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class

sys::Type

sys::Obj
  sys::Type

Type defines the contract of an Obj by the slots its supports. Types model the inheritance relationships and provide a mapping for all the slots both inherited and declared. You can create new types at runtime via the Type.makeDynamic constructor.

Slots

add

Void add(Slot slot)

Add a new slot to a dynamic type. If not a dynamic type or a duplicate slot name exists, then throw Err.

Refer to Dynamic Types for more details.

base

Type base()

The direct super class of this type (null for Obj). Return sys::Obj for all mixin types.

Examples:

Obj.type.base -> null
Int.type.base -> sys::Num
OutStream.type.base -> sys::Obj
doc

Str doc()

Return the raw fandoc for this type or null if not available.

facet

Obj facet(Str name, Obj def := def, Bool inherited := def)

Get a facet by name, or return the def is the facet is not defined. If inherited is true, then this type's inheritance chain is searched. See the Facets Doc for details.

facets

Str:Obj facets(Bool inherited := def)

Return all the facets defined for this slot or an empty map if no facets are defined. If inherited is true, then this method returns a map of all the facets of this type's inheritance. If looking up a facet by name, then use the facet method which will provide better performance. See the Facets Doc for details.

field

Field field(Str name, Bool checked := def)

Convenience for (Field)slot(name, checked)

fields

Field[] fields()

List of the all defined fields (including inherited fields).

find

static Type find(Str qname, Bool checked := def)

Find a Type by it's qualified name "pod::Type". If the type doesn't exist and checked is false then return null, otherwise throw UnknownTypeErr.

findByFacet

static Type[] findByFacet(Str facetName, Obj facetVal, Obj options := def)

Find all the types annotated with the specified facet name/value pair. The facet name must be declared as an indexed facet by an installed pod, otherwise Err is thrown. Return an empty list of no matches found.

If facetVal is a Type, then you may pass true for options to check facetVals inheritance hierarchy.

See Facet Indexing for details.

fits

Bool fits(Type t)

Does this type implement the specified type. If true, then this type is assignable to the specified type (although the converse is not necessarily true). This method provides the same semantics as the is operator, but between two types rather than an instance and a type. All types (including mixin types) fit sys::Obj.

Example:

Float.type.fits(Float.type) -> true
Float.type.fits(Num.type)  -> true
Float.type.fits(Obj.type)  -> true
Float.type.fits(Str.type)  -> false
Obj.type.fits(Float.type)  -> false
inheritance

Type[] inheritance()

Return a recursive flattened list of all the types this type inherits from. The result list always includes this type itself. The result of this method represents the complete list of types implemented by this type - instances of this type are assignable to any type in this list. All types (including mixins) will include sys::Obj in this list.

Examples:

Obj.type.inheritance -> [sys::Obj]
Int.type.inheritance -> [sys::Int, sys::Num, sys::Obj]
isAbstract

Bool isAbstract()

Return if this Type is abstract and cannot be instantiated. This method will always return true if the type is a mixin.

isClass

Bool isClass()

Return if this Type is a class (as opposed to enum or mixin)

isConst

Bool isConst()

Return if this is a const class which means instances of this class are immutable.

isDynamic

Bool isDynamic()

Return if this is a dynamic type which was created at runtime via the Type.makeDynamic method.

isEnum

Bool isEnum()

Return if this Type is an Enum type.

isFinal

Bool isFinal()

Return if this Type is marked final which means it may not be subclassed.

isGeneric

Bool isGeneric()

A generic type contains slot signatures which may be parameterized - for example Map's key and value types are generic as K and V. Fan supports three built-in generic types: List, Map, and Func. A parameterized type such as Str[] is not a generic type (all of its generic parameters have been filled in). User defined generic types are not supported in Fan.

Examples:

Str.type.isGeneric   -> false
List.type.isGeneric  -> true
Str[].type.isGeneric -> false
isInternal

Bool isInternal()

Return if this Type has internal protection scope.

isMixin

Bool isMixin()

Return if this Type is a mixin type and cannot be instantiated.

isPublic

Bool isPublic()

Return if this Type has public protection scope.

isSynthetic

Bool isSynthetic()

Return if this Type was generated by the compiler.

make

Obj make(Obj[] args := def)

Create a new instance of this Type using a public constructor called "make". Throw Err if public constructor "make" is not available.

makeDynamic

new makeDynamic(Type[] supers, Str:Obj facets := def)

Make a dynamic type which implements the specified list of existing types. Only one class type may be specified and it must be the first item in the list. All other types must be mixins. None of the supers may be dynamic, abstract, final, or const.

Refer to Dynamic Types for more details.

NOTE: creating dynamics using mixins is not supported yet.

method

Method method(Str name, Bool checked := def)

Convenience for (Method)slot(name, checked)

methods

Method[] methods()

List of the all defined methods (including inherited methods).

mixins

Type[] mixins()

Return the mixins directly implemented by this type.

Examples:

Obj.type.mixins -> [,]
Buf.type.mixins -> [sys::InStream, sys::OutStream]
OutStream.type.mixins -> [,]
name

Str name()

Simple name of the type such as "Str". For parameterized types derived from List, Map, or Func, this method always returns "List", "Map", or "Func" respectively. Return "dynamic" if dynamic type.

Examples:

Str.type.name         -> "Str"
acme::Foo.type.name   -> "Foo"
acme::Foo[].type.name -> "List"
parameterize

Type parameterize(Str:Type params)

If this is a generic type, then dynamically create a new parameterized type with the specified name to type map. If this type is not generic then throw UnsupportedErr. Throw ArgErr if params fails to specify the required parameters:

List -> V required
Map  -> K, V required
Func -> R required, A-H optional

Examples:

List.type.parameterize(["V":Bool.type]) -> Bool[]
Map.type.parameterize(["K":Str.type, "V":Obj.type]) -> Str:Obj
params

Str:Type params()

If this is a parameterized type, then return the map of names to types. If this is not a parameterized type return an empty map.

Examples:

Str.type.params -> [:]
Str[].type.params -> ["V":Str, "L":Str[]]
Int:Slot.type.params -> ["K":Int, "V":Slot, "M":Int:Slot]
|Int x, Float y->Bool|.type.params -> ["A":Int, "B":Float, "R":Bool]
pod

Pod pod()

Parent pod which defines this type. For parameterized types derived from List, Map, or Func, this method always returns the sys pod. Return null if dynamic type.

Examples:

Str.type.pod         -> sys
acme::Foo.type.pod   -> acme
acme::Foo[].type.pod -> sys
qname

Str qname()

Qualified name formatted as "pod::name". For parameterized types derived from List, Map, or Func, this method always returns "sys::List", "sys::Map", or "sys::Func" respectively. Return "dynamic" if dynamic type.

Examples:

Str.type.qname         -> "sys::Str"
acme::Foo.type.qname   -> "acme::Foo"
acme::Foo[].type.qname -> "sys::List"
remove

Void remove(Slot slot)

Remove a slot from a dynamic type. If not a dynamic type or the slot is inherited, then throw Err.

Refer to Dynamic Types for more details.

signature

Str signature()

Return the formal signature of this type. In the case of non-parameterized types the signature is the same as qname. Return "dynamic" if dynamic type. For parameterized types derived from List, Map, or Func the signature uses the following special syntax:

List -> V[]
Map  -> [K:V]
Func -> |A,B...->R|

Examples:

Str.type.signature -> "sys::Str"
Int[].type.signature -> "sys::Int[]"
Int:Str.type.signature -> "[sys::Int:sys::Str]"
Str:Buf[].type.signature -> [sys::Str:sys::Buf[]]
|Float x->Bool|.type.signature -> "|sys::Float->sys::Bool|"
|Float x, Int y|.type.signature -> |sys::Float,sys::Int->sys::Void|
slot

Slot slot(Str name, Bool checked := def)

Lookup a slot by name. If the slot doesn't exist and checked is false then return null, otherwise throw UnknownSlotErr.

slots

Slot[] slots()

List of the all defined slots, both fields and methods (including inherited slots).

toListOf

Type toListOf()

Convenience for List.type.parameterize(["V":this])

Examples:

Int.type.toListOf -> Int[]
Str[].type.toListOf -> Str[][]
toStr

override Str toStr()

Always return signature().