1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
|
# frozen_string_literal: true
module Unparser
# Module to allow class and methods to be abstract
#
# Original code before vendoring and reduction from: https://github.com/dkubb/abstract_type.
module AbstractType
# Hook called when module is included
#
# @param [Module] descendant
# the module or class including AbstractType
#
# @return [undefined]
#
# @api private
def self.included(descendant)
super
create_new_method(descendant)
descendant.extend(AbstractMethodDeclarations)
end
private_class_method :included
# Define the new method on the abstract type
#
# Ensures that the instance cannot be of the abstract type
# and must be a descendant.
#
# @param [Class] abstract_class
#
# @return [undefined]
#
# @api private
def self.create_new_method(abstract_class)
abstract_class.define_singleton_method(:new) do |*args, &block|
if equal?(abstract_class)
fail NotImplementedError, "#{self} is an abstract type"
else
super(*args, &block)
end
end
end
private_class_method :create_new_method
module AbstractMethodDeclarations
# Create abstract instance methods
#
# @example
# class Foo
# include AbstractType
#
# # Create an abstract instance method
# abstract_method :some_method
# end
#
# @param [Array<#to_s>] names
#
# @return [self]
#
# @api public
def abstract_method(*names)
names.each(&method(:create_abstract_instance_method))
self
end
# Create abstract singleton methods
#
# @example
# class Foo
# include AbstractType
#
# # Create an abstract instance method
# abstract_singleton_method :some_method
# end
#
# @param [Array<#to_s>] names
#
# @return [self]
#
# @api private
def abstract_singleton_method(*names)
names.each(&method(:create_abstract_singleton_method))
self
end
private
# Create abstract singleton method
#
# @param [#to_s] name
# the name of the method to create
#
# @return [undefined]
#
# @api private
def create_abstract_singleton_method(name)
define_singleton_method(name) do |*|
fail NotImplementedError, "#{self}.#{name} is not implemented"
end
end
# Create abstract instance method
#
# @param [#to_s] name
# the name of the method to create
#
# @return [undefined]
#
# @api private
def create_abstract_instance_method(name)
define_method(name) do |*|
fail NotImplementedError, "#{self.class}##{name} is not implemented"
end
end
end # AbstractMethodDeclarations
end # AbstractType
end # Unparser
|
