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 return mclasses_by_name
.get_or_null
(name
)
80 # Collections of properties grouped by their short name
81 private var mproperties_by_name
= new MultiHashMap[String, MProperty]
83 # Return all properties named `name`.
85 # If such a property does not exist, null is returned
86 # (instead of an empty array)
88 # Visibility or modules are not considered
89 fun get_mproperties_by_name
(name
: String): nullable Array[MProperty]
91 return mproperties_by_name
.get_or_null
(name
)
95 var null_type
= new MNullType(self)
97 # Build an ordered tree with from `concerns`
98 fun concerns_tree
(mconcerns
: Collection[MConcern]): ConcernsTree do
99 var seen
= new HashSet[MConcern]
100 var res
= new ConcernsTree
102 var todo
= new Array[MConcern]
103 todo
.add_all mconcerns
105 while not todo
.is_empty
do
107 if seen
.has
(c
) then continue
108 var pc
= c
.parent_concern
122 # An OrderedTree that can be easily refined for display purposes
124 super OrderedTree[MConcern]
128 # All the classes introduced in the module
129 var intro_mclasses
= new Array[MClass]
131 # All the class definitions of the module
132 # (introduction and refinement)
133 var mclassdefs
= new Array[MClassDef]
135 # Does the current module has a given class `mclass`?
136 # Return true if the mmodule introduces, refines or imports a class.
137 # Visibility is not considered.
138 fun has_mclass
(mclass
: MClass): Bool
140 return self.in_importation
<= mclass
.intro_mmodule
143 # Full hierarchy of introduced ans imported classes.
145 # Create a new hierarchy got by flattening the classes for the module
146 # and its imported modules.
147 # Visibility is not considered.
149 # Note: this function is expensive and is usually used for the main
150 # module of a program only. Do not use it to do you own subtype
152 fun flatten_mclass_hierarchy
: POSet[MClass]
154 var res
= self.flatten_mclass_hierarchy_cache
155 if res
!= null then return res
156 res
= new POSet[MClass]
157 for m
in self.in_importation
.greaters
do
158 for cd
in m
.mclassdefs
do
161 for s
in cd
.supertypes
do
162 res
.add_edge
(c
, s
.mclass
)
166 self.flatten_mclass_hierarchy_cache
= res
170 # Sort a given array of classes using the linearization order of the module
171 # The most general is first, the most specific is last
172 fun linearize_mclasses
(mclasses
: Array[MClass])
174 self.flatten_mclass_hierarchy
.sort
(mclasses
)
177 # Sort a given array of class definitions using the linearization order of the module
178 # the refinement link is stronger than the specialisation link
179 # The most general is first, the most specific is last
180 fun linearize_mclassdefs
(mclassdefs
: Array[MClassDef])
182 var sorter
= new MClassDefSorter(self)
183 sorter
.sort
(mclassdefs
)
186 # Sort a given array of property definitions using the linearization order of the module
187 # the refinement link is stronger than the specialisation link
188 # The most general is first, the most specific is last
189 fun linearize_mpropdefs
(mpropdefs
: Array[MPropDef])
191 var sorter
= new MPropDefSorter(self)
192 sorter
.sort
(mpropdefs
)
195 private var flatten_mclass_hierarchy_cache
: nullable POSet[MClass] = null
197 # The primitive type `Object`, the root of the class hierarchy
198 var object_type
: MClassType = self.get_primitive_class
("Object").mclass_type
is lazy
200 # The type `Pointer`, super class to all extern classes
201 var pointer_type
: MClassType = self.get_primitive_class
("Pointer").mclass_type
is lazy
203 # The primitive type `Bool`
204 var bool_type
: MClassType = self.get_primitive_class
("Bool").mclass_type
is lazy
206 # The primitive type `Int`
207 var int_type
: MClassType = self.get_primitive_class
("Int").mclass_type
is lazy
209 # The primitive type `Char`
210 var char_type
: MClassType = self.get_primitive_class
("Char").mclass_type
is lazy
212 # The primitive type `Float`
213 var float_type
: MClassType = self.get_primitive_class
("Float").mclass_type
is lazy
215 # The primitive type `String`
216 var string_type
: MClassType = self.get_primitive_class
("String").mclass_type
is lazy
218 # The primitive type `NativeString`
219 var native_string_type
: MClassType = self.get_primitive_class
("NativeString").mclass_type
is lazy
221 # A primitive type of `Array`
222 fun array_type
(elt_type
: MType): MClassType do return array_class
.get_mtype
([elt_type
])
224 # The primitive class `Array`
225 var array_class
: MClass = self.get_primitive_class
("Array") is lazy
227 # A primitive type of `NativeArray`
228 fun native_array_type
(elt_type
: MType): MClassType do return native_array_class
.get_mtype
([elt_type
])
230 # The primitive class `NativeArray`
231 var native_array_class
: MClass = self.get_primitive_class
("NativeArray") is lazy
233 # The primitive type `Sys`, the main type of the program, if any
234 fun sys_type
: nullable MClassType
236 var clas
= self.model
.get_mclasses_by_name
("Sys")
237 if clas
== null then return null
238 return get_primitive_class
("Sys").mclass_type
241 # The primitive type `Finalizable`
242 # Used to tag classes that need to be finalized.
243 fun finalizable_type
: nullable MClassType
245 var clas
= self.model
.get_mclasses_by_name
("Finalizable")
246 if clas
== null then return null
247 return get_primitive_class
("Finalizable").mclass_type
250 # Force to get the primitive class named `name` or abort
251 fun get_primitive_class
(name
: String): MClass
253 var cla
= self.model
.get_mclasses_by_name
(name
)
255 if name
== "Bool" and self.model
.get_mclasses_by_name
("Object") != null then
256 # Bool is injected because it is needed by engine to code the result
257 # of the implicit casts.
258 var c
= new MClass(self, name
, null, enum_kind
, public_visibility
)
259 var cladef
= new MClassDef(self, c
.mclass_type
, new Location(null, 0,0,0,0))
260 cladef
.set_supertypes
([object_type
])
261 cladef
.add_in_hierarchy
264 print
("Fatal Error: no primitive class {name}")
267 if cla
.length
!= 1 then
268 var msg
= "Fatal Error: more than one primitive class {name}:"
269 for c
in cla
do msg
+= " {c.full_name}"
276 # Try to get the primitive method named `name` on the type `recv`
277 fun try_get_primitive_method
(name
: String, recv
: MClass): nullable MMethod
279 var props
= self.model
.get_mproperties_by_name
(name
)
280 if props
== null then return null
281 var res
: nullable MMethod = null
282 for mprop
in props
do
283 assert mprop
isa MMethod
284 var intro
= mprop
.intro_mclassdef
285 for mclassdef
in recv
.mclassdefs
do
286 if not self.in_importation
.greaters
.has
(mclassdef
.mmodule
) then continue
287 if not mclassdef
.in_hierarchy
.greaters
.has
(intro
) then continue
290 else if res
!= mprop
then
291 print
("Fatal Error: ambigous property name '{name}'; conflict between {mprop.full_name} and {res.full_name}")
300 private class MClassDefSorter
302 redef type COMPARED: MClassDef
304 redef fun compare
(a
, b
)
308 if ca
!= cb
then return mmodule
.flatten_mclass_hierarchy
.compare
(ca
, cb
)
309 return mmodule
.model
.mclassdef_hierarchy
.compare
(a
, b
)
313 private class MPropDefSorter
315 redef type COMPARED: MPropDef
317 redef fun compare
(pa
, pb
)
323 if ca
!= cb
then return mmodule
.flatten_mclass_hierarchy
.compare
(ca
, cb
)
324 return mmodule
.model
.mclassdef_hierarchy
.compare
(a
, b
)
330 # `MClass` are global to the model; it means that a `MClass` is not bound to a
331 # specific `MModule`.
333 # This characteristic helps the reasoning about classes in a program since a
334 # single `MClass` object always denote the same class.
336 # The drawback is that classes (`MClass`) contain almost nothing by themselves.
337 # These do not really have properties nor belong to a hierarchy since the property and the
338 # hierarchy of a class depends of the refinement in the modules.
340 # Most services on classes require the precision of a module, and no one can asks what are
341 # the super-classes of a class nor what are properties of a class without precising what is
342 # the module considered.
344 # For instance, during the typing of a source-file, the module considered is the module of the file.
345 # eg. the question *is the method `foo` exists in the class `Bar`?* must be reformulated into
346 # *is the method `foo` exists in the class `Bar` in the current module?*
348 # During some global analysis, the module considered may be the main module of the program.
352 # The module that introduce the class
353 # While classes are not bound to a specific module,
354 # the introducing module is used for naming an visibility
355 var intro_mmodule
: MModule
357 # The short name of the class
358 # In Nit, the name of a class cannot evolve in refinements
359 redef var name
: String
361 # The canonical name of the class
363 # It is the name of the class prefixed by the full_name of the `intro_mmodule`
364 # Example: `"owner::module::MyClass"`
365 redef var full_name
is lazy
do
366 return "{self.intro_mmodule.namespace_for(visibility)}::{name}"
369 redef var c_name
is lazy
do
370 return "{intro_mmodule.c_namespace_for(visibility)}__{name.to_cmangle}"
373 # The number of generic formal parameters
374 # 0 if the class is not generic
375 var arity
: Int is noinit
377 # Each generic formal parameters in order.
378 # is empty if the class is not generic
379 var mparameters
= new Array[MParameterType]
381 # Initialize `mparameters` from their names.
382 protected fun setup_parameter_names
(parameter_names
: nullable Array[String]) is
385 if parameter_names
== null then
388 self.arity
= parameter_names
.length
391 # Create the formal parameter types
393 assert parameter_names
!= null
394 var mparametertypes
= new Array[MParameterType]
395 for i
in [0..arity
[ do
396 var mparametertype
= new MParameterType(self, i
, parameter_names
[i
])
397 mparametertypes
.add
(mparametertype
)
399 self.mparameters
= mparametertypes
400 var mclass_type
= new MGenericType(self, mparametertypes
)
401 self.mclass_type
= mclass_type
402 self.get_mtype_cache
[mparametertypes
] = mclass_type
404 self.mclass_type
= new MClassType(self)
408 # The kind of the class (interface, abstract class, etc.)
409 # In Nit, the kind of a class cannot evolve in refinements
412 # The visibility of the class
413 # In Nit, the visibility of a class cannot evolve in refinements
414 var visibility
: MVisibility
418 intro_mmodule
.intro_mclasses
.add
(self)
419 var model
= intro_mmodule
.model
420 model
.mclasses_by_name
.add_one
(name
, self)
421 model
.mclasses
.add
(self)
424 redef fun model
do return intro_mmodule
.model
426 # All class definitions (introduction and refinements)
427 var mclassdefs
= new Array[MClassDef]
430 redef fun to_s
do return self.name
432 # The definition that introduces the class.
434 # Warning: such a definition may not exist in the early life of the object.
435 # In this case, the method will abort.
436 var intro
: MClassDef is noinit
438 # Return the class `self` in the class hierarchy of the module `mmodule`.
440 # SEE: `MModule::flatten_mclass_hierarchy`
441 # REQUIRE: `mmodule.has_mclass(self)`
442 fun in_hierarchy
(mmodule
: MModule): POSetElement[MClass]
444 return mmodule
.flatten_mclass_hierarchy
[self]
447 # The principal static type of the class.
449 # For non-generic class, mclass_type is the only `MClassType` based
452 # For a generic class, the arguments are the formal parameters.
453 # i.e.: for the class Array[E:Object], the `mclass_type` is Array[E].
454 # If you want Array[Object] the see `MClassDef::bound_mtype`
456 # For generic classes, the mclass_type is also the way to get a formal
457 # generic parameter type.
459 # To get other types based on a generic class, see `get_mtype`.
461 # ENSURE: `mclass_type.mclass == self`
462 var mclass_type
: MClassType is noinit
464 # Return a generic type based on the class
465 # Is the class is not generic, then the result is `mclass_type`
467 # REQUIRE: `mtype_arguments.length == self.arity`
468 fun get_mtype
(mtype_arguments
: Array[MType]): MClassType
470 assert mtype_arguments
.length
== self.arity
471 if self.arity
== 0 then return self.mclass_type
472 var res
= get_mtype_cache
.get_or_null
(mtype_arguments
)
473 if res
!= null then return res
474 res
= new MGenericType(self, mtype_arguments
)
475 self.get_mtype_cache
[mtype_arguments
.to_a
] = res
479 private var get_mtype_cache
= new HashMap[Array[MType], MGenericType]
481 # Is there a `new` factory to allow the pseudo instantiation?
482 var has_new_factory
= false is writable
486 # A definition (an introduction or a refinement) of a class in a module
488 # A `MClassDef` is associated with an explicit (or almost) definition of a
489 # class. Unlike `MClass`, a `MClassDef` is a local definition that belong to
490 # a specific class and a specific module, and contains declarations like super-classes
493 # It is the class definitions that are the backbone of most things in the model:
494 # ClassDefs are defined with regard with other classdefs.
495 # Refinement and specialization are combined to produce a big poset called the `Model::mclassdef_hierarchy`.
497 # Moreover, the extension and the intention of types is defined by looking at the MClassDefs.
501 # The module where the definition is
504 # The associated `MClass`
505 var mclass
: MClass is noinit
507 # The bounded type associated to the mclassdef
509 # For a non-generic class, `bound_mtype` and `mclass.mclass_type`
513 # For the classdef Array[E: Object], the bound_mtype is Array[Object].
514 # If you want Array[E], then see `mclass.mclass_type`
516 # ENSURE: `bound_mtype.mclass == self.mclass`
517 var bound_mtype
: MClassType
519 # The origin of the definition
520 var location
: Location
522 # Internal name combining the module and the class
523 # Example: "mymodule#MyClass"
524 redef var to_s
: String is noinit
528 self.mclass
= bound_mtype
.mclass
529 mmodule
.mclassdefs
.add
(self)
530 mclass
.mclassdefs
.add
(self)
531 if mclass
.intro_mmodule
== mmodule
then
532 assert not isset mclass
._intro
535 self.to_s
= "{mmodule}#{mclass}"
538 # Actually the name of the `mclass`
539 redef fun name
do return mclass
.name
541 # The module and class name separated by a '#'.
543 # The short-name of the class is used for introduction.
544 # Example: "my_module#MyClass"
546 # The full-name of the class is used for refinement.
547 # Example: "my_module#intro_module::MyClass"
548 redef var full_name
is lazy
do
551 # private gives 'p::m#A'
552 return "{mmodule.namespace_for(mclass.visibility)}#{mclass.name}"
553 else if mclass
.intro_mmodule
.mproject
!= mmodule
.mproject
then
554 # public gives 'q::n#p::A'
555 # private gives 'q::n#p::m::A'
556 return "{mmodule.full_name}#{mclass.full_name}"
557 else if mclass
.visibility
> private_visibility
then
558 # public gives 'p::n#A'
559 return "{mmodule.full_name}#{mclass.name}"
561 # private gives 'p::n#::m::A' (redundant p is omitted)
562 return "{mmodule.full_name}#::{mclass.intro_mmodule.name}::{mclass.name}"
566 redef var c_name
is lazy
do
568 return "{mmodule.c_namespace_for(mclass.visibility)}___{mclass.c_name}"
569 else if mclass
.intro_mmodule
.mproject
== mmodule
.mproject
and mclass
.visibility
> private_visibility
then
570 return "{mmodule.c_name}___{mclass.name.to_cmangle}"
572 return "{mmodule.c_name}___{mclass.c_name}"
576 redef fun model
do return mmodule
.model
578 # All declared super-types
579 # FIXME: quite ugly but not better idea yet
580 var supertypes
= new Array[MClassType]
582 # Register some super-types for the class (ie "super SomeType")
584 # The hierarchy must not already be set
585 # REQUIRE: `self.in_hierarchy == null`
586 fun set_supertypes
(supertypes
: Array[MClassType])
588 assert unique_invocation
: self.in_hierarchy
== null
589 var mmodule
= self.mmodule
590 var model
= mmodule
.model
591 var mtype
= self.bound_mtype
593 for supertype
in supertypes
do
594 self.supertypes
.add
(supertype
)
596 # Register in full_type_specialization_hierarchy
597 model
.full_mtype_specialization_hierarchy
.add_edge
(mtype
, supertype
)
598 # Register in intro_type_specialization_hierarchy
599 if mclass
.intro_mmodule
== mmodule
and supertype
.mclass
.intro_mmodule
== mmodule
then
600 model
.intro_mtype_specialization_hierarchy
.add_edge
(mtype
, supertype
)
606 # Collect the super-types (set by set_supertypes) to build the hierarchy
608 # This function can only invoked once by class
609 # REQUIRE: `self.in_hierarchy == null`
610 # ENSURE: `self.in_hierarchy != null`
613 assert unique_invocation
: self.in_hierarchy
== null
614 var model
= mmodule
.model
615 var res
= model
.mclassdef_hierarchy
.add_node
(self)
616 self.in_hierarchy
= res
617 var mtype
= self.bound_mtype
619 # Here we need to connect the mclassdef to its pairs in the mclassdef_hierarchy
620 # The simpliest way is to attach it to collect_mclassdefs
621 for mclassdef
in mtype
.collect_mclassdefs
(mmodule
) do
622 res
.poset
.add_edge
(self, mclassdef
)
626 # The view of the class definition in `mclassdef_hierarchy`
627 var in_hierarchy
: nullable POSetElement[MClassDef] = null
629 # Is the definition the one that introduced `mclass`?
630 fun is_intro
: Bool do return mclass
.intro
== self
632 # All properties introduced by the classdef
633 var intro_mproperties
= new Array[MProperty]
635 # All property definitions in the class (introductions and redefinitions)
636 var mpropdefs
= new Array[MPropDef]
639 # A global static type
641 # MType are global to the model; it means that a `MType` is not bound to a
642 # specific `MModule`.
643 # This characteristic helps the reasoning about static types in a program
644 # since a single `MType` object always denote the same type.
646 # However, because a `MType` is global, it does not really have properties
647 # nor have subtypes to a hierarchy since the property and the class hierarchy
648 # depends of a module.
649 # Moreover, virtual types an formal generic parameter types also depends on
650 # a receiver to have sense.
652 # Therefore, most method of the types require a module and an anchor.
653 # The module is used to know what are the classes and the specialization
655 # The anchor is used to know what is the bound of the virtual types and formal
656 # generic parameter types.
658 # MType are not directly usable to get properties. See the `anchor_to` method
659 # and the `MClassType` class.
661 # FIXME: the order of the parameters is not the best. We mus pick on from:
662 # * foo(mmodule, anchor, othertype)
663 # * foo(othertype, anchor, mmodule)
664 # * foo(anchor, mmodule, othertype)
665 # * foo(othertype, mmodule, anchor)
669 redef fun name
do return to_s
671 # Return true if `self` is an subtype of `sup`.
672 # The typing is done using the standard typing policy of Nit.
674 # REQUIRE: `anchor == null implies not self.need_anchor and not sup.need_anchor`
675 # REQUIRE: `anchor != null implies self.can_resolve_for(anchor, null, mmodule) and sup.can_resolve_for(anchor, null, mmodule)`
676 fun is_subtype
(mmodule
: MModule, anchor
: nullable MClassType, sup
: MType): Bool
679 if sub
== sup
then return true
681 #print "1.is {sub} a {sup}? ===="
683 if anchor
== null then
684 assert not sub
.need_anchor
685 assert not sup
.need_anchor
687 # First, resolve the formal types to the simplest equivalent forms in the receiver
688 assert sub
.can_resolve_for
(anchor
, null, mmodule
)
689 sub
= sub
.lookup_fixed
(mmodule
, anchor
)
690 assert sup
.can_resolve_for
(anchor
, null, mmodule
)
691 sup
= sup
.lookup_fixed
(mmodule
, anchor
)
694 # Does `sup` accept null or not?
695 # Discard the nullable marker if it exists
696 var sup_accept_null
= false
697 if sup
isa MNullableType then
698 sup_accept_null
= true
700 else if sup
isa MNullType then
701 sup_accept_null
= true
704 # Can `sub` provide null or not?
705 # Thus we can match with `sup_accept_null`
706 # Also discard the nullable marker if it exists
707 if sub
isa MNullableType then
708 if not sup_accept_null
then return false
710 else if sub
isa MNullType then
711 return sup_accept_null
713 # Now the case of direct null and nullable is over.
715 # If `sub` is a formal type, then it is accepted if its bound is accepted
716 while sub
isa MFormalType do
717 #print "3.is {sub} a {sup}?"
719 # A unfixed formal type can only accept itself
720 if sub
== sup
then return true
722 assert anchor
!= null
723 sub
= sub
.lookup_bound
(mmodule
, anchor
)
725 #print "3.is {sub} a {sup}?"
727 # Manage the second layer of null/nullable
728 if sub
isa MNullableType then
729 if not sup_accept_null
then return false
731 else if sub
isa MNullType then
732 return sup_accept_null
735 #print "4.is {sub} a {sup}? <- no more resolution"
737 assert sub
isa MClassType # It is the only remaining type
739 # A unfixed formal type can only accept itself
740 if sup
isa MFormalType then
744 if sup
isa MNullType then
745 # `sup` accepts only null
749 assert sup
isa MClassType # It is the only remaining type
751 # Now both are MClassType, we need to dig
753 if sub
== sup
then return true
755 if anchor
== null then anchor
= sub
# UGLY: any anchor will work
756 var resolved_sub
= sub
.anchor_to
(mmodule
, anchor
)
757 var res
= resolved_sub
.collect_mclasses
(mmodule
).has
(sup
.mclass
)
758 if res
== false then return false
759 if not sup
isa MGenericType then return true
760 var sub2
= sub
.supertype_to
(mmodule
, anchor
, sup
.mclass
)
761 assert sub2
.mclass
== sup
.mclass
762 for i
in [0..sup
.mclass
.arity
[ do
763 var sub_arg
= sub2
.arguments
[i
]
764 var sup_arg
= sup
.arguments
[i
]
765 res
= sub_arg
.is_subtype
(mmodule
, anchor
, sup_arg
)
766 if res
== false then return false
771 # The base class type on which self is based
773 # This base type is used to get property (an internally to perform
774 # unsafe type comparison).
776 # Beware: some types (like null) are not based on a class thus this
779 # Basically, this function transform the virtual types and parameter
780 # types to their bounds.
785 # class B super A end
787 # class Y super X end
796 # Map[T,U] anchor_to H #-> Map[B,Y]
798 # Explanation of the example:
799 # In H, T is set to B, because "H super G[B]", and U is bound to Y,
800 # because "redef type U: Y". Therefore, Map[T, U] is bound to
803 # ENSURE: `not self.need_anchor implies result == self`
804 # ENSURE: `not result.need_anchor`
805 fun anchor_to
(mmodule
: MModule, anchor
: MClassType): MType
807 if not need_anchor
then return self
808 assert not anchor
.need_anchor
809 # Just resolve to the anchor and clear all the virtual types
810 var res
= self.resolve_for
(anchor
, null, mmodule
, true)
811 assert not res
.need_anchor
815 # Does `self` contain a virtual type or a formal generic parameter type?
816 # In order to remove those types, you usually want to use `anchor_to`.
817 fun need_anchor
: Bool do return true
819 # Return the supertype when adapted to a class.
821 # In Nit, for each super-class of a type, there is a equivalent super-type.
827 # class H[V] super G[V, Bool] end
829 # H[Int] supertype_to G #-> G[Int, Bool]
832 # REQUIRE: `super_mclass` is a super-class of `self`
833 # REQUIRE: `self.need_anchor implies anchor != null and self.can_resolve_for(anchor, null, mmodule)`
834 # ENSURE: `result.mclass = super_mclass`
835 fun supertype_to
(mmodule
: MModule, anchor
: nullable MClassType, super_mclass
: MClass): MClassType
837 if super_mclass
.arity
== 0 then return super_mclass
.mclass_type
838 if self isa MClassType and self.mclass
== super_mclass
then return self
840 if self.need_anchor
then
841 assert anchor
!= null
842 resolved_self
= self.anchor_to
(mmodule
, anchor
)
846 var supertypes
= resolved_self
.collect_mtypes
(mmodule
)
847 for supertype
in supertypes
do
848 if supertype
.mclass
== super_mclass
then
849 # FIXME: Here, we stop on the first goal. Should we check others and detect inconsistencies?
850 return supertype
.resolve_for
(self, anchor
, mmodule
, false)
856 # Replace formals generic types in self with resolved values in `mtype`
857 # If `cleanup_virtual` is true, then virtual types are also replaced
860 # This function returns self if `need_anchor` is false.
866 # class H[F] super G[F] end
870 # * Array[E].resolve_for(H[Int]) #-> Array[Int]
871 # * Array[E].resolve_for(G[Z], X[Int]) #-> Array[Z]
873 # Explanation of the example:
874 # * Array[E].need_anchor is true because there is a formal generic parameter type E
875 # * E makes sense for H[Int] because E is a formal parameter of G and H specialize G
876 # * Since "H[F] super G[F]", E is in fact F for H
877 # * More specifically, in H[Int], E is Int
878 # * So, in H[Int], Array[E] is Array[Int]
880 # This function is mainly used to inherit a signature.
881 # Because, unlike `anchor_to`, we do not want a full resolution of
882 # a type but only an adapted version of it.
888 # fun foo(e:E):E is abstract
890 # class B super A[Int] end
893 # The signature on foo is (e: E): E
894 # If we resolve the signature for B, we get (e:Int):Int
900 # fun foo(e:E):E is abstract
904 # fun bar do a.foo(x) # <- x is here
908 # The first question is: is foo available on `a`?
910 # The static type of a is `A[Array[F]]`, that is an open type.
911 # in order to find a method `foo`, whe must look at a resolved type.
913 # A[Array[F]].anchor_to(C[nullable Object]) #-> A[Array[nullable Object]]
915 # the method `foo` exists in `A[Array[nullable Object]]`, therefore `foo` exists for `a`.
917 # The next question is: what is the accepted types for `x`?
919 # the signature of `foo` is `foo(e:E)`, thus we must resolve the type E
921 # E.resolve_for(A[Array[F]],C[nullable Object]) #-> Array[F]
923 # The resolution can be done because `E` make sense for the class A (see `can_resolve_for`)
925 # FIXME: the parameter `cleanup_virtual` is just a bad idea, but having
926 # two function instead of one seems also to be a bad idea.
928 # REQUIRE: `can_resolve_for(mtype, anchor, mmodule)`
929 # ENSURE: `not self.need_anchor implies result == self`
930 fun resolve_for
(mtype
: MType, anchor
: nullable MClassType, mmodule
: MModule, cleanup_virtual
: Bool): MType is abstract
932 # Resolve formal type to its verbatim bound.
933 # If the type is not formal, just return self
935 # The result is returned exactly as declared in the "type" property (verbatim).
936 # So it could be another formal type.
938 # In case of conflict, the method aborts.
939 fun lookup_bound
(mmodule
: MModule, resolved_receiver
: MType): MType do return self
941 # Resolve the formal type to its simplest equivalent form.
943 # Formal types are either free or fixed.
944 # When it is fixed, it means that it is equivalent with a simpler type.
945 # When a formal type is free, it means that it is only equivalent with itself.
946 # This method return the most simple equivalent type of `self`.
948 # This method is mainly used for subtype test in order to sanely compare fixed.
950 # By default, return self.
951 # See the redefinitions for specific behavior in each kind of type.
952 fun lookup_fixed
(mmodule
: MModule, resolved_receiver
: MType): MType do return self
954 # Can the type be resolved?
956 # In order to resolve open types, the formal types must make sence.
966 # E.can_resolve_for(A[Int]) #-> true, E make sense in A
968 # E.can_resolve_for(B[Int]) #-> false, E does not make sense in B
970 # B[E].can_resolve_for(A[F], B[Object]) #-> true,
971 # # B[E] is a red hearing only the E is important,
972 # # E make sense in A
975 # REQUIRE: `anchor != null implies not anchor.need_anchor`
976 # REQUIRE: `mtype.need_anchor implies anchor != null and mtype.can_resolve_for(anchor, null, mmodule)`
977 # ENSURE: `not self.need_anchor implies result == true`
978 fun can_resolve_for
(mtype
: MType, anchor
: nullable MClassType, mmodule
: MModule): Bool is abstract
980 # Return the nullable version of the type
981 # If the type is already nullable then self is returned
982 fun as_nullable
: MType
984 var res
= self.as_nullable_cache
985 if res
!= null then return res
986 res
= new MNullableType(self)
987 self.as_nullable_cache
= res
991 # Return the not nullable version of the type
992 # Is the type is already not nullable, then self is returned.
994 # Note: this just remove the `nullable` notation, but the result can still contains null.
995 # For instance if `self isa MNullType` or self is a formal type bounded by a nullable type.
996 fun as_notnullable
: MType
1001 private var as_nullable_cache
: nullable MType = null
1004 # The depth of the type seen as a tree.
1011 # Formal types have a depth of 1.
1017 # The length of the type seen as a tree.
1024 # Formal types have a length of 1.
1030 # Compute all the classdefs inherited/imported.
1031 # The returned set contains:
1032 # * the class definitions from `mmodule` and its imported modules
1033 # * the class definitions of this type and its super-types
1035 # This function is used mainly internally.
1037 # REQUIRE: `not self.need_anchor`
1038 fun collect_mclassdefs
(mmodule
: MModule): Set[MClassDef] is abstract
1040 # Compute all the super-classes.
1041 # This function is used mainly internally.
1043 # REQUIRE: `not self.need_anchor`
1044 fun collect_mclasses
(mmodule
: MModule): Set[MClass] is abstract
1046 # Compute all the declared super-types.
1047 # Super-types are returned as declared in the classdefs (verbatim).
1048 # This function is used mainly internally.
1050 # REQUIRE: `not self.need_anchor`
1051 fun collect_mtypes
(mmodule
: MModule): Set[MClassType] is abstract
1053 # Is the property in self for a given module
1054 # This method does not filter visibility or whatever
1056 # REQUIRE: `not self.need_anchor`
1057 fun has_mproperty
(mmodule
: MModule, mproperty
: MProperty): Bool
1059 assert not self.need_anchor
1060 return self.collect_mclassdefs
(mmodule
).has
(mproperty
.intro_mclassdef
)
1064 # A type based on a class.
1066 # `MClassType` have properties (see `has_mproperty`).
1070 # The associated class
1073 redef fun model
do return self.mclass
.intro_mmodule
.model
1075 # TODO: private init because strongly bounded to its mclass. see `mclass.mclass_type`
1077 # The formal arguments of the type
1078 # ENSURE: `result.length == self.mclass.arity`
1079 var arguments
= new Array[MType]
1081 redef fun to_s
do return mclass
.to_s
1083 redef fun full_name
do return mclass
.full_name
1085 redef fun c_name
do return mclass
.c_name
1087 redef fun need_anchor
do return false
1089 redef fun anchor_to
(mmodule
: MModule, anchor
: MClassType): MClassType
1091 return super.as(MClassType)
1094 redef fun resolve_for
(mtype
: MType, anchor
: nullable MClassType, mmodule
: MModule, cleanup_virtual
: Bool): MClassType do return self
1096 redef fun can_resolve_for
(mtype
, anchor
, mmodule
) do return true
1098 redef fun collect_mclassdefs
(mmodule
)
1100 assert not self.need_anchor
1101 var cache
= self.collect_mclassdefs_cache
1102 if not cache
.has_key
(mmodule
) then
1103 self.collect_things
(mmodule
)
1105 return cache
[mmodule
]
1108 redef fun collect_mclasses
(mmodule
)
1110 if collect_mclasses_last_module
== mmodule
then return collect_mclasses_last_module_cache
1111 assert not self.need_anchor
1112 var cache
= self.collect_mclasses_cache
1113 if not cache
.has_key
(mmodule
) then
1114 self.collect_things
(mmodule
)
1116 var res
= cache
[mmodule
]
1117 collect_mclasses_last_module
= mmodule
1118 collect_mclasses_last_module_cache
= res
1122 private var collect_mclasses_last_module
: nullable MModule = null
1123 private var collect_mclasses_last_module_cache
: Set[MClass] is noinit
1125 redef fun collect_mtypes
(mmodule
)
1127 assert not self.need_anchor
1128 var cache
= self.collect_mtypes_cache
1129 if not cache
.has_key
(mmodule
) then
1130 self.collect_things
(mmodule
)
1132 return cache
[mmodule
]
1135 # common implementation for `collect_mclassdefs`, `collect_mclasses`, and `collect_mtypes`.
1136 private fun collect_things
(mmodule
: MModule)
1138 var res
= new HashSet[MClassDef]
1139 var seen
= new HashSet[MClass]
1140 var types
= new HashSet[MClassType]
1141 seen
.add
(self.mclass
)
1142 var todo
= [self.mclass
]
1143 while not todo
.is_empty
do
1144 var mclass
= todo
.pop
1145 #print "process {mclass}"
1146 for mclassdef
in mclass
.mclassdefs
do
1147 if not mmodule
.in_importation
<= mclassdef
.mmodule
then continue
1148 #print " process {mclassdef}"
1150 for supertype
in mclassdef
.supertypes
do
1151 types
.add
(supertype
)
1152 var superclass
= supertype
.mclass
1153 if seen
.has
(superclass
) then continue
1154 #print " add {superclass}"
1155 seen
.add
(superclass
)
1156 todo
.add
(superclass
)
1160 collect_mclassdefs_cache
[mmodule
] = res
1161 collect_mclasses_cache
[mmodule
] = seen
1162 collect_mtypes_cache
[mmodule
] = types
1165 private var collect_mclassdefs_cache
= new HashMap[MModule, Set[MClassDef]]
1166 private var collect_mclasses_cache
= new HashMap[MModule, Set[MClass]]
1167 private var collect_mtypes_cache
= new HashMap[MModule, Set[MClassType]]
1171 # A type based on a generic class.
1172 # A generic type a just a class with additional formal generic arguments.
1178 # TODO: private init because strongly bounded to its mclass. see `mclass.get_mtype`
1182 assert self.mclass
.arity
== arguments
.length
1184 self.need_anchor
= false
1185 for t
in arguments
do
1186 if t
.need_anchor
then
1187 self.need_anchor
= true
1192 self.to_s
= "{mclass}[{arguments.join(", ")}]"
1195 # The short-name of the class, then the full-name of each type arguments within brackets.
1196 # Example: `"Map[String, List[Int]]"`
1197 redef var to_s
: String is noinit
1199 # The full-name of the class, then the full-name of each type arguments within brackets.
1200 # Example: `"standard::Map[standard::String, standard::List[standard::Int]]"`
1201 redef var full_name
is lazy
do
1202 var args
= new Array[String]
1203 for t
in arguments
do
1204 args
.add t
.full_name
1206 return "{mclass.full_name}[{args.join(", ")}]"
1209 redef var c_name
is lazy
do
1210 var res
= mclass
.c_name
1211 # Note: because the arity is known, a prefix notation is enough
1212 for t
in arguments
do
1219 redef var need_anchor
: Bool is noinit
1221 redef fun resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1223 if not need_anchor
then return self
1224 assert can_resolve_for
(mtype
, anchor
, mmodule
)
1225 var types
= new Array[MType]
1226 for t
in arguments
do
1227 types
.add
(t
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
))
1229 return mclass
.get_mtype
(types
)
1232 redef fun can_resolve_for
(mtype
, anchor
, mmodule
)
1234 if not need_anchor
then return true
1235 for t
in arguments
do
1236 if not t
.can_resolve_for
(mtype
, anchor
, mmodule
) then return false
1245 for a
in self.arguments
do
1247 if d
> dmax
then dmax
= d
1255 for a
in self.arguments
do
1262 # A formal type (either virtual of parametric).
1264 # The main issue with formal types is that they offer very little information on their own
1265 # and need a context (anchor and mmodule) to be useful.
1266 abstract class MFormalType
1270 # A virtual formal type.
1274 # The property associated with the type.
1275 # Its the definitions of this property that determine the bound or the virtual type.
1276 var mproperty
: MVirtualTypeProp
1278 redef fun model
do return self.mproperty
.intro_mclassdef
.mmodule
.model
1280 redef fun lookup_bound
(mmodule
: MModule, resolved_receiver
: MType): MType
1282 return lookup_single_definition
(mmodule
, resolved_receiver
).bound
.as(not null)
1285 private fun lookup_single_definition
(mmodule
: MModule, resolved_receiver
: MType): MVirtualTypeDef
1287 assert not resolved_receiver
.need_anchor
1288 var props
= self.mproperty
.lookup_definitions
(mmodule
, resolved_receiver
)
1289 if props
.is_empty
then
1291 else if props
.length
== 1 then
1294 var types
= new ArraySet[MType]
1295 var res
= props
.first
1297 types
.add
(p
.bound
.as(not null))
1298 if not res
.is_fixed
then res
= p
1300 if types
.length
== 1 then
1306 # A VT is fixed when:
1307 # * the VT is (re-)defined with the annotation `is fixed`
1308 # * the VT is (indirectly) bound to an enum class (see `enum_kind`) since there is no subtype possible
1309 # * the receiver is an enum class since there is no subtype possible
1310 redef fun lookup_fixed
(mmodule
: MModule, resolved_receiver
: MType): MType
1312 assert not resolved_receiver
.need_anchor
1313 resolved_receiver
= resolved_receiver
.as_notnullable
1314 assert resolved_receiver
isa MClassType # It is the only remaining type
1316 var prop
= lookup_single_definition
(mmodule
, resolved_receiver
)
1317 var res
= prop
.bound
.as(not null)
1319 # Recursively lookup the fixed result
1320 res
= res
.lookup_fixed
(mmodule
, resolved_receiver
)
1322 # 1. For a fixed VT, return the resolved bound
1323 if prop
.is_fixed
then return res
1325 # 2. For a enum boud, return the bound
1326 if res
isa MClassType and res
.mclass
.kind
== enum_kind
then return res
1328 # 3. for a enum receiver return the bound
1329 if resolved_receiver
.mclass
.kind
== enum_kind
then return res
1334 redef fun resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1336 if not cleanup_virtual
then return self
1337 assert can_resolve_for
(mtype
, anchor
, mmodule
)
1338 # self is a virtual type declared (or inherited) in mtype
1339 # The point of the function it to get the bound of the virtual type that make sense for mtype
1340 # But because mtype is maybe a virtual/formal type, we need to get a real receiver first
1341 #print "{class_name}: {self}/{mtype}/{anchor}?"
1342 var resolved_receiver
1343 if mtype
.need_anchor
then
1344 assert anchor
!= null
1345 resolved_receiver
= mtype
.resolve_for
(anchor
, null, mmodule
, true)
1347 resolved_receiver
= mtype
1349 # Now, we can get the bound
1350 var verbatim_bound
= lookup_bound
(mmodule
, resolved_receiver
)
1351 # The bound is exactly as declared in the "type" property, so we must resolve it again
1352 var res
= verbatim_bound
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1357 redef fun can_resolve_for
(mtype
, anchor
, mmodule
)
1359 if mtype
.need_anchor
then
1360 assert anchor
!= null
1361 mtype
= mtype
.anchor_to
(mmodule
, anchor
)
1363 return mtype
.has_mproperty
(mmodule
, mproperty
)
1366 redef fun to_s
do return self.mproperty
.to_s
1368 redef fun full_name
do return self.mproperty
.full_name
1370 redef fun c_name
do return self.mproperty
.c_name
1373 # The type associated to a formal parameter generic type of a class
1375 # Each parameter type is associated to a specific class.
1376 # It means that all refinements of a same class "share" the parameter type,
1377 # but that a generic subclass has its own parameter types.
1379 # However, in the sense of the meta-model, a parameter type of a class is
1380 # a valid type in a subclass. The "in the sense of the meta-model" is
1381 # important because, in the Nit language, the programmer cannot refers
1382 # directly to the parameter types of the super-classes.
1387 # fun e: E is abstract
1393 # In the class definition B[F], `F` is a valid type but `E` is not.
1394 # However, `self.e` is a valid method call, and the signature of `e` is
1397 # Note that parameter types are shared among class refinements.
1398 # Therefore parameter only have an internal name (see `to_s` for details).
1399 class MParameterType
1402 # The generic class where the parameter belong
1405 redef fun model
do return self.mclass
.intro_mmodule
.model
1407 # The position of the parameter (0 for the first parameter)
1408 # FIXME: is `position` a better name?
1413 redef fun to_s
do return name
1415 redef var full_name
is lazy
do return "{mclass.full_name}::{name}"
1417 redef var c_name
is lazy
do return mclass
.c_name
+ "__" + "#{name}".to_cmangle
1419 redef fun lookup_bound
(mmodule
: MModule, resolved_receiver
: MType): MType
1421 assert not resolved_receiver
.need_anchor
1422 resolved_receiver
= resolved_receiver
.as_notnullable
1423 assert resolved_receiver
isa MClassType # It is the only remaining type
1424 var goalclass
= self.mclass
1425 if resolved_receiver
.mclass
== goalclass
then
1426 return resolved_receiver
.arguments
[self.rank
]
1428 var supertypes
= resolved_receiver
.collect_mtypes
(mmodule
)
1429 for t
in supertypes
do
1430 if t
.mclass
== goalclass
then
1431 # Yeah! c specialize goalclass with a "super `t'". So the question is what is the argument of f
1432 # FIXME: Here, we stop on the first goal. Should we check others and detect inconsistencies?
1433 var res
= t
.arguments
[self.rank
]
1440 # A PT is fixed when:
1441 # * Its bound is a enum class (see `enum_kind`).
1442 # The PT is just useless, but it is still a case.
1443 # * More usually, the `resolved_receiver` is a subclass of `self.mclass`,
1444 # so it is necessarily fixed in a `super` clause, either with a normal type
1445 # or with another PT.
1446 # See `resolve_for` for examples about related issues.
1447 redef fun lookup_fixed
(mmodule
: MModule, resolved_receiver
: MType): MType
1449 assert not resolved_receiver
.need_anchor
1450 resolved_receiver
= resolved_receiver
.as_notnullable
1451 assert resolved_receiver
isa MClassType # It is the only remaining type
1452 var res
= self.resolve_for
(resolved_receiver
.mclass
.mclass_type
, resolved_receiver
, mmodule
, false)
1456 redef fun resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1458 assert can_resolve_for
(mtype
, anchor
, mmodule
)
1459 #print "{class_name}: {self}/{mtype}/{anchor}?"
1461 if mtype
isa MGenericType and mtype
.mclass
== self.mclass
then
1462 var res
= mtype
.arguments
[self.rank
]
1463 if anchor
!= null and res
.need_anchor
then
1464 # Maybe the result can be resolved more if are bound to a final class
1465 var r2
= res
.anchor_to
(mmodule
, anchor
)
1466 if r2
isa MClassType and r2
.mclass
.kind
== enum_kind
then return r2
1471 # self is a parameter type of mtype (or of a super-class of mtype)
1472 # The point of the function it to get the bound of the virtual type that make sense for mtype
1473 # But because mtype is maybe a virtual/formal type, we need to get a real receiver first
1474 # FIXME: What happens here is far from clear. Thus this part must be validated and clarified
1475 var resolved_receiver
1476 if mtype
.need_anchor
then
1477 assert anchor
!= null
1478 resolved_receiver
= mtype
.resolve_for
(anchor
.mclass
.mclass_type
, anchor
, mmodule
, true)
1480 resolved_receiver
= mtype
1482 if resolved_receiver
isa MNullableType then resolved_receiver
= resolved_receiver
.mtype
1483 if resolved_receiver
isa MParameterType then
1484 assert resolved_receiver
.mclass
== anchor
.mclass
1485 resolved_receiver
= anchor
.arguments
[resolved_receiver
.rank
]
1486 if resolved_receiver
isa MNullableType then resolved_receiver
= resolved_receiver
.mtype
1488 assert resolved_receiver
isa MClassType # It is the only remaining type
1490 # Eh! The parameter is in the current class.
1491 # So we return the corresponding argument, no mater what!
1492 if resolved_receiver
.mclass
== self.mclass
then
1493 var res
= resolved_receiver
.arguments
[self.rank
]
1494 #print "{class_name}: {self}/{mtype}/{anchor} -> direct {res}"
1498 if resolved_receiver
.need_anchor
then
1499 assert anchor
!= null
1500 resolved_receiver
= resolved_receiver
.resolve_for
(anchor
, null, mmodule
, false)
1502 # Now, we can get the bound
1503 var verbatim_bound
= lookup_bound
(mmodule
, resolved_receiver
)
1504 # The bound is exactly as declared in the "type" property, so we must resolve it again
1505 var res
= verbatim_bound
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1507 #print "{class_name}: {self}/{mtype}/{anchor} -> indirect {res}"
1512 redef fun can_resolve_for
(mtype
, anchor
, mmodule
)
1514 if mtype
.need_anchor
then
1515 assert anchor
!= null
1516 mtype
= mtype
.anchor_to
(mmodule
, anchor
)
1518 return mtype
.collect_mclassdefs
(mmodule
).has
(mclass
.intro
)
1522 # A type prefixed with "nullable"
1526 # The base type of the nullable type
1529 redef fun model
do return self.mtype
.model
1533 self.to_s
= "nullable {mtype}"
1536 redef var to_s
: String is noinit
1538 redef var full_name
is lazy
do return "nullable {mtype.full_name}"
1540 redef var c_name
is lazy
do return "nullable__{mtype.c_name}"
1542 redef fun need_anchor
do return mtype
.need_anchor
1543 redef fun as_nullable
do return self
1544 redef fun as_notnullable
do return mtype
1545 redef fun resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1547 var res
= self.mtype
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1548 return res
.as_nullable
1551 redef fun can_resolve_for
(mtype
, anchor
, mmodule
)
1553 return self.mtype
.can_resolve_for
(mtype
, anchor
, mmodule
)
1556 # Efficiently returns `mtype.lookup_fixed(mmodule, resolved_receiver).as_nullable`
1557 redef fun lookup_fixed
(mmodule
, resolved_receiver
)
1559 var t
= mtype
.lookup_fixed
(mmodule
, resolved_receiver
)
1560 if t
== mtype
then return self
1561 return t
.as_nullable
1564 redef fun depth
do return self.mtype
.depth
1566 redef fun length
do return self.mtype
.length
1568 redef fun collect_mclassdefs
(mmodule
)
1570 assert not self.need_anchor
1571 return self.mtype
.collect_mclassdefs
(mmodule
)
1574 redef fun collect_mclasses
(mmodule
)
1576 assert not self.need_anchor
1577 return self.mtype
.collect_mclasses
(mmodule
)
1580 redef fun collect_mtypes
(mmodule
)
1582 assert not self.need_anchor
1583 return self.mtype
.collect_mtypes
(mmodule
)
1587 # The type of the only value null
1589 # The is only one null type per model, see `MModel::null_type`.
1592 redef var model
: Model
1593 redef fun to_s
do return "null"
1594 redef fun full_name
do return "null"
1595 redef fun c_name
do return "null"
1596 redef fun as_nullable
do return self
1597 redef fun need_anchor
do return false
1598 redef fun resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
) do return self
1599 redef fun can_resolve_for
(mtype
, anchor
, mmodule
) do return true
1601 redef fun collect_mclassdefs
(mmodule
) do return new HashSet[MClassDef]
1603 redef fun collect_mclasses
(mmodule
) do return new HashSet[MClass]
1605 redef fun collect_mtypes
(mmodule
) do return new HashSet[MClassType]
1608 # A signature of a method
1612 # The each parameter (in order)
1613 var mparameters
: Array[MParameter]
1615 # The return type (null for a procedure)
1616 var return_mtype
: nullable MType
1621 var t
= self.return_mtype
1622 if t
!= null then dmax
= t
.depth
1623 for p
in mparameters
do
1624 var d
= p
.mtype
.depth
1625 if d
> dmax
then dmax
= d
1633 var t
= self.return_mtype
1634 if t
!= null then res
+= t
.length
1635 for p
in mparameters
do
1636 res
+= p
.mtype
.length
1641 # REQUIRE: 1 <= mparameters.count p -> p.is_vararg
1644 var vararg_rank
= -1
1645 for i
in [0..mparameters
.length
[ do
1646 var parameter
= mparameters
[i
]
1647 if parameter
.is_vararg
then
1648 assert vararg_rank
== -1
1652 self.vararg_rank
= vararg_rank
1655 # The rank of the ellipsis (`...`) for vararg (starting from 0).
1656 # value is -1 if there is no vararg.
1657 # Example: for "(a: Int, b: Bool..., c: Char)" #-> vararg_rank=1
1658 var vararg_rank
: Int is noinit
1660 # The number or parameters
1661 fun arity
: Int do return mparameters
.length
1665 var b
= new FlatBuffer
1666 if not mparameters
.is_empty
then
1668 for i
in [0..mparameters
.length
[ do
1669 var mparameter
= mparameters
[i
]
1670 if i
> 0 then b
.append
(", ")
1671 b
.append
(mparameter
.name
)
1673 b
.append
(mparameter
.mtype
.to_s
)
1674 if mparameter
.is_vararg
then
1680 var ret
= self.return_mtype
1688 redef fun resolve_for
(mtype
: MType, anchor
: nullable MClassType, mmodule
: MModule, cleanup_virtual
: Bool): MSignature
1690 var params
= new Array[MParameter]
1691 for p
in self.mparameters
do
1692 params
.add
(p
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
))
1694 var ret
= self.return_mtype
1696 ret
= ret
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1698 var res
= new MSignature(params
, ret
)
1703 # A parameter in a signature
1707 # The name of the parameter
1708 redef var name
: String
1710 # The static type of the parameter
1713 # Is the parameter a vararg?
1719 return "{name}: {mtype}..."
1721 return "{name}: {mtype}"
1725 # Returns a new parameter with the `mtype` resolved.
1726 # See `MType::resolve_for` for details.
1727 fun resolve_for
(mtype
: MType, anchor
: nullable MClassType, mmodule
: MModule, cleanup_virtual
: Bool): MParameter
1729 if not self.mtype
.need_anchor
then return self
1730 var newtype
= self.mtype
.resolve_for
(mtype
, anchor
, mmodule
, cleanup_virtual
)
1731 var res
= new MParameter(self.name
, newtype
, self.is_vararg
)
1735 redef fun model
do return mtype
.model
1738 # A service (global property) that generalize method, attribute, etc.
1740 # `MProperty` are global to the model; it means that a `MProperty` is not bound
1741 # to a specific `MModule` nor a specific `MClass`.
1743 # A MProperty gather definitions (see `mpropdefs`) ; one for the introduction
1744 # and the other in subclasses and in refinements.
1746 # A `MProperty` is used to denotes services in polymorphic way (ie. independent
1747 # of any dynamic type).
1748 # For instance, a call site "x.foo" is associated to a `MProperty`.
1749 abstract class MProperty
1752 # The associated MPropDef subclass.
1753 # The two specialization hierarchy are symmetric.
1754 type MPROPDEF: MPropDef
1756 # The classdef that introduce the property
1757 # While a property is not bound to a specific module, or class,
1758 # the introducing mclassdef is used for naming and visibility
1759 var intro_mclassdef
: MClassDef
1761 # The (short) name of the property
1762 redef var name
: String
1764 # The canonical name of the property.
1766 # It is the short-`name` prefixed by the short-name of the class and the full-name of the module.
1767 # Example: "my_project::my_module::MyClass::my_method"
1768 redef var full_name
is lazy
do
1769 return "{intro_mclassdef.mmodule.namespace_for(visibility)}::{intro_mclassdef.mclass.name}::{name}"
1772 redef var c_name
is lazy
do
1773 # FIXME use `namespace_for`
1774 return "{intro_mclassdef.mmodule.c_name}__{intro_mclassdef.mclass.name.to_cmangle}__{name.to_cmangle}"
1777 # The visibility of the property
1778 var visibility
: MVisibility
1780 # Is the property usable as an initializer?
1781 var is_autoinit
= false is writable
1785 intro_mclassdef
.intro_mproperties
.add
(self)
1786 var model
= intro_mclassdef
.mmodule
.model
1787 model
.mproperties_by_name
.add_one
(name
, self)
1788 model
.mproperties
.add
(self)
1791 # All definitions of the property.
1792 # The first is the introduction,
1793 # The other are redefinitions (in refinements and in subclasses)
1794 var mpropdefs
= new Array[MPROPDEF]
1796 # The definition that introduces the property.
1798 # Warning: such a definition may not exist in the early life of the object.
1799 # In this case, the method will abort.
1800 var intro
: MPROPDEF is noinit
1802 redef fun model
do return intro
.model
1805 redef fun to_s
do return name
1807 # Return the most specific property definitions defined or inherited by a type.
1808 # The selection knows that refinement is stronger than specialization;
1809 # however, in case of conflict more than one property are returned.
1810 # If mtype does not know mproperty then an empty array is returned.
1812 # If you want the really most specific property, then look at `lookup_first_definition`
1814 # REQUIRE: `not mtype.need_anchor` to simplify the API (no `anchor` parameter)
1815 # ENSURE: `not mtype.has_mproperty(mmodule, self) == result.is_empty`
1816 fun lookup_definitions
(mmodule
: MModule, mtype
: MType): Array[MPROPDEF]
1818 assert not mtype
.need_anchor
1819 mtype
= mtype
.as_notnullable
1821 var cache
= self.lookup_definitions_cache
[mmodule
, mtype
]
1822 if cache
!= null then return cache
1824 #print "select prop {mproperty} for {mtype} in {self}"
1825 # First, select all candidates
1826 var candidates
= new Array[MPROPDEF]
1827 for mpropdef
in self.mpropdefs
do
1828 # If the definition is not imported by the module, then skip
1829 if not mmodule
.in_importation
<= mpropdef
.mclassdef
.mmodule
then continue
1830 # If the definition is not inherited by the type, then skip
1831 if not mtype
.is_subtype
(mmodule
, null, mpropdef
.mclassdef
.bound_mtype
) then continue
1833 candidates
.add
(mpropdef
)
1835 # Fast track for only one candidate
1836 if candidates
.length
<= 1 then
1837 self.lookup_definitions_cache
[mmodule
, mtype
] = candidates
1841 # Second, filter the most specific ones
1842 return select_most_specific
(mmodule
, candidates
)
1845 private var lookup_definitions_cache
= new HashMap2[MModule, MType, Array[MPROPDEF]]
1847 # Return the most specific property definitions inherited by a type.
1848 # The selection knows that refinement is stronger than specialization;
1849 # however, in case of conflict more than one property are returned.
1850 # If mtype does not know mproperty then an empty array is returned.
1852 # If you want the really most specific property, then look at `lookup_next_definition`
1854 # REQUIRE: `not mtype.need_anchor` to simplify the API (no `anchor` parameter)
1855 # ENSURE: `not mtype.has_mproperty(mmodule, self) implies result.is_empty`
1856 fun lookup_super_definitions
(mmodule
: MModule, mtype
: MType): Array[MPROPDEF]
1858 assert not mtype
.need_anchor
1859 mtype
= mtype
.as_notnullable
1861 # First, select all candidates
1862 var candidates
= new Array[MPROPDEF]
1863 for mpropdef
in self.mpropdefs
do
1864 # If the definition is not imported by the module, then skip
1865 if not mmodule
.in_importation
<= mpropdef
.mclassdef
.mmodule
then continue
1866 # If the definition is not inherited by the type, then skip
1867 if not mtype
.is_subtype
(mmodule
, null, mpropdef
.mclassdef
.bound_mtype
) then continue
1868 # If the definition is defined by the type, then skip (we want the super, so e skip the current)
1869 if mtype
== mpropdef
.mclassdef
.bound_mtype
and mmodule
== mpropdef
.mclassdef
.mmodule
then continue
1871 candidates
.add
(mpropdef
)
1873 # Fast track for only one candidate
1874 if candidates
.length
<= 1 then return candidates
1876 # Second, filter the most specific ones
1877 return select_most_specific
(mmodule
, candidates
)
1880 # Return an array containing olny the most specific property definitions
1881 # This is an helper function for `lookup_definitions` and `lookup_super_definitions`
1882 private fun select_most_specific
(mmodule
: MModule, candidates
: Array[MPROPDEF]): Array[MPROPDEF]
1884 var res
= new Array[MPROPDEF]
1885 for pd1
in candidates
do
1886 var cd1
= pd1
.mclassdef
1889 for pd2
in candidates
do
1890 if pd2
== pd1
then continue # do not compare with self!
1891 var cd2
= pd2
.mclassdef
1893 if c2
.mclass_type
== c1
.mclass_type
then
1894 if cd2
.mmodule
.in_importation
< cd1
.mmodule
then
1895 # cd2 refines cd1; therefore we skip pd1
1899 else if cd2
.bound_mtype
.is_subtype
(mmodule
, null, cd1
.bound_mtype
) and cd2
.bound_mtype
!= cd1
.bound_mtype
then
1900 # cd2 < cd1; therefore we skip pd1
1909 if res
.is_empty
then
1910 print
"All lost! {candidates.join(", ")}"
1911 # FIXME: should be abort!
1916 # Return the most specific definition in the linearization of `mtype`.
1918 # If you want to know the next properties in the linearization,
1919 # look at `MPropDef::lookup_next_definition`.
1921 # FIXME: the linearization is still unspecified
1923 # REQUIRE: `not mtype.need_anchor` to simplify the API (no `anchor` parameter)
1924 # REQUIRE: `mtype.has_mproperty(mmodule, self)`
1925 fun lookup_first_definition
(mmodule
: MModule, mtype
: MType): MPROPDEF
1927 return lookup_all_definitions
(mmodule
, mtype
).first
1930 # Return all definitions in a linearization order
1931 # Most specific first, most general last
1933 # REQUIRE: `not mtype.need_anchor` to simplify the API (no `anchor` parameter)
1934 # REQUIRE: `mtype.has_mproperty(mmodule, self)`
1935 fun lookup_all_definitions
(mmodule
: MModule, mtype
: MType): Array[MPROPDEF]
1937 mtype
= mtype
.as_notnullable
1939 var cache
= self.lookup_all_definitions_cache
[mmodule
, mtype
]
1940 if cache
!= null then return cache
1942 assert not mtype
.need_anchor
1943 assert mtype
.has_mproperty
(mmodule
, self)
1945 #print "select prop {mproperty} for {mtype} in {self}"
1946 # First, select all candidates
1947 var candidates
= new Array[MPROPDEF]
1948 for mpropdef
in self.mpropdefs
do
1949 # If the definition is not imported by the module, then skip
1950 if not mmodule
.in_importation
<= mpropdef
.mclassdef
.mmodule
then continue
1951 # If the definition is not inherited by the type, then skip
1952 if not mtype
.is_subtype
(mmodule
, null, mpropdef
.mclassdef
.bound_mtype
) then continue
1954 candidates
.add
(mpropdef
)
1956 # Fast track for only one candidate
1957 if candidates
.length
<= 1 then
1958 self.lookup_all_definitions_cache
[mmodule
, mtype
] = candidates
1962 mmodule
.linearize_mpropdefs
(candidates
)
1963 candidates
= candidates
.reversed
1964 self.lookup_all_definitions_cache
[mmodule
, mtype
] = candidates
1968 private var lookup_all_definitions_cache
= new HashMap2[MModule, MType, Array[MPROPDEF]]
1975 redef type MPROPDEF: MMethodDef
1977 # Is the property defined at the top_level of the module?
1978 # Currently such a property are stored in `Object`
1979 var is_toplevel
: Bool = false is writable
1981 # Is the property a constructor?
1982 # Warning, this property can be inherited by subclasses with or without being a constructor
1983 # therefore, you should use `is_init_for` the verify if the property is a legal constructor for a given class
1984 var is_init
: Bool = false is writable
1986 # The constructor is a (the) root init with empty signature but a set of initializers
1987 var is_root_init
: Bool = false is writable
1989 # Is the property a 'new' constructor?
1990 var is_new
: Bool = false is writable
1992 # Is the property a legal constructor for a given class?
1993 # As usual, visibility is not considered.
1994 # FIXME not implemented
1995 fun is_init_for
(mclass
: MClass): Bool
2001 # A global attribute
2005 redef type MPROPDEF: MAttributeDef
2009 # A global virtual type
2010 class MVirtualTypeProp
2013 redef type MPROPDEF: MVirtualTypeDef
2015 # The formal type associated to the virtual type property
2016 var mvirtualtype
= new MVirtualType(self)
2019 # A definition of a property (local property)
2021 # Unlike `MProperty`, a `MPropDef` is a local definition that belong to a
2022 # specific class definition (which belong to a specific module)
2023 abstract class MPropDef
2026 # The associated `MProperty` subclass.
2027 # the two specialization hierarchy are symmetric
2028 type MPROPERTY: MProperty
2031 type MPROPDEF: MPropDef
2033 # The class definition where the property definition is
2034 var mclassdef
: MClassDef
2036 # The associated global property
2037 var mproperty
: MPROPERTY
2039 # The origin of the definition
2040 var location
: Location
2044 mclassdef
.mpropdefs
.add
(self)
2045 mproperty
.mpropdefs
.add
(self)
2046 if mproperty
.intro_mclassdef
== mclassdef
then
2047 assert not isset mproperty
._intro
2048 mproperty
.intro
= self
2050 self.to_s
= "{mclassdef}#{mproperty}"
2053 # Actually the name of the `mproperty`
2054 redef fun name
do return mproperty
.name
2056 # The full-name of mpropdefs combine the information about the `classdef` and the `mproperty`.
2058 # Therefore the combination of identifiers is awful,
2059 # the worst case being
2061 # * a property "p::m::A::x"
2062 # * redefined in a refinement of a class "q::n::B"
2063 # * in a module "r::o"
2064 # * so "r::o#q::n::B#p::m::A::x"
2066 # Fortunately, the full-name is simplified when entities are repeated.
2067 # For the previous case, the simplest form is "p#A#x".
2068 redef var full_name
is lazy
do
2069 var res
= new FlatBuffer
2071 # The first part is the mclassdef. Worst case is "r::o#q::n::B"
2072 res
.append mclassdef
.full_name
2076 if mclassdef
.mclass
== mproperty
.intro_mclassdef
.mclass
then
2077 # intro are unambiguous in a class
2080 # Just try to simplify each part
2081 if mclassdef
.mmodule
.mproject
!= mproperty
.intro_mclassdef
.mmodule
.mproject
then
2082 # precise "p::m" only if "p" != "r"
2083 res
.append mproperty
.intro_mclassdef
.mmodule
.full_name
2085 else if mproperty
.visibility
<= private_visibility
then
2086 # Same project ("p"=="q"), but private visibility,
2087 # does the module part ("::m") need to be displayed
2088 if mclassdef
.mmodule
.namespace_for
(mclassdef
.mclass
.visibility
) != mproperty
.intro_mclassdef
.mmodule
.mproject
then
2090 res
.append mproperty
.intro_mclassdef
.mmodule
.name
2094 if mclassdef
.mclass
!= mproperty
.intro_mclassdef
.mclass
then
2095 # precise "B" only if not the same class than "A"
2096 res
.append mproperty
.intro_mclassdef
.name
2099 # Always use the property name "x"
2100 res
.append mproperty
.name
2105 redef var c_name
is lazy
do
2106 var res
= new FlatBuffer
2107 res
.append mclassdef
.c_name
2109 if mclassdef
.mclass
== mproperty
.intro_mclassdef
.mclass
then
2110 res
.append name
.to_cmangle
2112 if mclassdef
.mmodule
!= mproperty
.intro_mclassdef
.mmodule
then
2113 res
.append mproperty
.intro_mclassdef
.mmodule
.c_name
2116 if mclassdef
.mclass
!= mproperty
.intro_mclassdef
.mclass
then
2117 res
.append mproperty
.intro_mclassdef
.name
.to_cmangle
2120 res
.append mproperty
.name
.to_cmangle
2125 redef fun model
do return mclassdef
.model
2127 # Internal name combining the module, the class and the property
2128 # Example: "mymodule#MyClass#mymethod"
2129 redef var to_s
: String is noinit
2131 # Is self the definition that introduce the property?
2132 fun is_intro
: Bool do return mproperty
.intro
== self
2134 # Return the next definition in linearization of `mtype`.
2136 # This method is used to determine what method is called by a super.
2138 # REQUIRE: `not mtype.need_anchor`
2139 fun lookup_next_definition
(mmodule
: MModule, mtype
: MType): MPROPDEF
2141 assert not mtype
.need_anchor
2143 var mpropdefs
= self.mproperty
.lookup_all_definitions
(mmodule
, mtype
)
2144 var i
= mpropdefs
.iterator
2145 while i
.is_ok
and i
.item
!= self do i
.next
2146 assert has_property
: i
.is_ok
2148 assert has_next_property
: i
.is_ok
2153 # A local definition of a method
2157 redef type MPROPERTY: MMethod
2158 redef type MPROPDEF: MMethodDef
2160 # The signature attached to the property definition
2161 var msignature
: nullable MSignature = null is writable
2163 # The signature attached to the `new` call on a root-init
2164 # This is a concatenation of the signatures of the initializers
2166 # REQUIRE `mproperty.is_root_init == (new_msignature != null)`
2167 var new_msignature
: nullable MSignature = null is writable
2169 # List of initialisers to call in root-inits
2171 # They could be setters or attributes
2173 # REQUIRE `mproperty.is_root_init == (new_msignature != null)`
2174 var initializers
= new Array[MProperty]
2176 # Is the method definition abstract?
2177 var is_abstract
: Bool = false is writable
2179 # Is the method definition intern?
2180 var is_intern
= false is writable
2182 # Is the method definition extern?
2183 var is_extern
= false is writable
2185 # An optional constant value returned in functions.
2187 # Only some specific primitife value are accepted by engines.
2188 # Is used when there is no better implementation available.
2190 # Currently used only for the implementation of the `--define`
2191 # command-line option.
2192 # SEE: module `mixin`.
2193 var constant_value
: nullable Object = null is writable
2196 # A local definition of an attribute
2200 redef type MPROPERTY: MAttribute
2201 redef type MPROPDEF: MAttributeDef
2203 # The static type of the attribute
2204 var static_mtype
: nullable MType = null is writable
2207 # A local definition of a virtual type
2208 class MVirtualTypeDef
2211 redef type MPROPERTY: MVirtualTypeProp
2212 redef type MPROPDEF: MVirtualTypeDef
2214 # The bound of the virtual type
2215 var bound
: nullable MType = null is writable
2217 # Is the bound fixed?
2218 var is_fixed
= false is writable
2225 # * `interface_kind`
2229 # Note this class is basically an enum.
2230 # FIXME: use a real enum once user-defined enums are available
2232 redef var to_s
: String
2234 # Is a constructor required?
2237 # TODO: private init because enumeration.
2239 # Can a class of kind `self` specializes a class of kine `other`?
2240 fun can_specialize
(other
: MClassKind): Bool
2242 if other
== interface_kind
then return true # everybody can specialize interfaces
2243 if self == interface_kind
or self == enum_kind
then
2244 # no other case for interfaces
2246 else if self == extern_kind
then
2247 # only compatible with themselves
2248 return self == other
2249 else if other
== enum_kind
or other
== extern_kind
then
2250 # abstract_kind and concrete_kind are incompatible
2253 # remain only abstract_kind and concrete_kind
2258 # The class kind `abstract`
2259 fun abstract_kind
: MClassKind do return once
new MClassKind("abstract class", true)
2260 # The class kind `concrete`
2261 fun concrete_kind
: MClassKind do return once
new MClassKind("class", true)
2262 # The class kind `interface`
2263 fun interface_kind
: MClassKind do return once
new MClassKind("interface", false)
2264 # The class kind `enum`
2265 fun enum_kind
: MClassKind do return once
new MClassKind("enum", false)
2266 # The class kind `extern`
2267 fun extern_kind
: MClassKind do return once
new MClassKind("extern class", false)