class `Crystal::VirtualType`
inherits `Crystal::Type` ¶

A virtual type represents a type or any of its subclasses. It's created automatically by the compiler when a type is used in a generic argument and it either has subtypes, or it's abstract. A virtual type never exists for a non-abstract type that doesn't have subtypes.

A virtual type is denoted, internally, with a '+' sign following the type.

class Foo
end

class Bar < Foo
end

# Here the compiler actually makes this be [] of Foo+, so the array
# can actually hold a Foo or a Bar, transparently.
ary = [] of Foo

# Here the compiler leaves it as [] of Bar, because Bar has no subclasses.
another = [] of Bar

Included modules

Crystal::ClassVarContainer Crystal::DefInstanceContainer Crystal::InstanceVarContainer Crystal::MultiType Crystal::VirtualTypeLookup

class Crystal::VirtualType inherits Crystal::Type ¶

Included modules

Class methods¶

.new(program, base_type) ¶

Methods¶

#abstract? ¶

#abstract?(*args, **options) ¶

#add_subclasses_method_missing_matches(base_type, method_missing, signature, call) ¶

#all_class_vars ¶

#all_instance_vars ¶

#all_instance_vars(*args, **options) ¶

#ancestors ¶

#ancestors(*args, **options) ¶

#append_cover(array) ¶

#base_type : Type ¶

#check_method_missing(signature, call) ¶

#collect_subtypes(type, subtypes) ¶

#common_ancestor(other) ¶

#cover ¶

#cover_size ¶

#each_concrete_type ¶

#each_cover ¶

#implements? ¶

#implements?(*args, **options) ¶

#index_of_instance_var(*args, **options) ¶

#index_of_instance_var ¶

#leaf? ¶

#leaf?(*args, **options) ¶

#lookup_class_var?(name) ¶

#lookup_defs ¶

#lookup_defs(*args, **options) ¶

#lookup_defs_with_modules ¶

#lookup_defs_with_modules(*args, **options) ¶

#lookup_first_def ¶

#lookup_first_def(*args, **options) ¶

#lookup_instance_var(*args, **options) ¶

#lookup_instance_var ¶

#lookup_instance_var? ¶

#lookup_instance_var?(*args, **options) ¶

#lookup_macro ¶

#lookup_macro(*args, **options) ¶

#lookup_macros ¶

#lookup_macros(*args, **options) ¶

#lookup_path ¶

#lookup_path(*args, **options) ¶

#lookup_similar_def(*args, **options) ¶

#lookup_similar_def ¶

#lookup_similar_path(*args, **options) ¶

#lookup_similar_path ¶

#metaclass ¶

#name ¶

#remove_indirection ¶

#replace_type_parameters(instance) ¶

#restrict(other : Generic, context) ¶

#restrict(other : Type, context) ¶

#restriction_of?(other : Type, owner, strict = false) ¶

#struct? ¶

#struct?(*args, **options) ¶

#subtypes ¶

#subtypes(type) ¶

#superclass(*args, **options) ¶

#superclass ¶

#to_s_with_options(io : IO, skip_union_parens : Bool = false, generic_args : Bool = true, codegen : Bool = false) : Nil ¶

#type_var? ¶

#type_var?(*args, **options) ¶

class `Crystal::VirtualType`
inherits `Crystal::Type` ¶

`.new(program, base_type)` ¶

`#abstract?` ¶

`#abstract?(*args, **options)` ¶

`#add_subclasses_method_missing_matches(base_type, method_missing, signature, call)` ¶

`#all_class_vars` ¶

`#all_instance_vars` ¶

`#all_instance_vars(*args, **options)` ¶

`#ancestors` ¶

`#ancestors(*args, **options)` ¶

`#append_cover(array)` ¶

`#base_type : Type` ¶

`#check_method_missing(signature, call)` ¶

`#collect_subtypes(type, subtypes)` ¶

`#common_ancestor(other)` ¶

`#cover` ¶

`#cover_size` ¶

`#each_concrete_type` ¶

`#each_cover` ¶

`#implements?` ¶

`#implements?(*args, **options)` ¶

`#index_of_instance_var(*args, **options)` ¶

`#index_of_instance_var` ¶

`#leaf?` ¶

`#leaf?(*args, **options)` ¶

`#lookup_class_var?(name)` ¶

`#lookup_defs` ¶

`#lookup_defs(*args, **options)` ¶

`#lookup_defs_with_modules` ¶

`#lookup_defs_with_modules(*args, **options)` ¶

`#lookup_first_def` ¶

`#lookup_first_def(*args, **options)` ¶

`#lookup_instance_var(*args, **options)` ¶

`#lookup_instance_var` ¶

`#lookup_instance_var?` ¶

`#lookup_instance_var?(*args, **options)` ¶

`#lookup_macro` ¶

`#lookup_macro(*args, **options)` ¶

`#lookup_macros` ¶

`#lookup_macros(*args, **options)` ¶

`#lookup_path` ¶

`#lookup_path(*args, **options)` ¶

`#lookup_similar_def(*args, **options)` ¶

`#lookup_similar_def` ¶

`#lookup_similar_path(*args, **options)` ¶

`#lookup_similar_path` ¶

`#metaclass` ¶

`#name` ¶

`#remove_indirection` ¶

`#replace_type_parameters(instance)` ¶

`#restrict(other : Generic, context)` ¶

`#restrict(other : Type, context)` ¶

`#restriction_of?(other : Type, owner, strict = false)` ¶

`#struct?` ¶

`#struct?(*args, **options)` ¶

`#subtypes` ¶

`#subtypes(type)` ¶

`#superclass(*args, **options)` ¶

`#superclass` ¶

`#to_s_with_options(io : IO, skip_union_parens : Bool = false, generic_args : Bool = true, codegen : Bool = false) : Nil` ¶

`#type_var?` ¶

`#type_var?(*args, **options)` ¶