Merge pull request #3 from Kaligo/feature/add-object-deep-fetch

Add Object#deep_fetch

Author: imrefoldeskaligo

Diff for: lib/core_ext/deep_fetch.rb

@@ -1,50 +1,32 @@
 require 'backport_dig' if Gem::Version.new(RUBY_VERSION) < Gem::Version.new('2.3')
-require 'singleton'
 
-class VarCache
-
-  include Singleton
-
-  def self.fetch_or_store(key)
-    instance.fetch_or_store(key)
-  end
-
-  def initialize
-    @storage = {}
-  end
-
-  def fetch(key)
-    @storage[key]
-  end
-
-  def store(key)
-    @storage[key] = attributes(key)
-  end
-
-  def fetch_or_store(key)
-    fetch(key) || store(key)
-  end
-
-  private
-
-    def attributes(key)
-      key.to_s.split('.')
+class Object
+  def deep_fetch(keys, default = nil)
+    case keys.length
+    when 0
+      self
+    when 1
+      self.send(keys.first)
+    else
+      self.send(keys.first).deep_fetch(keys[1..-1], default)
     end
 
+    rescue
+      default
+  end
 end
 
 class Hash
-  def deep_fetch(key, default = nil)
-    keys = VarCache.fetch_or_store(key)
+  def deep_fetch(keys, default = nil)
     value = dig(*keys) rescue default
     value.nil? ? default : value  # value can be false (Boolean)
   end
 end
 
 class Array
-  def deep_fetch(index, default = nil)
-    indexes = VarCache.fetch_or_store(index).map(&:to_i)
-    value = dig(*indexes) rescue default
+  def deep_fetch(keys, default = nil)
+    indices = keys.map(&:to_i)
+    value = dig(*indices) rescue default
     value.nil? ? default : value  # value can be false (Boolean)
   end
 end

Diff for: lib/json_logic.rb

@@ -2,6 +2,8 @@
 require 'core_ext/stringify_keys'
 require 'json_logic/truthy'
 require 'json_logic/operation'
+require 'json_logic/var_cache'
+
 module JSONLogic
   def self.apply(logic, data)
     if logic.is_a?(Array)

Diff for: lib/json_logic/operation.rb

@@ -4,21 +4,25 @@ module JSONLogic
   class Operation
     LAMBDAS = {
       'var' => ->(v, d) do
-        if !(d.is_a?(Hash) || d.is_a?(Array))
+        if v.empty?
           d
-        else
-          if v == [JSONLogic::ITERABLE_KEY]
-            if d.is_a?(Array)
-              d
-            else
-              d[JSONLogic::ITERABLE_KEY]
-            end
+        elsif v == [JSONLogic::ITERABLE_KEY]
+          if d.is_a?(Hash)
+            d[JSONLogic::ITERABLE_KEY]
           else
-            d.deep_fetch(*v)
+            d
           end
+        else
+          keys = VarCache.fetch_or_store(v[0])
+          d.deep_fetch(keys, v[1])
+        end
+      end,
+      'missing' => ->(v, d) do
+        v.select do |val|
+          keys = VarCache.fetch_or_store(val)
+          d.deep_fetch(keys).nil?
         end
       end,
-      'missing' => ->(v, d) { v.select { |val| d.deep_fetch(val).nil? } },
       'missing_some' => ->(v, d) {
         present = v[1] & d.keys
         present.size >= v[0] ? [] : LAMBDAS['missing'].call(v[1], d)

Diff for: lib/json_logic/var_cache.rb

@@ -0,0 +1,33 @@
+require 'singleton'
+
+class VarCache
+
+  include Singleton
+
+  def self.fetch_or_store(key)
+    instance.fetch_or_store(key)
+  end
+
+  def initialize
+    @storage = {}
+  end
+
+  def fetch(key)
+    @storage[key]
+  end
+
+  def store(key)
+    @storage[key] = attributes(key)
+  end
+
+  def fetch_or_store(key)
+    fetch(key) || store(key)
+  end
+
+  private
+
+  def attributes(key)
+    key.to_s.split('.')
+  end
+
+end