type

Type

src const class Type : Obj

Type defines the contract of an Obj by the slots it supports. Types model the inheritance relationships and provide a mapping for all the slots both inherited and declared.

methods

base

The direct super class of this type (null for Obj).

doc

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

emptyList

Return an immutable empty list of this type.

facet

Get a facet by its type.

facets

Get the list of facets defined on this type or return an empty list if no facets are defined.

field

Convenience for (Field)slot(name, checked)

fields

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

find

Find a Type by its qualified name "pod::Type".

fits

Does this type implement the specified type.

hasFacet

Return if this type has the specified facet defined.

inheritance

Return a recursive flattened list of all the types this type inherits from.

isAbstract

Return if this Type is abstract and cannot be instantiated.

isClass

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

isConst

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

isEnum

Return if this Type is an Enum type.

isFacet

Return if this Type is a Facet type.

isFinal

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

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.

isInternal

Return if this Type has internal protection scope.

isMixin

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

isNullable

Is this a nullable type.

isPublic

Return if this Type has public protection scope.

isSynthetic

Return if this Type was generated by the compiler.

isVal

Is this a value type.

make

Create a new instance of this Type using the following rules

method

Convenience for (Method)slot(name, checked)

methods

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

mixins

Return the mixins directly implemented by this type.

name

Simple name of the type such as "Str".

of

Get the class Type of the given instance.

parameterize

If this is a generic type, then dynamically create a new parameterized type with the specified name to type map.

params

If this is a parameterized type, then return the map of names to types.

pod

Parent pod which defines this type.

qname

Qualified name formatted as "pod::name".

signature

Return the formal signature of this type.

slot

Lookup a slot by name.

slots

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

toListOf

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

toLocale

Return signature.

toNonNullable

Return this type as a non-nullable type.

toNullable

Return this type as a nullable type.

toStr

Always return signature().

Slot Details

base

src Type? base()

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

Examples:

Obj#.base        =>  null
Int#.base        =>  sys::Num
OutStream#.base  =>  sys::Obj

doc

src Str? doc()

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

emptyList

src Obj[] emptyList()

Return an immutable empty list of this type. Since immutable lists can be used safely everywhere, this allows signficant memory savings instead of allocating new empty lists.

Examples:

Str#.emptyList  =>  Str[,]

facet

src Facet? facet(Type type, Bool checked := true)

Get a facet by its type. If not found on this type then return null or throw UnknownFacetErr based on check flag. See Facets Doc for details.

facets

src Facet[] facets()

Get the list of facets defined on this type or return an empty list if no facets are defined. If looking up a facet by type, then use the facet method which will provide better performance. See Facets Doc for details.

field

src Field? field(Str name, Bool checked := true)

Convenience for (Field)slot(name, checked)

fields

src Field[] fields()

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

find

src static Type? find(Str qname, Bool checked := true)

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

fits

src 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.

This method implicitly ignores the nullability of both this and t such that this method is always equivalent to:

this.toNonNullable.fits(t.toNonNullable)

Example:

Float#.fits(Float#) =>  true
Float#.fits(Num#)   =>  true
Float#.fits(Obj#)   =>  true
Float#.fits(Str#)   =>  false
Obj#.fits(Float#)   =>  false

hasFacet

src Bool hasFacet(Type type)

Return if this type has the specified facet defined.

inheritance

src 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#.inheritance  =>  [sys::Obj]
Int#.inheritance  =>  [sys::Int, sys::Num, sys::Obj]

isAbstract

src 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

src Bool isClass()

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

isConst

src Bool isConst()

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

isEnum

src Bool isEnum()

Return if this Type is an Enum type.

isFacet

src Bool isFacet()

Return if this Type is a Facet type.

isFinal

src Bool isFinal()

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

isGeneric

src 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. Fantom 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 Fantom.

Examples:

Str#.isGeneric   => false
List#.isGeneric  => true
Str[]#.isGeneric => false

isInternal

src Bool isInternal()

Return if this Type has internal protection scope.

isMixin

src Bool isMixin()

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

isNullable

src Bool isNullable()

Is this a nullable type. Nullable types can store the null value, but non-nullables are never null. Null types are indicated with a trailing "?".

isPublic

src Bool isPublic()

Return if this Type has public protection scope.

isSynthetic

src Bool isSynthetic()

Return if this Type was generated by the compiler.

isVal

src Bool isVal()

Is this a value type. Fantom supports three implicit value types: Bool, Int, and Float.

make

src Obj make(Obj[]? args := null)

Create a new instance of this Type using the following rules:

  1. Call public constructor make with specified arguments
  2. If no public constructor called make or invalid number of of required arguments, then return value of defVal slot (must be static field or static method with zero params)
  3. If no public defVal field, then throw Err

method

src Method? method(Str name, Bool checked := true)

Convenience for (Method)slot(name, checked)

methods

src Method[] methods()

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

mixins

src Type[] mixins()

Return the mixins directly implemented by this type.

Examples:

Obj#.mixins        =>  [,]
Buf#.mixins        =>  [sys::InStream, sys::OutStream]
OutStream#.mixins  =>  [,]

name

src 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.

Examples:

Str#.name         => "Str"
acme::Foo#.name   => "Foo"
acme::Foo[]#.name => "List"

of

src static Type of(Obj obj)

Get the class Type of the given instance. Also see Obj.typeof which provides the same functionality.

parameterize

src 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#.parameterize(["V":Bool#]) => Bool[]
Map#.parameterize(["K":Str#, "V":Obj#]) => Str:Obj

params

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

pod

src Pod? pod()

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

Examples:

Str#.pod         => sys
acme::Foo#.pod   => acme
acme::Foo[]#.pod => sys

qname

src 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. If this is a nullable type, the qname does not include the "?".

Examples:

Str#.qname         => "sys::Str"
Str?#.qname        => "sys::Str"
acme::Foo#.qname   => "acme::Foo"
acme::Foo[]#.qname => "sys::List"

signature

src Str signature()

Return the formal signature of this type. In the case of non-parameterized types the signature is the same as qname. 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|

If this is a nullable type, the signature ends with "?" such as "sys::Int?".

Examples:

Str#.signature => "sys::Str"
Str?#.signature => "sys::Str?"
Int[]#.signature => "sys::Int[]"
Int:Str#.signature => "[sys::Int:sys::Str]"
Str:Buf[]#.signature => [sys::Str:sys::Buf[]]
|Float x->Bool|#.signature => "|sys::Float->sys::Bool|"
|Float x, Int y|#.signature => |sys::Float,sys::Int->sys::Void|

slot

src Slot? slot(Str name, Bool checked := true)

Lookup a slot by name. If the slot doesn't exist and checked is false then return null, otherwise throw UnknownSlotErr. Slots are any field or method in this type's scope including those defined directly by this type and those inherited from super class or mixins.

slots

src Slot[] slots()

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

toListOf

src Type toListOf()

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

Examples:

Int#.toListOf => Int[]
Str[]#.toListOf => Str[][]

toLocale

src Str toLocale()

Return signature. This method is used to enable toLocale to be used with duck typing across most built-in types. Note: we may change the specification of this method in the future to allow localized type names.

toNonNullable

src Type toNonNullable()

Return this type as a non-nullable type. If this type is already non-nullable then return this.

toNullable

src Type toNullable()

Return this type as a nullable type. If this type is already nullable then return this.

toStr

src virtual override Str toStr()

Always return signature().