diff options
Diffstat (limited to 'lib/arel')
| -rw-r--r-- | lib/arel/nodes/node.rb | 7 | ||||
| -rw-r--r-- | lib/arel/visitors.rb | 1 | ||||
| -rw-r--r-- | lib/arel/visitors/depth_first.rb | 75 |
3 files changed, 83 insertions, 0 deletions
diff --git a/lib/arel/nodes/node.rb b/lib/arel/nodes/node.rb index 841b954db9..90c63f0be9 100644 --- a/lib/arel/nodes/node.rb +++ b/lib/arel/nodes/node.rb @@ -3,6 +3,8 @@ module Arel ### # Abstract base class for all AST nodes class Node + include Enumerable + ### # Factory method to create a Nodes::Not node that has the recipient of # the caller as a child. @@ -32,6 +34,11 @@ module Arel viz = Visitors.for engine viz.accept self end + + # Iterate through AST, nodes will be yielded depth-first + def each &block + Visitors::DepthFirst.new(block).accept self + end end end end diff --git a/lib/arel/visitors.rb b/lib/arel/visitors.rb index 5d4c6084b2..2b0a06d534 100644 --- a/lib/arel/visitors.rb +++ b/lib/arel/visitors.rb @@ -1,4 +1,5 @@ require 'arel/visitors/visitor' +require 'arel/visitors/depth_first' require 'arel/visitors/to_sql' require 'arel/visitors/sqlite' require 'arel/visitors/postgresql' diff --git a/lib/arel/visitors/depth_first.rb b/lib/arel/visitors/depth_first.rb new file mode 100644 index 0000000000..19796b6e72 --- /dev/null +++ b/lib/arel/visitors/depth_first.rb @@ -0,0 +1,75 @@ +module Arel + module Visitors + class DepthFirst < Arel::Visitors::Visitor + def initialize block = nil + @block = block || Proc.new + end + + private + + def binary o + visit o.left + visit o.right + @block.call o + end + alias :visit_Arel_Nodes_And :binary + alias :visit_Arel_Nodes_Assignment :binary + alias :visit_Arel_Nodes_Between :binary + alias :visit_Arel_Nodes_DoesNotMatch :binary + alias :visit_Arel_Nodes_Equality :binary + alias :visit_Arel_Nodes_GreaterThan :binary + alias :visit_Arel_Nodes_GreaterThanOrEqual :binary + alias :visit_Arel_Nodes_In :binary + alias :visit_Arel_Nodes_LessThan :binary + alias :visit_Arel_Nodes_LessThanOrEqual :binary + alias :visit_Arel_Nodes_Matches :binary + alias :visit_Arel_Nodes_NotEqual :binary + alias :visit_Arel_Nodes_NotIn :binary + alias :visit_Arel_Nodes_Or :binary + + def visit_Arel_Attribute o + visit o.relation + visit o.name + @block.call o + end + alias :visit_Arel_Attributes_Integer :visit_Arel_Attribute + alias :visit_Arel_Attributes_Float :visit_Arel_Attribute + alias :visit_Arel_Attributes_String :visit_Arel_Attribute + alias :visit_Arel_Attributes_Time :visit_Arel_Attribute + alias :visit_Arel_Attributes_Boolean :visit_Arel_Attribute + alias :visit_Arel_Attributes_Attribute :visit_Arel_Attribute + + def visit_Arel_Table o + visit o.name + @block.call o + end + + def terminal o + @block.call o + end + alias :visit_Arel_Nodes_SqlLiteral :terminal + alias :visit_Arel_SqlLiteral :terminal + alias :visit_BigDecimal :terminal + alias :visit_Date :terminal + alias :visit_DateTime :terminal + alias :visit_FalseClass :terminal + alias :visit_Fixnum :terminal + alias :visit_Float :terminal + alias :visit_NilClass :terminal + alias :visit_String :terminal + alias :visit_Symbol :terminal + alias :visit_Time :terminal + alias :visit_TrueClass :terminal + + def visit_Array o + o.each { |i| visit i } + @block.call o + end + + def visit_Hash o + o.each { |k,v| visit(k); visit(v) } + @block.call o + end + end + end +end |