Attempting to simplify Memory store

.rubocop.yml

@@ -21,3 +21,6 @@ RSpec/ExampleLength:
 
 Metrics/ClassLength:
   Max: 150
+
+Layout/LineLength:
+  Max: 125

CHANGELOG.md

@@ -1,4 +1,4 @@
 
-#### 0.0.1 - TBD
+#### 0.0.2 - Monday, Sept. 5th, 2022
 
 * Initial proof-of-concept release.

lib/teton/key.rb

@@ -1,5 +1,7 @@
 # frozen_string_literal: true
 
+require_relative 'key_pointer'
+
 module Teton
   # Understands a fully-qualified path to a resource or resources.
   class Key
@@ -22,8 +24,10 @@ def to_s(suffix_keys = [])
       (parts + suffix_keys).join(separator)
     end
 
-    def traverse(&block)
-      parts.each_with_index(&block)
+    def traverse
+      parts.each_with_index do |_part, index|
+        yield KeyPointer.new(self, index)
+      end
     end
 
     def entry?
@@ -33,5 +37,9 @@ def entry?
     def resource?
       parts.length.odd?
     end
+
+    def last_part
+      parts.last
+    end
   end
 end

lib/teton/key_pointer.rb

@@ -0,0 +1,35 @@
+# frozen_string_literal: true
+
+module Teton
+  # Points to a section within a key's parts.  A section can either be a resource or an entry.
+  class KeyPointer
+    attr_reader :key, :index
+
+    def initialize(key, index)
+      @key   = key
+      @index = index.to_i
+
+      freeze
+    end
+
+    def value
+      key.parts[index]
+    end
+
+    def not_last?
+      !last?
+    end
+
+    def last?
+      index == key.parts.length - 1
+    end
+
+    def entry?
+      index.odd?
+    end
+
+    def resource?
+      index.even? || index.zero?
+    end
+  end
+end

lib/teton/stores/memory.rb

@@ -20,80 +20,45 @@ def initialize(store = {})
       # Main Object API
 
       def set(key, data)
-        pointer = store
-
-        key.traverse do |part, index|
-          if index < key.parts.length - 1
-            pointer = insert_traverse(index, pointer, part)
-          else
-            # last id
-            upsert(pointer, part, data)
-          end
-        end
+        store_pointer = insert_traverse_to_last(key)
+
+        upsert(store_pointer, key.last_part, data)
 
         self
       end
 
       def get(key)
-        pointer = store
-
-        key.traverse do |part, index|
-          break unless pointer
-
-          pointer =
-            if index < key.parts.length - 1
-              # not last part
-              traverse(index, pointer, part)
-            elsif key.resource?
-              # last part
-              entries(key, pointer, part)
-            else
-              # id
-              entry(key, pointer, part)
-            end
-        end
+        store_pointer = traverse_to_last(key)
 
-        pointer
+        return unless store_pointer
+
+        if key.resource?
+          entries(key, store_pointer, key.last_part)
+        else
+          entry(key, store_pointer, key.last_part)
+        end
       end
 
       def del(key)
-        pointer = store
-
-        key.traverse do |part, index|
-          break unless pointer
-
-          if index < key.parts.length - 1
-            # not last part
-            pointer = traverse(index, pointer, part)
-          else
-            # last part
-            pointer.delete(part)
-          end
-        end
+        store_pointer = traverse_to_last(key)
+
+        return self unless store_pointer
+
+        store_pointer.delete(key.last_part)
 
         self
       end
 
       def count(key)
-        count   = 0
-        pointer = store
-
-        key.traverse do |part, index|
-          break unless pointer
-
-          if index < key.parts.length - 1
-            # not last part
-            pointer = traverse(index, pointer, part)
-          elsif key.resource?
-            # last part
-            count = (pointer.dig(part, IDS_KEY) || {}).keys.length
-          else
-            # id
-            count = pointer.dig(part, DATA_KEY) ? 1 : 0
-          end
-        end
+        store_pointer = traverse_to_last(key)
+
+        return 0 unless store_pointer
 
-        count
+        if key.resource?
+          (store_pointer.dig(key.last_part, IDS_KEY) || {}).keys.length
+        else
+          store_pointer.dig(key.last_part, DATA_KEY) ? 1 : 0
+        end
       end
 
       # Persistence API
@@ -157,6 +122,28 @@ def traverse(index, pointer, part)
         end
       end
 
+      def insert_traverse_to_last(key)
+        store_pointer = store
+
+        key.traverse do |key_pointer|
+          store_pointer = insert_traverse(key_pointer.index, store_pointer, key_pointer.value) if key_pointer.not_last?
+        end
+
+        store_pointer
+      end
+
+      def traverse_to_last(key)
+        store_pointer = store
+
+        key.traverse do |key_pointer|
+          break unless store_pointer
+
+          store_pointer = traverse(key_pointer.index, store_pointer, key_pointer.value) if key_pointer.not_last?
+        end
+
+        store_pointer
+      end
+
       def entry(key, pointer, part)
         data = pointer.dig(part, DATA_KEY)
         meta = pointer.dig(part, META_KEY)

lib/teton/version.rb

@@ -1,5 +1,5 @@
 # frozen_string_literal: true
 
 module Teton
-  VERSION = '0.0.1'
+  VERSION = '0.0.2'
 end