make sense in A
929 # REQUIRE: `anchor != null implies not anchor.need_anchor`
930 # REQUIRE: `mtype.need_anchor implies anchor != null and mtype.can_resolve_for(anchor, null, mmodule)`
931 # ENSURE: `not self.need_anchor implies result == true`
932 fun can_resolve_for
(mtype
: MType, anchor
: nullable MClassType, mmodule
: MModule): Bool is abstract
934 # Return the nullable version of the type
935 # If the type is already nullable then self is returned
936 fun as_nullable
: MType
938 var res
= self.as_nullable_cache
939 if res
!= null then return res
940 res
= new MNullableType(self)
941 self.as_nullable_cache
= res
945 # Return the not nullable version of the type
946 # Is the type is already not nullable, then self is returned.
948 # Note: this just remove the `nullable` notation, but the result can still contains null.
949 # For instance if `self isa MNullType` or self is a formal type bounded by a nullable type.
950 fun as_notnullable
: MType
955 private var as_nullable_cache
: nullable MType = null
958 # The depth of the type seen as a tree.
965 # Formal types have a depth of 1.
971 # The length of the type seen as a tree.
978 # Formal types have a length of 1.
984 # Compute all the classdefs inherited/imported.
985 # The returned set contains:
986 # * the class definitions from `mmodule` and its imported modules
987 # * the class definitions of this type and its super-types
989 # This function is used mainly internally.
991 # REQUIRE: `not self.need_anchor`
992 fun collect_mclassdefs
(mmodule
: MModule): Set[MClassDef] is abstract
994 # Compute all the super-classes.
995 # This function is used mainly internally.
997 # REQUIRE: `not self.need_anchor`
998 fun collect_mclasses
(mmodule
: MModule): Set[MClass] is abstract
1000 # Compute all the declared super-types.
1001 # Super-types are returned as declared in the classdefs (verbatim).
1002 # This function is used mainly internally.
1004 # REQUIRE: `not self.need_anchor`
1005 fun collect_mtypes
(mmodule
: MModule): Set[MClassType] is abstract
1007 # Is the property in self for a given module
1008 # This method does not filter visibility or whatever
1010 # REQUIRE: `not self.need_anchor`
1011 fun has_mproperty
(mmodule
: MModule, mproperty
: MProperty): Bool
1013 assert not self.need_anchor
1014 return self.collect_mclassdefs
(mmodule
).has
(mproperty
.intro_mclassdef
)
1018 # A type based on a class.
1020 # `MClassType` have properties (see `has_mproperty`).
1024 # The associated class
1027 redef fun model
do return self.mclass
.intro_mmodule
.model
1029 # TODO: private init because strongly bounded to its mclass. see `mclass.mclass_type`
1031 # The formal arguments of the type
1032 # ENSURE: `result.length == self.mclass.arity`
1033 var arguments
= new Array[MType]
1035 redef fun to_s
do return mclass
.to_s
1037 redef fun need_anchor
do return false
1039 redef fun anchor_to
(mmodule
: MModule, anchor
: MClassType): MClassType
1041 return super.as(MClassType)
1044 redef fun resolve_for
(mtype
: MType, anchor
: nullable MClassType, mmodule
: MModule, cleanup_virtual
: Bool): MClassType do return self
1046 redef fun can_resolve_for
(mtype
, anchor
, mmodule
) do return true
1048 redef fun collect_mclassdefs
(mmodule
)
1050 assert not self.need_anchor
1051 var cache
= self.collect_mclassdefs_cache
1052 if not cache
.has_key
(mmodule
) then
1053 self.collect_things
(mmodule
)
1055 return cache
[mmodule
]
1058 redef fun collect_mclasses
(mmodule
)
1060 if collect_mclasses_last_module
== mmodule
then return collect_mclasses_last_module_cache
1061 assert not self.need_anchor
1062 var cache
= self.collect_mclasses_cache
1063 if not cache
.has_key
(mmodule
) then
1064 self.collect_things
(mmodule
)
1066 var res
= cache
[mmodule
]
1067 collect_mclasses_last_module
= mmodule
1068 collect_mclasses_last_module_cache
= res
1072 private var collect_mclasses_last_module
: nullable MModule = null
1073 private var collect_mclasses_last_module_cache
: Set[MClass] is noinit
1075 redef fun collect_mtypes
(mmodule
)
1077 assert not self.need_anchor
1078 var cache
= self.collect_mtypes_cache
1079 if not cache
.has_key
(mmodule
) then
1080 self.collect_things
(mmodule
)
1082 return cache
[mmodule
]
1085 # common implementation for `collect_mclassdefs`, `collect_mclasses`, and `collect_mtypes`.
1086 private fun collect_things
(mmodule
: MModule)
1088 var res
= new HashSet[MClassDef]
1089 var seen
= new HashSet[MClass]
1090 var types
= new HashSet[MClassType]
1091 seen
.add
(self.mclass
)
1092 var todo
= [self.mclass
]
1093 while not todo
.is_empty
do
1094 var mclass
= todo
.pop
1095 #print "process {mclass}"
1096 for mclassdef
in mclass
.mclassdefs
do
1097 if not mmodule
.in_importation
<= mclassdef
.mmodule
then continue
1098 #print " process {mclassdef}"
1100 for supertype
in mclassdef
.supertypes
do
1101 types
.add
(supertype
)
1102 var superclass
= supertype
.mclass
1103 if seen
.has
(superclass
) then continue
1104 #print " add {superclass}"
1105 seen
.add
(superclass
)
1106 todo
.add
(superclass
)
1110 collect_mclassdefs_cache
[mmodule
] = res
1111 collect_mclasses_cache
[mmodule
] = seen
1112 collect_mtypes_cache
[mmodule
] = types
1115 private var collect_mclassdefs_cache
= new HashMap[MModule, Set[MClassDef]]
1116 private var collect_mclasses_cache
= new HashMap[MModule, Set[MClass]]
1117 private var collect_mtypes_cache
= new HashMap[MModule, Set[MClassType]]
1121 # A type based on a generic class.
1122 # A generic type a just a class with additional formal generic arguments.
1128 # TODO: private init because strongly bounded to its mclass. see `mclass.get_mtype`
1132 assert self.mclass
.arity
== arguments
.length
1134 self.need_anchor
= false
1135 for t
in arguments
do
1136 if t
.need_anchor
then
1137 self.need_anchor
= true
1142 self.to_s
= "{mclass}[{arguments.join(", ")}]"
1145 # Recursively print the type of the arguments within brackets.
1146 # Example: `"Map[String, List[Int]]"`
1147 redef var to_s
: String is noinit
1149 redef var need_anchor
: Bool is noinit
1151 redef fun resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1153 if not need_anchor
then return self
1154 assert can_resolve_for
(mtype
, anchor
, mmodule
)
1155 var types
= new Array[MType]
1156 for t
in arguments
do
1157 types
.add
(t
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
))
1159 return mclass
.get_mtype
(types
)
1162 redef fun can_resolve_for
(mtype
, anchor
, mmodule
)
1164 if not need_anchor
then return true
1165 for t
in arguments
do
1166 if not t
.can_resolve_for
(mtype
, anchor
, mmodule
) then return false
1175 for a
in self.arguments
do
1177 if d
> dmax
then dmax
= d
1185 for a
in self.arguments
do
1192 # A virtual formal type.
1196 # The property associated with the type.
1197 # Its the definitions of this property that determine the bound or the virtual type.
1198 var mproperty
: MVirtualTypeProp
1200 redef fun model
do return self.mproperty
.intro_mclassdef
.mmodule
.model
1202 redef fun lookup_bound
(mmodule
: MModule, resolved_receiver
: MType): MType
1204 return lookup_single_definition
(mmodule
, resolved_receiver
).bound
.as(not null)
1207 private fun lookup_single_definition
(mmodule
: MModule, resolved_receiver
: MType): MVirtualTypeDef
1209 assert not resolved_receiver
.need_anchor
1210 var props
= self.mproperty
.lookup_definitions
(mmodule
, resolved_receiver
)
1211 if props
.is_empty
then
1213 else if props
.length
== 1 then
1216 var types
= new ArraySet[MType]
1217 var res
= props
.first
1219 types
.add
(p
.bound
.as(not null))
1220 if not res
.is_fixed
then res
= p
1222 if types
.length
== 1 then
1228 # A VT is fixed when:
1229 # * the VT is (re-)defined with the annotation `is fixed`
1230 # * the VT is (indirectly) bound to an enum class (see `enum_kind`) since there is no subtype possible
1231 # * the receiver is an enum class since there is no subtype possible
1232 redef fun lookup_fixed
(mmodule
: MModule, resolved_receiver
: MType): MType
1234 assert not resolved_receiver
.need_anchor
1235 resolved_receiver
= resolved_receiver
.as_notnullable
1236 assert resolved_receiver
isa MClassType # It is the only remaining type
1238 var prop
= lookup_single_definition
(mmodule
, resolved_receiver
)
1239 var res
= prop
.bound
.as(not null)
1241 # Recursively lookup the fixed result
1242 res
= res
.lookup_fixed
(mmodule
, resolved_receiver
)
1244 # 1. For a fixed VT, return the resolved bound
1245 if prop
.is_fixed
then return res
1247 # 2. For a enum boud, return the bound
1248 if res
isa MClassType and res
.mclass
.kind
== enum_kind
then return res
1250 # 3. for a enum receiver return the bound
1251 if resolved_receiver
.mclass
.kind
== enum_kind
then return res
1256 redef fun resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1258 if not cleanup_virtual
then return self
1259 assert can_resolve_for
(mtype
, anchor
, mmodule
)
1260 # self is a virtual type declared (or inherited) in mtype
1261 # The point of the function it to get the bound of the virtual type that make sense for mtype
1262 # But because mtype is maybe a virtual/formal type, we need to get a real receiver first
1263 #print "{class_name}: {self}/{mtype}/{anchor}?"
1264 var resolved_receiver
1265 if mtype
.need_anchor
then
1266 assert anchor
!= null
1267 resolved_receiver
= mtype
.resolve_for
(anchor
, null, mmodule
, true)
1269 resolved_receiver
= mtype
1271 # Now, we can get the bound
1272 var verbatim_bound
= lookup_bound
(mmodule
, resolved_receiver
)
1273 # The bound is exactly as declared in the "type" property, so we must resolve it again
1274 var res
= verbatim_bound
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1279 redef fun can_resolve_for
(mtype
, anchor
, mmodule
)
1281 if mtype
.need_anchor
then
1282 assert anchor
!= null
1283 mtype
= mtype
.anchor_to
(mmodule
, anchor
)
1285 return mtype
.has_mproperty
(mmodule
, mproperty
)
1288 redef fun to_s
do return self.mproperty
.to_s
1291 # The type associated to a formal parameter generic type of a class
1293 # Each parameter type is associated to a specific class.
1294 # It means that all refinements of a same class "share" the parameter type,
1295 # but that a generic subclass has its own parameter types.
1297 # However, in the sense of the meta-model, a parameter type of a class is
1298 # a valid type in a subclass. The "in the sense of the meta-model" is
1299 # important because, in the Nit language, the programmer cannot refers
1300 # directly to the parameter types of the super-classes.
1305 # fun e: E is abstract
1311 # In the class definition B[F], `F` is a valid type but `E` is not.
1312 # However, `self.e` is a valid method call, and the signature of `e` is
1315 # Note that parameter types are shared among class refinements.
1316 # Therefore parameter only have an internal name (see `to_s` for details).
1317 class MParameterType
1320 # The generic class where the parameter belong
1323 redef fun model
do return self.mclass
.intro_mmodule
.model
1325 # The position of the parameter (0 for the first parameter)
1326 # FIXME: is `position` a better name?
1331 redef fun to_s
do return name
1333 redef fun lookup_bound
(mmodule
: MModule, resolved_receiver
: MType): MType
1335 assert not resolved_receiver
.need_anchor
1336 resolved_receiver
= resolved_receiver
.as_notnullable
1337 assert resolved_receiver
isa MClassType # It is the only remaining type
1338 var goalclass
= self.mclass
1339 if resolved_receiver
.mclass
== goalclass
then
1340 return resolved_receiver
.arguments
[self.rank
]
1342 var supertypes
= resolved_receiver
.collect_mtypes
(mmodule
)
1343 for t
in supertypes
do
1344 if t
.mclass
== goalclass
then
1345 # Yeah! c specialize goalclass with a "super `t'". So the question is what is the argument of f
1346 # FIXME: Here, we stop on the first goal. Should we check others and detect inconsistencies?
1347 var res
= t
.arguments
[self.rank
]
1354 # A PT is fixed when:
1355 # * Its bound is a enum class (see `enum_kind`).
1356 # The PT is just useless, but it is still a case.
1357 # * More usually, the `resolved_receiver` is a subclass of `self.mclass`,
1358 # so it is necessarily fixed in a `super` clause, either with a normal type
1359 # or with another PT.
1360 # See `resolve_for` for examples about related issues.
1361 redef fun lookup_fixed
(mmodule
: MModule, resolved_receiver
: MType): MType
1363 assert not resolved_receiver
.need_anchor
1364 resolved_receiver
= resolved_receiver
.as_notnullable
1365 assert resolved_receiver
isa MClassType # It is the only remaining type
1366 var res
= self.resolve_for
(resolved_receiver
.mclass
.mclass_type
, resolved_receiver
, mmodule
, false)
1370 redef fun resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1372 assert can_resolve_for
(mtype
, anchor
, mmodule
)
1373 #print "{class_name}: {self}/{mtype}/{anchor}?"
1375 if mtype
isa MGenericType and mtype
.mclass
== self.mclass
then
1376 var res
= mtype
.arguments
[self.rank
]
1377 if anchor
!= null and res
.need_anchor
then
1378 # Maybe the result can be resolved more if are bound to a final class
1379 var r2
= res
.anchor_to
(mmodule
, anchor
)
1380 if r2
isa MClassType and r2
.mclass
.kind
== enum_kind
then return r2
1385 # self is a parameter type of mtype (or of a super-class of mtype)
1386 # The point of the function it to get the bound of the virtual type that make sense for mtype
1387 # But because mtype is maybe a virtual/formal type, we need to get a real receiver first
1388 # FIXME: What happens here is far from clear. Thus this part must be validated and clarified
1389 var resolved_receiver
1390 if mtype
.need_anchor
then
1391 assert anchor
!= null
1392 resolved_receiver
= mtype
.resolve_for
(anchor
.mclass
.mclass_type
, anchor
, mmodule
, true)
1394 resolved_receiver
= mtype
1396 if resolved_receiver
isa MNullableType then resolved_receiver
= resolved_receiver
.mtype
1397 if resolved_receiver
isa MParameterType then
1398 assert resolved_receiver
.mclass
== anchor
.mclass
1399 resolved_receiver
= anchor
.arguments
[resolved_receiver
.rank
]
1400 if resolved_receiver
isa MNullableType then resolved_receiver
= resolved_receiver
.mtype
1402 assert resolved_receiver
isa MClassType # It is the only remaining type
1404 # Eh! The parameter is in the current class.
1405 # So we return the corresponding argument, no mater what!
1406 if resolved_receiver
.mclass
== self.mclass
then
1407 var res
= resolved_receiver
.arguments
[self.rank
]
1408 #print "{class_name}: {self}/{mtype}/{anchor} -> direct {res}"
1412 if resolved_receiver
.need_anchor
then
1413 assert anchor
!= null
1414 resolved_receiver
= resolved_receiver
.resolve_for
(anchor
, null, mmodule
, false)
1416 # Now, we can get the bound
1417 var verbatim_bound
= lookup_bound
(mmodule
, resolved_receiver
)
1418 # The bound is exactly as declared in the "type" property, so we must resolve it again
1419 var res
= verbatim_bound
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1421 #print "{class_name}: {self}/{mtype}/{anchor} -> indirect {res}"
1426 redef fun can_resolve_for
(mtype
, anchor
, mmodule
)
1428 if mtype
.need_anchor
then
1429 assert anchor
!= null
1430 mtype
= mtype
.anchor_to
(mmodule
, anchor
)
1432 return mtype
.collect_mclassdefs
(mmodule
).has
(mclass
.intro
)
1436 # A type prefixed with "nullable"
1440 # The base type of the nullable type
1443 redef fun model
do return self.mtype
.model
1447 self.to_s
= "nullable {mtype}"
1450 redef var to_s
: String is noinit
1452 redef fun need_anchor
do return mtype
.need_anchor
1453 redef fun as_nullable
do return self
1454 redef fun as_notnullable
do return mtype
1455 redef fun resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1457 var res
= self.mtype
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1458 return res
.as_nullable
1461 redef fun can_resolve_for
(mtype
, anchor
, mmodule
)
1463 return self.mtype
.can_resolve_for
(mtype
, anchor
, mmodule
)
1466 # Efficiently returns `mtype.lookup_fixed(mmodule, resolved_receiver).as_nullable`
1467 redef fun lookup_fixed
(mmodule
, resolved_receiver
)
1469 var t
= mtype
.lookup_fixed
(mmodule
, resolved_receiver
)
1470 if t
== mtype
then return self
1471 return t
.as_nullable
1474 redef fun depth
do return self.mtype
.depth
1476 redef fun length
do return self.mtype
.length
1478 redef fun collect_mclassdefs
(mmodule
)
1480 assert not self.need_anchor
1481 return self.mtype
.collect_mclassdefs
(mmodule
)
1484 redef fun collect_mclasses
(mmodule
)
1486 assert not self.need_anchor
1487 return self.mtype
.collect_mclasses
(mmodule
)
1490 redef fun collect_mtypes
(mmodule
)
1492 assert not self.need_anchor
1493 return self.mtype
.collect_mtypes
(mmodule
)
1497 # The type of the only value null
1499 # The is only one null type per model, see `MModel::null_type`.
1502 redef var model
: Model
1503 redef fun to_s
do return "null"
1504 redef fun as_nullable
do return self
1505 redef fun need_anchor
do return false
1506 redef fun resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
) do return self
1507 redef fun can_resolve_for
(mtype
, anchor
, mmodule
) do return true
1509 redef fun collect_mclassdefs
(mmodule
) do return new HashSet[MClassDef]
1511 redef fun collect_mclasses
(mmodule
) do return new HashSet[MClass]
1513 redef fun collect_mtypes
(mmodule
) do return new HashSet[MClassType]
1516 # A signature of a method
1520 # The each parameter (in order)
1521 var mparameters
: Array[MParameter]
1523 # The return type (null for a procedure)
1524 var return_mtype
: nullable MType
1529 var t
= self.return_mtype
1530 if t
!= null then dmax
= t
.depth
1531 for p
in mparameters
do
1532 var d
= p
.mtype
.depth
1533 if d
> dmax
then dmax
= d
1541 var t
= self.return_mtype
1542 if t
!= null then res
+= t
.length
1543 for p
in mparameters
do
1544 res
+= p
.mtype
.length
1549 # REQUIRE: 1 <= mparameters.count p -> p.is_vararg
1552 var vararg_rank
= -1
1553 for i
in [0..mparameters
.length
[ do
1554 var parameter
= mparameters
[i
]
1555 if parameter
.is_vararg
then
1556 assert vararg_rank
== -1
1560 self.vararg_rank
= vararg_rank
1563 # The rank of the ellipsis (`...`) for vararg (starting from 0).
1564 # value is -1 if there is no vararg.
1565 # Example: for "(a: Int, b: Bool..., c: Char)" #-> vararg_rank=1
1566 var vararg_rank
: Int is noinit
1568 # The number or parameters
1569 fun arity
: Int do return mparameters
.length
1573 var b
= new FlatBuffer
1574 if not mparameters
.is_empty
then
1576 for i
in [0..mparameters
.length
[ do
1577 var mparameter
= mparameters
[i
]
1578 if i
> 0 then b
.append
(", ")
1579 b
.append
(mparameter
.name
)
1581 b
.append
(mparameter
.mtype
.to_s
)
1582 if mparameter
.is_vararg
then
1588 var ret
= self.return_mtype
1596 redef fun resolve_for
(mtype
: MType, anchor
: nullable MClassType, mmodule
: MModule, cleanup_virtual
: Bool): MSignature
1598 var params
= new Array[MParameter]
1599 for p
in self.mparameters
do
1600 params
.add
(p
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
))
1602 var ret
= self.return_mtype
1604 ret
= ret
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1606 var res
= new MSignature(params
, ret
)
1611 # A parameter in a signature
1615 # The name of the parameter
1616 redef var name
: String
1618 # The static type of the parameter
1621 # Is the parameter a vararg?
1627 return "{name}: {mtype}..."
1629 return "{name}: {mtype}"
1633 fun resolve_for
(mtype
: MType, anchor
: nullable MClassType, mmodule
: MModule, cleanup_virtual
: Bool): MParameter
1635 if not self.mtype
.need_anchor
then return self
1636 var newtype
= self.mtype
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1637 var res
= new MParameter(self.name
, newtype
, self.is_vararg
)
1641 redef fun model
do return mtype
.model
1644 # A service (global property) that generalize method, attribute, etc.
1646 # `MProperty` are global to the model; it means that a `MProperty` is not bound
1647 # to a specific `MModule` nor a specific `MClass`.
1649 # A MProperty gather definitions (see `mpropdefs`) ; one for the introduction
1650 # and the other in subclasses and in refinements.
1652 # A `MProperty` is used to denotes services in polymorphic way (ie. independent
1653 # of any dynamic type).
1654 # For instance, a call site "x.foo" is associated to a `MProperty`.
1655 abstract class MProperty
1658 # The associated MPropDef subclass.
1659 # The two specialization hierarchy are symmetric.
1660 type MPROPDEF: MPropDef
1662 # The classdef that introduce the property
1663 # While a property is not bound to a specific module, or class,
1664 # the introducing mclassdef is used for naming and visibility
1665 var intro_mclassdef
: MClassDef
1667 # The (short) name of the property
1668 redef var name
: String
1670 # The canonical name of the property.
1672 # It is the short-`name` prefixed by the short-name of the class and the full-name of the module.
1673 # Example: "my_project::my_module::MyClass::my_method"
1674 redef var full_name
is lazy
do
1675 return "{intro_mclassdef.mmodule.full_name}::{intro_mclassdef.mclass.name}::{name}"
1678 # The visibility of the property
1679 var visibility
: MVisibility
1683 intro_mclassdef
.intro_mproperties
.add
(self)
1684 var model
= intro_mclassdef
.mmodule
.model
1685 model
.mproperties_by_name
.add_one
(name
, self)
1686 model
.mproperties
.add
(self)
1689 # All definitions of the property.
1690 # The first is the introduction,
1691 # The other are redefinitions (in refinements and in subclasses)
1692 var mpropdefs
= new Array[MPROPDEF]
1694 # The definition that introduces the property.
1696 # Warning: such a definition may not exist in the early life of the object.
1697 # In this case, the method will abort.
1698 var intro
: MPROPDEF is noinit
1700 redef fun model
do return intro
.model
1703 redef fun to_s
do return name
1705 # Return the most specific property definitions defined or inherited by a type.
1706 # The selection knows that refinement is stronger than specialization;
1707 # however, in case of conflict more than one property are returned.
1708 # If mtype does not know mproperty then an empty array is returned.
1710 # If you want the really most specific property, then look at `lookup_first_definition`
1711 fun lookup_definitions
(mmodule
: MModule, mtype
: MType): Array[MPROPDEF]
1713 assert not mtype
.need_anchor
1714 mtype
= mtype
.as_notnullable
1716 var cache
= self.lookup_definitions_cache
[mmodule
, mtype
]
1717 if cache
!= null then return cache
1719 #print "select prop {mproperty} for {mtype} in {self}"
1720 # First, select all candidates
1721 var candidates
= new Array[MPROPDEF]
1722 for mpropdef
in self.mpropdefs
do
1723 # If the definition is not imported by the module, then skip
1724 if not mmodule
.in_importation
<= mpropdef
.mclassdef
.mmodule
then continue
1725 # If the definition is not inherited by the type, then skip
1726 if not mtype
.is_subtype
(mmodule
, null, mpropdef
.mclassdef
.bound_mtype
) then continue
1728 candidates
.add
(mpropdef
)
1730 # Fast track for only one candidate
1731 if candidates
.length
<= 1 then
1732 self.lookup_definitions_cache
[mmodule
, mtype
] = candidates
1736 # Second, filter the most specific ones
1737 return select_most_specific
(mmodule
, candidates
)
1740 private var lookup_definitions_cache
= new HashMap2[MModule, MType, Array[MPROPDEF]]
1742 # Return the most specific property definitions inherited by a type.
1743 # The selection knows that refinement is stronger than specialization;
1744 # however, in case of conflict more than one property are returned.
1745 # If mtype does not know mproperty then an empty array is returned.
1747 # If you want the really most specific property, then look at `lookup_next_definition`
1749 # FIXME: Move to `MPropDef`?
1750 fun lookup_super_definitions
(mmodule
: MModule, mtype
: MType): Array[MPROPDEF]
1752 assert not mtype
.need_anchor
1753 mtype
= mtype
.as_notnullable
1755 # First, select all candidates
1756 var candidates
= new Array[MPROPDEF]
1757 for mpropdef
in self.mpropdefs
do
1758 # If the definition is not imported by the module, then skip
1759 if not mmodule
.in_importation
<= mpropdef
.mclassdef
.mmodule
then continue
1760 # If the definition is not inherited by the type, then skip
1761 if not mtype
.is_subtype
(mmodule
, null, mpropdef
.mclassdef
.bound_mtype
) then continue
1762 # If the definition is defined by the type, then skip (we want the super, so e skip the current)
1763 if mtype
== mpropdef
.mclassdef
.bound_mtype
and mmodule
== mpropdef
.mclassdef
.mmodule
then continue
1765 candidates
.add
(mpropdef
)
1767 # Fast track for only one candidate
1768 if candidates
.length
<= 1 then return candidates
1770 # Second, filter the most specific ones
1771 return select_most_specific
(mmodule
, candidates
)
1774 # Return an array containing olny the most specific property definitions
1775 # This is an helper function for `lookup_definitions` and `lookup_super_definitions`
1776 private fun select_most_specific
(mmodule
: MModule, candidates
: Array[MPROPDEF]): Array[MPROPDEF]
1778 var res
= new Array[MPROPDEF]
1779 for pd1
in candidates
do
1780 var cd1
= pd1
.mclassdef
1783 for pd2
in candidates
do
1784 if pd2
== pd1
then continue # do not compare with self!
1785 var cd2
= pd2
.mclassdef
1787 if c2
.mclass_type
== c1
.mclass_type
then
1788 if cd2
.mmodule
.in_importation
< cd1
.mmodule
then
1789 # cd2 refines cd1; therefore we skip pd1
1793 else if cd2
.bound_mtype
.is_subtype
(mmodule
, null, cd1
.bound_mtype
) and cd2
.bound_mtype
!= cd1
.bound_mtype
then
1794 # cd2 < cd1; therefore we skip pd1
1803 if res
.is_empty
then
1804 print
"All lost! {candidates.join(", ")}"
1805 # FIXME: should be abort!
1810 # Return the most specific definition in the linearization of `mtype`.
1812 # If you want to know the next properties in the linearization,
1813 # look at `MPropDef::lookup_next_definition`.
1815 # FIXME: the linearization is still unspecified
1817 # REQUIRE: `not mtype.need_anchor`
1818 # REQUIRE: `mtype.has_mproperty(mmodule, self)`
1819 fun lookup_first_definition
(mmodule
: MModule, mtype
: MType): MPROPDEF
1821 assert mtype
.has_mproperty
(mmodule
, self)
1822 return lookup_all_definitions
(mmodule
, mtype
).first
1825 # Return all definitions in a linearization order
1826 # Most specific first, most general last
1827 fun lookup_all_definitions
(mmodule
: MModule, mtype
: MType): Array[MPROPDEF]
1829 assert not mtype
.need_anchor
1830 mtype
= mtype
.as_notnullable
1832 var cache
= self.lookup_all_definitions_cache
[mmodule
, mtype
]
1833 if cache
!= null then return cache
1835 #print "select prop {mproperty} for {mtype} in {self}"
1836 # First, select all candidates
1837 var candidates
= new Array[MPROPDEF]
1838 for mpropdef
in self.mpropdefs
do
1839 # If the definition is not imported by the module, then skip
1840 if not mmodule
.in_importation
<= mpropdef
.mclassdef
.mmodule
then continue
1841 # If the definition is not inherited by the type, then skip
1842 if not mtype
.is_subtype
(mmodule
, null, mpropdef
.mclassdef
.bound_mtype
) then continue
1844 candidates
.add
(mpropdef
)
1846 # Fast track for only one candidate
1847 if candidates
.length
<= 1 then
1848 self.lookup_all_definitions_cache
[mmodule
, mtype
] = candidates
1852 mmodule
.linearize_mpropdefs
(candidates
)
1853 candidates
= candidates
.reversed
1854 self.lookup_all_definitions_cache
[mmodule
, mtype
] = candidates
1858 private var lookup_all_definitions_cache
= new HashMap2[MModule, MType, Array[MPROPDEF]]
1865 redef type MPROPDEF: MMethodDef
1867 # Is the property defined at the top_level of the module?
1868 # Currently such a property are stored in `Object`
1869 var is_toplevel
: Bool = false is writable
1871 # Is the property a constructor?
1872 # Warning, this property can be inherited by subclasses with or without being a constructor
1873 # therefore, you should use `is_init_for` the verify if the property is a legal constructor for a given class
1874 var is_init
: Bool = false is writable
1876 # The constructor is a (the) root init with empty signature but a set of initializers
1877 var is_root_init
: Bool = false is writable
1879 # Is the property a 'new' constructor?
1880 var is_new
: Bool = false is writable
1882 # Is the property a legal constructor for a given class?
1883 # As usual, visibility is not considered.
1884 # FIXME not implemented
1885 fun is_init_for
(mclass
: MClass): Bool
1891 # A global attribute
1895 redef type MPROPDEF: MAttributeDef
1899 # A global virtual type
1900 class MVirtualTypeProp
1903 redef type MPROPDEF: MVirtualTypeDef
1905 # The formal type associated to the virtual type property
1906 var mvirtualtype
= new MVirtualType(self)
1909 # A definition of a property (local property)
1911 # Unlike `MProperty`, a `MPropDef` is a local definition that belong to a
1912 # specific class definition (which belong to a specific module)
1913 abstract class MPropDef
1916 # The associated `MProperty` subclass.
1917 # the two specialization hierarchy are symmetric
1918 type MPROPERTY: MProperty
1921 type MPROPDEF: MPropDef
1923 # The class definition where the property definition is
1924 var mclassdef
: MClassDef
1926 # The associated global property
1927 var mproperty
: MPROPERTY
1929 # The origin of the definition
1930 var location
: Location
1934 mclassdef
.mpropdefs
.add
(self)
1935 mproperty
.mpropdefs
.add
(self)
1936 if mproperty
.intro_mclassdef
== mclassdef
then
1937 assert not isset mproperty
._intro
1938 mproperty
.intro
= self
1940 self.to_s
= "{mclassdef}#{mproperty}"
1943 # Actually the name of the `mproperty`
1944 redef fun name
do return mproperty
.name
1946 redef fun model
do return mclassdef
.model
1948 # Internal name combining the module, the class and the property
1949 # Example: "mymodule#MyClass#mymethod"
1950 redef var to_s
: String is noinit
1952 # Is self the definition that introduce the property?
1953 fun is_intro
: Bool do return mproperty
.intro
== self
1955 # Return the next definition in linearization of `mtype`.
1957 # This method is used to determine what method is called by a super.
1959 # REQUIRE: `not mtype.need_anchor`
1960 fun lookup_next_definition
(mmodule
: MModule, mtype
: MType): MPROPDEF
1962 assert not mtype
.need_anchor
1964 var mpropdefs
= self.mproperty
.lookup_all_definitions
(mmodule
, mtype
)
1965 var i
= mpropdefs
.iterator
1966 while i
.is_ok
and i
.item
!= self do i
.next
1967 assert has_property
: i
.is_ok
1969 assert has_next_property
: i
.is_ok
1974 # A local definition of a method
1978 redef type MPROPERTY: MMethod
1979 redef type MPROPDEF: MMethodDef
1981 # The signature attached to the property definition
1982 var msignature
: nullable MSignature = null is writable
1984 # The signature attached to the `new` call on a root-init
1985 # This is a concatenation of the signatures of the initializers
1987 # REQUIRE `mproperty.is_root_init == (new_msignature != null)`
1988 var new_msignature
: nullable MSignature = null is writable
1990 # List of initialisers to call in root-inits
1992 # They could be setters or attributes
1994 # REQUIRE `mproperty.is_root_init == (new_msignature != null)`
1995 var initializers
= new Array[MProperty]
1997 # Is the method definition abstract?
1998 var is_abstract
: Bool = false is writable
2000 # Is the method definition intern?
2001 var is_intern
= false is writable
2003 # Is the method definition extern?
2004 var is_extern
= false is writable
2006 # An optional constant value returned in functions.
2008 # Only some specific primitife value are accepted by engines.
2009 # Is used when there is no better implementation available.
2011 # Currently used only for the implementation of the `--define`
2012 # command-line option.
2013 # SEE: module `mixin`.
2014 var constant_value
: nullable Object = null is writable
2017 # A local definition of an attribute
2021 redef type MPROPERTY: MAttribute
2022 redef type MPROPDEF: MAttributeDef
2024 # The static type of the attribute
2025 var static_mtype
: nullable MType = null is writable
2028 # A local definition of a virtual type
2029 class MVirtualTypeDef
2032 redef type MPROPERTY: MVirtualTypeProp
2033 redef type MPROPDEF: MVirtualTypeDef
2035 # The bound of the virtual type
2036 var bound
: nullable MType = null is writable
2038 # Is the bound fixed?
2039 var is_fixed
= false is writable
2046 # * `interface_kind`
2050 # Note this class is basically an enum.
2051 # FIXME: use a real enum once user-defined enums are available
2053 redef var to_s
: String
2055 # Is a constructor required?
2058 # TODO: private init because enumeration.
2060 # Can a class of kind `self` specializes a class of kine `other`?
2061 fun can_specialize
(other
: MClassKind): Bool
2063 if other
== interface_kind
then return true # everybody can specialize interfaces
2064 if self == interface_kind
or self == enum_kind
then
2065 # no other case for interfaces
2067 else if self == extern_kind
then
2068 # only compatible with themselves
2069 return self == other
2070 else if other
== enum_kind
or other
== extern_kind
then
2071 # abstract_kind and concrete_kind are incompatible
2074 # remain only abstract_kind and concrete_kind
2079 # The class kind `abstract`
2080 fun abstract_kind
: MClassKind do return once
new MClassKind("abstract class", true)
2081 # The class kind `concrete`
2082 fun concrete_kind
: MClassKind do return once
new MClassKind("class", true)
2083 # The class kind `interface`
2084 fun interface_kind
: MClassKind do return once
new MClassKind("interface", false)
2085 # The class kind `enum`
2086 fun enum_kind
: MClassKind do return once
new MClassKind("enum", false)
2087 # The class kind `extern`
2088 fun extern_kind
: MClassKind do return once
new MClassKind("extern class", false)