class Crystal::Macros::TypeNode

Overview

Represents a type in the program, like Int32 or String.

Defined in:

compiler/crystal/macros.cr

Instance Method Summary

Instance Method Detail

def <(other : TypeNode) : BoolLiteralSource

Returns true if other is an ancestor of self.

def <=(other : TypeNode) : BoolLiteralSource

Returns true if self is the same as other or if other is an ancestor of self.

def >(other : TypeNode) : BoolLiteralSource

Returns true if self is an ancestor of other.

def >=(other : TypeNode) : BoolLiteralSource

Returns true if other is the same as self or if self is an ancestor of other.

def [](key : SymbolLiteral | MacroId) : TypeNode | NilLiteralSource

Returns the type for the given key in this named tuple type. Gives a compile error if this is not a named tuple type.

def abstract? : BoolLiteralSource

Returns true if self is abstract, otherwise false.

module One; end

abstract struct Two; end

class Three; end

abstract class Four; end

{{One.abstract?}}   # => false
{{Two.abstract?}}   # => true
{{Three.abstract?}} # => false
{{Four.abstract?}}  # => true

def all_subclasses : ArrayLiteral(TypeNode)Source

Returns all subclasses of this type.

def ancestors : ArrayLiteral(TypeNode)Source

Returns all ancestors of this type.

def annotation(type : TypeNode) : Annotation | NilLiteralSource

Returns the last Annotation with the given type attached to this variable or NilLiteral if there are none.

def annotations(type : TypeNode) : ArrayLiteral(Annotation)Source

Returns an array of annotations with the given type attached to this variable, or an empty ArrayLiteral if there are none.

def class : TypeNodeSource

Returns the class of this type. With this you can, for example, obtain class methods by invoking type.class.methods.

def class? : BoolLiteralSource

Returns true if self is a #class, otherwise false.

module One; end

class Two; end

struct Three; end

{{One.class?}}   # => false
{{Two.class?}}   # => true
{{Three.class?}} # => false

def class_vars : ArrayLiteral(MetaVar)Source

Returns the class variables of this type.

def constant(name : StringLiteral | SymbolLiteral | MacroId) : ASTNodeSource

Returns a constant defined in this type.

If the constant is a constant (like A = 1), then its value as an ASTNode is returned. If the constant is a type, the type is returned as a TypeNode. Otherwise, NilLiteral is returned.

def constants : ArrayLiteral(MacroId)Source

Returns the constants and types defined by this type.

def has_constant?(name : StringLiteral | SymbolLiteral) : BoolLiteralSource

Returns true if this type has a constant. For example DEFAULT_OPTIONS (the name you pass to this method is "DEFAULT_OPTIONS" or :DEFAULT_OPTIONS in this cases).

def has_method?(name : StringLiteral | SymbolLiteral) : BoolLiteralSource

Returns true if this type has a method. For example default_options (the name you pass to this method is "default_options" or :default_options in this cases).

def includers : ArrayLiteral(TypeNode)Source

Returns all the types self is directly included in.

def instance : TypeNodeSource

Returns the instance type of this type, if it's a class type, or self otherwise. This is the opposite of #class.

def instance_vars : ArrayLiteral(MetaVar)Source

Returns the instance variables of this type. Can only be called from within methods (not top-level code), otherwise will return an empty list.

def keys : ArrayLiteral(MacroId)Source

Returns the keys in this named tuple type. Gives a compile error if this is not a named tuple type.

def methods : ArrayLiteral(Def)Source

Returns the instance methods defined by this type, without including inherited methods.

def module? : BoolLiteralSource

Returns true if self is a module, otherwise false.

module One; end

class Two; end

struct Three; end

{{One.module?}}   # => true
{{Two.module?}}   # => false
{{Three.module?}} # => false

def name(*, generic_args : BoolLiteral = true) : MacroIdSource

Returns the fully qualified name of this type. Optionally without generic_args if self is a generic type; see #type_vars.

class Foo(T); end

module Bar::Baz; end

{{Bar::Baz.name}}                 # => Bar::Baz
{{Foo.name}}                      # => Foo(T)
{{Foo.name(generic_args: false)}} # => Foo

def nilable? : BoolLiteralSource

Returns true if self is nilable (if it has Nil amongst its types), otherwise false.

{{String.nilable?}}                   # => false
{{String?.nilable?}}                  # => true
{{Union(String, Bool, Nil).nilable?}} # => true

def overrides?(type : TypeNode, method : StringLiteral | SymbolLiteral | MacroId) : BoolSource

Determines if self overrides any method named method from type type.

class Foo
  def one
    1
  end

  def two
    2
  end
end

class Bar < Foo
  def one
    11
  end
end

{{ Bar.overrides?(Foo, "one") }} # => true
{{ Bar.overrides?(Foo, "two") }} # => false

def resolve : TypeNodeSource

Returns self. This method exists so you can safely call #resolve on a node and resolve it to a type, even if it's a type already.

def resolve? : TypeNodeSource

Returns self. This method exists so you can safely call #resolve on a node and resolve it to a type, even if it's a type already.

def size : NumberLiteralSource

Returns the number of elements in this tuple type or tuple metaclass type. Gives a compile error if this is not one of those types.

def struct? : BoolLiteralSource

Returns true if self is a struct, otherwise false.

module One; end

class Two; end

struct Three; end

{{One.struct?}}   # => false
{{Two.struct?}}   # => false
{{Three.struct?}} # => true

def subclasses : ArrayLiteral(TypeNode)Source

Returns the direct subclasses of this type.

def superclass : TypeNode | NilLiteralSource

Returns the direct superclass of this type.

def type_vars : ArrayLiteral(TypeNode)Source

Returns the type variables of the generic type. If the type is not generic, an empty array is returned.

def union? : BoolLiteralSource

Returns true if self is a union type, otherwise false.

See also: #union_types.

{{String.union?}}              # => false
{{String?.union?}}             # => true
{{Union(String, Bool).union?}} # => true

def union_types : ArrayLiteral(TypeNode)Source

Returns the types forming a union type, if this is a union type. Otherwise returns this single type inside an array literal (so you can safely call #union_types on any type and treat all types uniformly).

See also: #union?.

© 2012–2021 Manas Technology Solutions.
Licensed under the Apache License, Version 2.0.
https://crystal-lang.org/api/1.2.1/Crystal/Macros/TypeNode.html