Class Sequel::SQL::Expression
In: lib/sequel/extensions/eval_inspect.rb
lib/sequel/sql.rb
Parent: Object

Base class for all SQL expression objects.

Methods

==   attr_reader   eql?   hash   inherited   inspect   inspect   lit   sql_literal  

Attributes

comparison_attrs  [R]  All attributes used for equality and hash methods.

Public Class 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.

[Source]

    # 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.

[Source]

    # 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

Public Instance methods

Alias of eql?

[Source]

     # File lib/sequel/sql.rb, line 101
101:       def ==(other)
102:         eql?(other)
103:       end

Returns true if the receiver is the same expression as the the other expression.

[Source]

     # 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

Make sure that the hash value is the same if the attributes are the same.

[Source]

     # File lib/sequel/sql.rb, line 112
112:       def hash
113:         ([self.class] + self.class.comparison_attrs.map{|x| send(x)}).hash
114:       end

Attempt to produce a string suitable for eval, such that:

  eval(obj.inspect) == obj

[Source]

    # 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.

[Source]

     # 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.

[Source]

     # File lib/sequel/sql.rb, line 123
123:       def lit
124:         self
125:       end

Alias of to_s

[Source]

     # File lib/sequel/sql.rb, line 128
128:       def sql_literal(ds)
129:         s = ''
130:         to_s_append(ds, s)
131:         s
132:       end

[Validate]