Class: ModelSet::Conditions

Inherits:
Object
  • Object
show all
Defined in:
lib/model_set/conditions.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(conditions, ops) ⇒ Conditions

Returns a new instance of Conditions.



11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
 
# File 'lib/model_set/conditions.rb', line 11

def initialize(conditions, ops)
  @ops = ops
  if conditions.kind_of?(Array)
    @operator = conditions.first.kind_of?(Symbol) ? conditions.shift : :and
    if @operator == :not
      # In this case, :not actually means :and :not.
      @conditions = ~Conditions.new([:and, conditions], @ops)
    else
      raise "invalid operator :#{operator}" unless [:and, :or].include?(@operator)
      # Compact the conditions if possible.
      @conditions = []
      conditions.each do |clause|
        self << clause
      end
    end
  else
    @conditions = [conditions]
  end
end

Instance Attribute Details

#conditions ⇒ Object (readonly)

Returns the value of attribute conditions.



5
6
7
 
# File 'lib/model_set/conditions.rb', line 5

def conditions
  @conditions
end

#operator ⇒ Object (readonly)

Returns the value of attribute operator.



5
6
7
 
# File 'lib/model_set/conditions.rb', line 5

def operator
  @operator
end

Instance Method Details

#&(other) ⇒ Object 



61
62
63
 
# File 'lib/model_set/conditions.rb', line 61

def &(other)
  new(:and, self, other)
end

#<<(clause) ⇒ Object 



35
36
37
38
39
40
41
42
43
44
45
46
47
 
# File 'lib/model_set/conditions.rb', line 35

def <<(clause)
  return self unless clause
  raise 'cannot append conditions to a terminal' if terminal?

  clause = new(clause, @ops) unless clause.kind_of?(Conditions)
  if clause.operator == operator
    @conditions.concat(clause.conditions)
  else
    @conditions << clause
  end
  @conditions.uniq!
  self
end

#eql?(other) ⇒ Boolean

Returns:

  • (Boolean) 


91
92
93
94
 
# File 'lib/model_set/conditions.rb', line 91

def eql?(other)
  # for uniq
  self.hash == other.hash
end

#hash ⇒ Object 



86
87
88
89
 
# File 'lib/model_set/conditions.rb', line 86

def hash
  # for uniq
  [operator, conditions].hash
end

#new(*args) ⇒ Object 



7
8
9
 
# File 'lib/model_set/conditions.rb', line 7

def new(*args)
  self.class.new(*args)
end

#op(type) ⇒ Object 



65
66
67
 
# File 'lib/model_set/conditions.rb', line 65

def op(type)
  @ops[type]
end

#terminal? ⇒ Boolean

Returns:

  • (Boolean) 


31
32
33
 
# File 'lib/model_set/conditions.rb', line 31

def terminal?
  operator.nil?
end

#to_s ⇒ Object 



69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
 
# File 'lib/model_set/conditions.rb', line 69

def to_s
  return conditions.first.to_s if terminal? or conditions.empty?

  condition_strings = conditions.collect do |condition|
    condition.operator == :not ? condition.to_s : "(#{condition.to_s})"
  end.sort_by {|s| s.size}

  case operator
  when :not then
    "#{op(:not)} #{condition_strings.first}"
  when :and then
    "#{condition_strings.join(op(:and))}"
  when :or then
    "#{condition_strings.join(op(:or))}"
  end
end

#|(other) ⇒ Object 



57
58
59
 
# File 'lib/model_set/conditions.rb', line 57

def |(other)
  new(:or, self, other)
end

#~ ⇒ Object 



49
50
51
52
53
54
55
 
# File 'lib/model_set/conditions.rb', line 49

def ~
  if operator == :not
    conditions.first.clone
  else
    new(:not, self)
  end
end