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

attr_reader(*args)

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
inherited(subclass)

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

==(other)

Alias of eql?

[Source]

     # File lib/sequel/sql.rb, line 111
111:       def ==(other)
112:         eql?(other)
113:       end
eql?(other)

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

[Source]

     # File lib/sequel/sql.rb, line 117
117:       def eql?(other)
118:         other.is_a?(self.class) && !self.class.comparison_attrs.find{|a| send(a) != other.send(a)}
119:       end
hash()

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

[Source]

     # File lib/sequel/sql.rb, line 122
122:       def hash
123:         ([self.class] + self.class.comparison_attrs.map{|x| send(x)}).hash
124:       end
inspect()

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
inspect()

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 128
128:       def inspect
129:         "#<#{self.class} #{instance_variables.map{|iv| "#{iv}=>#{instance_variable_get(iv).inspect}"}.join(', ')}>"
130:       end
lit()

Returns self, because SQL::Expression already acts like LiteralString.

[Source]

     # File lib/sequel/sql.rb, line 133
133:       def lit
134:         self
135:       end
sql_literal(ds)

Alias of to_s

[Source]

     # File lib/sequel/sql.rb, line 138
138:       def sql_literal(ds)
139:         s = ''
140:         to_s_append(ds, s)
141:         s
142:       end

[Validate]