Class | Sequel::SQL::Expression |
In: |
lib/sequel/extensions/eval_inspect.rb
lib/sequel/sql.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 76 76: def attr_reader(*args) 77: super 78: comparison_attrs.concat(args) 79: end
Copy the comparison_attrs into the subclass.
# File lib/sequel/sql.rb, line 82 82: def inherited(subclass) 83: super 84: subclass.instance_variable_set(:@comparison_attrs, comparison_attrs.dup) 85: end
Make clone/dup return self, since Expression objects are supposed to be frozen value objects
# File lib/sequel/sql.rb, line 103 103: def clone 104: self 105: end
Returns true if the receiver is the same expression as the the other expression.
# File lib/sequel/sql.rb, line 115 115: def eql?(other) 116: other.is_a?(self.class) && !self.class.comparison_attrs.find{|a| public_send(a) != other.public_send(a)} 117: end
Attempt to produce a string suitable for eval, such that:
eval(obj.inspect) == obj
# File lib/sequel/extensions/eval_inspect.rb, line 61 61: def inspect 62: # Assume by default that the object can be recreated by calling 63: # self.class.new with any attr_reader values defined on the class, 64: # in the order they were defined. 65: klass = self.class 66: args = inspect_args.map do |arg| 67: if arg.is_a?(String) && arg =~ /\A\*/ 68: # Special case string arguments starting with *, indicating that 69: # they should return an array to be splatted as the remaining arguments. 70: # Allow calling private methods to get inspect output. 71: send(arg.sub('*', '')).map{|a| Sequel.eval_inspect(a)}.join(', ') 72: else 73: # Allow calling private methods to get inspect output. 74: Sequel.eval_inspect(send(arg)) 75: end 76: end 77: "#{klass}.#{inspect_new_method}(#{args.join(', ')})" 78: end