aboutsummaryrefslogtreecommitdiffstats
path: root/lib/arel/visitors/reduce.rb
blob: 7948758e2fa01ff3ffcb1668a4cf87c189a6bd6b (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
# frozen_string_literal: true
require 'arel/visitors/visitor'

module Arel
  module Visitors
    class Reduce < Arel::Visitors::Visitor
      def accept object, collector
        visit object, collector
      end

      private

      def visit object, collector
        send dispatch[object.class], object, collector
      rescue NoMethodError => e
        raise e if respond_to?(dispatch[object.class], true)
        superklass = object.class.ancestors.find { |klass|
          respond_to?(dispatch[klass], true)
        }
        raise(TypeError, "Cannot visit #{object.class}") unless superklass
        dispatch[object.class] = dispatch[superklass]
        retry
      end
    end
  end
end