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
Returns true if the receiver is the same expression as the the other expression.
# File lib/sequel/sql.rb, line 107 107: def eql?(other) 108: other.is_a?(self.class) && !self.class.comparison_attrs.find{|a| send(a) != other.send(a)} 109: end
Attempt to produce a string suitable for eval, such that:
eval(obj.inspect) == obj
# File lib/sequel/extensions/eval_inspect.rb, line 63 63: def inspect 64: # Assume by default that the object can be recreated by calling 65: # self.class.new with any attr_reader values defined on the class, 66: # in the order they were defined. 67: klass = self.class 68: args = inspect_args.map do |arg| 69: if arg.is_a?(String) && arg =~ /\A\*/ 70: # Special case string arguments starting with *, indicating that 71: # they should return an array to be splatted as the remaining arguments 72: send(arg.sub('*', '')).map{|a| Sequel.eval_inspect(a)}.join(', ') 73: else 74: Sequel.eval_inspect(send(arg)) 75: end 76: end 77: "#{klass}.new(#{args.join(', ')})" 78: 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 118 118: def inspect 119: "#<#{self.class} #{instance_variables.map{|iv| "#{iv}=>#{instance_variable_get(iv).inspect}"}.join(', ')}>" 120: end
Returns self, because SQL::Expression already acts like LiteralString.
# File lib/sequel/sql.rb, line 123 123: def lit 124: self 125: end