2010-09-15 12:26:01 -04:00
|
|
|
module Arel
|
|
|
|
module Nodes
|
|
|
|
###
|
|
|
|
# Abstract base class for all AST nodes
|
|
|
|
class Node
|
2010-12-01 12:19:09 -05:00
|
|
|
include Enumerable
|
|
|
|
|
2010-11-23 19:24:41 -05:00
|
|
|
###
|
|
|
|
# Factory method to create a Nodes::Not node that has the recipient of
|
|
|
|
# the caller as a child.
|
|
|
|
def not
|
2010-12-06 12:36:02 -05:00
|
|
|
Nodes::Not.new Nodes::Grouping.new self
|
2010-11-23 19:24:41 -05:00
|
|
|
end
|
|
|
|
|
2010-09-15 12:26:01 -04:00
|
|
|
###
|
|
|
|
# Factory method to create a Nodes::Grouping node that has an Nodes::Or
|
|
|
|
# node as a child.
|
|
|
|
def or right
|
|
|
|
Nodes::Grouping.new Nodes::Or.new(self, right)
|
|
|
|
end
|
|
|
|
|
|
|
|
###
|
|
|
|
# Factory method to create an Nodes::And node.
|
|
|
|
def and right
|
|
|
|
Nodes::And.new self, right
|
|
|
|
end
|
2010-09-27 16:12:15 -04:00
|
|
|
|
|
|
|
# FIXME: this method should go away. I don't like people calling
|
|
|
|
# to_sql on non-head nodes. This forces us to walk the AST until we
|
|
|
|
# can find a node that has a "relation" member.
|
|
|
|
#
|
|
|
|
# Maybe we should just use `Table.engine`? :'(
|
|
|
|
def to_sql engine = Table.engine
|
2010-10-03 17:26:57 -04:00
|
|
|
viz = Visitors.for engine
|
2010-09-27 16:12:15 -04:00
|
|
|
viz.accept self
|
|
|
|
end
|
2010-11-29 17:11:28 -05:00
|
|
|
|
|
|
|
# Iterate through AST, nodes will be yielded depth-first
|
|
|
|
def each &block
|
2010-11-29 18:31:28 -05:00
|
|
|
return enum_for(:each) unless block_given?
|
|
|
|
|
2010-11-29 17:11:28 -05:00
|
|
|
Visitors::DepthFirst.new(block).accept self
|
|
|
|
end
|
2010-09-15 12:26:01 -04:00
|
|
|
end
|
|
|
|
end
|
|
|
|
end
|