lib/preval/node.rb in preval-0.2.0 vs lib/preval/node.rb in preval-0.3.0

@@ -1,19 +1,45 @@
 # frozen_string_literal: true
 
 module Preval
   class Node
+    class TypeMatch
+      attr_reader :types
+
+      def initialize(types)
+        @types = types
+      end
+
+      def match?(node)
+        node.body.size == types.size &&
+          node.body.zip(types).all? do |(left, right)|
+            left.is_a?(Node) && Array(right).include?(left.type)
+          end
+      end
+
+      def self.match?(types, node)
+        new(types).match?(node)
+      end
+    end
+
     include Format
 
     attr_reader :type, :body, :literal
 
     def initialize(type, body, literal = false)
       @type = type
       @body = body
       @literal = literal
     end
 
+    def dig(index, *args)
+      node = body[index]
+      return nil unless node
+
+      args.any? ? node.dig(*args) : node
+    end
+
     def join(delim = '')
       body.map(&:to_source).join(delim)
     end
 
     def is?(other)
@@ -40,9 +66,13 @@
       begin
         public_send(:"to_#{type}")
       rescue NoMethodError
         raise NotImplementedError, "#{type} has not yet been implemented"
       end
+    end
+
+    def type_match?(*types)
+      TypeMatch.new(types).match?(self)
     end
 
     def update(type, body)
       @type = type
       @body = body