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
|
# ObjectBuilder is a class to help you build Ruby-based configuration syntaxes.
# You can use it to make "builder" classes to help build particular types
# of objects, typically translating simple command-based syntax to creating
# classes and setting attributes. e.g. here is a description of a day at
# the zoo:
#
# person "Alice"
# person "Matthew"
#
# zoo("London") {
# enclosure("Butterfly House") {
#
# has_roof
# allow_visitors
#
# animals("moth", 10) {
# wings 2
# legs 2
# }
#
# animals("butterfly", 200) {
# wings 2
# legs 2
# }
# }
#
# enclosure("Aquarium") {
# no_roof
#
# animal("killer whale") {
# called "Shamu"
# wings 0
# legs 0
# tail
# }
# }
# }
#
# Here is the basic builder class for a Zoo...
#
# TODO: finish this convoluted example, if it kills me
#
class ObjectBuilder
class BuildException < Exception; end
attr_reader :result
def initialize(context, *args)
@context = context
builder_setup(*args)
end
def anonymous_name
@@sequence ||= 0 # not inherited, don't want it to be
@@sequence += 1
"anon.#{Time.now.to_i}.#{@@sequence}"
end
class << self
def is_builder(word, clazz)
define_method(word.to_sym) do |*args, &block|
builder = clazz.new(*([@context] + args))
builder.instance_eval(&block) if block
["created_#{word}", "created"].each do |created_method|
created_method = created_method.to_sym
if respond_to?(created_method)
__send__(created_method, builder.result)
break
end
end
end
end
# FIXME: implement is_builder_deferred to create object at end of block?
def is_block_attribute(word)
define_method(word.to_sym) do |*args, &block|
@result.__send__("#{word}=".to_sym, block)
end
end
def is_attribute(word)
define_method(word.to_sym) do |*args, &block|
@result.__send__("#{word}=".to_sym, args[0])
end
end
def is_flag_attribute(word)
define_method(word.to_sym) do |*args, &block|
@result.__send__("#{word}=".to_sym, true)
end
end
def load(file)
builder = self.new
builder.instance_eval(File.read(file), file)
builder.result
end
def inherited(*args)
initialize_class
end
def initialize_class
@words = {}
end
end
initialize_class
end
|
