Type

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.

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

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

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[,]

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.

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.

Convenience for (Field)slot(name, checked)

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

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.

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

Return if this type has the specified facet defined.

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]

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

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

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

Return if this Type is an Enum type.

Return if this Type is a Facet type.

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

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

Return if this Type has internal protection scope.

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

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 "?".

Return if this Type has public protection scope.

Return if this Type was generated by the compiler.

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

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

Convenience for (Method)slot(name, checked)

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

Return the mixins directly implemented by this type.

Examples:

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

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"

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

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

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]

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

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"

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|

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.

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

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

Examples:

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

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.

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

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

Always return signature().