Class | Sequel::SQL::Expression |
In: |
lib/sequel/sql.rb
lib/sequel/extensions/eval_inspect.rb |
Parent: | Object |
Base class for all SQL expression objects.
comparison_attrs | [R] | All attributes used for equality and hash methods. |
Expression objects are assumed to be value objects, where their attribute values can‘t change after assignment. In order to make it easy to define equality and hash methods, subclass instances assume that the only values that affect the results of such methods are the values of the object‘s attributes.
# File lib/sequel/sql.rb, line 100 100: def attr_reader(*args) 101: super 102: comparison_attrs.concat(args) 103: end
Copy the comparison_attrs into the subclass.
# File lib/sequel/sql.rb, line 106 106: def inherited(subclass) 107: super 108: subclass.instance_variable_set(:@comparison_attrs, comparison_attrs.dup) 109: end
Returns true if the receiver is the same expression as the the other expression.
# File lib/sequel/sql.rb, line 131 131: def eql?(other) 132: other.is_a?(self.class) && !self.class.comparison_attrs.find{|a| send(a) != other.send(a)} 133: end
Show the class name and instance variables for the object, necessary for correct operation on ruby 1.9.2.
# File lib/sequel/sql.rb, line 142 142: def inspect 143: "#<#{self.class} #{instance_variables.map{|iv| "#{iv}=>#{instance_variable_get(iv).inspect}"}.join(', ')}>" 144: end
Attempt to produce a string suitable for eval, such that:
eval(obj.inspect) == obj
# File lib/sequel/extensions/eval_inspect.rb, line 68 68: def inspect 69: # Assume by default that the object can be recreated by calling 70: # self.class.new with any attr_reader values defined on the class, 71: # in the order they were defined. 72: klass = self.class 73: args = inspect_args.map do |arg| 74: if arg.is_a?(String) && arg =~ /\A\*/ 75: # Special case string arguments starting with *, indicating that 76: # they should return an array to be splatted as the remaining arguments 77: send(arg.sub('*', '')).map{|a| Sequel.eval_inspect(a)}.join(', ') 78: else 79: Sequel.eval_inspect(send(arg)) 80: end 81: end 82: "#{klass}.#{inspect_new_method}(#{args.join(', ')})" 83: end
Returns self, because SQL::Expression already acts like LiteralString.
# File lib/sequel/sql.rb, line 147 147: def lit 148: self 149: end